Re: [hatari-devel] Keyup bug in SDL GUI

[Andreas Grabher <andreas_g86@xxxxxxxxxx>]

> Am 29.11.2022 um 18:06 schrieb Andreas Grabher <andreas_g86@xxxxxxxxxx>:
> 
> 
> 
>> Am 29.11.2022 um 11:21 schrieb Andreas Grabher <andreas_g86@xxxxxxxxxx>:
>> 
>> 
>>> Am 02.11.2022 um 18:42 schrieb Thomas Huth <th.huth@xxxxxxxxx>:
>>> 
>>> Am Wed, 2 Nov 2022 10:06:50 +0100
>>> schrieb Andreas Grabher <andreas_g86@xxxxxxxxxx>:
>>> 
>>>>>> Am 31.10.2022 um 19:48 schrieb Eero Tamminen <oak@xxxxxxxxxxxxxx>:
>>>>> 
>>>>> Hi,
>>>>> 
>>>>>> On 31.10.2022 20.35, Andreas Grabher wrote:
>>>>>> I might have found a bug in the SDL GUI. This scenario:
>>>>>> In the guest operating system I confirm some action by pressing enter  
>>>>>> —> SDL_KEYDOWN with SDLK_RETURN  
>>>>>> Due to some bug in the OS I get a double fault, which then activates Dialog_HaltDlg() before I am able to release the key
>>>>>> I then release the key  
>>>>>> —> SDL_KEYUP with SDLK_RETURN  
>>>>>> At this time we are already in the SDL_WaitEvent()-Loop in SDLGui_DoDialogExt() and the event is recognized as key up in the GUI. This leads to automatically pressing the default button which exits the dialog without me having a chance to select anything.
>>>>>> Can you confirm this? This will be difficult to fix.  
>>>>> 
>>>>> You can wait until all keys are up, before starting accepting input in SDL GUI.
>>>>> 
>>>>> No notify user about this wait, you can show a note about keys being down in statusbar.
>>>>> 
>>>>> If SDL does not provide information about pressed keys, keymap.c keeps count of them.
>>>>> 
>>>>> 
>>>>> - Eero
>>>>> 
>>>> Maybe calling SDL_ResetKeyboard() before entering the SDL_WaitEvent()-loop would be the solution?
>>> 
>>> I don't think this would be the right fix - in case you still hold the key
>>> when the SDL_ResetKeyboard() is done, you still get the KEYUP event
>>> afterwards once the key is released. I think you have to something like
>>> this (untested):
>>> 
>>> const Uint8 *keys = SDL_GetKeyboardState();
>>> while (keys[SDLK_RETURN])
>>>   SDL_PumpEvents();
>>> 
>>> HTH,
>>> Thomas
>>> 
>> I just read through the SDL code a bit and I think it should work with SDL_ResetKeyboard(). That function will send KEYUP event for all pressed keys. Releasing a key afterwards won‘t send another KEYUP event until the key is pressed again.
>> 
>> This should fix the issue:
>> SDL_ResetKeyboard();
>> SDL_PumpEvents();
>> SDL_FlushEvent(SDL_KEYUP);
>> 
>> I have some more keyboard issues. Calling host routines can cause stuck keys, especially stuck modifiers. Not sure how this can be fixed. 
>> 
> I can now confirm that the SDL_ResetKeyboard() function works as expected. There is no KEYUP event afterwards except if i hold the key long enough to trigger key repeat. Maybe repeated key events should also be ignored in the GUI code. 
> 
I found a way to improve things in Previous (getting modifier keys from sdlkey.mod and calling SDL_ResetKeyboard() in Main_UnPauseEmulation()). It seems Hatari works differently. Maybe this function helps:

struct {
	SDL_Scancode scancode;
	SDL_Keycode keycode;
} mainModifiers[] = {
	{ SDL_SCANCODE_LCTRL,  SDLK_LCTRL  },
	{ SDL_SCANCODE_LSHIFT, SDLK_LSHIFT },
	{ SDL_SCANCODE_RSHIFT, SDLK_RSHIFT },
	{ SDL_SCANCODE_LGUI,   SDLK_LGUI   },
	{ SDL_SCANCODE_RGUI,   SDLK_RGUI   },
	{ SDL_SCANCODE_LALT,   SDLK_LALT   },
	{ SDL_SCANCODE_RALT,   SDLK_RALT   }
};

void Main_ResetModifierKeys(void) {
	SDL_Event event;

	/* Release all modifiers */
	for (int i = 0; i < ARRAY_SIZE(mainModifiers); i++) {
		event.type = SDL_KEYUP;
		event.key.keysym.scancode = mainModifiers[i].scancode;
		event.key.keysym.sym      = mainModifiers[i].keycode;
		SDL_PushEvent(&event);
	}
	/* Release all other keys */
	SDL_ResetKeyboard();
}


The modifier list is made for NeXT keyboards. It might need some modification to work for Atari keyboards.