Improve examples.

Author: cloudwebrtc

example/lib/src/get_display_media_sample.dart

@@ -52,7 +52,8 @@ class _GetDisplayMediaSampleState extends State<GetDisplayMediaSample> {
     final mediaConstraints = <String, dynamic>{'audio': true, 'video': true};
 
     try {
-      var stream = await navigator.mediaDevices.getDisplayMedia(mediaConstraints);
+      var stream =
+          await navigator.mediaDevices.getDisplayMedia(mediaConstraints);
       stream.getVideoTracks()[0].onEnded = () {
         print(
             'By adding a listener on onEnded you can: 1) catch stop video sharing on Web');
@@ -108,8 +109,8 @@ class _GetDisplayMediaSampleState extends State<GetDisplayMediaSample> {
                 margin: EdgeInsets.fromLTRB(0.0, 0.0, 0.0, 0.0),
                 width: MediaQuery.of(context).size.width,
                 height: MediaQuery.of(context).size.height,
-                child: RTCVideoView(_localRenderer),
                 decoration: BoxDecoration(color: Colors.black54),
+                child: RTCVideoView(_localRenderer),
               )
             ]),
           );

example/lib/src/get_user_media_sample.dart

@@ -212,8 +212,8 @@ class _GetUserMediaSampleState extends State<GetUserMediaSample> {
               margin: EdgeInsets.fromLTRB(0.0, 0.0, 0.0, 0.0),
               width: MediaQuery.of(context).size.width,
               height: MediaQuery.of(context).size.height,
-              child: RTCVideoView(_localRenderer, mirror: true),
               decoration: BoxDecoration(color: Colors.black54),
+              child: RTCVideoView(_localRenderer, mirror: true),
             ),
           );
         },

example/lib/src/get_user_media_sample_web.dart

@@ -109,6 +109,7 @@ class _GetUserMediaSampleState extends State<GetUserMediaSample> {
       _mediaRecorder = null;
     });
     print(objectUrl);
+    // ignore: unsafe_html
     html.window.open(objectUrl, '_blank');
   }
 
@@ -124,8 +125,8 @@ class _GetUserMediaSampleState extends State<GetUserMediaSample> {
               content: Image.network(frame, height: 720, width: 1280),
               actions: <Widget>[
                 TextButton(
-                  child: Text('OK'),
                   onPressed: Navigator.of(context, rootNavigator: true).pop,
+                  child: Text('OK'),
                 )
               ],
             ));
@@ -175,8 +176,8 @@ class _GetUserMediaSampleState extends State<GetUserMediaSample> {
               margin: EdgeInsets.fromLTRB(0.0, 0.0, 0.0, 0.0),
               width: MediaQuery.of(context).size.width,
               height: MediaQuery.of(context).size.height,
-              child: RTCVideoView(_localRenderer, mirror: true),
               decoration: BoxDecoration(color: Colors.black54),
+              child: RTCVideoView(_localRenderer, mirror: true),
             ),
           );
         },

example/lib/src/loopback_sample.dart

@@ -106,6 +106,9 @@ class _MyAppState extends State<LoopBackSample> {
 
   void _onTrack(RTCTrackEvent event) {
     print('onTrack');
+    if (event.track.kind == 'video') {
+      _remoteRenderer.srcObject = event.streams[0];
+    }
   }
 
   void _onAddTrack(MediaStream stream, MediaStreamTrack track) {