Foreign keyboard handling issues

[dreammaster]

We've had two foreign keyboard related issues issues reported on the ScummVM bug tracker. I found the instructions in both kind of hard to understand, and with other priorities, I left them on the backburner for a while. But in both cases I realized they mention that the problems are also in your standalone engine as well, so I figured best to pass them onto you to review if they're legitimate bugs, or simply something that can't be fixed:
https://bugs.scummvm.org/ticket/12594
https://bugs.scummvm.org/ticket/12604

[ivan-mogilko]

I understand what the 12594 means, but it will be interesting to first find out if this is the engine's or game's behavior, because there's also a possibility that the game script has some kind of transliteration built in.

[ivan-mogilko]

There's a newer comment in scummvm's 12594 from HQ author, who confirms that this is a game's behavior.

EDIT: it also matches original behavior of a game exe.

[ivan-mogilko]

As for 12604, this is a long known issue in AGS; and I think the bug reporter explains correctly that:

For shortcuts to work as expected, raw keycodes should be used instead of keymap-translated keys

The thing is that changing anything there would likely affect any existing game which does key handling, because AGS script in the past did not make any difference between key as a raw key and key as a character. And if the game uses these keycodes for a custom text input, for example, changing their meaning would break that instead.

There have to be a way to approach this problem for the new versions of AGS, and separate way for backwards support.

1. For the new versions we might have to update key handling in script again. Since now we have a differentiation between on_key_press and on_text_input, perhaps a solution could be to let on_key_press get "raw keycodes" without keymap translation.
2. For the old games, maybe this could be done with some config setting, and setup for individual games; as frankly I doubt that we may predict whether game simply uses positional shortcuts, or a custom text input.

[ivan-mogilko]

For the future reference:
https://wiki.libsdl.org/SDL_Keycode
https://wiki.libsdl.org/SDL_Scancode

The scancode identifies the location of a key press and the corresponding SDL_Keycode gives that key press meaning in the context of the current keyboard layout.

For example, on a QWERTY keyboard Keycode and Scancode will be the same, but if using an AZERTY keyboard A should have A keycode and Q scancode, Z should have Z keycode and W scancode, and so forth.