[Scummvm-tracker] [ScummVM] #9617: Alt+Enter and other hotkeys are too sensitive

[Ori Avtalion]

#9617: Alt+Enter and other hotkeys are too sensitive
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Reporter:  salty-horse  |      Owner:
    Type:  defect       |     Status:  new
Priority:  normal       |  Component:  --Unset--
Keywords:               |       Game:
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 This is on Linux. Bug #9563 seems to describe totally different behavior
 on Windows/OSX.

 When I use either the SDL or OpenGL backends, pressing alt+enter will
 toggle the fullscreen setting several times, instead of just once. As long
 as alt+enter is held, it will keep toggling it. Even when I release ENTER
 very quickly, it still manages to toggle it a few times.

 This is bad. I would expect that if alt+enter is held, nothing will
 happen. It should only allow the next toggle after ENTER is released and
 then pressed again (assuming ALT is held).

 While investigating this I noticed that when we change resolutions, SDL
 sends a KEYUP event for keys that are currently held down.

 This means that pressing and holding ALT+ENTER for a moment will override
 any key delay code we have (where?) and call it several times. It also
 happens with CTRL+ALT+a which toggles aspect ratio.
 It does not happen with CTRL+ALT+f which toggles filtering. If you press
 that combination for a long time it will only toggle it a single time
 until you let go of 'F' and press it again.

 Why is this happening?

 This errant KEYUP event prevents any hacks around this problem. For
 example, I tried writing a hack to the SDL backend's handling of the
 fullscreen toggle to only allow it again once the enter key is released
 and pressed a second time. (See attachment). It works fine when I comment
 out `toggleFullScreen`, but the toggle actually happens, SDL (in
 `SdlEventSource::handleKeyUp`) sends a KEYUP event for ENTER without me
 having released it.

 Besides alt+enter, this behavior should also be implemented to the
 alt+ctrl+PLUS/MINUS that cycle between the scalers, and arguably for Alt+S
 which takes a screenshot. I wouldn't want to hold alt+s for a moment too
 long and take many screenshots. Any other relevant hotkeys I'm missing?

 Besides the SDL graphics backend, this should be implemented in the OpenGL
 backend. Their input-handling code has some similarities. Could they be
 merged?

 A related topic that I hope someone clarifies:
 ScummVM's keyboard events implement a 'repeat' flag, called 'synthetic',
 but it isn't set if I hold alt+enter. I couldn't quite figure out how it
 works. It seems to trigger only when the event queue is empty - but what
 prevents SDL from sending repeated KEYDOWN events if a key is continuously
 pressed?

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Ticket URL: <https://bugs.scummvm.org/ticket/9617>
ScummVM <https://bugs.scummvm.org>
ScummVM