Otherwise window.frame.height will always be 72, which is the height without the video view. This incorrect height will affect later calucations.

• I have read CONTRIBUTING.md
• This probably implements/fixes issue Playlist/Chapters no longer shows automatically in Music mode #4088.

Analysis

When I was tracking down the issue #4088, I found that in PlayerCore.switchToMiniPlayer, the videoView is removed from the main window and added into the mini player. However, even through constraints are set correctly, the window frame is not updated immediately, and the window height will be 72 throughout the function PlayerCore.switchToMiniPlayer.

When trying to restore the layout of the mini player, .musicModeShowAlbumArt is firstly tested, but miniPlayer.toggleVideoView() is not called, in which we manually set the window frame. This is because the default behavior is album art being shown (var isVideoVisible = true). So the window frame height is still 72.

After that, if .musicModeShowPlaylist is true, we will call miniPlayer.togglePlaylist(). When it wants to show the playlist, it uses window.frame to get the current window size (in our case it is still 72) and then calculate the new height, which is the height with the playlist. After setting the frame with the calculated new height and done the window resizing animation, the system will call windowDidEndLiveResize().

if window.frame.height < normalWindowHeight() + AutoHidePlaylistThreshold

In here, the left hand size is 72 + DefaultPlaylistHeight = 372.

private func normalWindowHeight() -> CGFloat {
  return 72 + (isVideoVisible ? videoWrapperView.frame.height : 0)
}

On the right hand side, the normalWindowHeight() is calculated based on isVideoVisible, which is always true by default, even if the window frame is not updated with videoWrapperView.frame.height, normalWindowHeight() incorrectly includes the height of the video. This will cause our window height not exceeding the threshold and make it automatically collapse the playlist.

Solution

After setting up the constraints for video in the mini player, I manually layout the mini player, so that the window frame got updated immediately (should be 72 + height of the video), so that in windowDidEndLiveResize() the window height is correct, which will pass the threshold thus will not trigger a collapse.

I'm not sure whether this will fix #4088 but it at least fix some part of that issue.