Dictionary
valid song - a song is valid if it exists and is playable
existing song - a local media file that's on your disk or a stream that is reachable at the moment
playable song - a media file or stream with a format that your GStreamer's installation understands and can play
General rule
A general rule is to grey out a song in the playlist if it's not valid. Also, if a song was once invalid and at some point it becomes valid again, we want it to be repainted black.
Be aware that we are NOT monitoring your playlist items in the background hence you won't see any unexpected "flickering" of colors in your playlists. All the factors that might trigger a change of colors are described below.
Built-in features
Playing a once valid song
Whenever you try to play a song that was once valid, Clementine will check if the file or stream is still valid.
If that's not the case, the item will be greyed out in the playlist view and Clementine will automatically jump to a next song.
All this applies to both manual and automatic playback requests.
Playing a once broken song
Whenever you try to play a song which was once broken and is hence greyed out, Clementine will recheck it's validity.
If the song is now valid again, it's metadata will be reloaded and the song will be repainted black in the playlist view. The playback will start normally and everything will look like there was nothing wrong with the file in the first place.
All this applies to both manual and automatic playback requests.
Startup of the player
If you have the "Grey out non existent songs in my playlists" setting on (check out the "Behavior" section of Clementine's settings), a scan of all your playlist items will be ran each time the player is started.
Clementine will scan all of your playlists and:
- all local songs that exist will be painted black
- all local songs that don't exist anymore will be greyed out
Please note that this cannot detect unplayable items - only deleted ones.
Even though the setting is turned off by default you shouldn't be afraid of turning it on. The scan is asynchronous and pretty lightweight.