Upgrade to 4.5.7 and add some plugin

[perso/Immae/Projets/packagist/connexionswing-ckeditor-component.git] / sources / core / style.js

/**
 * @license Copyright (c) 2003-2016, CKSource - Frederico Knabben. All rights reserved.
 * For licensing, see LICENSE.md or http://ckeditor.com/license
 */

'use strict';

/**
 * Block style type.
 *
 * Read more in the {@link CKEDITOR.style} class documentation.
 *
 * @readonly
 * @property {Number} [=1]
 * @member CKEDITOR
 */
CKEDITOR.STYLE_BLOCK = 1;

/**
 * Inline style type.
 *
 * Read more in the {@link CKEDITOR.style} class documentation.
 *
 * @readonly
 * @property {Number} [=2]
 * @member CKEDITOR
 */
CKEDITOR.STYLE_INLINE = 2;

/**
 * Object style type.
 *
 * Read more in the {@link CKEDITOR.style} class documentation.
 *
 * @readonly
 * @property {Number} [=3]
 * @member CKEDITOR
 */
CKEDITOR.STYLE_OBJECT = 3;

( function() {
        var blockElements = {
                        address: 1, div: 1, h1: 1, h2: 1, h3: 1, h4: 1, h5: 1, h6: 1, p: 1,
                        pre: 1, section: 1, header: 1, footer: 1, nav: 1, article: 1, aside: 1, figure: 1,
                        dialog: 1, hgroup: 1, time: 1, meter: 1, menu: 1, command: 1, keygen: 1, output: 1,
                        progress: 1, details: 1, datagrid: 1, datalist: 1
                },

                objectElements = {
                        a: 1, blockquote: 1, embed: 1, hr: 1, img: 1, li: 1, object: 1, ol: 1, table: 1, td: 1,
                        tr: 1, th: 1, ul: 1, dl: 1, dt: 1, dd: 1, form: 1, audio: 1, video: 1
                };

        var semicolonFixRegex = /\s*(?:;\s*|$)/,
                varRegex = /#\((.+?)\)/g;

        var notBookmark = CKEDITOR.dom.walker.bookmark( 0, 1 ),
                nonWhitespaces = CKEDITOR.dom.walker.whitespaces( 1 );

        /**
         * A class representing a style instance for the specific style definition.
         * In this approach, a style is a set of properties, like attributes and styles,
         * which can be applied to and removed from a {@link CKEDITOR.dom.selection selection} through
         * {@link CKEDITOR.editor editor} methods: {@link CKEDITOR.editor#applyStyle} and {@link CKEDITOR.editor#removeStyle},
         * respectively.
         *
         * Three default style types are available: {@link CKEDITOR#STYLE_BLOCK STYLE_BLOCK}, {@link CKEDITOR#STYLE_INLINE STYLE_INLINE},
         * and {@link CKEDITOR#STYLE_OBJECT STYLE_OBJECT}. Based on its type, a style heavily changes its behavior.
         * You can read more about style types in the [Style Types section of the Styles guide](#!/guide/dev_styles-section-style-types).
         *
         * It is possible to define a custom style type by subclassing this class by using the {@link #addCustomHandler} method.
         * However, because of great complexity of the styles handling job, it is only possible in very specific cases.
         *
         * ### Usage
         *
         * Basic usage:
         *
         *              // Define a block style.
         *              var style = new CKEDITOR.style( { element: 'h1' } );
         *
         *              // Considering the following selection:
         *              // <p>Foo</p><p>Bar^</p>
         *              // Executing:
         *              editor.applyStyle( style );
         *              // Will give:
         *              // <p>Foo</p><h1>Bar^</h1>
         *              style.checkActive( editor.elementPath(), editor ); // -> true
         *
         *              editor.removeStyle( style );
         *              // Will give:
         *              // <p>Foo</p><p>Bar^</p>
         *
         *              style.checkActive( editor.elementPath(), editor ); // -> false
         *
         * Object style:
         *
         *              // Define an object style.
         *              var style = new CKEDITOR.style( { element: 'img', attributes: { 'class': 'foo' } } );
         *
         *              // Considering the following selection:
         *              // <p><img src="bar.png" alt="" />Foo^</p>
         *              // Executing:
         *              editor.applyStyle( style );
         *              // Will not apply the style, because the image is not selected.
         *              // You can check if a style can be applied on the current selection with:
         *              style.checkApplicable( editor.elementPath(), editor ); // -> false
         *
         *              // Considering the following selection:
         *              // <p>[<img src="bar.png" alt="" />]Foo</p>
         *              // Executing
         *              editor.applyStyle( style );
         *              // Will give:
         *              // <p>[<img src="bar.png" alt="" class="foo" />]Foo</p>
         *
         * ### API changes introduced in CKEditor 4.4
         *
         * Before CKEditor 4.4 all style instances had no access at all to the {@link CKEDITOR.editor editor instance}
         * within which the style is used. Neither the style constructor, nor style methods were requiring
         * passing the editor instance which made styles independent of the editor and hence its settings and state.
         * This design decision came from CKEditor 3; it started causing problems and became an unsolvable obstacle for
         * the {@link CKEDITOR.style.customHandlers.widget widget style handler} which we introduced in CKEditor 4.4.
         *
         * There were two possible solutions. Passing an editor instance to the style constructor or to every method.
         * The first approach would be clean, however, having in mind the backward compatibility, we did not decide
         * to go for it. It would bind the style to one editor instance, making it unusable with other editor instances.
         * That could break many implementations reusing styles between editors. Therefore, we decided to take the longer
         * but safer path &mdash; the editor instance became an argument for nearly all style methods, however,
         * for backward compatibility reasons, all these methods will work without it. Even the newly
         * implemented {@link CKEDITOR.style.customHandlers.widget widget style handler}'s methods will not fail,
         * although they will also not work by aborting at an early stage.
         *
         * Therefore, you can safely upgrade to CKEditor 4.4 even if you use style methods without providing
         * the editor instance. You must only align your code if your implementation should handle widget styles
         * or any other custom style handler. Of course, we recommend doing this in any case to avoid potential
         * problems in the future.
         *
         * @class
         * @constructor Creates a style class instance.
         * @param styleDefinition
         * @param variablesValues
         */
        CKEDITOR.style = function( styleDefinition, variablesValues ) {
                if ( typeof styleDefinition.type == 'string' )
                        return new CKEDITOR.style.customHandlers[ styleDefinition.type ]( styleDefinition );

                // Inline style text as attribute should be converted
                // to styles object.
                var attrs = styleDefinition.attributes;
                if ( attrs && attrs.style ) {
                        styleDefinition.styles = CKEDITOR.tools.extend( {},
                                styleDefinition.styles, CKEDITOR.tools.parseCssText( attrs.style ) );
                        delete attrs.style;
                }

                if ( variablesValues ) {
                        styleDefinition = CKEDITOR.tools.clone( styleDefinition );

                        replaceVariables( styleDefinition.attributes, variablesValues );
                        replaceVariables( styleDefinition.styles, variablesValues );
                }

                var element = this.element = styleDefinition.element ?
                        (
                                typeof styleDefinition.element == 'string' ?
                                        styleDefinition.element.toLowerCase() : styleDefinition.element
                        ) : '*';

                this.type = styleDefinition.type ||
                        (
                                blockElements[ element ] ? CKEDITOR.STYLE_BLOCK :
                                objectElements[ element ] ? CKEDITOR.STYLE_OBJECT :
                                CKEDITOR.STYLE_INLINE
                        );

                // If the 'element' property is an object with a set of possible element, it will be applied like an object style: only to existing elements
                if ( typeof this.element == 'object' )
                        this.type = CKEDITOR.STYLE_OBJECT;

                this._ = {
                        definition: styleDefinition
                };
        };

        CKEDITOR.style.prototype = {
                /**
                 * Applies the style on the editor's current selection.
                 *
                 * Before the style is applied, the method checks if the {@link #checkApplicable style is applicable}.
                 *
                 * **Note:** The recommended way of applying the style is by using the
                 * {@link CKEDITOR.editor#applyStyle} method, which is a shorthand for this method.
                 *
                 * @param {CKEDITOR.editor/CKEDITOR.dom.document} editor The editor instance in which
                 * the style will be applied.
                 * A {@link CKEDITOR.dom.document} instance is accepted for backward compatibility
                 * reasons, although since CKEditor 4.4 this type of argument is deprecated. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 */
                apply: function( editor ) {
                        // Backward compatibility.
                        if ( editor instanceof CKEDITOR.dom.document )
                                return applyStyleOnSelection.call( this, editor.getSelection() );

                        if ( this.checkApplicable( editor.elementPath(), editor ) ) {
                                var initialEnterMode = this._.enterMode;

                                // See comment in removeStyle.
                                if ( !initialEnterMode )
                                        this._.enterMode = editor.activeEnterMode;
                                applyStyleOnSelection.call( this, editor.getSelection(), 0, editor );
                                this._.enterMode = initialEnterMode;
                        }
                },

                /**
                 * Removes the style from the editor's current selection.
                 *
                 * Before the style is applied, the method checks if {@link #checkApplicable style could be applied}.
                 *
                 * **Note:** The recommended way of removing the style is by using the
                 * {@link CKEDITOR.editor#removeStyle} method, which is a shorthand for this method.
                 *
                 * @param {CKEDITOR.editor/CKEDITOR.dom.document} editor The editor instance in which
                 * the style will be removed.
                 * A {@link CKEDITOR.dom.document} instance is accepted for backward compatibility
                 * reasons, although since CKEditor 4.4 this type of argument is deprecated. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 */
                remove: function( editor ) {
                        // Backward compatibility.
                        if ( editor instanceof CKEDITOR.dom.document )
                                return applyStyleOnSelection.call( this, editor.getSelection(), 1 );

                        if ( this.checkApplicable( editor.elementPath(), editor ) ) {
                                var initialEnterMode = this._.enterMode;

                                // Before CKEditor 4.4 style knew nothing about editor, so in order to provide enterMode
                                // which should be used developers were forced to hack the style object (see #10190).
                                // Since CKEditor 4.4 style knows about editor (at least when it's being applied/removed), but we
                                // use _.enterMode for backward compatibility with those hacks.
                                // Note: we should not change style's enter mode if it was already set.
                                if ( !initialEnterMode )
                                        this._.enterMode = editor.activeEnterMode;
                                applyStyleOnSelection.call( this, editor.getSelection(), 1, editor );
                                this._.enterMode = initialEnterMode;
                        }
                },

                /**
                 * Applies the style on the provided range. Unlike {@link #apply} this
                 * method does not take care of setting the selection, however, the range
                 * is updated to the correct place.
                 *
                 * **Note:** If you want to apply the style on the editor selection,
                 * you probably want to use {@link CKEDITOR.editor#applyStyle}.
                 *
                 * @param {CKEDITOR.dom.range} range
                 * @param {CKEDITOR.editor} editor The editor instance. Required argument since
                 * CKEditor 4.4. The style system will work without it, but it is highly
                 * recommended to provide it for integration with all features.  Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 */
                applyToRange: function( range ) {
                        this.applyToRange =
                                this.type == CKEDITOR.STYLE_INLINE ? applyInlineStyle :
                                this.type == CKEDITOR.STYLE_BLOCK ? applyBlockStyle :
                                this.type == CKEDITOR.STYLE_OBJECT ? applyObjectStyle :
                                null;

                        return this.applyToRange( range );
                },

                /**
                 * Removes the style from the provided range. Unlike {@link #remove} this
                 * method does not take care of setting the selection, however, the range
                 * is updated to the correct place.
                 *
                 * **Note:** If you want to remove the style from the editor selection,
                 * you probably want to use {@link CKEDITOR.editor#removeStyle}.
                 *
                 * @param {CKEDITOR.dom.range} range
                 * @param {CKEDITOR.editor} editor The editor instance. Required argument since
                 * CKEditor 4.4. The style system will work without it, but it is highly
                 * recommended to provide it for integration with all features. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 */
                removeFromRange: function( range ) {
                        this.removeFromRange =
                                this.type == CKEDITOR.STYLE_INLINE ? removeInlineStyle :
                                this.type == CKEDITOR.STYLE_BLOCK ? removeBlockStyle :
                                this.type == CKEDITOR.STYLE_OBJECT ? removeObjectStyle :
                                null;

                        return this.removeFromRange( range );
                },

                /**
                 * Applies the style to the element. This method bypasses all checks
                 * and applies the style attributes directly on the provided element. Use with caution.
                 *
                 * See {@link CKEDITOR.editor#applyStyle}.
                 *
                 * @param {CKEDITOR.dom.element} element
                 * @param {CKEDITOR.editor} editor The editor instance. Required argument since
                 * CKEditor 4.4. The style system will work without it, but it is highly
                 * recommended to provide it for integration with all features. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 */
                applyToObject: function( element ) {
                        setupElement( element, this );
                },

                /**
                 * Gets the style state inside the elements path.
                 *
                 * @param {CKEDITOR.dom.elementPath} elementPath
                 * @param {CKEDITOR.editor} editor The editor instance. Required argument since
                 * CKEditor 4.4. The style system will work without it, but it is highly
                 * recommended to provide it for integration with all features. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 * @returns {Boolean} `true` if the element is active in the elements path.
                 */
                checkActive: function( elementPath, editor ) {
                        switch ( this.type ) {
                                case CKEDITOR.STYLE_BLOCK:
                                        return this.checkElementRemovable( elementPath.block || elementPath.blockLimit, true, editor );

                                case CKEDITOR.STYLE_OBJECT:
                                case CKEDITOR.STYLE_INLINE:

                                        var elements = elementPath.elements;

                                        for ( var i = 0, element; i < elements.length; i++ ) {
                                                element = elements[ i ];

                                                if ( this.type == CKEDITOR.STYLE_INLINE && ( element == elementPath.block || element == elementPath.blockLimit ) )
                                                        continue;

                                                if ( this.type == CKEDITOR.STYLE_OBJECT ) {
                                                        var name = element.getName();
                                                        if ( !( typeof this.element == 'string' ? name == this.element : name in this.element ) )
                                                                continue;
                                                }

                                                if ( this.checkElementRemovable( element, true, editor ) )
                                                        return true;
                                        }
                        }
                        return false;
                },

                /**
                 * Whether this style can be applied at the specified elements path.
                 *
                 * @param {CKEDITOR.dom.elementPath} elementPath The elements path to
                 * check the style against.
                 * @param {CKEDITOR.editor} editor The editor instance. Required argument since
                 * CKEditor 4.4. The style system will work without it, but it is highly
                 * recommended to provide it for integration with all features. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 * @param {CKEDITOR.filter} [filter] If defined, the style will be
                 * checked against this filter as well.
                 * @returns {Boolean} `true` if this style can be applied at the elements path.
                 */
                checkApplicable: function( elementPath, editor, filter ) {
                        // Backward compatibility.
                        if ( editor && editor instanceof CKEDITOR.filter )
                                filter = editor;

                        if ( filter && !filter.check( this ) )
                                return false;

                        switch ( this.type ) {
                                case CKEDITOR.STYLE_OBJECT:
                                        return !!elementPath.contains( this.element );
                                case CKEDITOR.STYLE_BLOCK:
                                        return !!elementPath.blockLimit.getDtd()[ this.element ];
                        }

                        return true;
                },

                /**
                 * Checks if the element matches the current style definition.
                 *
                 * @param {CKEDITOR.dom.element} element
                 * @param {Boolean} fullMatch
                 * @param {CKEDITOR.editor} editor The editor instance. Required argument since
                 * CKEditor 4.4. The style system will work without it, but it is highly
                 * recommended to provide it for integration with all features. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 * @returns {Boolean}
                 */
                checkElementMatch: function( element, fullMatch ) {
                        var def = this._.definition;

                        if ( !element || !def.ignoreReadonly && element.isReadOnly() )
                                return false;

                        var attribs,
                                name = element.getName();

                        // If the element name is the same as the style name.
                        if ( typeof this.element == 'string' ? name == this.element : name in this.element ) {
                                // If no attributes are defined in the element.
                                if ( !fullMatch && !element.hasAttributes() )
                                        return true;

                                attribs = getAttributesForComparison( def );

                                if ( attribs._length ) {
                                        for ( var attName in attribs ) {
                                                if ( attName == '_length' )
                                                        continue;

                                                var elementAttr = element.getAttribute( attName ) || '';

                                                // Special treatment for 'style' attribute is required.
                                                if ( attName == 'style' ? compareCssText( attribs[ attName ], elementAttr ) : attribs[ attName ] == elementAttr ) {
                                                        if ( !fullMatch )
                                                                return true;
                                                } else if ( fullMatch ) {
                                                        return false;
                                                }
                                        }
                                        if ( fullMatch )
                                                return true;
                                } else {
                                        return true;
                                }
                        }

                        return false;
                },

                /**
                 * Checks if an element, or any of its attributes, is removable by the
                 * current style definition.
                 *
                 * @param {CKEDITOR.dom.element} element
                 * @param {Boolean} fullMatch
                 * @param {CKEDITOR.editor} editor The editor instance. Required argument since
                 * CKEditor 4.4. The style system will work without it, but it is highly
                 * recommended to provide it for integration with all features. Read more about
                 * the signature change in the {@link CKEDITOR.style} documentation.
                 * @returns {Boolean}
                 */
                checkElementRemovable: function( element, fullMatch, editor ) {
                        // Check element matches the style itself.
                        if ( this.checkElementMatch( element, fullMatch, editor ) )
                                return true;

                        // Check if the element matches the style overrides.
                        var override = getOverrides( this )[ element.getName() ];
                        if ( override ) {
                                var attribs, attName;

                                // If no attributes have been defined, remove the element.
                                if ( !( attribs = override.attributes ) )
                                        return true;

                                for ( var i = 0; i < attribs.length; i++ ) {
                                        attName = attribs[ i ][ 0 ];
                                        var actualAttrValue = element.getAttribute( attName );
                                        if ( actualAttrValue ) {
                                                var attValue = attribs[ i ][ 1 ];

                                                // Remove the attribute if:
                                                //    - The override definition value is null;
                                                //    - The override definition value is a string that
                                                //      matches the attribute value exactly.
                                                //    - The override definition value is a regex that
                                                //      has matches in the attribute value.
                                                if ( attValue === null )
                                                        return true;
                                                if ( typeof attValue == 'string' ) {
                                                        if ( actualAttrValue == attValue )
                                                                return true;
                                                } else if ( attValue.test( actualAttrValue ) ) {
                                                        return true;
                                                }
                                        }
                                }
                        }
                        return false;
                },

                /**
                 * Builds the preview HTML based on the styles definition.
                 *
                 * @param {String} [label] The label used in the style preview.
                 * @return {String} The HTML of preview.
                 */
                buildPreview: function( label ) {
                        var styleDefinition = this._.definition,
                                html = [],
                                elementName = styleDefinition.element;

                        // Avoid <bdo> in the preview.
                        if ( elementName == 'bdo' )
                                elementName = 'span';

                        html = [ '<', elementName ];

                        // Assign all defined attributes.
                        var attribs = styleDefinition.attributes;
                        if ( attribs ) {
                                for ( var att in attribs )
                                        html.push( ' ', att, '="', attribs[ att ], '"' );
                        }

                        // Assign the style attribute.
                        var cssStyle = CKEDITOR.style.getStyleText( styleDefinition );
                        if ( cssStyle )
                                html.push( ' style="', cssStyle, '"' );

                        html.push( '>', ( label || styleDefinition.name ), '</', elementName, '>' );

                        return html.join( '' );
                },

                /**
                 * Returns the style definition.
                 *
                 * @since 4.1
                 * @returns {Object}
                 */
                getDefinition: function() {
                        return this._.definition;
                }

                /**
                 * If defined (for example by {@link CKEDITOR.style#addCustomHandler custom style handler}), it returns
                 * the {@link CKEDITOR.filter.allowedContentRules allowed content rules} which should be added to the
                 * {@link CKEDITOR.filter} when enabling this style.
                 *
                 * **Note:** This method is not defined in the {@link CKEDITOR.style} class.
                 *
                 * @since 4.4
                 * @method toAllowedContentRules
                 * @param {CKEDITOR.editor} [editor] The editor instance.
                 * @returns {CKEDITOR.filter.allowedContentRules} The rules that should represent this style in the {@link CKEDITOR.filter}.
                 */
        };

        /**
         * Builds the inline style text based on the style definition.
         *
         * @static
         * @param styleDefinition
         * @returns {String} Inline style text.
         */
        CKEDITOR.style.getStyleText = function( styleDefinition ) {
                // If we have already computed it, just return it.
                var stylesDef = styleDefinition._ST;
                if ( stylesDef )
                        return stylesDef;

                stylesDef = styleDefinition.styles;

                // Builds the StyleText.
                var stylesText = ( styleDefinition.attributes && styleDefinition.attributes.style ) || '',
                        specialStylesText = '';

                if ( stylesText.length )
                        stylesText = stylesText.replace( semicolonFixRegex, ';' );

                for ( var style in stylesDef ) {
                        var styleVal = stylesDef[ style ],
                                text = ( style + ':' + styleVal ).replace( semicolonFixRegex, ';' );

                        // Some browsers don't support 'inherit' property value, leave them intact. (#5242)
                        if ( styleVal == 'inherit' )
                                specialStylesText += text;
                        else
                                stylesText += text;
                }

                // Browsers make some changes to the style when applying them. So, here
                // we normalize it to the browser format.
                if ( stylesText.length )
                        stylesText = CKEDITOR.tools.normalizeCssText( stylesText, true );

                stylesText += specialStylesText;

                // Return it, saving it to the next request.
                return ( styleDefinition._ST = stylesText );
        };

        /**
         * Namespace containing custom style handlers added with {@link CKEDITOR.style#addCustomHandler}.
         *
         * @since 4.4
         * @class
         * @singleton
         */
        CKEDITOR.style.customHandlers = {};

        /**
         * Creates a {@link CKEDITOR.style} subclass and registers it in the style system.
         * Registered class will be used as a handler for a style of this type. This allows
         * to extend the styles system, which by default uses only the {@link CKEDITOR.style}, with
         * new functionality. Registered classes are accessible in the {@link CKEDITOR.style.customHandlers}.
         *
         * ### The Style Class Definition
         *
         * The definition object is used to override properties in a prototype inherited
         * from the {@link CKEDITOR.style} class. It must contain a `type` property which is
         * a name of the new type and therefore it must be unique. The default style types
         * ({@link CKEDITOR#STYLE_BLOCK STYLE_BLOCK}, {@link CKEDITOR#STYLE_INLINE STYLE_INLINE},
         * and {@link CKEDITOR#STYLE_OBJECT STYLE_OBJECT}) are integers, but for easier identification
         * it is recommended to use strings as custom type names.
         *
         * Besides `type`, the definition may contain two more special properties:
         *
         *  * `setup {Function}` &ndash; An optional callback executed when a style instance is created.
         * Like the style constructor, it is executed in style context and with the style definition as an argument.
         *  * `assignedTo {Number}` &ndash; Can be set to one of the default style types. Some editor
         * features like the Styles drop-down assign styles to one of the default groups based on
         * the style type. By using this property it is possible to notify them to which group this
         * custom style should be assigned. It defaults to the {@link CKEDITOR#STYLE_OBJECT}.
         *
         * Other properties of the definition object will just be used to extend the prototype inherited
         * from the {@link CKEDITOR.style} class. So if the definition contains an `apply` method, it will
         * override the {@link CKEDITOR.style#apply} method.
         *
         * ### Usage
         *
         * Registering a basic handler:
         *
         *              var styleClass = CKEDITOR.style.addCustomHandler( {
         *                      type: 'custom'
         *              } );
         *
         *              var style = new styleClass( { ... } );
         *              style instanceof styleClass; // -> true
         *              style instanceof CKEDITOR.style; // -> true
         *              style.type; // -> 'custom'
         *
         * The {@link CKEDITOR.style} constructor used as a factory:
         *
         *              var styleClass = CKEDITOR.style.addCustomHandler( {
         *                      type: 'custom'
         *              } );
         *
         *              // Style constructor accepts style definition (do not confuse with style class definition).
         *              var style = new CKEDITOR.style( { type: 'custom', attributes: ... } );
         *              style instanceof styleClass; // -> true
         *
         * Thanks to that, integration code using styles does not need to know
         * which style handler it should use. It is determined by the {@link CKEDITOR.style} constructor.
         *
         * Overriding existing {@link CKEDITOR.style} methods:
         *
         *              var styleClass = CKEDITOR.style.addCustomHandler( {
         *                      type: 'custom',
         *                      apply: function( editor ) {
         *                              console.log( 'apply' );
         *                      },
         *                      remove: function( editor ) {
         *                              console.log( 'remove' );
         *                      }
         *              } );
         *
         *              var style = new CKEDITOR.style( { type: 'custom', attributes: ... } );
         *              editor.applyStyle( style ); // logged 'apply'
         *
         *              style = new CKEDITOR.style( { element: 'img', attributes: { 'class': 'foo' } } );
         *              editor.applyStyle( style ); // style is really applied if image was selected
         *
         * ### Practical Recommendations
         *
         * The style handling job, which includes such tasks as applying, removing, checking state, and
         * checking if a style can be applied, is very complex. Therefore without deep knowledge
         * about DOM and especially {@link CKEDITOR.dom.range ranges} and {@link CKEDITOR.dom.walker DOM walker} it is impossible
         * to implement a completely custom style handler able to handle block, inline, and object type styles.
         * However, it is possible to customize the default implementation by overriding default methods and
         * reusing them.
         *
         * The only style handler which can be implemented from scratch without huge effort is a style
         * applicable to objects ([read more about types](http://docs.ckeditor.com/#!/guide/dev_styles-section-style-types)).
         * Such style can only be applied when a specific object is selected. An example implementation can
         * be found in the [widget plugin](https://github.com/ckeditor/ckeditor-dev/blob/master/plugins/widget/plugin.js).
         *
         * When implementing a style handler from scratch at least the following methods must be defined:
         *
         * * {@link CKEDITOR.style#apply apply} and {@link CKEDITOR.style#remove remove},
         * * {@link CKEDITOR.style#checkElementRemovable checkElementRemovable} and
         * {@link CKEDITOR.style#checkElementMatch checkElementMatch} &ndash; Note that both methods reuse the same logic,
         * * {@link CKEDITOR.style#checkActive checkActive} &ndash; Reuses
         * {@link CKEDITOR.style#checkElementMatch checkElementMatch},
         * * {@link CKEDITOR.style#toAllowedContentRules toAllowedContentRules} &ndash; Not required, but very useful in
         * case of a custom style that has to notify the {@link CKEDITOR.filter} which rules it allows when registered.
         *
         * @since 4.4
         * @static
         * @member CKEDITOR.style
         * @param definition The style class definition.
         * @returns {CKEDITOR.style} The new style class created for the provided definition.
         */
        CKEDITOR.style.addCustomHandler = function( definition ) {
                var styleClass = function( styleDefinition ) {
                        this._ = {
                                definition: styleDefinition
                        };

                        if ( this.setup )
                                this.setup( styleDefinition );
                };

                styleClass.prototype = CKEDITOR.tools.extend(
                        // Prototype of CKEDITOR.style.
                        CKEDITOR.tools.prototypedCopy( CKEDITOR.style.prototype ),
                        // Defaults.
                        {
                                assignedTo: CKEDITOR.STYLE_OBJECT
                        },
                        // Passed definition - overrides.
                        definition,
                        true
                );

                this.customHandlers[ definition.type ] = styleClass;

                return styleClass;
        };

        // Gets the parent element which blocks the styling for an element. This
        // can be done through read-only elements (contenteditable=false) or
        // elements with the "data-nostyle" attribute.
        function getUnstylableParent( element, root ) {
                var unstylable, editable;

                while ( ( element = element.getParent() ) ) {
                        if ( element.equals( root ) )
                                break;

                        if ( element.getAttribute( 'data-nostyle' ) )
                                unstylable = element;
                        else if ( !editable ) {
                                var contentEditable = element.getAttribute( 'contentEditable' );

                                if ( contentEditable == 'false' )
                                        unstylable = element;
                                else if ( contentEditable == 'true' )
                                        editable = 1;
                        }
                }

                return unstylable;
        }

        var posPrecedingIdenticalContained =
                        CKEDITOR.POSITION_PRECEDING | CKEDITOR.POSITION_IDENTICAL | CKEDITOR.POSITION_IS_CONTAINED,
                posFollowingIdenticalContained =
                        CKEDITOR.POSITION_FOLLOWING | CKEDITOR.POSITION_IDENTICAL | CKEDITOR.POSITION_IS_CONTAINED;

        // Checks if the current node can be a child of the style element.
        function checkIfNodeCanBeChildOfStyle( def, currentNode, lastNode, nodeName, dtd, nodeIsNoStyle, nodeIsReadonly, includeReadonly ) {
                // Style can be applied to text node.
                if ( !nodeName )
                        return 1;

                // Style definitely cannot be applied if DTD or data-nostyle do not allow.
                if ( !dtd[ nodeName ] || nodeIsNoStyle  )
                        return 0;

                // Non-editable element cannot be styled is we shouldn't include readonly elements.
                if ( nodeIsReadonly && !includeReadonly  )
                        return 0;

                // Check that we haven't passed lastNode yet and that style's childRule allows this style on current element.
                return checkPositionAndRule( currentNode, lastNode, def, posPrecedingIdenticalContained );
        }

        // Check if the style element can be a child of the current
        // node parent or if the element is not defined in the DTD.
        function checkIfStyleCanBeChildOf( def, currentParent, elementName, isUnknownElement ) {
                return currentParent &&
                        ( ( currentParent.getDtd() || CKEDITOR.dtd.span )[ elementName ] || isUnknownElement ) &&
                        ( !def.parentRule || def.parentRule( currentParent ) );
        }

        function checkIfStartsRange( nodeName, currentNode, lastNode ) {
                return (
                        !nodeName || !CKEDITOR.dtd.$removeEmpty[ nodeName ] ||
                        ( currentNode.getPosition( lastNode ) | posPrecedingIdenticalContained ) == posPrecedingIdenticalContained
                );
        }

        function checkIfTextOrReadonlyOrEmptyElement( currentNode, nodeIsReadonly ) {
                var nodeType = currentNode.type;
                return nodeType == CKEDITOR.NODE_TEXT || nodeIsReadonly || ( nodeType == CKEDITOR.NODE_ELEMENT && !currentNode.getChildCount() );
        }

        // Checks if position is a subset of posBitFlags and that nodeA fulfills style def rule.
        function checkPositionAndRule( nodeA, nodeB, def, posBitFlags ) {
                return ( nodeA.getPosition( nodeB ) | posBitFlags ) == posBitFlags &&
                        ( !def.childRule || def.childRule( nodeA ) );
        }

        function applyInlineStyle( range ) {
                var document = range.document;

                if ( range.collapsed ) {
                        // Create the element to be inserted in the DOM.
                        var collapsedElement = getElement( this, document );

                        // Insert the empty element into the DOM at the range position.
                        range.insertNode( collapsedElement );

                        // Place the selection right inside the empty element.
                        range.moveToPosition( collapsedElement, CKEDITOR.POSITION_BEFORE_END );

                        return;
                }

                var elementName = this.element,
                        def = this._.definition,
                        isUnknownElement;

                // Indicates that fully selected read-only elements are to be included in the styling range.
                var ignoreReadonly = def.ignoreReadonly,
                        includeReadonly = ignoreReadonly || def.includeReadonly;

                // If the read-only inclusion is not available in the definition, try
                // to get it from the root data (most often it's the editable).
                if ( includeReadonly == null )
                        includeReadonly = range.root.getCustomData( 'cke_includeReadonly' );

                // Get the DTD definition for the element. Defaults to "span".
                var dtd = CKEDITOR.dtd[ elementName ];
                if ( !dtd ) {
                        isUnknownElement = true;
                        dtd = CKEDITOR.dtd.span;
                }

                // Expand the range.
                range.enlarge( CKEDITOR.ENLARGE_INLINE, 1 );
                range.trim();

                // Get the first node to be processed and the last, which concludes the processing.
                var boundaryNodes = range.createBookmark(),
                        firstNode = boundaryNodes.startNode,
                        lastNode = boundaryNodes.endNode,
                        currentNode = firstNode,
                        styleRange;

                if ( !ignoreReadonly ) {
                        // Check if the boundaries are inside non stylable elements.
                        var root = range.getCommonAncestor(),
                                firstUnstylable = getUnstylableParent( firstNode, root ),
                                lastUnstylable = getUnstylableParent( lastNode, root );

                        // If the first element can't be styled, we'll start processing right
                        // after its unstylable root.
                        if ( firstUnstylable )
                                currentNode = firstUnstylable.getNextSourceNode( true );

                        // If the last element can't be styled, we'll stop processing on its
                        // unstylable root.
                        if ( lastUnstylable )
                                lastNode = lastUnstylable;
                }

                // Do nothing if the current node now follows the last node to be processed.
                if ( currentNode.getPosition( lastNode ) == CKEDITOR.POSITION_FOLLOWING )
                        currentNode = 0;

                while ( currentNode ) {
                        var applyStyle = false;

                        if ( currentNode.equals( lastNode ) ) {
                                currentNode = null;
                                applyStyle = true;
                        } else {
                                var nodeName = currentNode.type == CKEDITOR.NODE_ELEMENT ? currentNode.getName() : null,
                                        nodeIsReadonly = nodeName && ( currentNode.getAttribute( 'contentEditable' ) == 'false' ),
                                        nodeIsNoStyle = nodeName && currentNode.getAttribute( 'data-nostyle' );

                                // Skip bookmarks.
                                if ( nodeName && currentNode.data( 'cke-bookmark' ) ) {
                                        currentNode = currentNode.getNextSourceNode( true );
                                        continue;
                                }

                                // Find all nested editables of a non-editable block and apply this style inside them.
                                if ( nodeIsReadonly && includeReadonly && CKEDITOR.dtd.$block[ nodeName ] )
                                        applyStyleOnNestedEditables.call( this, currentNode );

                                // Check if the current node can be a child of the style element.
                                if ( checkIfNodeCanBeChildOfStyle( def, currentNode, lastNode, nodeName, dtd, nodeIsNoStyle, nodeIsReadonly, includeReadonly ) ) {
                                        var currentParent = currentNode.getParent();

                                        // Check if the style element can be a child of the current
                                        // node parent or if the element is not defined in the DTD.
                                        if ( checkIfStyleCanBeChildOf( def, currentParent, elementName, isUnknownElement ) ) {
                                                // This node will be part of our range, so if it has not
                                                // been started, place its start right before the node.
                                                // In the case of an element node, it will be included
                                                // only if it is entirely inside the range.
                                                if ( !styleRange && checkIfStartsRange( nodeName, currentNode, lastNode ) ) {
                                                        styleRange = range.clone();
                                                        styleRange.setStartBefore( currentNode );
                                                }

                                                // Non element nodes, readonly elements, or empty
                                                // elements can be added completely to the range.
                                                if ( checkIfTextOrReadonlyOrEmptyElement( currentNode, nodeIsReadonly ) ) {
                                                        var includedNode = currentNode;
                                                        var parentNode;

                                                        // This node is about to be included completelly, but,
                                                        // if this is the last node in its parent, we must also
                                                        // check if the parent itself can be added completelly
                                                        // to the range, otherwise apply the style immediately.
                                                        while (
                                                                ( applyStyle = !includedNode.getNext( notBookmark ) ) &&
                                                                ( parentNode = includedNode.getParent(), dtd[ parentNode.getName() ] ) &&
                                                                checkPositionAndRule( parentNode, firstNode, def, posFollowingIdenticalContained )
                                                        ) {
                                                                includedNode = parentNode;
                                                        }

                                                        styleRange.setEndAfter( includedNode );

                                                }
                                        } else {
                                                applyStyle = true;
                                        }
                                }
                                // Style isn't applicable to current element, so apply style to
                                // range ending at previously chosen position, or nowhere if we haven't
                                // yet started styleRange.
                                else {
                                        applyStyle = true;
                                }

                                // Get the next node to be processed.
                                // If we're currently on a non-editable element or non-styleable element,
                                // then we'll be moved to current node's sibling (or even further), so we'll
                                // avoid messing up its content.
                                currentNode = currentNode.getNextSourceNode( nodeIsNoStyle || nodeIsReadonly );
                        }

                        // Apply the style if we have something to which apply it.
                        if ( applyStyle && styleRange && !styleRange.collapsed ) {
                                // Build the style element, based on the style object definition.
                                var styleNode = getElement( this, document ),
                                        styleHasAttrs = styleNode.hasAttributes();

                                // Get the element that holds the entire range.
                                var parent = styleRange.getCommonAncestor();

                                var removeList = {
                                        styles: {},
                                        attrs: {},
                                        // Styles cannot be removed.
                                        blockedStyles: {},
                                        // Attrs cannot be removed.
                                        blockedAttrs: {}
                                };

                                var attName, styleName, value;

                                // Loop through the parents, removing the redundant attributes
                                // from the element to be applied.
                                while ( styleNode && parent ) {
                                        if ( parent.getName() == elementName ) {
                                                for ( attName in def.attributes ) {
                                                        if ( removeList.blockedAttrs[ attName ] || !( value = parent.getAttribute( styleName ) ) )
                                                                continue;

                                                        if ( styleNode.getAttribute( attName ) == value )
                                                                removeList.attrs[ attName ] = 1;
                                                        else
                                                                removeList.blockedAttrs[ attName ] = 1;
                                                }

                                                for ( styleName in def.styles ) {
                                                        if ( removeList.blockedStyles[ styleName ] || !( value = parent.getStyle( styleName ) ) )
                                                                continue;

                                                        if ( styleNode.getStyle( styleName ) == value )
                                                                removeList.styles[ styleName ] = 1;
                                                        else
                                                                removeList.blockedStyles[ styleName ] = 1;
                                                }
                                        }

                                        parent = parent.getParent();
                                }

                                for ( attName in removeList.attrs )
                                        styleNode.removeAttribute( attName );

                                for ( styleName in removeList.styles )
                                        styleNode.removeStyle( styleName );

                                if ( styleHasAttrs && !styleNode.hasAttributes() )
                                        styleNode = null;

                                if ( styleNode ) {
                                        // Move the contents of the range to the style element.
                                        styleRange.extractContents().appendTo( styleNode );

                                        // Insert it into the range position (it is collapsed after
                                        // extractContents.
                                        styleRange.insertNode( styleNode );

                                        // Here we do some cleanup, removing all duplicated
                                        // elements from the style element.
                                        removeFromInsideElement.call( this, styleNode );

                                        // Let's merge our new style with its neighbors, if possible.
                                        styleNode.mergeSiblings();

                                        // As the style system breaks text nodes constantly, let's normalize
                                        // things for performance.
                                        // With IE, some paragraphs get broken when calling normalize()
                                        // repeatedly. Also, for IE, we must normalize body, not documentElement.
                                        // IE is also known for having a "crash effect" with normalize().
                                        // We should try to normalize with IE too in some way, somewhere.
                                        if ( !CKEDITOR.env.ie )
                                                styleNode.$.normalize();
                                }
                                // Style already inherit from parents, left just to clear up any internal overrides. (#5931)
                                else {
                                        styleNode = new CKEDITOR.dom.element( 'span' );
                                        styleRange.extractContents().appendTo( styleNode );
                                        styleRange.insertNode( styleNode );
                                        removeFromInsideElement.call( this, styleNode );
                                        styleNode.remove( true );
                                }

                                // Style applied, let's release the range, so it gets
                                // re-initialization in the next loop.
                                styleRange = null;
                        }
                }

                // Remove the bookmark nodes.
                range.moveToBookmark( boundaryNodes );

                // Minimize the result range to exclude empty text nodes. (#5374)
                range.shrink( CKEDITOR.SHRINK_TEXT );

                // Get inside the remaining element if range.shrink( TEXT ) has failed because of non-editable elements inside.
                // E.g. range.shrink( TEXT ) will not get inside:
                // [<b><i contenteditable="false">x</i></b>]
                // but range.shrink( ELEMENT ) will.
                range.shrink( CKEDITOR.NODE_ELEMENT, true );
        }

        function removeInlineStyle( range ) {
                // Make sure our range has included all "collpased" parent inline nodes so
                // that our operation logic can be simpler.
                range.enlarge( CKEDITOR.ENLARGE_INLINE, 1 );

                var bookmark = range.createBookmark(),
                        startNode = bookmark.startNode;

                if ( range.collapsed ) {
                        var startPath = new CKEDITOR.dom.elementPath( startNode.getParent(), range.root ),
                                // The topmost element in elementspatch which we should jump out of.
                                boundaryElement;


                        for ( var i = 0, element; i < startPath.elements.length && ( element = startPath.elements[ i ] ); i++ ) {
                                // 1. If it's collaped inside text nodes, try to remove the style from the whole element.
                                //
                                // 2. Otherwise if it's collapsed on element boundaries, moving the selection
                                //  outside the styles instead of removing the whole tag,
                                //  also make sure other inner styles were well preserverd.(#3309)
                                if ( element == startPath.block || element == startPath.blockLimit )
                                        break;

                                if ( this.checkElementRemovable( element ) ) {
                                        var isStart;

                                        if ( range.collapsed && ( range.checkBoundaryOfElement( element, CKEDITOR.END ) || ( isStart = range.checkBoundaryOfElement( element, CKEDITOR.START ) ) ) ) {
                                                boundaryElement = element;
                                                boundaryElement.match = isStart ? 'start' : 'end';
                                        } else {
                                                // Before removing the style node, there may be a sibling to the style node
                                                // that's exactly the same to the one to be removed. To the user, it makes
                                                // no difference that they're separate entities in the DOM tree. So, merge
                                                // them before removal.
                                                element.mergeSiblings();
                                                if ( element.is( this.element ) )
                                                        removeFromElement.call( this, element );
                                                else
                                                        removeOverrides( element, getOverrides( this )[ element.getName() ] );
                                        }
                                }
                        }

                        // Re-create the style tree after/before the boundary element,
                        // the replication start from bookmark start node to define the
                        // new range.
                        if ( boundaryElement ) {
                                var clonedElement = startNode;
                                for ( i = 0; ; i++ ) {
                                        var newElement = startPath.elements[ i ];
                                        if ( newElement.equals( boundaryElement ) )
                                                break;
                                        // Avoid copying any matched element.
                                        else if ( newElement.match )
                                                continue;
                                        else
                                                newElement = newElement.clone();
                                        newElement.append( clonedElement );
                                        clonedElement = newElement;
                                }
                                clonedElement[ boundaryElement.match == 'start' ? 'insertBefore' : 'insertAfter' ]( boundaryElement );
                        }
                } else {
                        // Now our range isn't collapsed. Lets walk from the start node to the end
                        // node via DFS and remove the styles one-by-one.
                        var endNode = bookmark.endNode,
                                me = this;

                        breakNodes();

                        // Now, do the DFS walk.
                        var currentNode = startNode;
                        while ( !currentNode.equals( endNode ) ) {
                                // Need to get the next node first because removeFromElement() can remove
                                // the current node from DOM tree.
                                var nextNode = currentNode.getNextSourceNode();
                                if ( currentNode.type == CKEDITOR.NODE_ELEMENT && this.checkElementRemovable( currentNode ) ) {
                                        // Remove style from element or overriding element.
                                        if ( currentNode.getName() == this.element )
                                                removeFromElement.call( this, currentNode );
                                        else
                                                removeOverrides( currentNode, getOverrides( this )[ currentNode.getName() ] );

                                        // removeFromElement() may have merged the next node with something before
                                        // the startNode via mergeSiblings(). In that case, the nextNode would
                                        // contain startNode and we'll have to call breakNodes() again and also
                                        // reassign the nextNode to something after startNode.
                                        if ( nextNode.type == CKEDITOR.NODE_ELEMENT && nextNode.contains( startNode ) ) {
                                                breakNodes();
                                                nextNode = startNode.getNext();
                                        }
                                }
                                currentNode = nextNode;
                        }
                }

                range.moveToBookmark( bookmark );
                // See the comment for range.shrink in applyInlineStyle.
                range.shrink( CKEDITOR.NODE_ELEMENT, true );

                // Find out the style ancestor that needs to be broken down at startNode
                // and endNode.
                function breakNodes() {
                        var startPath = new CKEDITOR.dom.elementPath( startNode.getParent() ),
                                endPath = new CKEDITOR.dom.elementPath( endNode.getParent() ),
                                breakStart = null,
                                breakEnd = null;

                        for ( var i = 0; i < startPath.elements.length; i++ ) {
                                var element = startPath.elements[ i ];

                                if ( element == startPath.block || element == startPath.blockLimit )
                                        break;

                                if ( me.checkElementRemovable( element, true ) )
                                        breakStart = element;
                        }

                        for ( i = 0; i < endPath.elements.length; i++ ) {
                                element = endPath.elements[ i ];

                                if ( element == endPath.block || element == endPath.blockLimit )
                                        break;

                                if ( me.checkElementRemovable( element, true ) )
                                        breakEnd = element;
                        }

                        if ( breakEnd )
                                endNode.breakParent( breakEnd );
                        if ( breakStart )
                                startNode.breakParent( breakStart );
                }
        }

        // Apply style to nested editables inside editablesContainer.
        // @param {CKEDITOR.dom.element} editablesContainer
        // @context CKEDITOR.style
        function applyStyleOnNestedEditables( editablesContainer ) {
                var editables = findNestedEditables( editablesContainer ),
                        editable,
                        l = editables.length,
                        i = 0,
                        range = l && new CKEDITOR.dom.range( editablesContainer.getDocument() );

                for ( ; i < l; ++i ) {
                        editable = editables[ i ];
                        // Check if style is allowed by this editable's ACF.
                        if ( checkIfAllowedInEditable( editable, this ) ) {
                                range.selectNodeContents( editable );
                                applyInlineStyle.call( this, range );
                        }
                }
        }

        // Finds nested editables within container. Does not return
        // editables nested in another editable (twice).
        function findNestedEditables( container ) {
                var editables = [];

                container.forEach( function( element ) {
                        if ( element.getAttribute( 'contenteditable' ) == 'true' ) {
                                editables.push( element );
                                return false; // Skip children.
                        }
                }, CKEDITOR.NODE_ELEMENT, true );

                return editables;
        }

        // Checks if style is allowed in this editable.
        function checkIfAllowedInEditable( editable, style ) {
                var filter = CKEDITOR.filter.instances[ editable.data( 'cke-filter' ) ];

                return filter ? filter.check( style ) : 1;
        }

        // Checks if style is allowed by iterator's active filter.
        function checkIfAllowedByIterator( iterator, style ) {
                return iterator.activeFilter ? iterator.activeFilter.check( style ) : 1;
        }

        function applyObjectStyle( range ) {
                // Selected or parent element. (#9651)
                var start = range.getEnclosedNode() || range.getCommonAncestor( false, true ),
                        element = new CKEDITOR.dom.elementPath( start, range.root ).contains( this.element, 1 );

                element && !element.isReadOnly() && setupElement( element, this );
        }

        function removeObjectStyle( range ) {
                var parent = range.getCommonAncestor( true, true ),
                        element = new CKEDITOR.dom.elementPath( parent, range.root ).contains( this.element, 1 );

                if ( !element )
                        return;

                var style = this,
                        def = style._.definition,
                        attributes = def.attributes;

                // Remove all defined attributes.
                if ( attributes ) {
                        for ( var att in attributes )
                                element.removeAttribute( att, attributes[ att ] );
                }

                // Assign all defined styles.
                if ( def.styles ) {
                        for ( var i in def.styles ) {
                                if ( def.styles.hasOwnProperty( i ) )
                                        element.removeStyle( i );
                        }
                }
        }

        function applyBlockStyle( range ) {
                // Serializible bookmarks is needed here since
                // elements may be merged.
                var bookmark = range.createBookmark( true );

                var iterator = range.createIterator();
                iterator.enforceRealBlocks = true;

                // make recognize <br /> tag as a separator in ENTER_BR mode (#5121)
                if ( this._.enterMode )
                        iterator.enlargeBr = ( this._.enterMode != CKEDITOR.ENTER_BR );

                var block,
                        doc = range.document,
                        newBlock;

                while ( ( block = iterator.getNextParagraph() ) ) {
                        if ( !block.isReadOnly() && checkIfAllowedByIterator( iterator, this ) ) {
                                newBlock = getElement( this, doc, block );
                                replaceBlock( block, newBlock );
                        }
                }

                range.moveToBookmark( bookmark );
        }

        function removeBlockStyle( range ) {
                // Serializible bookmarks is needed here since
                // elements may be merged.
                var bookmark = range.createBookmark( 1 );

                var iterator = range.createIterator();
                iterator.enforceRealBlocks = true;
                iterator.enlargeBr = this._.enterMode != CKEDITOR.ENTER_BR;

                var block,
                        newBlock;

                while ( ( block = iterator.getNextParagraph() ) ) {
                        if ( this.checkElementRemovable( block ) ) {
                                // <pre> get special treatment.
                                if ( block.is( 'pre' ) ) {
                                        newBlock = this._.enterMode == CKEDITOR.ENTER_BR ? null :
                                                        range.document.createElement( this._.enterMode == CKEDITOR.ENTER_P ? 'p' : 'div' );

                                        newBlock && block.copyAttributes( newBlock );
                                        replaceBlock( block, newBlock );
                                } else {
                                        removeFromElement.call( this, block );
                                }
                        }
                }

                range.moveToBookmark( bookmark );
        }

        // Replace the original block with new one, with special treatment
        // for <pre> blocks to make sure content format is well preserved, and merging/splitting adjacent
        // when necessary. (#3188)
        function replaceBlock( block, newBlock ) {
                // Block is to be removed, create a temp element to
                // save contents.
                var removeBlock = !newBlock;
                if ( removeBlock ) {
                        newBlock = block.getDocument().createElement( 'div' );
                        block.copyAttributes( newBlock );
                }

                var newBlockIsPre = newBlock && newBlock.is( 'pre' ),
                        blockIsPre = block.is( 'pre' ),
                        isToPre = newBlockIsPre && !blockIsPre,
                        isFromPre = !newBlockIsPre && blockIsPre;

                if ( isToPre )
                        newBlock = toPre( block, newBlock );
                else if ( isFromPre )
                        // Split big <pre> into pieces before start to convert.
                        newBlock = fromPres( removeBlock ? [ block.getHtml() ] : splitIntoPres( block ), newBlock );
                else
                        block.moveChildren( newBlock );

                newBlock.replace( block );

                if ( newBlockIsPre ) {
                        // Merge previous <pre> blocks.
                        mergePre( newBlock );
                } else if ( removeBlock ) {
                        removeNoAttribsElement( newBlock );
                }
        }

        // Merge a <pre> block with a previous sibling if available.
        function mergePre( preBlock ) {
                var previousBlock;
                if ( !( ( previousBlock = preBlock.getPrevious( nonWhitespaces ) ) && previousBlock.type == CKEDITOR.NODE_ELEMENT && previousBlock.is( 'pre' ) ) )
                        return;

                // Merge the previous <pre> block contents into the current <pre>
                // block.
                //
                // Another thing to be careful here is that currentBlock might contain
                // a '\n' at the beginning, and previousBlock might contain a '\n'
                // towards the end. These new lines are not normally displayed but they
                // become visible after merging.
                var mergedHtml = replace( previousBlock.getHtml(), /\n$/, '' ) + '\n\n' +
                        replace( preBlock.getHtml(), /^\n/, '' );

                // Krugle: IE normalizes innerHTML from <pre>, breaking whitespaces.
                if ( CKEDITOR.env.ie )
                        preBlock.$.outerHTML = '<pre>' + mergedHtml + '</pre>';
                else
                        preBlock.setHtml( mergedHtml );

                previousBlock.remove();
        }

        // Split into multiple <pre> blocks separated by double line-break.
        function splitIntoPres( preBlock ) {
                // Exclude the ones at header OR at tail,
                // and ignore bookmark content between them.
                var duoBrRegex = /(\S\s*)\n(?:\s|(<span[^>]+data-cke-bookmark.*?\/span>))*\n(?!$)/gi,
                        pres = [],
                        splitedHtml = replace( preBlock.getOuterHtml(), duoBrRegex, function( match, charBefore, bookmark ) {
                                return charBefore + '</pre>' + bookmark + '<pre>';
                        } );

                splitedHtml.replace( /<pre\b.*?>([\s\S]*?)<\/pre>/gi, function( match, preContent ) {
                        pres.push( preContent );
                } );
                return pres;
        }

        // Wrapper function of String::replace without considering of head/tail bookmarks nodes.
        function replace( str, regexp, replacement ) {
                var headBookmark = '',
                        tailBookmark = '';

                str = str.replace( /(^<span[^>]+data-cke-bookmark.*?\/span>)|(<span[^>]+data-cke-bookmark.*?\/span>$)/gi, function( str, m1, m2 ) {
                        m1 && ( headBookmark = m1 );
                        m2 && ( tailBookmark = m2 );
                        return '';
                } );
                return headBookmark + str.replace( regexp, replacement ) + tailBookmark;
        }

        // Converting a list of <pre> into blocks with format well preserved.
        function fromPres( preHtmls, newBlock ) {
                var docFrag;
                if ( preHtmls.length > 1 )
                        docFrag = new CKEDITOR.dom.documentFragment( newBlock.getDocument() );

                for ( var i = 0; i < preHtmls.length; i++ ) {
                        var blockHtml = preHtmls[ i ];

                        // 1. Trim the first and last line-breaks immediately after and before <pre>,
                        // they're not visible.
                        blockHtml = blockHtml.replace( /(\r\n|\r)/g, '\n' );
                        blockHtml = replace( blockHtml, /^[ \t]*\n/, '' );
                        blockHtml = replace( blockHtml, /\n$/, '' );
                        // 2. Convert spaces or tabs at the beginning or at the end to &nbsp;
                        blockHtml = replace( blockHtml, /^[ \t]+|[ \t]+$/g, function( match, offset ) {
                                if ( match.length == 1 ) // one space, preserve it
                                        return '&nbsp;';
                                else if ( !offset ) // beginning of block
                                        return CKEDITOR.tools.repeat( '&nbsp;', match.length - 1 ) + ' ';
                                else // end of block
                                        return ' ' + CKEDITOR.tools.repeat( '&nbsp;', match.length - 1 );
                        } );

                        // 3. Convert \n to <BR>.
                        // 4. Convert contiguous (i.e. non-singular) spaces or tabs to &nbsp;
                        blockHtml = blockHtml.replace( /\n/g, '<br>' );
                        blockHtml = blockHtml.replace( /[ \t]{2,}/g, function( match ) {
                                return CKEDITOR.tools.repeat( '&nbsp;', match.length - 1 ) + ' ';
                        } );

                        if ( docFrag ) {
                                var newBlockClone = newBlock.clone();
                                newBlockClone.setHtml( blockHtml );
                                docFrag.append( newBlockClone );
                        } else {
                                newBlock.setHtml( blockHtml );
                        }
                }

                return docFrag || newBlock;
        }

        // Converting from a non-PRE block to a PRE block in formatting operations.
        function toPre( block, newBlock ) {
                var bogus = block.getBogus();
                bogus && bogus.remove();

                // First trim the block content.
                var preHtml = block.getHtml();

                // 1. Trim head/tail spaces, they're not visible.
                preHtml = replace( preHtml, /(?:^[ \t\n\r]+)|(?:[ \t\n\r]+$)/g, '' );
                // 2. Delete ANSI whitespaces immediately before and after <BR> because
                //    they are not visible.
                preHtml = preHtml.replace( /[ \t\r\n]*(<br[^>]*>)[ \t\r\n]*/gi, '$1' );
                // 3. Compress other ANSI whitespaces since they're only visible as one
                //    single space previously.
                // 4. Convert &nbsp; to spaces since &nbsp; is no longer needed in <PRE>.
                preHtml = preHtml.replace( /([ \t\n\r]+|&nbsp;)/g, ' ' );
                // 5. Convert any <BR /> to \n. This must not be done earlier because
                //    the \n would then get compressed.
                preHtml = preHtml.replace( /<br\b[^>]*>/gi, '\n' );

                // Krugle: IE normalizes innerHTML to <pre>, breaking whitespaces.
                if ( CKEDITOR.env.ie ) {
                        var temp = block.getDocument().createElement( 'div' );
                        temp.append( newBlock );
                        newBlock.$.outerHTML = '<pre>' + preHtml + '</pre>';
                        newBlock.copyAttributes( temp.getFirst() );
                        newBlock = temp.getFirst().remove();
                } else {
                        newBlock.setHtml( preHtml );
                }

                return newBlock;
        }

        // Removes a style from an element itself, don't care about its subtree.
        function removeFromElement( element, keepDataAttrs ) {
                var def = this._.definition,
                        attributes = def.attributes,
                        styles = def.styles,
                        overrides = getOverrides( this )[ element.getName() ],
                        // If the style is only about the element itself, we have to remove the element.
                        removeEmpty = CKEDITOR.tools.isEmpty( attributes ) && CKEDITOR.tools.isEmpty( styles );

                // Remove definition attributes/style from the elemnt.
                for ( var attName in attributes ) {
                        // The 'class' element value must match (#1318).
                        if ( ( attName == 'class' || this._.definition.fullMatch ) && element.getAttribute( attName ) != normalizeProperty( attName, attributes[ attName ] ) )
                                continue;

                        // Do not touch data-* attributes (#11011) (#11258).
                        if ( keepDataAttrs && attName.slice( 0, 5 ) == 'data-' )
                                continue;

                        removeEmpty = element.hasAttribute( attName );
                        element.removeAttribute( attName );
                }

                for ( var styleName in styles ) {
                        // Full match style insist on having fully equivalence. (#5018)
                        if ( this._.definition.fullMatch && element.getStyle( styleName ) != normalizeProperty( styleName, styles[ styleName ], true ) )
                                continue;

                        removeEmpty = removeEmpty || !!element.getStyle( styleName );
                        element.removeStyle( styleName );
                }

                // Remove overrides, but don't remove the element if it's a block element
                removeOverrides( element, overrides, blockElements[ element.getName() ] );

                if ( removeEmpty ) {
                        if ( this._.definition.alwaysRemoveElement )
                                removeNoAttribsElement( element, 1 );
                        else {
                                if ( !CKEDITOR.dtd.$block[ element.getName() ] || this._.enterMode == CKEDITOR.ENTER_BR && !element.hasAttributes() )
                                        removeNoAttribsElement( element );
                                else
                                        element.renameNode( this._.enterMode == CKEDITOR.ENTER_P ? 'p' : 'div' );
                        }
                }
        }

        // Removes a style from inside an element. Called on applyStyle to make cleanup
        // before apply. During clean up this function keep data-* attribute in contrast
        // to removeFromElement.
        function removeFromInsideElement( element ) {
                var overrides = getOverrides( this ),
                        innerElements = element.getElementsByTag( this.element ),
                        innerElement;

                for ( var i = innerElements.count(); --i >= 0; ) {
                        innerElement = innerElements.getItem( i );

                        // Do not remove elements which are read only (e.g. duplicates inside widgets).
                        if ( !innerElement.isReadOnly() )
                                removeFromElement.call( this, innerElement, true );
                }

                // Now remove any other element with different name that is
                // defined to be overriden.
                for ( var overrideElement in overrides ) {
                        if ( overrideElement != this.element ) {
                                innerElements = element.getElementsByTag( overrideElement );

                                for ( i = innerElements.count() - 1; i >= 0; i-- ) {
                                        innerElement = innerElements.getItem( i );

                                        // Do not remove elements which are read only (e.g. duplicates inside widgets).
                                        if ( !innerElement.isReadOnly() )
                                                removeOverrides( innerElement, overrides[ overrideElement ] );
                                }
                        }
                }
        }

        // Remove overriding styles/attributes from the specific element.
        // Note: Remove the element if no attributes remain.
        // @param {Object} element
        // @param {Object} overrides
        // @param {Boolean} Don't remove the element
        function removeOverrides( element, overrides, dontRemove ) {
                var attributes = overrides && overrides.attributes;

                if ( attributes ) {
                        for ( var i = 0; i < attributes.length; i++ ) {
                                var attName = attributes[ i ][ 0 ],
                                        actualAttrValue;

                                if ( ( actualAttrValue = element.getAttribute( attName ) ) ) {
                                        var attValue = attributes[ i ][ 1 ];

                                        // Remove the attribute if:
                                        //    - The override definition value is null ;
                                        //    - The override definition valie is a string that
                                        //      matches the attribute value exactly.
                                        //    - The override definition value is a regex that
                                        //      has matches in the attribute value.
                                        if ( attValue === null || ( attValue.test && attValue.test( actualAttrValue ) ) || ( typeof attValue == 'string' && actualAttrValue == attValue ) )
                                                element.removeAttribute( attName );
                                }
                        }
                }

                if ( !dontRemove )
                        removeNoAttribsElement( element );
        }

        // If the element has no more attributes, remove it.
        function removeNoAttribsElement( element, forceRemove ) {
                // If no more attributes remained in the element, remove it,
                // leaving its children.
                if ( !element.hasAttributes() || forceRemove ) {
                        if ( CKEDITOR.dtd.$block[ element.getName() ] ) {
                                var previous = element.getPrevious( nonWhitespaces ),
                                        next = element.getNext( nonWhitespaces );

                                if ( previous && ( previous.type == CKEDITOR.NODE_TEXT || !previous.isBlockBoundary( { br: 1 } ) ) )
                                        element.append( 'br', 1 );
                                if ( next && ( next.type == CKEDITOR.NODE_TEXT || !next.isBlockBoundary( { br: 1 } ) ) )
                                        element.append( 'br' );

                                element.remove( true );
                        } else {
                                // Removing elements may open points where merging is possible,
                                // so let's cache the first and last nodes for later checking.
                                var firstChild = element.getFirst();
                                var lastChild = element.getLast();

                                element.remove( true );

                                if ( firstChild ) {
                                        // Check the cached nodes for merging.
                                        firstChild.type == CKEDITOR.NODE_ELEMENT && firstChild.mergeSiblings();

                                        if ( lastChild && !firstChild.equals( lastChild ) && lastChild.type == CKEDITOR.NODE_ELEMENT )
                                                lastChild.mergeSiblings();
                                }

                        }
                }
        }

        function getElement( style, targetDocument, element ) {
                var el,
                        elementName = style.element;

                // The "*" element name will always be a span for this function.
                if ( elementName == '*' )
                        elementName = 'span';

                // Create the element.
                el = new CKEDITOR.dom.element( elementName, targetDocument );

                // #6226: attributes should be copied before the new ones are applied
                if ( element )
                        element.copyAttributes( el );

                el = setupElement( el, style );

                // Avoid ID duplication.
                if ( targetDocument.getCustomData( 'doc_processing_style' ) && el.hasAttribute( 'id' ) )
                        el.removeAttribute( 'id' );
                else
                        targetDocument.setCustomData( 'doc_processing_style', 1 );

                return el;
        }

        function setupElement( el, style ) {
                var def = style._.definition,
                        attributes = def.attributes,
                        styles = CKEDITOR.style.getStyleText( def );

                // Assign all defined attributes.
                if ( attributes ) {
                        for ( var att in attributes )
                                el.setAttribute( att, attributes[ att ] );
                }

                // Assign all defined styles.
                if ( styles )
                        el.setAttribute( 'style', styles );

                return el;
        }

        function replaceVariables( list, variablesValues ) {
                for ( var item in list ) {
                        list[ item ] = list[ item ].replace( varRegex, function( match, varName ) {
                                return variablesValues[ varName ];
                        } );
                }
        }

        // Returns an object that can be used for style matching comparison.
        // Attributes names and values are all lowercased, and the styles get
        // merged with the style attribute.
        function getAttributesForComparison( styleDefinition ) {
                // If we have already computed it, just return it.
                var attribs = styleDefinition._AC;
                if ( attribs )
                        return attribs;

                attribs = {};

                var length = 0;

                // Loop through all defined attributes.
                var styleAttribs = styleDefinition.attributes;
                if ( styleAttribs ) {
                        for ( var styleAtt in styleAttribs ) {
                                length++;
                                attribs[ styleAtt ] = styleAttribs[ styleAtt ];
                        }
                }

                // Includes the style definitions.
                var styleText = CKEDITOR.style.getStyleText( styleDefinition );
                if ( styleText ) {
                        if ( !attribs.style )
                                length++;
                        attribs.style = styleText;
                }

                // Appends the "length" information to the object.
                attribs._length = length;

                // Return it, saving it to the next request.
                return ( styleDefinition._AC = attribs );
        }

        // Get the the collection used to compare the elements and attributes,
        // defined in this style overrides, with other element. All information in
        // it is lowercased.
        // @param {CKEDITOR.style} style
        function getOverrides( style ) {
                if ( style._.overrides )
                        return style._.overrides;

                var overrides = ( style._.overrides = {} ),
                        definition = style._.definition.overrides;

                if ( definition ) {
                        // The override description can be a string, object or array.
                        // Internally, well handle arrays only, so transform it if needed.
                        if ( !CKEDITOR.tools.isArray( definition ) )
                                definition = [ definition ];

                        // Loop through all override definitions.
                        for ( var i = 0; i < definition.length; i++ ) {
                                var override = definition[ i ],
                                        elementName,
                                        overrideEl,
                                        attrs;

                                // If can be a string with the element name.
                                if ( typeof override == 'string' )
                                        elementName = override.toLowerCase();
                                // Or an object.
                                else {
                                        elementName = override.element ? override.element.toLowerCase() : style.element;
                                        attrs = override.attributes;
                                }

                                // We can have more than one override definition for the same
                                // element name, so we attempt to simply append information to
                                // it if it already exists.
                                overrideEl = overrides[ elementName ] || ( overrides[ elementName ] = {} );

                                if ( attrs ) {
                                        // The returning attributes list is an array, because we
                                        // could have different override definitions for the same
                                        // attribute name.
                                        var overrideAttrs = ( overrideEl.attributes = overrideEl.attributes || [] );
                                        for ( var attName in attrs ) {
                                                // Each item in the attributes array is also an array,
                                                // where [0] is the attribute name and [1] is the
                                                // override value.
                                                overrideAttrs.push( [ attName.toLowerCase(), attrs[ attName ] ] );
                                        }
                                }
                        }
                }

                return overrides;
        }

        // Make the comparison of attribute value easier by standardizing it.
        function normalizeProperty( name, value, isStyle ) {
                var temp = new CKEDITOR.dom.element( 'span' );
                temp[ isStyle ? 'setStyle' : 'setAttribute' ]( name, value );
                return temp[ isStyle ? 'getStyle' : 'getAttribute' ]( name );
        }

        // Compare two bunch of styles, with the speciality that value 'inherit'
        // is treated as a wildcard which will match any value.
        // @param {Object/String} source
        // @param {Object/String} target
        function compareCssText( source, target ) {
                if ( typeof source == 'string' )
                        source = CKEDITOR.tools.parseCssText( source );
                if ( typeof target == 'string' )
                        target = CKEDITOR.tools.parseCssText( target, true );

                for ( var name in source ) {
                        if ( !( name in target && ( target[ name ] == source[ name ] || source[ name ] == 'inherit' || target[ name ] == 'inherit' ) ) )
                                return false;
                }
                return true;
        }

        function applyStyleOnSelection( selection, remove, editor ) {
                var doc = selection.document,
                        ranges = selection.getRanges(),
                        func = remove ? this.removeFromRange : this.applyToRange,
                        range;

                var iterator = ranges.createIterator();
                while ( ( range = iterator.getNextRange() ) )
                        func.call( this, range, editor );

                selection.selectRanges( ranges );
                doc.removeCustomData( 'doc_processing_style' );
        }
} )();

/**
 * Generic style command. It applies a specific style when executed.
 *
 *              var boldStyle = new CKEDITOR.style( { element: 'strong' } );
 *              // Register the "bold" command, which applies the bold style.
 *              editor.addCommand( 'bold', new CKEDITOR.styleCommand( boldStyle ) );
 *
 * @class
 * @constructor Creates a styleCommand class instance.
 * @extends CKEDITOR.commandDefinition
 * @param {CKEDITOR.style} style The style to be applied when command is executed.
 * @param {Object} [ext] Additional command definition's properties.
 */
CKEDITOR.styleCommand = function( style, ext ) {
        this.style = style;
        this.allowedContent = style;
        this.requiredContent = style;

        CKEDITOR.tools.extend( this, ext, true );
};

/**
 * @param {CKEDITOR.editor} editor
 * @todo
 */
CKEDITOR.styleCommand.prototype.exec = function( editor ) {
        editor.focus();

        if ( this.state == CKEDITOR.TRISTATE_OFF )
                editor.applyStyle( this.style );
        else if ( this.state == CKEDITOR.TRISTATE_ON )
                editor.removeStyle( this.style );
};

/**
 * Manages styles registration and loading. See also {@link CKEDITOR.config#stylesSet}.
 *
 *              // The set of styles for the <b>Styles</b> drop-down list.
 *              CKEDITOR.stylesSet.add( 'default', [
 *                      // Block Styles
 *                      { name: 'Blue Title',           element: 'h3',          styles: { 'color': 'Blue' } },
 *                      { name: 'Red Title',            element: 'h3',          styles: { 'color': 'Red' } },
 *
 *                      // Inline Styles
 *                      { name: 'Marker: Yellow',       element: 'span',        styles: { 'background-color': 'Yellow' } },
 *                      { name: 'Marker: Green',        element: 'span',        styles: { 'background-color': 'Lime' } },
 *
 *                      // Object Styles
 *                      {
 *                              name: 'Image on Left',
 *                              element: 'img',
 *                              attributes: {
 *                                      style: 'padding: 5px; margin-right: 5px',
 *                                      border: '2',
 *                                      align: 'left'
 *                              }
 *                      }
 *              ] );
 *
 * @since 3.2
 * @class
 * @singleton
 * @extends CKEDITOR.resourceManager
 */
CKEDITOR.stylesSet = new CKEDITOR.resourceManager( '', 'stylesSet' );

// Backward compatibility (#5025).
CKEDITOR.addStylesSet = CKEDITOR.tools.bind( CKEDITOR.stylesSet.add, CKEDITOR.stylesSet );
CKEDITOR.loadStylesSet = function( name, url, callback ) {
        CKEDITOR.stylesSet.addExternal( name, url, '' );
        CKEDITOR.stylesSet.load( name, callback );
};

CKEDITOR.tools.extend( CKEDITOR.editor.prototype, {
        /**
         * Registers a function to be called whenever the selection position changes in the
         * editing area. The current state is passed to the function. The possible
         * states are {@link CKEDITOR#TRISTATE_ON} and {@link CKEDITOR#TRISTATE_OFF}.
         *
         *              // Create a style object for the <b> element.
         *              var style = new CKEDITOR.style( { element: 'b' } );
         *              var editor = CKEDITOR.instances.editor1;
         *              editor.attachStyleStateChange( style, function( state ) {
         *                      if ( state == CKEDITOR.TRISTATE_ON )
         *                              alert( 'The current state for the B element is ON' );
         *                      else
         *                              alert( 'The current state for the B element is OFF' );
         *              } );
         *
         * @member CKEDITOR.editor
         * @param {CKEDITOR.style} style The style to be watched.
         * @param {Function} callback The function to be called.
         */
        attachStyleStateChange: function( style, callback ) {
                // Try to get the list of attached callbacks.
                var styleStateChangeCallbacks = this._.styleStateChangeCallbacks;

                // If it doesn't exist, it means this is the first call. So, let's create
                // all the structure to manage the style checks and the callback calls.
                if ( !styleStateChangeCallbacks ) {
                        // Create the callbacks array.
                        styleStateChangeCallbacks = this._.styleStateChangeCallbacks = [];

                        // Attach to the selectionChange event, so we can check the styles at
                        // that point.
                        this.on( 'selectionChange', function( ev ) {
                                // Loop throw all registered callbacks.
                                for ( var i = 0; i < styleStateChangeCallbacks.length; i++ ) {
                                        var callback = styleStateChangeCallbacks[ i ];

                                        // Check the current state for the style defined for that callback.
                                        var currentState = callback.style.checkActive( ev.data.path, this ) ?
                                                CKEDITOR.TRISTATE_ON : CKEDITOR.TRISTATE_OFF;

                                        // Call the callback function, passing the current state to it.
                                        callback.fn.call( this, currentState );
                                }
                        } );
                }

                // Save the callback info, so it can be checked on the next occurrence of
                // selectionChange.
                styleStateChangeCallbacks.push( { style: style, fn: callback } );
        },

        /**
         * Applies the style upon the editor's current selection. Shorthand for
         * {@link CKEDITOR.style#apply}.
         *
         * @member CKEDITOR.editor
         * @param {CKEDITOR.style} style
         */
        applyStyle: function( style ) {
                style.apply( this );
        },

        /**
         * Removes the style from the editor's current selection. Shorthand for
         * {@link CKEDITOR.style#remove}.
         *
         * @member CKEDITOR.editor
         * @param {CKEDITOR.style} style
         */
        removeStyle: function( style ) {
                style.remove( this );
        },

        /**
         * Gets the current `stylesSet` for this instance.
         *
         *              editor.getStylesSet( function( stylesDefinitions ) {} );
         *
         * See also {@link CKEDITOR.editor#stylesSet} event.
         *
         * @member CKEDITOR.editor
         * @param {Function} callback The function to be called with the styles data.
         */
        getStylesSet: function( callback ) {
                if ( !this._.stylesDefinitions ) {
                        var editor = this,
                                // Respect the backwards compatible definition entry
                                configStyleSet = editor.config.stylesCombo_stylesSet || editor.config.stylesSet;

                        // The false value means that none styles should be loaded.
                        if ( configStyleSet === false ) {
                                callback( null );
                                return;
                        }

                        // #5352 Allow to define the styles directly in the config object
                        if ( configStyleSet instanceof Array ) {
                                editor._.stylesDefinitions = configStyleSet;
                                callback( configStyleSet );
                                return;
                        }

                        // Default value is 'default'.
                        if ( !configStyleSet )
                                configStyleSet = 'default';

                        var partsStylesSet = configStyleSet.split( ':' ),
                                styleSetName = partsStylesSet[ 0 ],
                                externalPath = partsStylesSet[ 1 ];

                        CKEDITOR.stylesSet.addExternal( styleSetName, externalPath ? partsStylesSet.slice( 1 ).join( ':' ) : CKEDITOR.getUrl( 'styles.js' ), '' );

                        CKEDITOR.stylesSet.load( styleSetName, function( stylesSet ) {
                                editor._.stylesDefinitions = stylesSet[ styleSetName ];
                                callback( editor._.stylesDefinitions );
                        } );
                } else {
                        callback( this._.stylesDefinitions );
                }
        }
} );

/**
 * Indicates that fully selected read-only elements will be included when
 * applying the style (for inline styles only).
 *
 * @since 3.5
 * @property {Boolean} [includeReadonly=false]
 * @member CKEDITOR.style
 */

/**
 * Indicates that any matches element of this style will be eventually removed
 * when calling {@link CKEDITOR.editor#removeStyle}.
 *
 * @since 4.0
 * @property {Boolean} [alwaysRemoveElement=false]
 * @member CKEDITOR.style
 */

/**
 * Disables inline styling on read-only elements.
 *
 * @since 3.5
 * @cfg {Boolean} [disableReadonlyStyling=false]
 * @member CKEDITOR.config
 */

/**
 * The "styles definition set" to use in the editor. They will be used in the
 * styles combo and the style selector of the div container.
 *
 * The styles may be defined in the page containing the editor, or can be
 * loaded on demand from an external file. In the second case, if this setting
 * contains only a name, the `styles.js` file will be loaded from the
 * CKEditor root folder (what ensures backward compatibility with CKEditor 4.0).
 *
 * Otherwise, this setting has the `name:url` syntax, making it
 * possible to set the URL from which the styles file will be loaded.
 * Note that the `name` has to be equal to the name used in
 * {@link CKEDITOR.stylesSet#add} while registering the styles set.
 *
 * **Note**: Since 4.1 it is possible to set `stylesSet` to `false`
 * to prevent loading any styles set.
 *
 * Read more in the [documentation](#!/guide/dev_styles)
 * and see the [SDK sample](http://sdk.ckeditor.com/samples/styles.html).
 *
 *              // Do not load any file. The styles set is empty.
 *              config.stylesSet = false;
 *
 *              // Load the 'mystyles' styles set from the styles.js file.
 *              config.stylesSet = 'mystyles';
 *
 *              // Load the 'mystyles' styles set from a relative URL.
 *              config.stylesSet = 'mystyles:/editorstyles/styles.js';
 *
 *              // Load the 'mystyles' styles set from a full URL.
 *              config.stylesSet = 'mystyles:http://www.example.com/editorstyles/styles.js';
 *
 *              // Load from a list of definitions.
 *              config.stylesSet = [
 *                      { name: 'Strong Emphasis', element: 'strong' },
 *                      { name: 'Emphasis', element: 'em' },
 *                      ...
 *              ];
 *
 * @since 3.3
 * @cfg {String/Array/Boolean} [stylesSet='default']
 * @member CKEDITOR.config
 */