Avalonia: VideoView Content Bug

Summary

Found an issue with VideoView.UpdateOverlayPosition() not being called in certain circumstances when it should be. The bug is shown here where the unmodified VideoView's content remains in-place despite the changing layout:

Example

It only seems to occur when the view is shifted, it works properly on resizing and with window adjustments/drags. Note that it is only the VideoView Content that fails to update: the video playback window adjusts correctly.

Minimal project and steps to reproduce

The reproduced example and found solution can be found here. I discovered it like it is shown in the example, with the VideoView nested in two grids:

  <!-- Set up so that the left splitter shifts and the right one resizes -->
  <!-- Right Border, Splitter, VideoView, Splitter, Left Border-->
  <Grid ColumnDefinitions="50, 7, 500, 7, *">
        <Panel Grid.Column="0">...

        <GridSplitter Grid.Column="1">...

        <Grid Grid.Column="2" RowDefinitions="*">

            <vlc:VideoView Grid.Row="1">
                <Panel>...
            </vlc:VideoView>

        </Grid>

        <GridSplitter Grid.Column="3">...

        <Panel Grid.Column="4">...
  </Grid>

Though there may be more circumstances where it is a problem.

What is the current bug behavior?

VideoView.Content is not updated when shifted by grids.

What is the expected correct behavior?

VideoView.Content moves with the VideoView window/control.

Environment

• OS: Manjaro Linux (Wayland)
• Version 6.10.13-3-MANJARO
• Avalonia 11.1.0
• LibVLC 3.0.21, x64
• LibVLCSharp 3.9.0

Possible fixes

The fixes I found are located here. Changes are to line 83, and 219-221

1. Adding an event handler for VideoView.Visual.LayoutUpdated in InitializeNativeOverlay().
2. Removing event handler for Visual.BoundsProperty.Changed as it's no longer needed.
3. Adding to the guard clause in UpdateOverlayPosition() so LayoutUpdated doesn't pelt a IsVisible = false VideoView with updates; Layout is updated on being made visible.

changed the description

Hi,

thanks for the report! Please open a PR at https://github.com/videolan/libvlcsharp.

Side node: Have you had no problems integrating the video view with Wayland? libvlc only supports X11 currently.

added avalonia bug labels

Will do!

Haven't found any libvlcSharp or Avalonia.VideoView Wayland issues. But, and only over Bluetooth, libvlc has audio stuttering at the start of playback which affects all instances of VLC. I haven't tested it very much but that doesn't seem happen in X11 on the same install.

Haven't found any libvlcSharp or Avalonia.VideoView Wayland issues

Hmm that's weird coz Wayland is not supported in libvlc... See #644 (closed) from just yesterday. Which desktop environment are you using?

But, and only over Bluetooth, libvlc has audio stuttering at the start of playback which affects all instances of VLC

You may find more info about this in verbose libvlc logs.

KDE Plasma 6.1.5

I'll let you know if I find anything interesting in the logs for BT/Speaker playback.

closed with commit 9d363bee

mentioned in commit bd396c33