Validation initiale

[perso/Immae/Projets/packagist/ludivine-ckeditor-component.git] / sources / plugins / clipboard / plugin.js

/**
 * @license Copyright (c) 2003-2017, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md or http://ckeditor.com/license
 */

/**
 * @ignore
 * File overview: Clipboard support.
 */

//
// COPY & PASTE EXECUTION FLOWS:
// -- CTRL+C
//              * if ( isCustomCopyCutSupported )
//                      * dataTransfer.setData( 'text/html', getSelectedHtml )
//              * else
//                      * browser's default behavior
// -- CTRL+X
//              * listen onKey (onkeydown)
//              * fire 'saveSnapshot' on editor
//              * if ( isCustomCopyCutSupported )
//                      * dataTransfer.setData( 'text/html', getSelectedHtml )
//                      * extractSelectedHtml // remove selected contents
//              * else
//                      * browser's default behavior
//              * deferred second 'saveSnapshot' event
// -- CTRL+V
//              * listen onKey (onkeydown)
//              * simulate 'beforepaste' for non-IEs on editable
//              * listen 'onpaste' on editable ('onbeforepaste' for IE)
//              * fire 'beforePaste' on editor
//              * if ( !canceled && ( htmlInDataTransfer || !external paste) && dataTransfer is not empty ) getClipboardDataByPastebin
//              * fire 'paste' on editor
//              * !canceled && fire 'afterPaste' on editor
// -- Copy command
//              * tryToCutCopy
//                      * execCommand
//              * !success && notification
// -- Cut command
//              * fixCut
//              * tryToCutCopy
//                      * execCommand
//              * !success && notification
// -- Paste command
//              * fire 'paste' on editable ('beforepaste' for IE)
//              * !canceled && execCommand 'paste'
//              * !success && fire 'pasteDialog' on editor
// -- Paste from native context menu & menubar
//              (Fx & Webkits are handled in 'paste' default listener.
//              Opera cannot be handled at all because it doesn't fire any events
//              Special treatment is needed for IE, for which is this part of doc)
//              * listen 'onpaste'
//              * cancel native event
//              * fire 'beforePaste' on editor
//              * if ( !canceled && ( htmlInDataTransfer || !external paste) && dataTransfer is not empty ) getClipboardDataByPastebin
//              * execIECommand( 'paste' ) -> this fires another 'paste' event, so cancel it
//              * fire 'paste' on editor
//              * !canceled && fire 'afterPaste' on editor
//
//
// PASTE EVENT - PREPROCESSING:
// -- Possible dataValue types: auto, text, html.
// -- Possible dataValue contents:
//              * text (possible \n\r)
//              * htmlified text (text + br,div,p - no presentational markup & attrs - depends on browser)
//              * html
// -- Possible flags:
//              * htmlified - if true then content is a HTML even if no markup inside. This flag is set
//                      for content from editable pastebins, because they 'htmlify' pasted content.
//
// -- Type: auto:
//              * content: htmlified text ->    filter, unify text markup (brs, ps, divs), set type: text
//              * content: html ->                              filter, set type: html
// -- Type: text:
//              * content: htmlified text ->    filter, unify text markup
//              * content: html ->                              filter, strip presentational markup, unify text markup
// -- Type: html:
//              * content: htmlified text ->    filter, unify text markup
//              * content: html ->                              filter
//
// -- Phases:
//              * if dataValue is empty copy data from dataTransfer to dataValue (priority 1)
//              * filtering (priorities 3-5) - e.g. pastefromword filters
//              * content type sniffing (priority 6)
//              * markup transformations for text (priority 6)
//
// DRAG & DROP EXECUTION FLOWS:
// -- Drag
//              * save to the global object:
//                      * drag timestamp (with 'cke-' prefix),
//                      * selected html,
//                      * drag range,
//                      * editor instance.
//              * put drag timestamp into event.dataTransfer.text
// -- Drop
//              * if events text == saved timestamp && editor == saved editor
//                      internal drag & drop occurred
//                      * getRangeAtDropPosition
//                      * create bookmarks for drag and drop ranges starting from the end of the document
//                      * dragRange.deleteContents()
//                      * fire 'paste' with saved html and drop range
//              * if events text == saved timestamp && editor != saved editor
//                      cross editor drag & drop occurred
//                      * getRangeAtDropPosition
//                      * fire 'paste' with saved html
//                      * dragRange.deleteContents()
//                      * FF: refreshCursor on afterPaste
//              * if events text != saved timestamp
//                      drop form external source occurred
//                      * getRangeAtDropPosition
//                      * if event contains html data then fire 'paste' with html
//                      * else if event contains text data then fire 'paste' with encoded text
//                      * FF: refreshCursor on afterPaste

'use strict';

( function() {
        // Register the plugin.
        CKEDITOR.plugins.add( 'clipboard', {
                requires: 'dialog',
                // jscs:disable maximumLineLength
                lang: 'af,ar,az,bg,bn,bs,ca,cs,cy,da,de,de-ch,el,en,en-au,en-ca,en-gb,eo,es,et,eu,fa,fi,fo,fr,fr-ca,gl,gu,he,hi,hr,hu,id,is,it,ja,ka,km,ko,ku,lt,lv,mk,mn,ms,nb,nl,no,oc,pl,pt,pt-br,ro,ru,si,sk,sl,sq,sr,sr-latn,sv,th,tr,tt,ug,uk,vi,zh,zh-cn', // %REMOVE_LINE_CORE%
                // jscs:enable maximumLineLength
                icons: 'copy,copy-rtl,cut,cut-rtl,paste,paste-rtl', // %REMOVE_LINE_CORE%
                hidpi: true, // %REMOVE_LINE_CORE%
                init: function( editor ) {
                        var filterType,
                                filtersFactory = filtersFactoryFactory();

                        if ( editor.config.forcePasteAsPlainText ) {
                                filterType = 'plain-text';
                        } else if ( editor.config.pasteFilter ) {
                                filterType = editor.config.pasteFilter;
                        }
                        // On Webkit the pasteFilter defaults 'semantic-content' because pasted data is so terrible
                        // that it must be always filtered.
                        else if ( CKEDITOR.env.webkit && !( 'pasteFilter' in editor.config ) ) {
                                filterType = 'semantic-content';
                        }

                        editor.pasteFilter = filtersFactory.get( filterType );

                        initPasteClipboard( editor );
                        initDragDrop( editor );

                        CKEDITOR.dialog.add( 'paste', CKEDITOR.getUrl( this.path + 'dialogs/paste.js' ) );

                        // Convert image file (if present) to base64 string for Firefox. Do it as the first
                        // step as the conversion is asynchronous and should hold all further paste processing.
                        if ( CKEDITOR.env.gecko ) {
                                var supportedImageTypes = [ 'image/png', 'image/jpeg', 'image/gif' ],
                                        latestId;

                                editor.on( 'paste', function( evt ) {
                                        var dataObj = evt.data,
                                                data = dataObj.dataValue,
                                                dataTransfer = dataObj.dataTransfer;

                                        // If data empty check for image content inside data transfer. #16705
                                        if ( !data && dataObj.method == 'paste' && dataTransfer && dataTransfer.getFilesCount() == 1 && latestId != dataTransfer.id ) {
                                                var file = dataTransfer.getFile( 0 );

                                                if ( CKEDITOR.tools.indexOf( supportedImageTypes, file.type ) != -1 ) {
                                                        var fileReader = new FileReader();

                                                        // Convert image file to img tag with base64 image.
                                                        fileReader.addEventListener( 'load', function() {
                                                                evt.data.dataValue = '<img src="' + fileReader.result + '" />';
                                                                editor.fire( 'paste', evt.data );
                                                        }, false );

                                                        // Proceed with normal flow if reading file was aborted.
                                                        fileReader.addEventListener( 'abort', function() {
                                                                editor.fire( 'paste', evt.data );
                                                        }, false );

                                                        // Proceed with normal flow if reading file failed.
                                                        fileReader.addEventListener( 'error', function() {
                                                                editor.fire( 'paste', evt.data );
                                                        }, false );

                                                        fileReader.readAsDataURL( file );

                                                        latestId = dataObj.dataTransfer.id;

                                                        evt.stop();
                                                }
                                        }
                                }, null, null, 1 );
                        }

                        editor.on( 'paste', function( evt ) {
                                // Init `dataTransfer` if `paste` event was fired without it, so it will be always available.
                                if ( !evt.data.dataTransfer ) {
                                        evt.data.dataTransfer = new CKEDITOR.plugins.clipboard.dataTransfer();
                                }

                                // If dataValue is already set (manually or by paste bin), so do not override it.
                                if ( evt.data.dataValue ) {
                                        return;
                                }

                                var dataTransfer = evt.data.dataTransfer,
                                        // IE support only text data and throws exception if we try to get html data.
                                        // This html data object may also be empty if we drag content of the textarea.
                                        value = dataTransfer.getData( 'text/html' );

                                if ( value ) {
                                        evt.data.dataValue = value;
                                        evt.data.type = 'html';
                                } else {
                                        // Try to get text data otherwise.
                                        value = dataTransfer.getData( 'text/plain' );

                                        if ( value ) {
                                                evt.data.dataValue = editor.editable().transformPlainTextToHtml( value );
                                                evt.data.type = 'text';
                                        }
                                }
                        }, null, null, 1 );

                        editor.on( 'paste', function( evt ) {
                                var data = evt.data.dataValue,
                                        blockElements = CKEDITOR.dtd.$block;

                                // Filter webkit garbage.
                                if ( data.indexOf( 'Apple-' ) > -1 ) {
                                        // Replace special webkit's &nbsp; with simple space, because webkit
                                        // produces them even for normal spaces.
                                        data = data.replace( /<span class="Apple-converted-space">&nbsp;<\/span>/gi, ' ' );

                                        // Strip <span> around white-spaces when not in forced 'html' content type.
                                        // This spans are created only when pasting plain text into Webkit,
                                        // but for safety reasons remove them always.
                                        if ( evt.data.type != 'html' ) {
                                                data = data.replace( /<span class="Apple-tab-span"[^>]*>([^<]*)<\/span>/gi, function( all, spaces ) {
                                                        // Replace tabs with 4 spaces like Fx does.
                                                        return spaces.replace( /\t/g, '&nbsp;&nbsp; &nbsp;' );
                                                } );
                                        }

                                        // This br is produced only when copying & pasting HTML content.
                                        if ( data.indexOf( '<br class="Apple-interchange-newline">' ) > -1 ) {
                                                evt.data.startsWithEOL = 1;
                                                evt.data.preSniffing = 'html'; // Mark as not text.
                                                data = data.replace( /<br class="Apple-interchange-newline">/, '' );
                                        }

                                        // Remove all other classes.
                                        data = data.replace( /(<[^>]+) class="Apple-[^"]*"/gi, '$1' );
                                }

                                // Strip editable that was copied from inside. (#9534)
                                if ( data.match( /^<[^<]+cke_(editable|contents)/i ) ) {
                                        var tmp,
                                                editable_wrapper,
                                                wrapper = new CKEDITOR.dom.element( 'div' );

                                        wrapper.setHtml( data );
                                        // Verify for sure and check for nested editor UI parts. (#9675)
                                        while ( wrapper.getChildCount() == 1 &&
                                                        ( tmp = wrapper.getFirst() ) &&
                                                        tmp.type == CKEDITOR.NODE_ELEMENT &&    // Make sure first-child is element.
                                                        ( tmp.hasClass( 'cke_editable' ) || tmp.hasClass( 'cke_contents' ) ) ) {
                                                wrapper = editable_wrapper = tmp;
                                        }

                                        // If editable wrapper was found strip it and bogus <br> (added on FF).
                                        if ( editable_wrapper )
                                                data = editable_wrapper.getHtml().replace( /<br>$/i, '' );
                                }

                                if ( CKEDITOR.env.ie ) {
                                        // &nbsp; <p> -> <p> (br.cke-pasted-remove will be removed later)
                                        data = data.replace( /^&nbsp;(?: |\r\n)?<(\w+)/g, function( match, elementName ) {
                                                if ( elementName.toLowerCase() in blockElements ) {
                                                        evt.data.preSniffing = 'html'; // Mark as not a text.
                                                        return '<' + elementName;
                                                }
                                                return match;
                                        } );
                                } else if ( CKEDITOR.env.webkit ) {
                                        // </p><div><br></div> -> </p><br>
                                        // We don't mark br, because this situation can happen for htmlified text too.
                                        data = data.replace( /<\/(\w+)><div><br><\/div>$/, function( match, elementName ) {
                                                if ( elementName in blockElements ) {
                                                        evt.data.endsWithEOL = 1;
                                                        return '</' + elementName + '>';
                                                }
                                                return match;
                                        } );
                                } else if ( CKEDITOR.env.gecko ) {
                                        // Firefox adds bogus <br> when user pasted text followed by space(s).
                                        data = data.replace( /(\s)<br>$/, '$1' );
                                }

                                evt.data.dataValue = data;
                        }, null, null, 3 );

                        editor.on( 'paste', function( evt ) {
                                var dataObj = evt.data,
                                        type = dataObj.type,
                                        data = dataObj.dataValue,
                                        trueType,
                                        // Default is 'html'.
                                        defaultType = editor.config.clipboard_defaultContentType || 'html',
                                        transferType = dataObj.dataTransfer.getTransferType( editor );

                                // If forced type is 'html' we don't need to know true data type.
                                if ( type == 'html' || dataObj.preSniffing == 'html' ) {
                                        trueType = 'html';
                                } else {
                                        trueType = recogniseContentType( data );
                                }

                                // Unify text markup.
                                if ( trueType == 'htmlifiedtext' ) {
                                        data = htmlifiedTextHtmlification( editor.config, data );
                                }

                                // Strip presentational markup & unify text markup.
                                // Forced plain text (dialog or forcePAPT).
                                // Note: we do not check dontFilter option in this case, because forcePAPT was implemented
                                // before pasteFilter and pasteFilter is automatically used on Webkit&Blink since 4.5, so
                                // forcePAPT should have priority as it had before 4.5.
                                if ( type == 'text' && trueType == 'html' ) {
                                        data = filterContent( editor, data, filtersFactory.get( 'plain-text' ) );
                                }
                                // External paste and pasteFilter exists and filtering isn't disabled.
                                else if ( transferType == CKEDITOR.DATA_TRANSFER_EXTERNAL && editor.pasteFilter && !dataObj.dontFilter ) {
                                        data = filterContent( editor, data, editor.pasteFilter );
                                }

                                if ( dataObj.startsWithEOL ) {
                                        data = '<br data-cke-eol="1">' + data;
                                }
                                if ( dataObj.endsWithEOL ) {
                                        data += '<br data-cke-eol="1">';
                                }

                                if ( type == 'auto' ) {
                                        type = ( trueType == 'html' || defaultType == 'html' ) ? 'html' : 'text';
                                }

                                dataObj.type = type;
                                dataObj.dataValue = data;
                                delete dataObj.preSniffing;
                                delete dataObj.startsWithEOL;
                                delete dataObj.endsWithEOL;
                        }, null, null, 6 );

                        // Inserts processed data into the editor at the end of the
                        // events chain.
                        editor.on( 'paste', function( evt ) {
                                var data = evt.data;

                                if ( data.dataValue ) {
                                        editor.insertHtml( data.dataValue, data.type, data.range );

                                        // Defer 'afterPaste' so all other listeners for 'paste' will be fired first.
                                        // Fire afterPaste only if paste inserted some HTML.
                                        setTimeout( function() {
                                                editor.fire( 'afterPaste' );
                                        }, 0 );
                                }
                        }, null, null, 1000 );

                        editor.on( 'pasteDialog', function( evt ) {
                                // TODO it's possible that this setTimeout is not needed any more,
                                // because of changes introduced in the same commit as this comment.
                                // Editor.getClipboardData adds listener to the dialog's events which are
                                // fired after a while (not like 'showDialog').
                                setTimeout( function() {
                                        // Open default paste dialog.
                                        editor.openDialog( 'paste', evt.data );
                                }, 0 );
                        } );
                }
        } );

        function firePasteEvents( editor, data, withBeforePaste ) {
                if ( !data.type ) {
                        data.type = 'auto';
                }

                if ( withBeforePaste ) {
                        // Fire 'beforePaste' event so clipboard flavor get customized
                        // by other plugins.
                        if ( editor.fire( 'beforePaste', data ) === false )
                                return false; // Event canceled
                }

                // Do not fire paste if there is no data (dataValue and dataTranfser are empty).
                // This check should be done after firing 'beforePaste' because for native paste
                // 'beforePaste' is by default fired even for empty clipboard.
                if ( !data.dataValue && data.dataTransfer.isEmpty() ) {
                        return false;
                }

                if ( !data.dataValue ) {
                        data.dataValue = '';
                }

                // Because of FF bug we need to use this hack, otherwise cursor is hidden
                // or it is not possible to move it (#12420).
                // Also, check that editor.toolbox exists, because the toolbar plugin might not be loaded (#13305).
                if ( CKEDITOR.env.gecko && data.method == 'drop' && editor.toolbox ) {
                        editor.once( 'afterPaste', function() {
                                editor.toolbox.focus();
                        } );
                }

                return editor.fire( 'paste', data );
        }

        function initPasteClipboard( editor ) {
                var clipboard = CKEDITOR.plugins.clipboard,
                        preventBeforePasteEvent = 0,
                        preventPasteEvent = 0,
                        inReadOnly = 0;

                addListeners();
                addButtonsCommands();

                /**
                 * Gets clipboard data by directly accessing the clipboard (IE only) or opening the paste dialog window.
                 *
                 *              editor.getClipboardData( { title: 'Get my data' }, function( data ) {
                 *                      if ( data )
                 *                              alert( data.type + ' ' + data.dataValue );
                 *              } );
                 *
                 * @member CKEDITOR.editor
                 * @param {Object} options
                 * @param {String} [options.title] The title of the paste dialog window.
                 * @param {Function} callback A function that will be executed with `data.type` and `data.dataValue`
                 * or `null` if none of the capturing methods succeeded.
                 */
                editor.getClipboardData = function( options, callback ) {
                        var beforePasteNotCanceled = false,
                                dataType = 'auto',
                                dialogCommited = false;

                        // Options are optional - args shift.
                        if ( !callback ) {
                                callback = options;
                                options = null;
                        }

                        // Listen with maximum priority to handle content before everyone else.
                        // This callback will handle paste event that will be fired if direct
                        // access to the clipboard succeed in IE.
                        editor.on( 'paste', onPaste, null, null, 0 );

                        // Listen at the end of listeners chain to see if event wasn't canceled
                        // and to retrieve modified data.type.
                        editor.on( 'beforePaste', onBeforePaste, null, null, 1000 );

                        // getClipboardDataDirectly() will fire 'beforePaste' synchronously, so we can
                        // check if it was canceled and if any listener modified data.type.

                        // If command didn't succeed (only IE allows to access clipboard and only if
                        // user agrees) open and handle paste dialog.
                        if ( getClipboardDataDirectly() === false ) {
                                // Direct access to the clipboard wasn't successful so remove listener.
                                editor.removeListener( 'paste', onPaste );

                                // If beforePaste was canceled do not open dialog.
                                // Add listeners only if dialog really opened. 'pasteDialog' can be canceled.
                                if ( beforePasteNotCanceled && editor.fire( 'pasteDialog', onDialogOpen ) ) {
                                        editor.on( 'pasteDialogCommit', onDialogCommit );

                                        // 'dialogHide' will be fired after 'pasteDialogCommit'.
                                        editor.on( 'dialogHide', function( evt ) {
                                                evt.removeListener();
                                                evt.data.removeListener( 'pasteDialogCommit', onDialogCommit );

                                                // Because Opera has to wait a while in pasteDialog we have to wait here.
                                                setTimeout( function() {
                                                        // Notify even if user canceled dialog (clicked 'cancel', ESC, etc).
                                                        if ( !dialogCommited )
                                                                callback( null );
                                                }, 10 );
                                        } );
                                } else {
                                        callback( null );
                                }
                        }

                        function onPaste( evt ) {
                                evt.removeListener();
                                evt.cancel();
                                callback( evt.data );
                        }

                        function onBeforePaste( evt ) {
                                evt.removeListener();
                                beforePasteNotCanceled = true;
                                dataType = evt.data.type;
                        }

                        function onDialogCommit( evt ) {
                                evt.removeListener();
                                // Cancel pasteDialogCommit so paste dialog won't automatically fire
                                // 'paste' evt by itself.
                                evt.cancel();
                                dialogCommited = true;
                                callback( {
                                        type: dataType,
                                        dataValue: evt.data.dataValue,
                                        dataTransfer: evt.data.dataTransfer,
                                        method: 'paste'
                                } );
                        }

                        function onDialogOpen() {
                                this.customTitle = ( options && options.title );
                        }
                };

                function addButtonsCommands() {
                        addButtonCommand( 'Cut', 'cut', createCutCopyCmd( 'cut' ), 10, 1 );
                        addButtonCommand( 'Copy', 'copy', createCutCopyCmd( 'copy' ), 20, 4 );
                        addButtonCommand( 'Paste', 'paste', createPasteCmd(), 30, 8 );

                        function addButtonCommand( buttonName, commandName, command, toolbarOrder, ctxMenuOrder ) {
                                var lang = editor.lang.clipboard[ commandName ];

                                editor.addCommand( commandName, command );
                                editor.ui.addButton && editor.ui.addButton( buttonName, {
                                        label: lang,
                                        command: commandName,
                                        toolbar: 'clipboard,' + toolbarOrder
                                } );

                                // If the "menu" plugin is loaded, register the menu item.
                                if ( editor.addMenuItems ) {
                                        editor.addMenuItem( commandName, {
                                                label: lang,
                                                command: commandName,
                                                group: 'clipboard',
                                                order: ctxMenuOrder
                                        } );
                                }
                        }
                }

                function addListeners() {
                        editor.on( 'key', onKey );
                        editor.on( 'contentDom', addPasteListenersToEditable );

                        // For improved performance, we're checking the readOnly state on selectionChange instead of hooking a key event for that.
                        editor.on( 'selectionChange', function( evt ) {
                                inReadOnly = evt.data.selection.getRanges()[ 0 ].checkReadOnly();
                                setToolbarStates();
                        } );

                        // If the "contextmenu" plugin is loaded, register the listeners.
                        if ( editor.contextMenu ) {
                                editor.contextMenu.addListener( function( element, selection ) {
                                        inReadOnly = selection.getRanges()[ 0 ].checkReadOnly();
                                        return {
                                                cut: stateFromNamedCommand( 'cut' ),
                                                copy: stateFromNamedCommand( 'copy' ),
                                                paste: stateFromNamedCommand( 'paste' )
                                        };
                                } );
                        }
                }

                // Add events listeners to editable.
                function addPasteListenersToEditable() {
                        var editable = editor.editable();

                        if ( CKEDITOR.plugins.clipboard.isCustomCopyCutSupported ) {
                                var initOnCopyCut = function( evt ) {
                                        // If user tries to cut in read-only editor, we must prevent default action. (#13872)
                                        if ( !editor.readOnly || evt.name != 'cut' ) {
                                                clipboard.initPasteDataTransfer( evt, editor );
                                        }
                                        evt.data.preventDefault();
                                };

                                editable.on( 'copy', initOnCopyCut );
                                editable.on( 'cut', initOnCopyCut );

                                // Delete content with the low priority so one can overwrite cut data.
                                editable.on( 'cut', function() {
                                        // If user tries to cut in read-only editor, we must prevent default action. (#13872)
                                        if ( !editor.readOnly ) {
                                                editor.extractSelectedHtml();
                                        }
                                }, null, null, 999 );
                        }

                        // We'll be catching all pasted content in one line, regardless of whether
                        // it's introduced by a document command execution (e.g. toolbar buttons) or
                        // user paste behaviors (e.g. CTRL+V).
                        editable.on( clipboard.mainPasteEvent, function( evt ) {
                                if ( clipboard.mainPasteEvent == 'beforepaste' && preventBeforePasteEvent ) {
                                        return;
                                }

                                // If you've just asked yourself why preventPasteEventNow() is not here, but
                                // in listener for CTRL+V and exec method of 'paste' command
                                // you've asked the same question we did.
                                //
                                // THE ANSWER:
                                //
                                // First thing to notice - this answer makes sense only for IE,
                                // because other browsers don't listen for 'paste' event.
                                //
                                // What would happen if we move preventPasteEventNow() here?
                                // For:
                                // * CTRL+V - IE fires 'beforepaste', so we prevent 'paste' and pasteDataFromClipboard(). OK.
                                // * editor.execCommand( 'paste' ) - we fire 'beforepaste', so we prevent
                                //              'paste' and pasteDataFromClipboard() and doc.execCommand( 'Paste' ). OK.
                                // * native context menu - IE fires 'beforepaste', so we prevent 'paste', but unfortunately
                                //              on IE we fail with pasteDataFromClipboard() here, because of... we don't know why, but
                                //              we just fail, so... we paste nothing. FAIL.
                                // * native menu bar - the same as for native context menu.
                                //
                                // But don't you know any way to distinguish first two cases from last two?
                                // Only one - special flag set in CTRL+V handler and exec method of 'paste'
                                // command. And that's what we did using preventPasteEventNow().

                                pasteDataFromClipboard( evt );
                        } );

                        // It's not possible to clearly handle all four paste methods (ctrl+v, native menu bar
                        // native context menu, editor's command) in one 'paste/beforepaste' event in IE.
                        //
                        // For ctrl+v & editor's command it's easy to handle pasting in 'beforepaste' listener,
                        // so we do this. For another two methods it's better to use 'paste' event.
                        //
                        // 'paste' is always being fired after 'beforepaste' (except of weird one on opening native
                        // context menu), so for two methods handled in 'beforepaste' we're canceling 'paste'
                        // using preventPasteEvent state.
                        //
                        // 'paste' event in IE is being fired before getClipboardDataByPastebin executes its callback.
                        //
                        // QUESTION: Why didn't you handle all 4 paste methods in handler for 'paste'?
                        //              Wouldn't this just be simpler?
                        // ANSWER: Then we would have to evt.data.preventDefault() only for native
                        //              context menu and menu bar pastes. The same with execIECommand().
                        //              That would force us to mark CTRL+V and editor's paste command with
                        //              special flag, other than preventPasteEvent. But we still would have to
                        //              have preventPasteEvent for the second event fired by execIECommand.
                        //              Code would be longer and not cleaner.
                        if ( clipboard.mainPasteEvent == 'beforepaste' ) {
                                editable.on( 'paste', function( evt ) {
                                        if ( preventPasteEvent ) {
                                                return;
                                        }

                                        // Cancel next 'paste' event fired by execIECommand( 'paste' )
                                        // at the end of this callback.
                                        preventPasteEventNow();

                                        // Prevent native paste.
                                        evt.data.preventDefault();

                                        pasteDataFromClipboard( evt );

                                        // Force IE to paste content into pastebin so pasteDataFromClipboard will work.
                                        if ( !execIECommand( 'paste' ) ) {
                                                editor.openDialog( 'paste' );
                                        }
                                } );

                                // If mainPasteEvent is 'beforePaste' (IE before Edge),
                                // dismiss the (wrong) 'beforepaste' event fired on context/toolbar menu open. (#7953)
                                editable.on( 'contextmenu', preventBeforePasteEventNow, null, null, 0 );

                                editable.on( 'beforepaste', function( evt ) {
                                        // Do not prevent event on CTRL+V and SHIFT+INS because it blocks paste (#11970).
                                        if ( evt.data && !evt.data.$.ctrlKey && !evt.data.$.shiftKey )
                                                preventBeforePasteEventNow();
                                }, null, null, 0 );
                        }

                        editable.on( 'beforecut', function() {
                                !preventBeforePasteEvent && fixCut( editor );
                        } );

                        var mouseupTimeout;

                        // Use editor.document instead of editable in non-IEs for observing mouseup
                        // since editable won't fire the event if selection process started within
                        // iframe and ended out of the editor (#9851).
                        editable.attachListener( CKEDITOR.env.ie ? editable : editor.document.getDocumentElement(), 'mouseup', function() {
                                mouseupTimeout = setTimeout( function() {
                                        setToolbarStates();
                                }, 0 );
                        } );

                        // Make sure that deferred mouseup callback isn't executed after editor instance
                        // had been destroyed. This may happen when editor.destroy() is called in parallel
                        // with mouseup event (i.e. a button with onclick callback) (#10219).
                        editor.on( 'destroy', function() {
                                clearTimeout( mouseupTimeout );
                        } );

                        editable.on( 'keyup', setToolbarStates );
                }

                // Create object representing Cut or Copy commands.
                function createCutCopyCmd( type ) {
                        return {
                                type: type,
                                canUndo: type == 'cut', // We can't undo copy to clipboard.
                                startDisabled: true,
                                fakeKeystroke: type == 'cut' ? CKEDITOR.CTRL + 88 /*X*/ :  CKEDITOR.CTRL + 67 /*C*/,
                                exec: function() {
                                        // Attempts to execute the Cut and Copy operations.
                                        function tryToCutCopy( type ) {
                                                if ( CKEDITOR.env.ie )
                                                        return execIECommand( type );

                                                // non-IEs part
                                                try {
                                                        // Other browsers throw an error if the command is disabled.
                                                        return editor.document.$.execCommand( type, false, null );
                                                } catch ( e ) {
                                                        return false;
                                                }
                                        }

                                        this.type == 'cut' && fixCut();

                                        var success = tryToCutCopy( this.type );

                                        if ( !success ) {
                                                // Show cutError or copyError.
                                                editor.showNotification( editor.lang.clipboard[ this.type + 'Error' ] ); // jshint ignore:line
                                        }

                                        return success;
                                }
                        };
                }

                function createPasteCmd() {
                        return {
                                // Snapshots are done manually by editable.insertXXX methods.
                                canUndo: false,
                                async: true,
                                fakeKeystroke: CKEDITOR.CTRL + 86 /*V*/,
                                exec: function( editor, data ) {
                                        var cmd = this,
                                                fire = function( data, withBeforePaste ) {
                                                        data && firePasteEvents( editor, data, !!withBeforePaste );

                                                        editor.fire( 'afterCommandExec', {
                                                                name: 'paste',
                                                                command: cmd,
                                                                returnValue: !!data
                                                        } );
                                                };

                                        // Check data precisely - don't open dialog on empty string.
                                        if ( typeof data == 'string' )
                                                fire( {
                                                                dataValue: data,
                                                                method: 'paste',
                                                                dataTransfer: clipboard.initPasteDataTransfer()
                                                        }, 1 );
                                        else
                                                editor.getClipboardData( fire );
                                }
                        };
                }

                function preventPasteEventNow() {
                        preventPasteEvent = 1;
                        // For safety reason we should wait longer than 0/1ms.
                        // We don't know how long execution of quite complex getClipboardData will take
                        // and in for example 'paste' listener execCommand() (which fires 'paste') is called
                        // after getClipboardData finishes.
                        // Luckily, it's impossible to immediately fire another 'paste' event we want to handle,
                        // because we only handle there native context menu and menu bar.
                        setTimeout( function() {
                                preventPasteEvent = 0;
                        }, 100 );
                }

                function preventBeforePasteEventNow() {
                        preventBeforePasteEvent = 1;
                        setTimeout( function() {
                                preventBeforePasteEvent = 0;
                        }, 10 );
                }

                // Tries to execute any of the paste, cut or copy commands in IE. Returns a
                // boolean indicating that the operation succeeded.
                // @param {String} command *LOWER CASED* name of command ('paste', 'cut', 'copy').
                function execIECommand( command ) {
                        var doc = editor.document,
                                body = doc.getBody(),
                                enabled = false,
                                onExec = function() {
                                        enabled = true;
                                };

                        // The following seems to be the only reliable way to detect that
                        // clipboard commands are enabled in IE. It will fire the
                        // onpaste/oncut/oncopy events only if the security settings allowed
                        // the command to execute.
                        body.on( command, onExec );

                        // IE7: document.execCommand has problem to paste into positioned element.
                        if ( CKEDITOR.env.version > 7 ) {
                                doc.$.execCommand( command );
                        } else {
                                doc.$.selection.createRange().execCommand( command );
                        }

                        body.removeListener( command, onExec );

                        return enabled;
                }

                // Cutting off control type element in IE standards breaks the selection entirely. (#4881)
                function fixCut() {
                        if ( !CKEDITOR.env.ie || CKEDITOR.env.quirks )
                                return;

                        var sel = editor.getSelection(),
                                control, range, dummy;

                        if ( ( sel.getType() == CKEDITOR.SELECTION_ELEMENT ) && ( control = sel.getSelectedElement() ) ) {
                                range = sel.getRanges()[ 0 ];
                                dummy = editor.document.createText( '' );
                                dummy.insertBefore( control );
                                range.setStartBefore( dummy );
                                range.setEndAfter( control );
                                sel.selectRanges( [ range ] );

                                // Clear up the fix if the paste wasn't succeeded.
                                setTimeout( function() {
                                        // Element still online?
                                        if ( control.getParent() ) {
                                                dummy.remove();
                                                sel.selectElement( control );
                                        }
                                }, 0 );
                        }
                }

                // Allow to peek clipboard content by redirecting the
                // pasting content into a temporary bin and grab the content of it.
                function getClipboardDataByPastebin( evt, callback ) {
                        var doc = editor.document,
                                editable = editor.editable(),
                                cancel = function( evt ) {
                                        evt.cancel();
                                },
                                blurListener;

                        // Avoid recursions on 'paste' event or consequent paste too fast. (#5730)
                        if ( doc.getById( 'cke_pastebin' ) )
                                return;

                        var sel = editor.getSelection();
                        var bms = sel.createBookmarks();

                        // #11384. On IE9+ we use native selectionchange (i.e. editor#selectionCheck) to cache the most
                        // recent selection which we then lock on editable blur. See selection.js for more info.
                        // selectionchange fired before getClipboardDataByPastebin() cached selection
                        // before creating bookmark (cached selection will be invalid, because bookmarks modified the DOM),
                        // so we need to fire selectionchange one more time, to store current seleciton.
                        // Selection will be locked when we focus pastebin.
                        if ( CKEDITOR.env.ie )
                                sel.root.fire( 'selectionchange' );

                        // Create container to paste into.
                        // For rich content we prefer to use "body" since it holds
                        // the least possibility to be splitted by pasted content, while this may
                        // breaks the text selection on a frame-less editable, "div" would be
                        // the best one in that case.
                        // In another case on old IEs moving the selection into a "body" paste bin causes error panic.
                        // Body can't be also used for Opera which fills it with <br>
                        // what is indistinguishable from pasted <br> (copying <br> in Opera isn't possible,
                        // but it can be copied from other browser).
                        var pastebin = new CKEDITOR.dom.element(
                                ( CKEDITOR.env.webkit || editable.is( 'body' ) ) && !CKEDITOR.env.ie ? 'body' : 'div', doc );

                        pastebin.setAttributes( {
                                id: 'cke_pastebin',
                                'data-cke-temp': '1'
                        } );

                        var containerOffset = 0,
                                offsetParent,
                                win = doc.getWindow();

                        if ( CKEDITOR.env.webkit ) {
                                // It's better to paste close to the real paste destination, so inherited styles
                                // (which Webkits will try to compensate by styling span) differs less from the destination's one.
                                editable.append( pastebin );
                                // Style pastebin like .cke_editable, to minimize differences between origin and destination. (#9754)
                                pastebin.addClass( 'cke_editable' );

                                // Compensate position of offsetParent.
                                if ( !editable.is( 'body' ) ) {
                                        // We're not able to get offsetParent from pastebin (body element), so check whether
                                        // its parent (editable) is positioned.
                                        if ( editable.getComputedStyle( 'position' ) != 'static' )
                                                offsetParent = editable;
                                        // And if not - safely get offsetParent from editable.
                                        else
                                                offsetParent = CKEDITOR.dom.element.get( editable.$.offsetParent );

                                        containerOffset = offsetParent.getDocumentPosition().y;
                                }
                        } else {
                                // Opera and IE doesn't allow to append to html element.
                                editable.getAscendant( CKEDITOR.env.ie ? 'body' : 'html', 1 ).append( pastebin );
                        }

                        pastebin.setStyles( {
                                position: 'absolute',
                                // Position the bin at the top (+10 for safety) of viewport to avoid any subsequent document scroll.
                                top: ( win.getScrollPosition().y - containerOffset + 10 ) + 'px',
                                width: '1px',
                                // Caret has to fit in that height, otherwise browsers like Chrome & Opera will scroll window to show it.
                                // Set height equal to viewport's height - 20px (safety gaps), minimum 1px.
                                height: Math.max( 1, win.getViewPaneSize().height - 20 ) + 'px',
                                overflow: 'hidden',
                                // Reset styles that can mess up pastebin position.
                                margin: 0,
                                padding: 0
                        } );

                        // Paste fails in Safari when the body tag has 'user-select: none'. (#12506)
                        if ( CKEDITOR.env.safari )
                                pastebin.setStyles( CKEDITOR.tools.cssVendorPrefix( 'user-select', 'text' ) );

                        // Check if the paste bin now establishes new editing host.
                        var isEditingHost = pastebin.getParent().isReadOnly();

                        if ( isEditingHost ) {
                                // Hide the paste bin.
                                pastebin.setOpacity( 0 );
                                // And make it editable.
                                pastebin.setAttribute( 'contenteditable', true );
                        }
                        // Transparency is not enough since positioned non-editing host always shows
                        // resize handler, pull it off the screen instead.
                        else {
                                pastebin.setStyle( editor.config.contentsLangDirection == 'ltr' ? 'left' : 'right', '-10000px' );
                        }

                        editor.on( 'selectionChange', cancel, null, null, 0 );

                        // Webkit fill fire blur on editable when moving selection to
                        // pastebin (if body is used). Cancel it because it causes incorrect
                        // selection lock in case of inline editor (#10644).
                        // The same seems to apply to Firefox (#10787).
                        if ( CKEDITOR.env.webkit || CKEDITOR.env.gecko )
                                blurListener = editable.once( 'blur', cancel, null, null, -100 );

                        // Temporarily move selection to the pastebin.
                        isEditingHost && pastebin.focus();
                        var range = new CKEDITOR.dom.range( pastebin );
                        range.selectNodeContents( pastebin );
                        var selPastebin = range.select();

                        // If non-native paste is executed, IE will open security alert and blur editable.
                        // Editable will then lock selection inside itself and after accepting security alert
                        // this selection will be restored. We overwrite stored selection, so it's restored
                        // in pastebin. (#9552)
                        if ( CKEDITOR.env.ie ) {
                                blurListener = editable.once( 'blur', function() {
                                        editor.lockSelection( selPastebin );
                                } );
                        }

                        var scrollTop = CKEDITOR.document.getWindow().getScrollPosition().y;

                        // Wait a while and grab the pasted contents.
                        setTimeout( function() {
                                // Restore main window's scroll position which could have been changed
                                // by browser in cases described in #9771.
                                if ( CKEDITOR.env.webkit )
                                        CKEDITOR.document.getBody().$.scrollTop = scrollTop;

                                // Blur will be fired only on non-native paste. In other case manually remove listener.
                                blurListener && blurListener.removeListener();

                                // Restore properly the document focus. (#8849)
                                if ( CKEDITOR.env.ie )
                                        editable.focus();

                                // IE7: selection must go before removing pastebin. (#8691)
                                sel.selectBookmarks( bms );
                                pastebin.remove();

                                // Grab the HTML contents.
                                // We need to look for a apple style wrapper on webkit it also adds
                                // a div wrapper if you copy/paste the body of the editor.
                                // Remove hidden div and restore selection.
                                var bogusSpan;
                                if ( CKEDITOR.env.webkit && ( bogusSpan = pastebin.getFirst() ) && ( bogusSpan.is && bogusSpan.hasClass( 'Apple-style-span' ) ) )
                                        pastebin = bogusSpan;

                                editor.removeListener( 'selectionChange', cancel );
                                callback( pastebin.getHtml() );
                        }, 0 );
                }

                // Try to get content directly on IE from clipboard, without native event
                // being fired before. In other words - synthetically get clipboard data, if it's possible.
                // mainPasteEvent will be fired, so if forced native paste:
                // * worked, getClipboardDataByPastebin will grab it,
                // * didn't work, dataValue and dataTransfer will be empty and editor#paste won't be fired.
                // Clipboard data can be accessed directly only on IEs older than Edge.
                // On other browsers we should fire beforePaste event and return false.
                function getClipboardDataDirectly() {
                        if ( clipboard.mainPasteEvent == 'paste' ) {
                                // beforePaste should be fired when dialog open so it can be canceled.
                                editor.fire( 'beforePaste', { type: 'auto', method: 'paste' } );
                                return false;
                        }

                        // Prevent IE from pasting at the begining of the document.
                        editor.focus();

                        // Command will be handled by 'beforepaste', but as
                        // execIECommand( 'paste' ) will fire also 'paste' event
                        // we're canceling it.
                        preventPasteEventNow();

                        // #9247: Lock focus to prevent IE from hiding toolbar for inline editor.
                        var focusManager = editor.focusManager;
                        focusManager.lock();

                        if ( editor.editable().fire( clipboard.mainPasteEvent ) && !execIECommand( 'paste' ) ) {
                                focusManager.unlock();
                                return false;
                        }
                        focusManager.unlock();

                        return true;
                }

                // Listens for some clipboard related keystrokes, so they get customized.
                // Needs to be bind to keydown event.
                function onKey( event ) {
                        if ( editor.mode != 'wysiwyg' )
                                return;

                        switch ( event.data.keyCode ) {
                                // Paste
                                case CKEDITOR.CTRL + 86: // CTRL+V
                                case CKEDITOR.SHIFT + 45: // SHIFT+INS
                                        var editable = editor.editable();

                                        // Cancel 'paste' event because ctrl+v is for IE handled
                                        // by 'beforepaste'.
                                        preventPasteEventNow();

                                        // Simulate 'beforepaste' event for all browsers using 'paste' as main event.
                                        if ( clipboard.mainPasteEvent == 'paste' ) {
                                                editable.fire( 'beforepaste' );
                                        }

                                        return;

                                        // Cut
                                case CKEDITOR.CTRL + 88: // CTRL+X
                                case CKEDITOR.SHIFT + 46: // SHIFT+DEL
                                        // Save Undo snapshot.
                                        editor.fire( 'saveSnapshot' ); // Save before cut
                                        setTimeout( function() {
                                                editor.fire( 'saveSnapshot' ); // Save after cut
                                        }, 50 ); // OSX is slow (#11416).
                        }
                }

                function pasteDataFromClipboard( evt ) {
                        // Default type is 'auto', but can be changed by beforePaste listeners.
                        var eventData = {
                                        type: 'auto',
                                        method: 'paste',
                                        dataTransfer: clipboard.initPasteDataTransfer( evt )
                                };

                        eventData.dataTransfer.cacheData();

                        // Fire 'beforePaste' event so clipboard flavor get customized by other plugins.
                        // If 'beforePaste' is canceled continue executing getClipboardDataByPastebin and then do nothing
                        // (do not fire 'paste', 'afterPaste' events). This way we can grab all - synthetically
                        // and natively pasted content and prevent its insertion into editor
                        // after canceling 'beforePaste' event.
                        var beforePasteNotCanceled = editor.fire( 'beforePaste', eventData ) !== false;

                        // Do not use paste bin if the browser let us get HTML or files from dataTranfer.
                        if ( beforePasteNotCanceled && clipboard.canClipboardApiBeTrusted( eventData.dataTransfer, editor ) ) {
                                evt.data.preventDefault();
                                setTimeout( function() {
                                        firePasteEvents( editor, eventData );
                                }, 0 );
                        } else {
                                getClipboardDataByPastebin( evt, function( data ) {
                                        // Clean up.
                                        eventData.dataValue = data.replace( /<span[^>]+data-cke-bookmark[^<]*?<\/span>/ig, '' );

                                        // Fire remaining events (without beforePaste)
                                        beforePasteNotCanceled && firePasteEvents( editor, eventData );
                                } );
                        }
                }

                function setToolbarStates() {
                        if ( editor.mode != 'wysiwyg' )
                                return;

                        var pasteState = stateFromNamedCommand( 'paste' );

                        editor.getCommand( 'cut' ).setState( stateFromNamedCommand( 'cut' ) );
                        editor.getCommand( 'copy' ).setState( stateFromNamedCommand( 'copy' ) );
                        editor.getCommand( 'paste' ).setState( pasteState );
                        editor.fire( 'pasteState', pasteState );
                }

                function stateFromNamedCommand( command ) {
                        if ( inReadOnly && command in { paste: 1, cut: 1 } )
                                return CKEDITOR.TRISTATE_DISABLED;

                        if ( command == 'paste' )
                                return CKEDITOR.TRISTATE_OFF;

                        // Cut, copy - check if the selection is not empty.
                        var sel = editor.getSelection(),
                                ranges = sel.getRanges(),
                                selectionIsEmpty = sel.getType() == CKEDITOR.SELECTION_NONE || ( ranges.length == 1 && ranges[ 0 ].collapsed );

                        return selectionIsEmpty ? CKEDITOR.TRISTATE_DISABLED : CKEDITOR.TRISTATE_OFF;
                }
        }

        // Returns:
        // * 'htmlifiedtext' if content looks like transformed by browser from plain text.
        //              See clipboard/paste.html TCs for more info.
        // * 'html' if it is not 'htmlifiedtext'.
        function recogniseContentType( data ) {
                if ( CKEDITOR.env.webkit ) {
                        // Plain text or ( <div><br></div> and text inside <div> ).
                        if ( !data.match( /^[^<]*$/g ) && !data.match( /^(<div><br( ?\/)?><\/div>|<div>[^<]*<\/div>)*$/gi ) )
                                return 'html';
                } else if ( CKEDITOR.env.ie ) {
                        // Text and <br> or ( text and <br> in <p> - paragraphs can be separated by new \r\n ).
                        if ( !data.match( /^([^<]|<br( ?\/)?>)*$/gi ) && !data.match( /^(<p>([^<]|<br( ?\/)?>)*<\/p>|(\r\n))*$/gi ) )
                                return 'html';
                } else if ( CKEDITOR.env.gecko ) {
                        // Text or <br>.
                        if ( !data.match( /^([^<]|<br( ?\/)?>)*$/gi ) )
                                return 'html';
                } else {
                        return 'html';
                }

                return 'htmlifiedtext';
        }

        // This function transforms what browsers produce when
        // pasting plain text into editable element (see clipboard/paste.html TCs
        // for more info) into correct HTML (similar to that produced by text2Html).
        function htmlifiedTextHtmlification( config, data ) {
                function repeatParagraphs( repeats ) {
                        // Repeat blocks floor((n+1)/2) times.
                        // Even number of repeats - add <br> at the beginning of last <p>.
                        return CKEDITOR.tools.repeat( '</p><p>', ~~( repeats / 2 ) ) + ( repeats % 2 == 1 ? '<br>' : '' );
                }

                        // Replace adjacent white-spaces (EOLs too - Fx sometimes keeps them) with one space.
                data = data.replace( /\s+/g, ' ' )
                        // Remove spaces from between tags.
                        .replace( /> +</g, '><' )
                        // Normalize XHTML syntax and upper cased <br> tags.
                        .replace( /<br ?\/>/gi, '<br>' );

                // IE - lower cased tags.
                data = data.replace( /<\/?[A-Z]+>/g, function( match ) {
                        return match.toLowerCase();
                } );

                // Don't touch single lines (no <br|p|div>) - nothing to do here.
                if ( data.match( /^[^<]$/ ) )
                        return data;

                // Webkit.
                if ( CKEDITOR.env.webkit && data.indexOf( '<div>' ) > -1 ) {
                                // One line break at the beginning - insert <br>
                        data = data.replace( /^(<div>(<br>|)<\/div>)(?!$|(<div>(<br>|)<\/div>))/g, '<br>' )
                                // Two or more - reduce number of new lines by one.
                                .replace( /^(<div>(<br>|)<\/div>){2}(?!$)/g, '<div></div>' );

                        // Two line breaks create one paragraph in Webkit.
                        if ( data.match( /<div>(<br>|)<\/div>/ ) ) {
                                data = '<p>' + data.replace( /(<div>(<br>|)<\/div>)+/g, function( match ) {
                                        return repeatParagraphs( match.split( '</div><div>' ).length + 1 );
                                } ) + '</p>';
                        }

                        // One line break create br.
                        data = data.replace( /<\/div><div>/g, '<br>' );

                        // Remove remaining divs.
                        data = data.replace( /<\/?div>/g, '' );
                }

                // Opera and Firefox and enterMode != BR.
                if ( CKEDITOR.env.gecko && config.enterMode != CKEDITOR.ENTER_BR ) {
                        // Remove bogus <br> - Fx generates two <brs> for one line break.
                        // For two line breaks it still produces two <brs>, but it's better to ignore this case than the first one.
                        if ( CKEDITOR.env.gecko )
                                data = data.replace( /^<br><br>$/, '<br>' );

                        // This line satisfy edge case when for Opera we have two line breaks
                        //data = data.replace( /)

                        if ( data.indexOf( '<br><br>' ) > -1 ) {
                                // Two line breaks create one paragraph, three - 2, four - 3, etc.
                                data = '<p>' + data.replace( /(<br>){2,}/g, function( match ) {
                                        return repeatParagraphs( match.length / 4 );
                                } ) + '</p>';
                        }
                }

                return switchEnterMode( config, data );
        }

        function filtersFactoryFactory() {
                var filters = {};

                function setUpTags() {
                        var tags = {};

                        for ( var tag in CKEDITOR.dtd ) {
                                if ( tag.charAt( 0 ) != '$' && tag != 'div' && tag != 'span' ) {
                                        tags[ tag ] = 1;
                                }
                        }

                        return tags;
                }

                function createSemanticContentFilter() {
                        var filter = new CKEDITOR.filter();

                        filter.allow( {
                                $1: {
                                        elements: setUpTags(),
                                        attributes: true,
                                        styles: false,
                                        classes: false
                                }
                        } );

                        return filter;
                }

                return {
                        get: function( type ) {
                                if ( type == 'plain-text' ) {
                                        // Does this look confusing to you? Did we forget about enter mode?
                                        // It is a trick that let's us creating one filter for edidtor, regardless of its
                                        // activeEnterMode (which as the name indicates can change during runtime).
                                        //
                                        // How does it work?
                                        // The active enter mode is passed to the filter.applyTo method.
                                        // The filter first marks all elements except <br> as disallowed and then tries to remove
                                        // them. However, it cannot remove e.g. a <p> element completely, because it's a basic structural element,
                                        // so it tries to replace it with an element created based on the active enter mode, eventually doing nothing.
                                        //
                                        // Now you can sleep well.
                                        return filters.plainText || ( filters.plainText = new CKEDITOR.filter( 'br' ) );
                                } else if ( type == 'semantic-content' ) {
                                        return filters.semanticContent || ( filters.semanticContent = createSemanticContentFilter() );
                                } else if ( type ) {
                                        // Create filter based on rules (string or object).
                                        return new CKEDITOR.filter( type );
                                }

                                return null;
                        }
                };
        }

        function filterContent( editor, data, filter ) {
                var fragment = CKEDITOR.htmlParser.fragment.fromHtml( data ),
                        writer = new CKEDITOR.htmlParser.basicWriter();

                filter.applyTo( fragment, true, false, editor.activeEnterMode );
                fragment.writeHtml( writer );

                return writer.getHtml();
        }

        function switchEnterMode( config, data ) {
                if ( config.enterMode == CKEDITOR.ENTER_BR ) {
                        data = data.replace( /(<\/p><p>)+/g, function( match ) {
                                return CKEDITOR.tools.repeat( '<br>', match.length / 7 * 2 );
                        } ).replace( /<\/?p>/g, '' );
                } else if ( config.enterMode == CKEDITOR.ENTER_DIV ) {
                        data = data.replace( /<(\/)?p>/g, '<$1div>' );
                }

                return data;
        }

        function preventDefaultSetDropEffectToNone( evt ) {
                evt.data.preventDefault();
                evt.data.$.dataTransfer.dropEffect = 'none';
        }

        function initDragDrop( editor ) {
                var clipboard = CKEDITOR.plugins.clipboard;

                editor.on( 'contentDom', function() {
                        var editable = editor.editable(),
                                dropTarget = CKEDITOR.plugins.clipboard.getDropTarget( editor ),
                                top = editor.ui.space( 'top' ),
                                bottom = editor.ui.space( 'bottom' );

                        // -------------- DRAGOVER TOP & BOTTOM --------------

                        // Not allowing dragging on toolbar and bottom (#12613).
                        clipboard.preventDefaultDropOnElement( top );
                        clipboard.preventDefaultDropOnElement( bottom );

                        // -------------- DRAGSTART --------------
                        // Listed on dragstart to mark internal and cross-editor drag & drop
                        // and save range and selected HTML.

                        editable.attachListener( dropTarget, 'dragstart', fireDragEvent );

                        // Make sure to reset data transfer (in case dragend was not called or was canceled).
                        editable.attachListener( editor, 'dragstart', clipboard.resetDragDataTransfer, clipboard, null, 1 );

                        // Create a dataTransfer object and save it globally.
                        editable.attachListener( editor, 'dragstart', function( evt ) {
                                clipboard.initDragDataTransfer( evt, editor );
                        }, null, null, 2 );

                        editable.attachListener( editor, 'dragstart', function() {
                                // Save drag range globally for cross editor D&D.
                                var dragRange = clipboard.dragRange = editor.getSelection().getRanges()[ 0 ];

                                // Store number of children, so we can later tell if any text node was split on drop. (#13011, #13447)
                                if ( CKEDITOR.env.ie && CKEDITOR.env.version < 10 ) {
                                        clipboard.dragStartContainerChildCount = dragRange ? getContainerChildCount( dragRange.startContainer ) : null;
                                        clipboard.dragEndContainerChildCount = dragRange ? getContainerChildCount( dragRange.endContainer ) : null;
                                }
                        }, null, null, 100 );

                        // -------------- DRAGEND --------------
                        // Clean up on dragend.

                        editable.attachListener( dropTarget, 'dragend', fireDragEvent );

                        // Init data transfer if someone wants to use it in dragend.
                        editable.attachListener( editor, 'dragend', clipboard.initDragDataTransfer, clipboard, null, 1 );

                        // When drag & drop is done we need to reset dataTransfer so the future
                        // external drop will be not recognize as internal.
                        editable.attachListener( editor, 'dragend', clipboard.resetDragDataTransfer, clipboard, null, 100 );

                        // -------------- DRAGOVER --------------
                        // We need to call preventDefault on dragover because otherwise if
                        // we drop image it will overwrite document.

                        editable.attachListener( dropTarget, 'dragover', function( evt ) {
                                var target = evt.data.getTarget();

                                // Prevent reloading page when dragging image on empty document (#12619).
                                if ( target && target.is && target.is( 'html' ) ) {
                                        evt.data.preventDefault();
                                        return;
                                }

                                // If we do not prevent default dragover on IE the file path
                                // will be loaded and we will lose content. On the other hand
                                // if we prevent it the cursor will not we shown, so we prevent
                                // dragover only on IE, on versions which support file API and only
                                // if the event contains files.
                                if ( CKEDITOR.env.ie &&
                                        CKEDITOR.plugins.clipboard.isFileApiSupported &&
                                        evt.data.$.dataTransfer.types.contains( 'Files' ) ) {
                                        evt.data.preventDefault();
                                }
                        } );

                        // -------------- DROP --------------

                        editable.attachListener( dropTarget, 'drop', function( evt ) {
                                // Do nothing if event was already prevented. (#13879)
                                if ( evt.data.$.defaultPrevented ) {
                                        return;
                                }

                                // Cancel native drop.
                                evt.data.preventDefault();

                                var target = evt.data.getTarget(),
                                        readOnly = target.isReadOnly();

                                // Do nothing if drop on non editable element (#13015).
                                // The <html> tag isn't editable (body is), but we want to allow drop on it
                                // (so it is possible to drop below editor contents).
                                if ( readOnly && !( target.type == CKEDITOR.NODE_ELEMENT && target.is( 'html' ) ) ) {
                                        return;
                                }

                                // Getting drop position is one of the most complex parts.
                                var dropRange = clipboard.getRangeAtDropPosition( evt, editor ),
                                        dragRange = clipboard.dragRange;

                                // Do nothing if it was not possible to get drop range.
                                if ( !dropRange ) {
                                        return;
                                }

                                // Fire drop.
                                fireDragEvent( evt, dragRange, dropRange  );
                        }, null, null, 9999 );

                        // Create dataTransfer or get it, if it was created before.
                        editable.attachListener( editor, 'drop', clipboard.initDragDataTransfer, clipboard, null, 1 );

                        // Execute drop action, fire paste.
                        editable.attachListener( editor, 'drop', function( evt ) {
                                var data = evt.data;

                                if ( !data ) {
                                        return;
                                }

                                // Let user modify drag and drop range.
                                var dropRange = data.dropRange,
                                        dragRange = data.dragRange,
                                        dataTransfer = data.dataTransfer;

                                if ( dataTransfer.getTransferType( editor ) == CKEDITOR.DATA_TRANSFER_INTERNAL ) {
                                        // Execute drop with a timeout because otherwise selection, after drop,
                                        // on IE is in the drag position, instead of drop position.
                                        setTimeout( function() {
                                                clipboard.internalDrop( dragRange, dropRange, dataTransfer, editor );
                                        }, 0 );
                                } else if ( dataTransfer.getTransferType( editor ) == CKEDITOR.DATA_TRANSFER_CROSS_EDITORS ) {
                                        crossEditorDrop( dragRange, dropRange, dataTransfer );
                                } else {
                                        externalDrop( dropRange, dataTransfer );
                                }
                        }, null, null, 9999 );

                        // Cross editor drag and drop (drag in one Editor and drop in the other).
                        function crossEditorDrop( dragRange, dropRange, dataTransfer ) {
                                // Paste event should be fired before delete contents because otherwise
                                // Chrome have a problem with drop range (Chrome split the drop
                                // range container so the offset is bigger then container length).
                                dropRange.select();
                                firePasteEvents( editor, { dataTransfer: dataTransfer, method: 'drop' }, 1 );

                                // Remove dragged content and make a snapshot.
                                dataTransfer.sourceEditor.fire( 'saveSnapshot' );

                                dataTransfer.sourceEditor.editable().extractHtmlFromRange( dragRange );

                                // Make some selection before saving snapshot, otherwise error will be thrown, because
                                // there will be no valid selection after content is removed.
                                dataTransfer.sourceEditor.getSelection().selectRanges( [ dragRange ] );
                                dataTransfer.sourceEditor.fire( 'saveSnapshot' );
                        }

                        // Drop from external source.
                        function externalDrop( dropRange, dataTransfer ) {
                                // Paste content into the drop position.
                                dropRange.select();

                                firePasteEvents( editor, { dataTransfer: dataTransfer, method: 'drop' }, 1 );

                                // Usually we reset DataTranfer on dragend,
                                // but dragend is called on the same element as dragstart
                                // so it will not be called on on external drop.
                                clipboard.resetDragDataTransfer();
                        }

                        // Fire drag/drop events (dragstart, dragend, drop).
                        function fireDragEvent( evt, dragRange, dropRange ) {
                                var eventData = {
                                                $: evt.data.$,
                                                target: evt.data.getTarget()
                                        };

                                if ( dragRange ) {
                                        eventData.dragRange = dragRange;
                                }
                                if ( dropRange ) {
                                        eventData.dropRange = dropRange;
                                }

                                if ( editor.fire( evt.name, eventData ) === false ) {
                                        evt.data.preventDefault();
                                }
                        }

                        function getContainerChildCount( container ) {
                                if ( container.type != CKEDITOR.NODE_ELEMENT ) {
                                        container = container.getParent();
                                }

                                return container.getChildCount();
                        }
                } );
        }

        /**
         * @singleton
         * @class CKEDITOR.plugins.clipboard
         */
        CKEDITOR.plugins.clipboard = {
                /**
                 * True if the environment allows to set data on copy or cut manually. This value is false in IE, because this browser
                 * shows the security dialog window when the script tries to set clipboard data and on iOS, because custom data is
                 * not saved to clipboard there.
                 *
                 * @since 4.5
                 * @readonly
                 * @property {Boolean}
                 */
                isCustomCopyCutSupported: !CKEDITOR.env.ie && !CKEDITOR.env.iOS,

                /**
                 * True if the environment supports MIME types and custom data types in dataTransfer/cliboardData getData/setData methods.
                 *
                 * @since 4.5
                 * @readonly
                 * @property {Boolean}
                 */
                isCustomDataTypesSupported: !CKEDITOR.env.ie,

                /**
                 * True if the environment supports File API.
                 *
                 * @since 4.5
                 * @readonly
                 * @property {Boolean}
                 */
                isFileApiSupported: !CKEDITOR.env.ie || CKEDITOR.env.version > 9,

                /**
                 * Main native paste event editable should listen to.
                 *
                 * **Note:** Safari does not like the {@link CKEDITOR.editor#beforePaste} event &mdash; it sometimes does not
                 * handle <kbd>Ctrl+C</kbd> properly. This is probably caused by some race condition between events.
                 * Chrome, Firefox and Edge work well with both events, so it is better to use {@link CKEDITOR.editor#paste}
                 * which will handle pasting from e.g. browsers' menu bars.
                 * IE7/8 does not like the {@link CKEDITOR.editor#paste} event for which it is throwing random errors.
                 *
                 * @since 4.5
                 * @readonly
                 * @property {String}
                 */
                mainPasteEvent: ( CKEDITOR.env.ie && !CKEDITOR.env.edge ) ? 'beforepaste' : 'paste',

                /**
                 * Returns `true` if it is expected that a browser provides HTML data through the Clipboard API.
                 * If not, this method returns `false` and as a result CKEditor will use the paste bin. Read more in
                 * the [Clipboard Integration](http://docs.ckeditor.com/#!/guide/dev_clipboard-section-clipboard-api) guide.
                 *
                 * @since 4.5.2
                 * @returns {Boolean}
                 */
                canClipboardApiBeTrusted: function( dataTransfer, editor ) {
                        // If it's an internal or cross-editor data transfer, then it means that custom cut/copy/paste support works
                        // and that the data were put manually on the data transfer so we can be sure that it's available.
                        if ( dataTransfer.getTransferType( editor ) != CKEDITOR.DATA_TRANSFER_EXTERNAL ) {
                                return true;
                        }

                        // In Chrome we can trust Clipboard API, with the exception of Chrome on Android (in both - mobile and desktop modes), where
                        // clipboard API is not available so we need to check it (#13187).
                        if ( CKEDITOR.env.chrome && !dataTransfer.isEmpty() ) {
                                return true;
                        }

                        // Because of a Firefox bug HTML data are not available in some cases (e.g. paste from Word), in such cases we
                        // need to use the pastebin (#13528, https://bugzilla.mozilla.org/show_bug.cgi?id=1183686).
                        if ( CKEDITOR.env.gecko && ( dataTransfer.getData( 'text/html' ) || dataTransfer.getFilesCount() ) ) {
                                return true;
                        }

                        // In Safari and IE HTML data is not available though the Clipboard API.
                        // In Edge things are a bit messy at the moment -
                        // https://connect.microsoft.com/IE/feedback/details/1572456/edge-clipboard-api-text-html-content-messed-up-in-event-clipboarddata
                        // It is safer to use the paste bin in unknown cases.
                        return false;
                },

                /**
                 * Returns the element that should be used as the target for the drop event.
                 *
                 * @since 4.5
                 * @param {CKEDITOR.editor} editor The editor instance.
                 * @returns {CKEDITOR.dom.domObject} the element that should be used as the target for the drop event.
                 */
                getDropTarget: function( editor ) {
                        var editable = editor.editable();

                        // #11123 Firefox needs to listen on document, because otherwise event won't be fired.
                        // #11086 IE8 cannot listen on document.
                        if ( ( CKEDITOR.env.ie && CKEDITOR.env.version < 9 ) || editable.isInline() ) {
                                return editable;
                        } else {
                                return editor.document;
                        }
                },

                /**
                 * IE 8 & 9 split text node on drop so the first node contains the
                 * text before the drop position and the second contains the rest. If you
                 * drag the content from the same node you will be not be able to get
                 * it (the range becomes invalid), so you need to join them back.
                 *
                 * Note that the first node in IE 8 & 9 is the original node object
                 * but with shortened content.
                 *
                 *              Before:
                 *                --- Text Node A ----------------------------------
                 *                                                           /\
                 *                                                      Drag position
                 *
                 *              After (IE 8 & 9):
                 *                --- Text Node A -----  --- Text Node B -----------
                 *                                     /\                    /\
                 *                                Drop position        Drag position
                 *                                                       (invalid)
                 *
                 *              After (other browsers):
                 *                --- Text Node A ----------------------------------
                 *                                     /\                    /\
                 *                                Drop position        Drag position
                 *
                 * **Note:** This function is in the public scope for tests usage only.
                 *
                 * @since 4.5
                 * @private
                 * @param {CKEDITOR.dom.range} dragRange The drag range.
                 * @param {CKEDITOR.dom.range} dropRange The drop range.
                 * @param {Number} preDragStartContainerChildCount The number of children of the drag range start container before the drop.
                 * @param {Number} preDragEndContainerChildCount The number of children of the drag range end container before the drop.
                 */
                fixSplitNodesAfterDrop: function( dragRange, dropRange, preDragStartContainerChildCount, preDragEndContainerChildCount ) {
                        var dropContainer = dropRange.startContainer;

                        if (
                                typeof preDragEndContainerChildCount != 'number' ||
                                typeof preDragStartContainerChildCount != 'number'
                        ) {
                                return;
                        }

                        // We are only concerned about ranges anchored in elements.
                        if ( dropContainer.type != CKEDITOR.NODE_ELEMENT ) {
                                return;
                        }

                        if ( handleContainer( dragRange.startContainer, dropContainer, preDragStartContainerChildCount ) ) {
                                return;
                        }

                        if ( handleContainer( dragRange.endContainer, dropContainer, preDragEndContainerChildCount ) ) {
                                return;
                        }

                        function handleContainer( dragContainer, dropContainer, preChildCount ) {
                                var dragElement = dragContainer;
                                if ( dragElement.type == CKEDITOR.NODE_TEXT ) {
                                        dragElement = dragContainer.getParent();
                                }

                                if ( dragElement.equals( dropContainer ) && preChildCount != dropContainer.getChildCount() ) {
                                        applyFix( dropRange );
                                        return true;
                                }
                        }

                        function applyFix( dropRange ) {
                                var nodeBefore = dropRange.startContainer.getChild( dropRange.startOffset - 1 ),
                                        nodeAfter = dropRange.startContainer.getChild( dropRange.startOffset );

                                if (
                                        nodeBefore && nodeBefore.type == CKEDITOR.NODE_TEXT &&
                                        nodeAfter && nodeAfter.type == CKEDITOR.NODE_TEXT
                                ) {
                                        var offset = nodeBefore.getLength();

                                        nodeBefore.setText( nodeBefore.getText() + nodeAfter.getText() );
                                        nodeAfter.remove();

                                        dropRange.setStart( nodeBefore, offset );
                                        dropRange.collapse( true );
                                }
                        }
                },

                /**
                 * Checks whether turning the drag range into bookmarks will invalidate the drop range.
                 * This usually happens when the drop range shares the container with the drag range and is
                 * located after the drag range, but there are countless edge cases.
                 *
                 * This function is stricly related to {@link #internalDrop} which toggles
                 * order in which it creates bookmarks for both ranges based on a value returned
                 * by this method. In some cases this method returns a value which is not necessarily
                 * true in terms of what it was meant to check, but it is convenient, because
                 * we know how it is interpreted in {@link #internalDrop}, so the correct
                 * behavior of the entire algorithm is assured.
                 *
                 * **Note:** This function is in the public scope for tests usage only.
                 *
                 * @since 4.5
                 * @private
                 * @param {CKEDITOR.dom.range} dragRange The first range to compare.
                 * @param {CKEDITOR.dom.range} dropRange The second range to compare.
                 * @returns {Boolean} `true` if the first range is before the second range.
                 */
                isDropRangeAffectedByDragRange: function( dragRange, dropRange ) {
                        var dropContainer = dropRange.startContainer,
                                dropOffset = dropRange.endOffset;

                        // Both containers are the same and drop offset is at the same position or later.
                        // " A L] A " " M A "
                        //       ^ ^
                        if ( dragRange.endContainer.equals( dropContainer ) && dragRange.endOffset <= dropOffset ) {
                                return true;
                        }

                        // Bookmark for drag start container will mess up with offsets.
                        // " O [L A " " M A "
                        //           ^       ^
                        if (
                                dragRange.startContainer.getParent().equals( dropContainer ) &&
                                dragRange.startContainer.getIndex() < dropOffset
                        ) {
                                return true;
                        }

                        // Bookmark for drag end container will mess up with offsets.
                        // " O] L A " " M A "
                        //           ^       ^
                        if (
                                dragRange.endContainer.getParent().equals( dropContainer ) &&
                                dragRange.endContainer.getIndex() < dropOffset
                        ) {
                                return true;
                        }

                        return false;
                },

                /**
                 * Internal drag and drop (drag and drop in the same editor instance).
                 *
                 * **Note:** This function is in the public scope for tests usage only.
                 *
                 * @since 4.5
                 * @private
                 * @param {CKEDITOR.dom.range} dragRange The first range to compare.
                 * @param {CKEDITOR.dom.range} dropRange The second range to compare.
                 * @param {CKEDITOR.plugins.clipboard.dataTransfer} dataTransfer
                 * @param {CKEDITOR.editor} editor
                 */
                internalDrop: function( dragRange, dropRange, dataTransfer, editor ) {
                        var clipboard = CKEDITOR.plugins.clipboard,
                                editable = editor.editable(),
                                dragBookmark, dropBookmark, isDropRangeAffected;

                        // Save and lock snapshot so there will be only
                        // one snapshot for both remove and insert content.
                        editor.fire( 'saveSnapshot' );
                        editor.fire( 'lockSnapshot', { dontUpdate: 1 } );

                        if ( CKEDITOR.env.ie && CKEDITOR.env.version < 10 ) {
                                this.fixSplitNodesAfterDrop(
                                        dragRange,
                                        dropRange,
                                        clipboard.dragStartContainerChildCount,
                                        clipboard.dragEndContainerChildCount
                                );
                        }

                        // Because we manipulate multiple ranges we need to do it carefully,
                        // changing one range (event creating a bookmark) may make other invalid.
                        // We need to change ranges into bookmarks so we can manipulate them easily in the future.
                        // We can change the range which is later in the text before we change the preceding range.
                        // We call isDropRangeAffectedByDragRange to test the order of ranges.
                        isDropRangeAffected = this.isDropRangeAffectedByDragRange( dragRange, dropRange );
                        if ( !isDropRangeAffected ) {
                                dragBookmark = dragRange.createBookmark( false );
                        }
                        dropBookmark = dropRange.clone().createBookmark( false );
                        if ( isDropRangeAffected ) {
                                dragBookmark = dragRange.createBookmark( false );
                        }

                        // Check if drop range is inside range.
                        // This is an edge case when we drop something on editable's margin/padding.
                        // That space is not treated as a part of the range we drag, so it is possible to drop there.
                        // When we drop, browser tries to find closest drop position and it finds it inside drag range. (#13453)
                        var startNode = dragBookmark.startNode,
                                endNode = dragBookmark.endNode,
                                dropNode = dropBookmark.startNode,
                                dropInsideDragRange =
                                        // Must check endNode because dragRange could be collapsed in some edge cases (simulated DnD).
                                        endNode &&
                                        ( startNode.getPosition( dropNode ) & CKEDITOR.POSITION_PRECEDING ) &&
                                        ( endNode.getPosition( dropNode ) & CKEDITOR.POSITION_FOLLOWING );

                        // If the drop range happens to be inside drag range change it's position to the beginning of the drag range.
                        if ( dropInsideDragRange ) {
                                // We only change position of bookmark span that is connected with dropBookmark.
                                // dropRange will be overwritten and set to the dropBookmark later.
                                dropNode.insertBefore( startNode );
                        }

                        // No we can safely delete content for the drag range...
                        dragRange = editor.createRange();
                        dragRange.moveToBookmark( dragBookmark );
                        editable.extractHtmlFromRange( dragRange, 1 );

                        // ...and paste content into the drop position.
                        dropRange = editor.createRange();
                        dropRange.moveToBookmark( dropBookmark );

                        // We do not select drop range, because of may be in the place we can not set the selection
                        // (e.g. between blocks, in case of block widget D&D). We put range to the paste event instead.
                        firePasteEvents( editor, { dataTransfer: dataTransfer, method: 'drop', range: dropRange }, 1 );

                        editor.fire( 'unlockSnapshot' );
                },

                /**
                 * Gets the range from the `drop` event.
                 *
                 * @since 4.5
                 * @param {Object} domEvent A native DOM drop event object.
                 * @param {CKEDITOR.editor} editor The source editor instance.
                 * @returns {CKEDITOR.dom.range} range at drop position.
                 */
                getRangeAtDropPosition: function( dropEvt, editor ) {
                        var $evt = dropEvt.data.$,
                                x = $evt.clientX,
                                y = $evt.clientY,
                                $range,
                                defaultRange = editor.getSelection( true ).getRanges()[ 0 ],
                                range = editor.createRange();

                        // Make testing possible.
                        if ( dropEvt.data.testRange )
                                return dropEvt.data.testRange;

                        // Webkits.
                        if ( document.caretRangeFromPoint ) {
                                $range = editor.document.$.caretRangeFromPoint( x, y );
                                range.setStart( CKEDITOR.dom.node( $range.startContainer ), $range.startOffset );
                                range.collapse( true );
                        }
                        // FF.
                        else if ( $evt.rangeParent ) {
                                range.setStart( CKEDITOR.dom.node( $evt.rangeParent ), $evt.rangeOffset );
                                range.collapse( true );
                        }
                        // IEs 9+.
                        // We check if editable is focused to make sure that it's an internal DnD. External DnD must use the second
                        // mechanism because of http://dev.ckeditor.com/ticket/13472#comment:6.
                        else if ( CKEDITOR.env.ie && CKEDITOR.env.version > 8 && defaultRange && editor.editable().hasFocus ) {
                                // On IE 9+ range by default is where we expected it.
                                // defaultRange may be undefined if dragover was canceled (file drop).
                                return defaultRange;
                        }
                        // IE 8 and all IEs if !defaultRange or external DnD.
                        else if ( document.body.createTextRange ) {
                                // To use this method we need a focus (which may be somewhere else in case of external drop).
                                editor.focus();

                                $range = editor.document.getBody().$.createTextRange();
                                try {
                                        var sucess = false;

                                        // If user drop between text line IEs moveToPoint throws exception:
                                        //
                                        //              Lorem ipsum pulvinar purus et euismod
                                        //
                                        //              dolor sit amet,| consectetur adipiscing
                                        //                             *
                                        //              vestibulum tincidunt augue eget tempus.
                                        //
                                        // * - drop position
                                        // | - expected cursor position
                                        //
                                        // So we try to call moveToPoint with +-1px up to +-20px above or
                                        // below original drop position to find nearest good drop position.
                                        for ( var i = 0; i < 20 && !sucess; i++ ) {
                                                if ( !sucess ) {
                                                        try {
                                                                $range.moveToPoint( x, y - i );
                                                                sucess = true;
                                                        } catch ( err ) {
                                                        }
                                                }
                                                if ( !sucess ) {
                                                        try {
                                                                $range.moveToPoint( x, y + i );
                                                                sucess = true;
                                                        } catch ( err ) {
                                                        }
                                                }
                                        }

                                        if ( sucess ) {
                                                var id = 'cke-temp-' + ( new Date() ).getTime();
                                                $range.pasteHTML( '<span id="' + id + '">\u200b</span>' );

                                                var span = editor.document.getById( id );
                                                range.moveToPosition( span, CKEDITOR.POSITION_BEFORE_START );
                                                span.remove();
                                        } else {
                                                // If the fist method does not succeed we might be next to
                                                // the short element (like header):
                                                //
                                                //              Lorem ipsum pulvinar purus et euismod.
                                                //
                                                //
                                                //              SOME HEADER|        *
                                                //
                                                //
                                                //              vestibulum tincidunt augue eget tempus.
                                                //
                                                // * - drop position
                                                // | - expected cursor position
                                                //
                                                // In such situation elementFromPoint returns proper element. Using getClientRect
                                                // it is possible to check if the cursor should be at the beginning or at the end
                                                // of paragraph.
                                                var $element = editor.document.$.elementFromPoint( x, y ),
                                                        element = new CKEDITOR.dom.element( $element ),
                                                        rect;

                                                if ( !element.equals( editor.editable() ) && element.getName() != 'html' ) {
                                                        rect = element.getClientRect();

                                                        if ( x < rect.left ) {
                                                                range.setStartAt( element, CKEDITOR.POSITION_AFTER_START );
                                                                range.collapse( true );
                                                        } else {
                                                                range.setStartAt( element, CKEDITOR.POSITION_BEFORE_END );
                                                                range.collapse( true );
                                                        }
                                                }
                                                // If drop happens on no element elementFromPoint returns html or body.
                                                //
                                                //              *      |Lorem ipsum pulvinar purus et euismod.
                                                //
                                                //                     vestibulum tincidunt augue eget tempus.
                                                //
                                                // * - drop position
                                                // | - expected cursor position
                                                //
                                                // In such case we can try to use default selection. If startContainer is not
                                                // 'editable' element it is probably proper selection.
                                                else if ( defaultRange && defaultRange.startContainer &&
                                                        !defaultRange.startContainer.equals( editor.editable() ) ) {
                                                        return defaultRange;

                                                // Otherwise we can not find any drop position and we have to return null
                                                // and cancel drop event.
                                                } else {
                                                        return null;
                                                }

                                        }
                                } catch ( err ) {
                                        return null;
                                }
                        } else {
                                return null;
                        }

                        return range;
                },

                /**
                 * This function tries to link the `evt.data.dataTransfer` property of the {@link CKEDITOR.editor#dragstart},
                 * {@link CKEDITOR.editor#dragend} and {@link CKEDITOR.editor#drop} events to a single
                 * {@link CKEDITOR.plugins.clipboard.dataTransfer} object.
                 *
                 * This method is automatically used by the core of the drag and drop functionality and
                 * usually does not have to be called manually when using the drag and drop events.
                 *
                 * This method behaves differently depending on whether the drag and drop events were fired
                 * artificially (to represent a non-native drag and drop) or whether they were caused by the native drag and drop.
                 *
                 * If the native event is not available, then it will create a new {@link CKEDITOR.plugins.clipboard.dataTransfer}
                 * instance (if it does not exist already) and will link it to this and all following event objects until
                 * the {@link #resetDragDataTransfer} method is called. It means that all three drag and drop events must be fired
                 * in order to ensure that the data transfer is bound correctly.
                 *
                 * If the native event is available, then the {@link CKEDITOR.plugins.clipboard.dataTransfer} is identified
                 * by its ID and a new instance is assigned to the `evt.data.dataTransfer` only if the ID changed or
                 * the {@link #resetDragDataTransfer} method was called.
                 *
                 * @since 4.5
                 * @param {CKEDITOR.dom.event} [evt] A drop event object.
                 * @param {CKEDITOR.editor} [sourceEditor] The source editor instance.
                 */
                initDragDataTransfer: function( evt, sourceEditor ) {
                        // Create a new dataTransfer object based on the drop event.
                        // If this event was used on dragstart to create dataTransfer
                        // both dataTransfer objects will have the same id.
                        var nativeDataTransfer = evt.data.$ ? evt.data.$.dataTransfer : null,
                                dataTransfer = new this.dataTransfer( nativeDataTransfer, sourceEditor );

                        if ( !nativeDataTransfer ) {
                                // No native event.
                                if ( this.dragData ) {
                                        dataTransfer = this.dragData;
                                } else {
                                        this.dragData = dataTransfer;
                                }
                        } else {
                                // Native event. If there is the same id we will replace dataTransfer with the one
                                // created on drag, because it contains drag editor, drag content and so on.
                                // Otherwise (in case of drag from external source) we save new object to
                                // the global clipboard.dragData.
                                if ( this.dragData && dataTransfer.id == this.dragData.id ) {
                                        dataTransfer = this.dragData;
                                } else {
                                        this.dragData = dataTransfer;
                                }
                        }

                        evt.data.dataTransfer = dataTransfer;
                },

                /**
                 * Removes the global {@link #dragData} so the next call to {@link #initDragDataTransfer}
                 * always creates a new instance of {@link CKEDITOR.plugins.clipboard.dataTransfer}.
                 *
                 * @since 4.5
                 */
                resetDragDataTransfer: function() {
                        this.dragData = null;
                },

                /**
                 * Global object storing the data transfer of the current drag and drop operation.
                 * Do not use it directly, use {@link #initDragDataTransfer} and {@link #resetDragDataTransfer}.
                 *
                 * Note: This object is global (meaning that it is not related to a single editor instance)
                 * in order to handle drag and drop from one editor into another.
                 *
                 * @since 4.5
                 * @private
                 * @property {CKEDITOR.plugins.clipboard.dataTransfer} dragData
                 */

                /**
                 * Range object to save the drag range and remove its content after the drop.
                 *
                 * @since 4.5
                 * @private
                 * @property {CKEDITOR.dom.range} dragRange
                 */

                /**
                 * Initializes and links data transfer objects based on the paste event. If the data
                 * transfer object was already initialized on this event, the function will
                 * return that object. In IE it is not possible to link copy/cut and paste events
                 * so the method always returns a new object. The same happens if there is no paste event
                 * passed to the method.
                 *
                 * @since 4.5
                 * @param {CKEDITOR.dom.event} [evt] A paste event object.
                 * @param {CKEDITOR.editor} [sourceEditor] The source editor instance.
                 * @returns {CKEDITOR.plugins.clipboard.dataTransfer} The data transfer object.
                 */
                initPasteDataTransfer: function( evt, sourceEditor ) {
                        if ( !this.isCustomCopyCutSupported ) {
                                // Edge does not support custom copy/cut, but it have some useful data in the clipboardData (#13755).
                                return new this.dataTransfer( ( CKEDITOR.env.edge && evt && evt.data.$ && evt.data.$.clipboardData ) || null, sourceEditor );
                        } else if ( evt && evt.data && evt.data.$ ) {
                                var dataTransfer = new this.dataTransfer( evt.data.$.clipboardData, sourceEditor );

                                if ( this.copyCutData && dataTransfer.id == this.copyCutData.id ) {
                                        dataTransfer = this.copyCutData;
                                        dataTransfer.$ = evt.data.$.clipboardData;
                                } else {
                                        this.copyCutData = dataTransfer;
                                }

                                return dataTransfer;
                        } else {
                                return new this.dataTransfer( null, sourceEditor );
                        }
                },

                /**
                 * Prevents dropping on the specified element.
                 *
                 * @since 4.5
                 * @param {CKEDITOR.dom.element} element The element on which dropping should be disabled.
                 */
                preventDefaultDropOnElement: function( element ) {
                        element && element.on( 'dragover', preventDefaultSetDropEffectToNone );
                }
        };

        // Data type used to link drag and drop events.
        //
        // In IE URL data type is buggie and there is no way to mark drag & drop  without
        // modifying text data (which would be displayed if user drop content to the textarea)
        // so we just read dragged text.
        //
        // In Chrome and Firefox we can use custom data types.
        var clipboardIdDataType = CKEDITOR.plugins.clipboard.isCustomDataTypesSupported ? 'cke/id' : 'Text';
        /**
         * Facade for the native `dataTransfer`/`clipboadData` object to hide all differences
         * between browsers.
         *
         * @since 4.5
         * @class CKEDITOR.plugins.clipboard.dataTransfer
         * @constructor Creates a class instance.
         * @param {Object} [nativeDataTransfer] A native data transfer object.
         * @param {CKEDITOR.editor} [editor] The source editor instance. If the editor is defined, dataValue will
         * be created based on the editor content and the type will be 'html'.
         */
        CKEDITOR.plugins.clipboard.dataTransfer = function( nativeDataTransfer, editor ) {
                if ( nativeDataTransfer ) {
                        this.$ = nativeDataTransfer;
                }

                this._ = {
                        metaRegExp: /^<meta.*?>/i,
                        bodyRegExp: /<body(?:[\s\S]*?)>([\s\S]*)<\/body>/i,
                        fragmentRegExp: /<!--(?:Start|End)Fragment-->/g,

                        data: {},
                        files: [],

                        normalizeType: function( type ) {
                                type = type.toLowerCase();

                                if ( type == 'text' || type == 'text/plain' ) {
                                        return 'Text'; // IE support only Text and URL;
                                } else if ( type == 'url' ) {
                                        return 'URL'; // IE support only Text and URL;
                                } else {
                                        return type;
                                }
                        }
                };

                // Check if ID is already created.
                this.id = this.getData( clipboardIdDataType );

                // If there is no ID we need to create it. Different browsers needs different ID.
                if ( !this.id ) {
                        if ( clipboardIdDataType == 'Text' ) {
                                // For IE10+ only Text data type is supported and we have to compare dragged
                                // and dropped text. If the ID is not set it means that empty string was dragged
                                // (ex. image with no alt). We change null to empty string.
                                this.id = '';
                        } else {
                                // String for custom data type.
                                this.id = 'cke-' + CKEDITOR.tools.getUniqueId();
                        }
                }

                // In IE10+ we can not use any data type besides text, so we do not call setData.
                if ( clipboardIdDataType != 'Text' ) {
                        // Try to set ID so it will be passed from the drag to the drop event.
                        // On some browsers with some event it is not possible to setData so we
                        // need to catch exceptions.
                        try {
                                this.$.setData( clipboardIdDataType, this.id );
                        } catch ( err ) {}
                }

                if ( editor ) {
                        this.sourceEditor = editor;

                        this.setData( 'text/html', editor.getSelectedHtml( 1 ) );

                        // Without setData( 'text', ... ) on dragstart there is no drop event in Safari.
                        // Also 'text' data is empty as drop to the textarea does not work if we do not put there text.
                        if ( clipboardIdDataType != 'Text' && !this.getData( 'text/plain' ) ) {
                                this.setData( 'text/plain', editor.getSelection().getSelectedText() );
                        }
                }

                /**
                 * Data transfer ID used to bind all dataTransfer
                 * objects based on the same event (e.g. in drag and drop events).
                 *
                 * @readonly
                 * @property {String} id
                 */

                /**
                 * A native DOM event object.
                 *
                 * @readonly
                 * @property {Object} $
                 */

                /**
                 * Source editor &mdash; the editor where the drag starts.
                 * Might be undefined if the drag starts outside the editor (e.g. when dropping files to the editor).
                 *
                 * @readonly
                 * @property {CKEDITOR.editor} sourceEditor
                 */

                /**
                 * Private properties and methods.
                 *
                 * @private
                 * @property {Object} _
                 */
        };

        /**
         * Data transfer operation (drag and drop or copy and paste) started and ended in the same
         * editor instance.
         *
         * @since 4.5
         * @readonly
         * @property {Number} [=1]
         * @member CKEDITOR
         */
        CKEDITOR.DATA_TRANSFER_INTERNAL = 1;

        /**
         * Data transfer operation (drag and drop or copy and paste) started in one editor
         * instance and ended in another.
         *
         * @since 4.5
         * @readonly
         * @property {Number} [=2]
         * @member CKEDITOR
         */
        CKEDITOR.DATA_TRANSFER_CROSS_EDITORS = 2;

        /**
         * Data transfer operation (drag and drop or copy and paste) started outside of the editor.
         * The source of the data may be a textarea, HTML, another application, etc.
         *
         * @since 4.5
         * @readonly
         * @property {Number} [=3]
         * @member CKEDITOR
         */
        CKEDITOR.DATA_TRANSFER_EXTERNAL = 3;

        CKEDITOR.plugins.clipboard.dataTransfer.prototype = {
                /**
                 * Facade for the native `getData` method.
                 *
                 * @param {String} type The type of data to retrieve.
                 * @returns {String} type Stored data for the given type or an empty string if the data for that type does not exist.
                 */
                getData: function( type ) {
                        function isEmpty( data ) {
                                return data === undefined || data === null || data === '';
                        }

                        type = this._.normalizeType( type );

                        var data = this._.data[ type ],
                                result;

                        if ( isEmpty( data ) ) {
                                try {
                                        data = this.$.getData( type );
                                } catch ( e ) {}
                        }

                        if ( isEmpty( data ) ) {
                                data = '';
                        }

                        // Some browsers add <meta http-equiv="content-type" content="text/html; charset=utf-8"> at the begging of the HTML data
                        // or surround it with <html><head>...</head><body>(some content)<!--StartFragment--> and <!--EndFragment-->(some content)</body></html>
                        // This code removes meta tags and returns only the contents of the <body> element if found. Note that
                        // some significant content may be placed outside Start/EndFragment comments so it's kept.
                        //
                        // See #13583 for more details.
                        if ( type == 'text/html' ) {
                                data = data.replace( this._.metaRegExp, '' );

                                // Keep only contents of the <body> element
                                result = this._.bodyRegExp.exec( data );
                                if ( result && result.length ) {
                                        data = result[ 1 ];

                                        // Remove also comments.
                                        data = data.replace( this._.fragmentRegExp, '' );
                                }
                        }
                        // Firefox on Linux put files paths as a text/plain data if there are files
                        // in the dataTransfer object. We need to hide it, because files should be
                        // handled on paste only if dataValue is empty.
                        else if ( type == 'Text' && CKEDITOR.env.gecko && this.getFilesCount() &&
                                data.substring( 0, 7 ) == 'file://' ) {
                                data = '';
                        }

                        return data;
                },

                /**
                 * Facade for the native `setData` method.
                 *
                 * @param {String} type The type of data to retrieve.
                 * @param {String} value The data to add.
                 */
                setData: function( type, value ) {
                        type = this._.normalizeType( type );

                        this._.data[ type ] = value;

                        // There is "Unexpected call to method or property access." error if you try
                        // to set data of unsupported type on IE.
                        if ( !CKEDITOR.plugins.clipboard.isCustomDataTypesSupported && type != 'URL' && type != 'Text' ) {
                                return;
                        }

                        // If we use the text type to bind the ID, then if someone tries to set the text, we must also
                        // update ID accordingly. #13468.
                        if ( clipboardIdDataType == 'Text' && type == 'Text' ) {
                                this.id = value;
                        }

                        try {
                                this.$.setData( type, value );
                        } catch ( e ) {}
                },

                /**
                 * Gets the data transfer type.
                 *
                 * @param {CKEDITOR.editor} targetEditor The drop/paste target editor instance.
                 * @returns {Number} Possible values: {@link CKEDITOR#DATA_TRANSFER_INTERNAL},
                 * {@link CKEDITOR#DATA_TRANSFER_CROSS_EDITORS}, {@link CKEDITOR#DATA_TRANSFER_EXTERNAL}.
                 */
                getTransferType: function( targetEditor ) {
                        if ( !this.sourceEditor ) {
                                return CKEDITOR.DATA_TRANSFER_EXTERNAL;
                        } else if ( this.sourceEditor == targetEditor ) {
                                return CKEDITOR.DATA_TRANSFER_INTERNAL;
                        } else {
                                return CKEDITOR.DATA_TRANSFER_CROSS_EDITORS;
                        }
                },

                /**
                 * Copies the data from the native data transfer to a private cache.
                 * This function is needed because the data from the native data transfer
                 * is available only synchronously to the event listener. It is not possible
                 * to get the data asynchronously, after a timeout, and the {@link CKEDITOR.editor#paste}
                 * event is fired asynchronously &mdash; hence the need for caching the data.
                 */
                cacheData: function() {
                        if ( !this.$ ) {
                                return;
                        }

                        var that = this,
                                i, file;

                        function getAndSetData( type ) {
                                type = that._.normalizeType( type );

                                var data = that.getData( type );
                                if ( data ) {
                                        that._.data[ type ] = data;
                                }
                        }

                        // Copy data.
                        if ( CKEDITOR.plugins.clipboard.isCustomDataTypesSupported ) {
                                if ( this.$.types ) {
                                        for ( i = 0; i < this.$.types.length; i++ ) {
                                                getAndSetData( this.$.types[ i ] );
                                        }
                                }
                        } else {
                                getAndSetData( 'Text' );
                                getAndSetData( 'URL' );
                        }

                        // Copy files references.
                        file = this._getImageFromClipboard();
                        if ( ( this.$ && this.$.files ) || file ) {
                                this._.files = [];

                                // Edge have empty files property with no length (#13755).
                                if ( this.$.files && this.$.files.length ) {
                                        for ( i = 0; i < this.$.files.length; i++ ) {
                                                this._.files.push( this.$.files[ i ] );
                                        }
                                }

                                // Don't include $.items if both $.files and $.items contains files, because,
                                // according to spec and browsers behavior, they contain the same files.
                                if ( this._.files.length === 0 && file ) {
                                        this._.files.push( file );
                                }
                        }
                },

                /**
                 * Gets the number of files in the dataTransfer object.
                 *
                 * @returns {Number} The number of files.
                 */
                getFilesCount: function() {
                        if ( this._.files.length ) {
                                return this._.files.length;
                        }

                        if ( this.$ && this.$.files && this.$.files.length ) {
                                return this.$.files.length;
                        }

                        return this._getImageFromClipboard() ? 1 : 0;
                },

                /**
                 * Gets the file at the index given.
                 *
                 * @param {Number} i Index.
                 * @returns {File} File instance.
                 */
                getFile: function( i ) {
                        if ( this._.files.length ) {
                                return this._.files[ i ];
                        }

                        if ( this.$ && this.$.files && this.$.files.length ) {
                                return this.$.files[ i ];
                        }

                        // File or null if the file was not found.
                        return i === 0 ? this._getImageFromClipboard() : undefined;
                },

                /**
                 * Checks if the data transfer contains any data.
                 *
                 * @returns {Boolean} `true` if the object contains no data.
                 */
                isEmpty: function() {
                        var typesToCheck = {},
                                type;

                        // If dataTransfer contains files it is not empty.
                        if ( this.getFilesCount() ) {
                                return false;
                        }

                        // Add custom types.
                        for ( type in this._.data ) {
                                typesToCheck[ type ] = 1;
                        }

                        // Add native types.
                        if ( this.$ ) {
                                if ( CKEDITOR.plugins.clipboard.isCustomDataTypesSupported ) {
                                        if ( this.$.types ) {
                                                for ( var i = 0; i < this.$.types.length; i++ ) {
                                                        typesToCheck[ this.$.types[ i ] ] = 1;
                                                }
                                        }
                                } else {
                                        typesToCheck.Text = 1;
                                        typesToCheck.URL = 1;
                                }
                        }

                        // Remove ID.
                        if ( clipboardIdDataType != 'Text' ) {
                                typesToCheck[ clipboardIdDataType ] = 0;
                        }

                        for ( type in typesToCheck ) {
                                if ( typesToCheck[ type ] && this.getData( type ) !== '' ) {
                                        return false;
                                }
                        }

                        return true;
                },

                /**
                 * When the content of the clipboard is pasted in Chrome, the clipboard data object has an empty `files` property,
                 * but it is possible to get the file as `items[0].getAsFile();` (#12961).
                 *
                 * @private
                 * @returns {File} File instance or `null` if not found.
                 */
                _getImageFromClipboard: function() {
                        var file;

                        if ( this.$ && this.$.items && this.$.items[ 0 ] ) {
                                try {
                                        file = this.$.items[ 0 ].getAsFile();
                                        // Duck typing
                                        if ( file && file.type ) {
                                                return file;
                                        }
                                } catch ( err ) {
                                        // noop
                                }
                        }

                        return undefined;
                }
        };
} )();

/**
 * The default content type that is used when pasted data cannot be clearly recognized as HTML or text.
 *
 * For example: `'foo'` may come from a plain text editor or a website. It is not possible to recognize the content
 * type in this case, so the default type will be used. At the same time it is clear that `'<b>example</b> text'` is
 * HTML and its origin is a web page, email or another rich text editor.
 *
 * **Note:** If content type is text, then styles of the paste context are preserved.
 *
 *              CKEDITOR.config.clipboard_defaultContentType = 'text';
 *
 * See also the {@link CKEDITOR.editor#paste} event and read more about the integration with clipboard
 * in the [Clipboard Deep Dive guide](#!/guide/dev_clipboard).
 *
 * @since 4.0
 * @cfg {'html'/'text'} [clipboard_defaultContentType='html']
 * @member CKEDITOR.config
 */

/**
 * Fired after the user initiated a paste action, but before the data is inserted into the editor.
 * The listeners to this event are able to process the content before its insertion into the document.
 *
 * Read more about the integration with clipboard in the [Clipboard Deep Dive guide](#!/guide/dev_clipboard).
 *
 * See also:
 *
 * * the {@link CKEDITOR.config#pasteFilter} option,
 * * the {@link CKEDITOR.editor#drop} event,
 * * the {@link CKEDITOR.plugins.clipboard.dataTransfer} class.
 *
 * @since 3.1
 * @event paste
 * @member CKEDITOR.editor
 * @param {CKEDITOR.editor} editor This editor instance.
 * @param data
 * @param {String} data.type The type of data in `data.dataValue`. Usually `'html'` or `'text'`, but for listeners
 * with a priority smaller than `6` it may also be `'auto'` which means that the content type has not been recognised yet
 * (this will be done by the content type sniffer that listens with priority `6`).
 * @param {String} data.dataValue HTML to be pasted.
 * @param {String} data.method Indicates the data transfer method. It could be drag and drop or copy and paste.
 * Possible values: `'drop'`, `'paste'`. Introduced in CKEditor 4.5.
 * @param {CKEDITOR.plugins.clipboard.dataTransfer} data.dataTransfer Facade for the native dataTransfer object
 * which provides access to various data types and files, and passes some data between linked events
 * (like drag and drop). Introduced in CKEditor 4.5.
 * @param {Boolean} [data.dontFilter=false] Whether the {@link CKEDITOR.editor#pasteFilter paste filter} should not
 * be applied to data. This option has no effect when `data.type` equals `'text'` which means that for instance
 * {@link CKEDITOR.config#forcePasteAsPlainText} has a higher priority. Introduced in CKEditor 4.5.
 */

/**
 * Fired before the {@link #paste} event. Allows to preset data type.
 *
 * **Note:** This event is deprecated. Add a `0` priority listener for the
 * {@link #paste} event instead.
 *
 * @deprecated
 * @event beforePaste
 * @member CKEDITOR.editor
 */

 /**
 * Fired after the {@link #paste} event if content was modified. Note that if the paste
 * event does not insert any data, the `afterPaste` event will not be fired.
 *
 * @event afterPaste
 * @member CKEDITOR.editor
 */

/**
 * Internal event to open the Paste dialog window.
 *
 * @private
 * @event pasteDialog
 * @member CKEDITOR.editor
 * @param {CKEDITOR.editor} editor This editor instance.
 * @param {Function} [data] Callback that will be passed to {@link CKEDITOR.editor#openDialog}.
 */

/**
 * Facade for the native `drop` event. Fired when the native `drop` event occurs.
 *
 * **Note:** To manipulate dropped data, use the {@link CKEDITOR.editor#paste} event.
 * Use the `drop` event only to control drag and drop operations (e.g. to prevent the ability to drop some content).
 *
 * Read more about integration with drag and drop in the [Clipboard Deep Dive guide](#!/guide/dev_clipboard).
 *
 * See also:
 *
 * * The {@link CKEDITOR.editor#paste} event,
 * * The {@link CKEDITOR.editor#dragstart} and {@link CKEDITOR.editor#dragend} events,
 * * The {@link CKEDITOR.plugins.clipboard.dataTransfer} class.
 *
 * @since 4.5
 * @event drop
 * @member CKEDITOR.editor
 * @param {CKEDITOR.editor} editor This editor instance.
 * @param data
 * @param {Object} data.$ Native drop event.
 * @param {CKEDITOR.dom.node} data.target Drop target.
 * @param {CKEDITOR.plugins.clipboard.dataTransfer} data.dataTransfer DataTransfer facade.
 * @param {CKEDITOR.dom.range} data.dragRange Drag range, lets you manipulate the drag range.
 * Note that dragged HTML is saved as `text/html` data on `dragstart` so if you change the drag range
 * on drop, dropped HTML will not change. You need to change it manually using
 * {@link CKEDITOR.plugins.clipboard.dataTransfer#setData dataTransfer.setData}.
 * @param {CKEDITOR.dom.range} data.dropRange Drop range, lets you manipulate the drop range.
 */

/**
 * Facade for the native `dragstart` event. Fired when the native `dragstart` event occurs.
 *
 * This event can be canceled in order to block the drag start operation. It can also be fired to mimic the start of the drag and drop
 * operation. For instance, the `widget` plugin uses this option to integrate its custom block widget drag and drop with
 * the entire system.
 *
 * Read more about integration with drag and drop in the [Clipboard Deep Dive guide](#!/guide/dev_clipboard).
 *
 * See also:
 *
 * * The {@link CKEDITOR.editor#paste} event,
 * * The {@link CKEDITOR.editor#drop} and {@link CKEDITOR.editor#dragend} events,
 * * The {@link CKEDITOR.plugins.clipboard.dataTransfer} class.
 *
 * @since 4.5
 * @event dragstart
 * @member CKEDITOR.editor
 * @param {CKEDITOR.editor} editor This editor instance.
 * @param data
 * @param {Object} data.$ Native dragstart event.
 * @param {CKEDITOR.dom.node} data.target Drag target.
 * @param {CKEDITOR.plugins.clipboard.dataTransfer} data.dataTransfer DataTransfer facade.
 */

/**
 * Facade for the native `dragend` event. Fired when the native `dragend` event occurs.
 *
 * Read more about integration with drag and drop in the [Clipboard Deep Dive guide](#!/guide/dev_clipboard).
 *
 * See also:
 *
 * * The {@link CKEDITOR.editor#paste} event,
 * * The {@link CKEDITOR.editor#drop} and {@link CKEDITOR.editor#dragend} events,
 * * The {@link CKEDITOR.plugins.clipboard.dataTransfer} class.
 *
 * @since 4.5
 * @event dragend
 * @member CKEDITOR.editor
 * @param {CKEDITOR.editor} editor This editor instance.
 * @param data
 * @param {Object} data.$ Native dragend event.
 * @param {CKEDITOR.dom.node} data.target Drag target.
 * @param {CKEDITOR.plugins.clipboard.dataTransfer} data.dataTransfer DataTransfer facade.
 */

/**
 * Defines a filter which is applied to external data pasted or dropped into the editor. Possible values are:
 *
 * * `'plain-text'` &ndash; Content will be pasted as a plain text.
 * * `'semantic-content'` &ndash; Known tags (except `div`, `span`) with all attributes (except
 * `style` and `class`) will be kept.
 * * `'h1 h2 p div'` &ndash; Custom rules compatible with {@link CKEDITOR.filter}.
 * * `null` &ndash; Content will not be filtered by the paste filter (but it still may be filtered
 * by [Advanced Content Filter](#!/guide/dev_advanced_content_filter)). This value can be used to
 * disable the paste filter in Chrome and Safari, where this option defaults to `'semantic-content'`.
 *
 * Example:
 *
 *              config.pasteFilter = 'plain-text';
 *
 * Custom setting:
 *
 *              config.pasteFilter = 'h1 h2 p ul ol li; img[!src, alt]; a[!href]';
 *
 * Based on this configuration option, a proper {@link CKEDITOR.filter} instance will be defined and assigned to the editor
 * as a {@link CKEDITOR.editor#pasteFilter}. You can tweak the paste filter settings on the fly on this object
 * as well as delete or replace it.
 *
 *              var editor = CKEDITOR.replace( 'editor', {
 *                      pasteFilter: 'semantic-content'
 *              } );
 *
 *              editor.on( 'instanceReady', function() {
 *                      // The result of this will be that all semantic content will be preserved
 *                      // except tables.
 *                      editor.pasteFilter.disallow( 'table' );
 *              } );
 *
 * Note that the paste filter is applied only to **external** data. There are three data sources:
 *
 * * copied and pasted in the same editor (internal),
 * * copied from one editor and pasted into another (cross-editor),
 * * coming from all other sources like websites, MS Word, etc. (external).
 *
 * If {@link CKEDITOR.config#allowedContent Advanced Content Filter} is not disabled, then
 * it will also be applied to pasted and dropped data. The paste filter job is to "normalize"
 * external data which often needs to be handled differently than content produced by the editor.
 *
 * This setting defaults to `'semantic-content'` in Chrome, Opera and Safari (all Blink and Webkit based browsers)
 * due to messy HTML which these browsers keep in the clipboard. In other browsers it defaults to `null`.
 *
 * @since 4.5
 * @cfg {String} [pasteFilter='semantic-content' in Chrome and Safari and `null` in other browsers]
 * @member CKEDITOR.config
 */

/**
 * {@link CKEDITOR.filter Content filter} which is used when external data is pasted or dropped into the editor
 * or a forced paste as plain text occurs.
 *
 * This object might be used on the fly to define rules for pasted external content.
 * This object is available and used if the {@link CKEDITOR.plugins.clipboard clipboard} plugin is enabled and
 * {@link CKEDITOR.config#pasteFilter} or {@link CKEDITOR.config#forcePasteAsPlainText} was defined.
 *
 * To enable the filter:
 *
 *              var editor = CKEDITOR.replace( 'editor', {
 *                      pasteFilter: 'plain-text'
 *              } );
 *
 * You can also modify the filter on the fly later on:
 *
 *              editor.pasteFilter = new CKEDITOR.filter( 'p h1 h2; a[!href]' );
 *
 * Note that the paste filter is only applied to **external** data. There are three data sources:
 *
 * * copied and pasted in the same editor (internal),
 * * copied from one editor and pasted into another (cross-editor),
 * * coming from all other sources like websites, MS Word, etc. (external).
 *
 * If {@link CKEDITOR.config#allowedContent Advanced Content Filter} is not disabled, then
 * it will also be applied to pasted and dropped data. The paste filter job is to "normalize"
 * external data which often needs to be handled differently than content produced by the editor.
 *
 * @since 4.5
 * @readonly
 * @property {CKEDITOR.filter} [pasteFilter]
 * @member CKEDITOR.editor
 */