Added onVideoInit callback for video documents. See description for details (#867)

example/lib/universal_ui/universal_ui.dart

@@ -25,8 +25,13 @@ class UniversalUI {
 
 var ui = UniversalUI();
 
-Widget defaultEmbedBuilderWeb(BuildContext context, QuillController controller,
-    Embed node, bool readOnly) {
+Widget defaultEmbedBuilderWeb(
+  BuildContext context,
+  QuillController controller,
+  Embed node,
+  bool readOnly,
+  void Function(GlobalKey videoContainerKey)? onVideoInit,
+) {
   switch (node.value.type) {
     case 'image':
       final imageUrl = node.value.data;

lib/src/widgets/delegate.dart

@@ -6,8 +6,13 @@ import 'package:flutter/scheduler.dart';
 import '../../flutter_quill.dart';
 import 'text_selection.dart';
 
-typedef EmbedBuilder = Widget Function(BuildContext context,
-    QuillController controller, Embed node, bool readOnly);
+typedef EmbedBuilder = Widget Function(
+  BuildContext context,
+  QuillController controller,
+  Embed node,
+  bool readOnly,
+  void Function(GlobalKey videoContainerKey)? onVideoInit,
+);
 
 typedef CustomStyleBuilder = TextStyle Function(Attribute attribute);
 

lib/src/widgets/embeds/default_embed_builder.dart

@@ -16,8 +16,13 @@ import 'image_resizer.dart';
 import 'video_app.dart';
 import 'youtube_video_app.dart';
 
-Widget defaultEmbedBuilder(BuildContext context, QuillController controller,
-    leaf.Embed node, bool readOnly) {
+Widget defaultEmbedBuilder(
+  BuildContext context,
+  QuillController controller,
+  leaf.Embed node,
+  bool readOnly,
+  void Function(GlobalKey videoContainerKey)? onVideoInit,
+) {
   assert(!kIsWeb, 'Please provide EmbedBuilder for Web');
 
   Tuple2<double?, double?>? _widthHeight;
@@ -140,7 +145,12 @@ Widget defaultEmbedBuilder(BuildContext context, QuillController controller,
         return YoutubeVideoApp(
             videoUrl: videoUrl, context: context, readOnly: readOnly);
       }
-      return VideoApp(videoUrl: videoUrl, context: context, readOnly: readOnly);
+      return VideoApp(
+        videoUrl: videoUrl,
+        context: context,
+        readOnly: readOnly,
+        onVideoInit: onVideoInit,
+      );
     default:
       throw UnimplementedError(
         'Embeddable type "${node.value.type}" is not supported by default '

lib/src/widgets/embeds/video_app.dart

@@ -10,12 +10,17 @@ import '../../../flutter_quill.dart';
 /// Widget for playing back video
 /// Refer to https://github.com/flutter/plugins/tree/master/packages/video_player/video_player
 class VideoApp extends StatefulWidget {
-  const VideoApp(
-      {required this.videoUrl, required this.context, required this.readOnly});
+  const VideoApp({
+    required this.videoUrl,
+    required this.context,
+    required this.readOnly,
+    this.onVideoInit,
+  });
 
   final String videoUrl;
   final BuildContext context;
   final bool readOnly;
+  final void Function(GlobalKey videoContainerKey)? onVideoInit;
 
   @override
   _VideoAppState createState() => _VideoAppState();
@@ -23,6 +28,7 @@ class VideoApp extends StatefulWidget {
 
 class _VideoAppState extends State<VideoApp> {
   late VideoPlayerController _controller;
+  GlobalKey videoContainerKey = GlobalKey();
 
   @override
   void initState() {
@@ -35,6 +41,9 @@ class _VideoAppState extends State<VideoApp> {
         // Ensure the first frame is shown after the video is initialized,
         // even before the play button has been pressed.
         setState(() {});
+        if (widget.onVideoInit != null) {
+          widget.onVideoInit?.call(videoContainerKey);
+        }
       }).catchError((error) {
         setState(() {});
       });
@@ -65,7 +74,8 @@ class _VideoAppState extends State<VideoApp> {
     }
 
     return Container(
-      height: 300,
+      key: videoContainerKey,
+      // height: 300,
       child: InkWell(
         onTap: () {
           setState(() {

lib/src/widgets/text_line.dart

@@ -135,8 +135,15 @@ class _TextLineState extends State<TextLine> {
     if (widget.line.hasEmbed && widget.line.childCount == 1) {
       // For video, it is always single child
       final embed = widget.line.children.single as Embed;
-      return EmbedProxy(widget.embedBuilder(
-          context, widget.controller, embed, widget.readOnly));
+      return EmbedProxy(
+        widget.embedBuilder(
+          context,
+          widget.controller,
+          embed,
+          widget.readOnly,
+          null,
+        ),
+      );
     }
     final textSpan = _getTextSpanForWholeLine(context);
     final strutStyle = StrutStyle.fromTextStyle(textSpan.style!);
@@ -176,8 +183,16 @@ class _TextLineState extends State<TextLine> {
         }
         // Here it should be image
         final embed = WidgetSpan(
-            child: EmbedProxy(widget.embedBuilder(
-                context, widget.controller, child, widget.readOnly)));
+          child: EmbedProxy(
+            widget.embedBuilder(
+              context,
+              widget.controller,
+              child,
+              widget.readOnly,
+              null,
+            ),
+          ),
+        );
         textSpanChildren.add(embed);
         continue;
       }