Mouse wheel bindings have always been a cause of user confusion.
Previously, on Wayland and macOS, precise touchpads would generate AXIS
keycodes and notched mouse wheels would generate mouse button keycodes.
On Windows, both types of device would generate AXIS keycodes and on
X11, both types of device would generate mouse button keycodes. This
made it pretty difficult for users to modify their mouse-wheel bindings,
since it differed between platforms and in some cases, between devices.
To make it more confusing, the keycodes used on Windows were changed in
18a45a42d5 without a deprecation period or adequate communication to
users.
This change aims to make mouse wheel binds less confusing. Both the
mouse button and AXIS keycodes are now deprecated aliases of the new
WHEEL keycodes. This will technically break input configs on Wayland and
macOS that assign different commands to precise and non-precise scroll
events, but this is probably uncommon (if anyone does it at all) and I
think it's a fair tradeoff for finally fixing mouse wheel-related
confusion on other platforms.
mpv's mouse button numbering is based on X11 button numbering, which
allows for an arbitrary number of buttons and includes mouse wheel input
as buttons 3-6. This button numbering was used throughout the codebase
and exposed in input.conf, and it was difficult to remember which
physical button each number actually referred to and which referred to
the scroll wheel.
In practice, PC mice only have between two and five buttons and one or
two scroll wheel axes, which are more or less in the same location and
have more or less the same function. This allows us to use names to
refer to the buttons instead of numbers, which makes input.conf syntax a
lot easier to remember. It also makes the syntax robust to changes in
mpv's underlying numbering. The old MOUSE_BTNx names are still
understood as deprecated aliases of the named buttons.
This changes both the input.conf syntax and the MP_MOUSE_BTNx symbols in
the codebase, since I think both would benefit from using names over
numbers, especially since some platforms don't use X11 button numbering
and handle different mouse buttons in different windowing system events.
This also makes the names shorter, since otherwise they would be pretty
long, and it removes the high-numbered MOUSE_BTNx_DBL names, since they
weren't used.
Names are the same as used in Qt:
https://doc.qt.io/qt-5/qt.html#MouseButton-enum
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.
There was a complaint that the naming is inaccurate. That's probably
right. Just use the official name instead, which is a bit clunky, but
surely correct.
Why did this exist in the first place? Other than being completely
useless, this even caused some regressions in the past. For example,
there was the case of a laptop exposing its accelerometer as joystick
device, which led to extremely fun things due to the default mappings of
axis movement being mapped to seeking.
I suppose those who really want to use their joystick to control a media
player (???) can configure it as mouse device or so.
bstr.c doesn't really deserve its own directory, and compat had just
a few files, most of which may as well be in osdep. There isn't really
any justification for these extra directories, so get rid of them.
The compat/libav.h was empty - just delete it. We changed our approach
to API compatibility, and will likely not need it anymore.
"Shift+X" didn't actually map any key, as opposed to "Shift+x". This is
because shift usually changes the case of a character, so a plain
printable character like "X" simply can never be combined with shift.
But this is not very intuitive. Always remove the shift code from
printable characters. Also, for ASCII, actually apply the case mapping
to uppercase characters if combined with shift. Doing this for unicode
in general would be nice, but that would require lookup tables. In
general, we don't know anyway what character a key produces when
combined with shift - it could be anything, and depends on the keyboard
layout.
