ScrCpy Should Support Android Shortcut Keys

[xcjs]

• I have checked that a similar feature request does not already exist.

There are requests for custom keymaps, but I feel that these mappings should just work.

Is your feature request related to a problem? Please describe.
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I'm frustrated that keys on my keyboard don't map to Android the same way that bluetooth keyboards do.

Describe the solution you'd like
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Certain keys on Android trigger specific actions:

Home: Navigates to the default configured Android launcher
Esc: Equivalent to the Back button
Media keys: My keyboard has a dedicated set of volume keys (up, down, and mute) that typically work on Android keyboards. Some keyboards also have dedicated key codes for play/pause, skip, and previous track that should also work in Android. It would be nice if these work as expected.

I would like these key codes to work as they normally would if passed forward to an Android device.

Describe alternatives you've considered
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The alternative is not having the feature as I don't see any other way to get this to work.

Additional context
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[rom1v]

Home: Navigates to the default configured Android launcher

Home is now bound to MOVE_HOME to be consistent with MOVE_END: 5d473ef (#555).

MOD+h or middle-click pressed HOME.

Esc: Equivalent to the Back button

Esc injects ESCAPE (like adb shell input keyevent ESCAPE). It often has the same effect as BACK, but not always.

Media keys: My keyboard has a dedicated set of volume keys (up, down, and mute) that typically work on Android keyboards. Some keyboards also have dedicated key codes for play/pause, skip, and previous track that should also work in Android. It would be nice if these work as expected.

Refs #1824

If you want to work on it, please add the mapping here (on dev branch):

scrcpy/app/src/event_converter.c

Lines 80 to 99 in adc547f

	switch (from) {
	MAP(SDLK_RETURN, AKEYCODE_ENTER);
	MAP(SDLK_KP_ENTER, AKEYCODE_NUMPAD_ENTER);
	MAP(SDLK_ESCAPE, AKEYCODE_ESCAPE);
	MAP(SDLK_BACKSPACE, AKEYCODE_DEL);
	MAP(SDLK_TAB, AKEYCODE_TAB);
	MAP(SDLK_PAGEUP, AKEYCODE_PAGE_UP);
	MAP(SDLK_DELETE, AKEYCODE_FORWARD_DEL);
	MAP(SDLK_HOME, AKEYCODE_MOVE_HOME);
	MAP(SDLK_END, AKEYCODE_MOVE_END);
	MAP(SDLK_PAGEDOWN, AKEYCODE_PAGE_DOWN);
	MAP(SDLK_RIGHT, AKEYCODE_DPAD_RIGHT);
	MAP(SDLK_LEFT, AKEYCODE_DPAD_LEFT);
	MAP(SDLK_DOWN, AKEYCODE_DPAD_DOWN);
	MAP(SDLK_UP, AKEYCODE_DPAD_UP);
	MAP(SDLK_LCTRL, AKEYCODE_CTRL_LEFT);
	MAP(SDLK_RCTRL, AKEYCODE_CTRL_RIGHT);
	MAP(SDLK_LSHIFT, AKEYCODE_SHIFT_LEFT);
	MAP(SDLK_RSHIFT, AKEYCODE_SHIFT_RIGHT);
	}

[guanzhangrtk]

[Edit: Actually on the Mac seems the MOD button is alt/option instead of command, so it is actually working as intended]

Do these shortcut keys work on the Mac? Command-H seems to be able to bring you back to HOME however these shortcut keys seems to conflict with Mac internal shortcut keys (for instance command-H is hide program).

Thanks!

[rom1v]

Actually on the Mac seems the MOD button is alt/option instead of command, so it is actually working as intended

Both Alt/Super trigger shortcuts, unless the system capture them before transmitting the key to scrcpy.

https://github.com/Genymobile/scrcpy#shortcuts