Mercurial > sdl-ios-xcode
view README.WinCE @ 4384:6800e2560310 SDL-1.2
Fixed bugs #882 and 865, re-opening bug #634
Ronald Lamprecht to SDL
Hi,
Sam Lantinga wrote:
The problem with that fix is that it breaks IME events again. Maybe
we can handle keyboard events differently to prevent this issue?
Spending an hour reading MSDN, analysing SDL and another hour testing the reality on XP I am really wondering how patch r4990 could have ever worked in any situation. It's main effect is to break the unicode translation and causing spurious activation events!
Why does TranslateMessage(&msg) nothing useful? Simply because it does not affect "msg" at all! All keyboard events are dispatched without the slightest change (see MSDN). TranslateMessage() just appends additional WM_CHAR, WM_DEADCHAR, WM_SYSCHAR, WM_SYSDEADCHAR event messages to the queue. But I could not find any SDL event handling routine that catches these events and transforms them to proper SDL keyevents while eliminating the corresponding WM_KEYDOWN, etc. events. Thus any IME input like the '@' generated by "Alt + 6(Numpad) + 4(Numpad)" is simply lost.
But the situation is even worse! Up to r4990 the TranslateKey()/ToUnicode() calls did evaluate dead keys and did deliver proper key events for subsequent key strokes like '´' + 'e' resulting in 'é'. ToUnicode() needs proper key state informations to be able to handle these substitutions. But unfortunatly TranslateMessage() needs the same state information and eats it up while generating the WM_CHAR messages :-( Thus the current 1.2.14 breakes the partial IME support of previous releases, too.
The key state race condition between ToUnicode() and TranslateMessage() requires to avoid any ToUnicode() usage for receiving proper WM_CHAR, etc. messages generated by TranslateMessage(). (Yes - the '@' and 'é' appear as WM_CHAR messages when unicode is switched off).
The spurious SDL activation events are *not* caused by additional WM_ACTIVATE Windows messages! Besides DIB_HandleMessage() SDL_PrivateAppActive() is called by another source which I am not yet aware of - any hints?
Thus I do strongly recommend the deletion of the TranslateMessage(&msg) call as a quick fix.
A proper support of unicode and IME requires a clean SDL keyboard input concept first. Which SDL keyboards events should be transmitted to the app when the user presses '´' + 'e' ? Within the current unicode handling the first key stroke is hidden. Even though ToUnicode() delivers the proper key SDL does ignore it in TranslateKey(). Just the composed key event is transmitted to the app. That is what you expect for text input, but the app can no longer use keys like '^' as a key button because it will never receive a key event for it!
With a given concept it seems to be necessary to regenerate SDL key events out of the WM_CHAR, etc. events and to drop all related direct WM_KEYDOWN, etc. events while the remaining basic WM_KEYDOWN, etc. events would still have to result in SDL key events.
Anyway the source of the spurious WM_ACTIVATE should be located to avoid future trouble.
Greets,
Ronald
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 17 Nov 2009 04:59:13 +0000 |
parents | 86d0d01290ea |
children |
line wrap: on
line source
Project files for embedded Visual C++ 3.0, 4.0 and Visual Studio 2005 can be found in VisualCE.zip SDL supports GAPI and WinDib output for Windows CE. GAPI driver supports: - all possible WinCE devices (Pocket PC, Smartphones, HPC) with different orientations of video memory and resolutions. - 4, 8 and 16 bpp devices - special handling of 8bpp on 8bpp devices - VGA mode, you can even switch between VGA and GAPI in runtime (between 240x320 and 480x640 for example). On VGA devices you can use either GAPI or VGA. - Landscape mode and automatic rotation of buttons and stylus coordinates. To enable landscape mode make width of video screen bigger than height. For example: SDL_SetVideoMode(320,240,16,SDL_FULLSCREEN) - WM2005 - SDL_ListModes NOTE: There are several SDL features not available in the WinCE port of SDL. - DirectX is not yet available - Semaphores are not available - Joystick support is not available - CD-ROM control is not available In addition, there are several features that run in "degraded" mode: Preprocessor Symbol Effect =================== ================================= SDL_systimer.c: USE_GETTICKCOUNT Less accurate values for SDL time functions USE_SETTIMER Use only a single marginally accurate timer SDL_syswm.c: DISABLE_ICON_SUPPORT Can't set the runtime window icon SDL_sysmouse.c: USE_STATIC_CURSOR Only the arrow cursor is available SDL_sysevents.c: NO_GETKEYBOARDSTATE Can't get modifier state on keyboard focus SDL_dibevents.c: NO_GETKEYBOARDSTATE Very limited keycode translation SDL_dibvideo.c: NO_GETDIBITS Can't distinguish between 15 bpp and 16 bpp NO_CHANGEDISPLAYSETTINGS No fullscreen support NO_GAMMA_SUPPORT Gamma correction not available