Skip to content
Permalink
Browse files

Fixed bug 2096 - Mapping from scancode to keycode doesn't work for re…

…mapped modifier keys

Jacob Lee

If a user has a non-standard keyboard mapping -- say, their caps lock key has been mapped to Ctrl -- then SDL_GetModState() is no longer accurate: it only considers the unmapped keys. This is a regression from SDL 1.2.

I think there are two parts to this bug: first, GetModState should use keycodes, rather than scancodes, which is easy enough.

Unfortunately, on my system, SDL considers Caps Lock, even when mapped as Control, to be both SDL_SCANCODE_CAPSLOCK and SDLK_CAPSLOCK. The output from checkkeys for it is:

INFO: Key pressed :  scancode 57 = CapsLock, keycode 0x40000039 = CapsLock  modifiers: CAPS

Whereas the output for xev is:

KeyPress event, serial 41, synthetic NO, window 0x4a00001,
    root 0x9a, subw 0x0, time 40218333, (144,177), root:(1458,222),
    state 0x10, keycode 66 (keysym 0xffe3, Control_L), same_screen YES,
    XKeysymToKeycode returns keycode: 37
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

I think the problem is that X11_UpdateKeymap in SDL_x11keyboard.c only builds a mapping for keycodes associated with a Unicode character (anything where X11_KeyCodeToUcs returns a value). In the case of caps lock, SDL scancode 57 becomes x11 keycode 66, which becomes x11 keysym 65507(Control_L), which does not have a unicode value.

To fix this, I suspect that SDL needs a mapping of the rest of the x11 keysyms to their corresponding SDL key codes.
  • Loading branch information
slouken committed May 28, 2015
1 parent 4d1626d commit 32d6dcdb47a8999f0dea6d7e91cbf15f6020fb3c
Showing with 59 additions and 79 deletions.
  1. +56 −77 src/events/SDL_keyboard.c
  2. +3 −2 src/video/x11/SDL_x11keyboard.c
@@ -662,6 +662,8 @@ SDL_SendKeyboardKey(Uint8 state, SDL_Scancode scancode)
{
SDL_Keyboard *keyboard = &SDL_keyboard;
int posted;
SDL_Keymod modifier;
SDL_Keycode keycode;
Uint16 modstate;
Uint32 type;
Uint8 repeat;
@@ -673,82 +675,6 @@ SDL_SendKeyboardKey(Uint8 state, SDL_Scancode scancode)
printf("The '%s' key has been %s\n", SDL_GetScancodeName(scancode),
state == SDL_PRESSED ? "pressed" : "released");
#endif
if (state == SDL_PRESSED) {
modstate = keyboard->modstate;
switch (scancode) {
case SDL_SCANCODE_NUMLOCKCLEAR:
keyboard->modstate ^= KMOD_NUM;
break;
case SDL_SCANCODE_CAPSLOCK:
keyboard->modstate ^= KMOD_CAPS;
break;
case SDL_SCANCODE_LCTRL:
keyboard->modstate |= KMOD_LCTRL;
break;
case SDL_SCANCODE_RCTRL:
keyboard->modstate |= KMOD_RCTRL;
break;
case SDL_SCANCODE_LSHIFT:
keyboard->modstate |= KMOD_LSHIFT;
break;
case SDL_SCANCODE_RSHIFT:
keyboard->modstate |= KMOD_RSHIFT;
break;
case SDL_SCANCODE_LALT:
keyboard->modstate |= KMOD_LALT;
break;
case SDL_SCANCODE_RALT:
keyboard->modstate |= KMOD_RALT;
break;
case SDL_SCANCODE_LGUI:
keyboard->modstate |= KMOD_LGUI;
break;
case SDL_SCANCODE_RGUI:
keyboard->modstate |= KMOD_RGUI;
break;
case SDL_SCANCODE_MODE:
keyboard->modstate |= KMOD_MODE;
break;
default:
break;
}
} else {
switch (scancode) {
case SDL_SCANCODE_NUMLOCKCLEAR:
case SDL_SCANCODE_CAPSLOCK:
break;
case SDL_SCANCODE_LCTRL:
keyboard->modstate &= ~KMOD_LCTRL;
break;
case SDL_SCANCODE_RCTRL:
keyboard->modstate &= ~KMOD_RCTRL;
break;
case SDL_SCANCODE_LSHIFT:
keyboard->modstate &= ~KMOD_LSHIFT;
break;
case SDL_SCANCODE_RSHIFT:
keyboard->modstate &= ~KMOD_RSHIFT;
break;
case SDL_SCANCODE_LALT:
keyboard->modstate &= ~KMOD_LALT;
break;
case SDL_SCANCODE_RALT:
keyboard->modstate &= ~KMOD_RALT;
break;
case SDL_SCANCODE_LGUI:
keyboard->modstate &= ~KMOD_LGUI;
break;
case SDL_SCANCODE_RGUI:
keyboard->modstate &= ~KMOD_RGUI;
break;
case SDL_SCANCODE_MODE:
keyboard->modstate &= ~KMOD_MODE;
break;
default:
break;
}
modstate = keyboard->modstate;
}

/* Figure out what type of event this is */
switch (state) {
@@ -775,6 +701,59 @@ SDL_SendKeyboardKey(Uint8 state, SDL_Scancode scancode)
/* Update internal keyboard state */
keyboard->keystate[scancode] = state;

keycode = keyboard->keymap[scancode];

/* Update modifiers state if applicable */
switch (keycode) {
case SDLK_LCTRL:
modifier = KMOD_LCTRL;
break;
case SDLK_RCTRL:
modifier = KMOD_RCTRL;
break;
case SDLK_LSHIFT:
modifier = KMOD_LSHIFT;
break;
case SDLK_RSHIFT:
modifier = KMOD_RSHIFT;
break;
case SDLK_LALT:
modifier = KMOD_LALT;
break;
case SDLK_RALT:
modifier = KMOD_RALT;
break;
case SDLK_LGUI:
modifier = KMOD_LGUI;
break;
case SDLK_RGUI:
modifier = KMOD_RGUI;
break;
case SDLK_MODE:
modifier = KMOD_MODE;
break;
default:
modifier = KMOD_NONE;
break;
}
if (SDL_KEYDOWN == type) {
modstate = keyboard->modstate;
switch (keycode) {
case SDLK_NUMLOCKCLEAR:
keyboard->modstate ^= KMOD_NUM;
break;
case SDLK_CAPSLOCK:
keyboard->modstate ^= KMOD_CAPS;
break;
default:
keyboard->modstate |= modifier;
break;
}
} else {
keyboard->modstate &= ~modifier;
modstate = keyboard->modstate;
}

/* Post the event, if desired */
posted = 0;
if (SDL_GetEventState(type) == SDL_ENABLE) {
@@ -783,7 +762,7 @@ SDL_SendKeyboardKey(Uint8 state, SDL_Scancode scancode)
event.key.state = state;
event.key.repeat = repeat;
event.key.keysym.scancode = scancode;
event.key.keysym.sym = keyboard->keymap[scancode];
event.key.keysym.sym = keycode;
event.key.keysym.mod = modstate;
event.key.windowID = keyboard->focus ? keyboard->focus->id : 0;
posted = (SDL_PushEvent(&event) > 0);
@@ -252,8 +252,7 @@ X11_InitKeyboard(_THIS)
#endif
SDL_memcpy(&data->key_layout[min_keycode], scancode_set[best_index].table,
sizeof(SDL_Scancode) * scancode_set[best_index].table_size);
}
else {
} else {
SDL_Keycode keymap[SDL_NUM_SCANCODES];

printf
@@ -316,6 +315,8 @@ X11_UpdateKeymap(_THIS)
key = X11_KeyCodeToUcs4(data->display, (KeyCode)i);
if (key) {
keymap[scancode] = key;
} else {
keymap[scancode] = SDL_SCANCODE_TO_KEYCODE(X11_KeyCodeToSDLScancode(data->display, (KeyCode)i));
}
}
SDL_SetKeymap(0, keymap, SDL_NUM_SCANCODES);

0 comments on commit 32d6dcd

Please sign in to comment.