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Bug 3332 - [patch] Win32: reset deadkeys in StartTextInput/StopTextInput
Summary: [patch] Win32: reset deadkeys in StartTextInput/StopTextInput
Status: RESOLVED FIXED
Alias: None
Product: SDL
Classification: Unclassified
Component: events (show other bugs)
Version: HG 2.1
Hardware: x86_64 Windows (All)
: P2 normal
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-05-11 07:00 UTC by Eric Wasylishen
Modified: 2016-10-01 19:19 UTC (History)
1 user (show)

See Also:

Attachments
patch to test program to demonstrate the bug (713 bytes, patch)
2016-05-11 07:00 UTC, Eric Wasylishen 		Details | Diff
proposed fix (1.42 KB, patch)
2016-05-11 07:02 UTC, Eric Wasylishen 		Details | Diff
patch for SDL 1.2 (1.79 KB, patch)
2016-05-24 21:39 UTC, Eric Wasylishen 		Details | Diff
Updated sdl2 patch (2.24 KB, patch)
2016-05-25 22:32 UTC, Eric Wasylishen 		Details | Diff
Updated sdl1.2 patch (1.90 KB, patch)
2016-05-25 22:33 UTC, Eric Wasylishen 		Details | Diff
Show Obsolete (2) View All Add an attachment (proposed patch, testcase, etc.)

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Description Eric Wasylishen 2016-05-11 07:00:20 UTC 
Created attachment 2451 [details]
patch to test program to demonstrate the bug

The bug here is that a dead keys pressed before calling SDL_StartTextInput() carries over into future text input, so the next key pressed will have the deadkey applied to it.

This in undesirable, imho, and doesn't occur on OS X (haven't check Linux or elsewhere). It's causing a problem for Quakespasm on German keyboard layouts, where we use the ^ deadkey to toggle the console (which enables/disables text input), and ^ characters are showing up in the TEXTINPUT events.



Attaching a patch. Unfortunately there's no clean API to reset the dead key state, the only way appears to be using ToUnicode.

Also attached a patch to the checkkeys sample so you can reproduce this; it makes clicking the mouse toggle SDL_StartTextInput() and SDL_StopTextInput().

Steps to reproduce with the patched 'checkkeys':
1. switch to a keyboard layout with deadkeys, e.g. German
2. launch "checkkeys", click the mouse to disable text input
3. press the a deadkey, e.g. ^ below Escape on the German layout
4. click the mouse again to cause a SDL_StartTextInput() call
5. press "a" key. 
expected: the TEXTINPUT event in the log should just be a regular "a"
observed: the "a" has an accent
Comment 1 Eric Wasylishen 2016-05-11 07:02:02 UTC 
Created attachment 2452 [details]
proposed fix
Comment 2 Eric Wasylishen 2016-05-24 21:39:18 UTC 
Created attachment 2462 [details]
patch for SDL 1.2
Comment 3 Eric Wasylishen 2016-05-25 22:32:27 UTC 
Created attachment 2463 [details]
Updated sdl2 patch

Updated SDL2 patch from Ozkan:
-make C89
-call WIN_ResetDeadKeys() from SDL_KeyboardQuit so dead keys pressed just before exiting don't carry over to other applications
Comment 4 Eric Wasylishen 2016-05-25 22:33:28 UTC 
Created attachment 2464 [details]
Updated sdl1.2 patch

Updated SDL1.2 patch from Ozkan, same changes as for SDL2
Comment 5 Sam Lantinga 2016-10-01 19:19:08 UTC 
Fixed, thanks!
I used a slightly different way of resetting dead keys on exit that also covers alt-tab away from the SDL window.

https://hg.libsdl.org/SDL/rev/e9dd9ecf3fe5
https://hg.libsdl.org/SDL/rev/9012ec687429