The clipboard.read_text_finish method might throw an error when something goes wrong. Catch it and print in debug message. There is no alternative clipboard reading, so simply ignore.
D&D folder with videos onto Clapper window to play them as video playlist. If folder contains exactly one video and subtitle file, then that video will be played with subtitles automatically applied.
Play video with external subtiles by:
* selecting and opening both video+subs from file chooser/manager
* dropping subtitles file on player window
* opening subtiles from file chooser/manager while video plays
* send their file path/uri to player via WebSocket message
The "clapper_src" directory name was unusual. This was done to make it work as a widget for other apps. Now that this functionality got removed it can be named simply "src" as recommended by guidelines.