Signed-off-by: Nnpes87184 <npes87184@gmail.com>

Send repeated events when holding volume up/down shortcuts.

Shortcuts generated instant DOWN/UP key events. Instead, generate DOWN
event on Ctrl+key down and UP event on Ctrl+key up.

Fixes <https://github.com/Genymobile/scrcpy/issues/166>.

Replace "implying" by "involving" (both "impliquant" in French).

I could not make Ctrl+'+' and Ctrl+'-' work for every keyboard on every
platform.

Instead, use Ctrl+UP and Ctrl+DOWN (like in VLC) to change the volume.

Fixes <https://github.com/Genymobile/scrcpy/issues/103>.

Double-clicks were not sent to the device anymore since the
"double-click on black borders" feature.

When a double click occurs inside the device screen, send the event to
the device normally.

Fixes <https://github.com/Genymobile/scrcpy/issues/97>.

Ctrl+s was mapped to MENU, while Ctrl+m was mapped to APP_SWITCH.

To avoid confusion, swap the shortcuts:
 - Ctrl+m like _M_enu
 - Ctrl+s like _S_witch

The action sends AKEYCODE_MENU, so just name it "menu".

See <https://github.com/Genymobile/scrcpy/pull/85>.

Mouse "wheel button" is meaningless :)

Resize the window to fit the device screen on click on black borders
(same as Ctrl+x).
Suggested-by: NGuillaume Roche <groche@genymobile.com>

Middle-click is useless in practice. Use it for HOME.

Right-click was used to turn the screen on. It did nothing when the
screen was already on.

Instead, in that case, press BACK (like Vysor).

Suggested by: <https://www.reddit.com/r/Android/comments/834zmr/introducing_scrcpy_an_app_to_display_and_control/dvfueft/>

Paste computer clipboard to the device on Ctrl+v.

The other direction (pasting the device clipboard to the computer) is
not implemented. It would require a communication channel from the
device to the computer, other than the socket used by the video stream.

Initializing with braces initializes the other fields to 0, which is not
necessary.

Initialize variables only when necessary.

SDL_MouseWheelEvent does not provide the mouse location, so we used
SDL_GetMouseState() to retrieve it.

Unfortunately, SDL_GetMouseState() returns a position expressed in the
window coordinate system while the position filled in SDL events are
expressed in the renderer coordinate system. As a consequence, the
scroll was not applied at the right position on the device.

Therefore, convert the coordinate system.

See <https://stackoverflow.com/questions/49111054/how-to-get-mouse-position-on-mouse-wheel-event>.

Disable FPS counter on start, and use Ctrl+i to enable/disable it.

The "screen control" handled user input, which happened to be only
used to control the screen.

The controller and screen were passed to every function. Instead, group
them in a struct input_manager.

The purpose is to add a new shortcut to enable/disable FPS counter. This
feature is not related to "screen control", and will require access to
the "frames" instance.

Use macros to wrap SDL_Log* functions with the "application" category.

Avoid to send the command twice, once on mouse down, once on mouse up.

Move the code handling user input from scrcpy.c to a separate file,
screencontrol.c.