According to MS documentation, an application should return TRUE from
WM_XBUTTONUP and WM_XBUTTONDOWN if it processes these messages.
DefWindowProc generates the WM_APPCOMMAND message when it processes the
WM_XBUTTONUP message, so if an application properly handles WM_XBUTTONUP
messages, extra WM_APPCOMMAND messages won't be generated.
Because mpv doesn't properly handle these messages,
WM_XBUTTONUP causes APPCOMMAND_BROWSER_BACKWARD to be generated, resulting
in duplicated keys and improper fix 438ead7a, which prevents the processing
of the appcommand from sources other than mouse clicks.
Fix this by following the documentation, and the back and forward
appcommands can be added.
x11 and wayland had a lot of multimedia keys mapped that were missing
on windows.
Now the only ones they map that windows doesn't are `MP_KEY_WWW`,
`MP_KEY_ZOOMIN` and `MP_KEY_ZOOMOUT`, which apparently don't have any
equivalent ones on windows.
So far all the keypad keys except for `0` and `,` mapped to the same
MP_KEY_* independent of numlock state, even though different key codes
are received.
Now all the alternative functions map to appropriate MP_KEY_* defines,
with missing ones added.
This was attempted before in fc9695e63b, but it was reverted in
1b7ce759b1 because it caused conflicts with other software watching
the same keys (See #2041.) It seems like some PCs ship with OEM software
that watches the volume keys without consuming key events and this
causes them to be handled twice, once by mpv and once by the other
software.
In order to prevent conflicts like this, use the WM_APPCOMMAND message
to handle media keys. Returning TRUE from the WM_APPCOMMAND handler
should indicate to the operating system that we consumed the key event
and it should not be propogated to the shell. Also, we now only listen
for keys that are directly related to multimedia playback (eg. the
APPCOMMAND_MEDIA_* keys.) Keys like APPCOMMAND_VOLUME_* are ignored, so
they can be handled by the shell, or by other mixer software.
This reverts commit fc9695e63b.
Users were complaining that both mpv and something else (what? I don't
know) respond to some multimedia keys, such as volume change.
