Set scroll position at top of the textarea when opening the subtitle editor.

## Description

This set the position of the scrollbar at the top of the textarea when opening the __subtitle editor__.
Previously the textarea scroll position was at the bottom of the textarea which doesn't make much sense when you want to edit a subtitle : you most likely want to edit the beginning of the subtitle first.

This also set the caret position on the first character.

## Design decision

I had to use a *component approach* instead of an `<ng-template>` for the edition modal because the `@viewChild` directive doesn't work for elements __inside__ an `<ng-template>`.
I needed the `viewChild` directive to get an `ElementRef` of the `textarea`.

> See the following issue and its workaround :
> - https://github.com/valor-software/ngx-bootstrap/issues/3825
> - https://stackblitz.com/edit/angular-t5dfp7
> - https://medium.com/@izzatnadiri/how-to-pass-data-to-and-receive-from-ng-bootstrap-modals-916f2ad5d66e

## Related issues
Closes [peertube-plugin-transcription/#39](https://gitlab.com/apps_education/peertube/plugin-transcription/-/issues/39)

1 files changed, 11 insertions, 3 deletions

diff --git a/client/src/app/+videos/+video-edit/shared/video-edit.component.ts b/client/src/app/+videos/+video-edit/shared/video-edit.component.ts
index 99f8c9034..0275f66f5 100644
--- a/client/src/app/+videos/+video-edit/shared/video-edit.component.ts
+++ b/client/src/app/+videos/+video-edit/shared/video-edit.component.ts
@@ -35,10 +35,11 @@ import {
 } from '@shared/models'
 import { I18nPrimengCalendarService } from './i18n-primeng-calendar.service'
 import { VideoCaptionAddModalComponent } from './video-caption-add-modal.component'
-import { VideoCaptionEditModalComponent } from './video-caption-edit-modal/video-caption-edit-modal.component'
+import { VideoCaptionEditModalContentComponent } from './video-caption-edit-modal-content/video-caption-edit-modal-content.component'
 import { VideoEditType } from './video-edit.type'
 import { VideoSource } from '@shared/models/videos/video-source'
 import { logger } from '@root-helpers/logger'
+import { NgbModal } from '@ng-bootstrap/ng-bootstrap'
 
 type VideoLanguages = VideoConstant<string> & { group?: string }
 type PluginField = {
@@ -70,7 +71,6 @@ export class VideoEditComponent implements OnInit, OnDestroy {
   @Input() liveVideo: LiveVideo
 
   @ViewChild('videoCaptionAddModal', { static: true }) videoCaptionAddModal: VideoCaptionAddModalComponent
-  @ViewChild('videoCaptionEditModal', { static: true }) editCaptionModal: VideoCaptionEditModalComponent
 
   @Output() formBuilt = new EventEmitter<void>()
   @Output() pluginFieldsAdded = new EventEmitter<void>()
@@ -128,7 +128,8 @@ export class VideoEditComponent implements OnInit, OnDestroy {
     private i18nPrimengCalendarService: I18nPrimengCalendarService,
     private ngZone: NgZone,
     private hooks: HooksService,
-    private cd: ChangeDetectorRef
+    private cd: ChangeDetectorRef,
+    private modalService: NgbModal
   ) {
     this.calendarTimezone = this.i18nPrimengCalendarService.getTimezone()
     this.calendarDateFormat = this.i18nPrimengCalendarService.getDateFormat()
@@ -286,6 +287,13 @@ export class VideoEditComponent implements OnInit, OnDestroy {
     this.videoCaptionAddModal.show()
   }
 
+  openEditCaptionModal (videoCaption: VideoCaptionWithPathEdit) {
+    const modalRef = this.modalService.open(VideoCaptionEditModalContentComponent, { centered: true, keyboard: false })
+    modalRef.componentInstance.videoCaption = videoCaption
+    modalRef.componentInstance.serverConfig = this.serverConfig
+    modalRef.componentInstance.captionEdited.subscribe(this.onCaptionEdited.bind(this))
+  }
+
   isSaveReplayEnabled () {
     return this.serverConfig.live.allowReplay
   }