bluetooth "pause" control only works if window active

[brainchild0]

Description

A "pause" signal produced a Bluetooth device operating as the active sound device causes playback to pause, but only if the application window playing the media has the focus from the window manager. The application should respond equally to the signal regardless of the window status.

Steps to Reproduce

1. Connect a Bluetooth audio device that has support for the Bluetooth "pause" signal as sound device.
2. Open audio file, or video file with sound, in application.
3. Begin playback.
4. Keeping application window active, that is, with the focus from window manager, pause playback using the Bluetooth device. Confirm that playback is paused.
5. Resume playback.
6. Bring alternative window to front.
7. Attempt to pause playback as before. Confirm that playback continues.

Actual Results

Playback continues.

Expected Results

Playback pauses.

Version

• Celluoid 0.20
• Linux Mint 20.1
• Cinnamon 4.8.6
• Pulseaudio 13.99.1
• BlueZ 5.53
• ALSA 1.0.25