Improved i18n key input for X11. Which means languages like cyrillic work now.

Japanese not yet, but we're even a little closer to that now.
Dead-key handling is not working. I just can't figure it out (X11 documentation and examples make me swear badly).
Users which have language input with dead-keys (like ^) will now have those characters always ignored.
Before it had just printed the characters but set a complete wrong key-code. So dead keys partly better, partly worse.
But this solution is going in the right direction. Either we figure out later why X11 doesn't handle dead-keys or we handle them ourselves.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4743 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

 --------------------------
 Changes in 1.9 (not yet released)
 
+- Improved i18n key input for X11 (languages like cyrillic work now).
 - Fix bug that ListBox would not allow to 'tab' to the next element (thx @ FlavourBoat for reporting)
 - IGUIEnvironment::getNextElement now public (was only in CGUIEnvironment before).
 - Add an overwrite mode to editbox. Patch provided by Adam(aka kingadami).
@@ -12,7 +13,7 @@ Changes in 1.9 (not yet released)
 - Fix c::b project obj folder names. Some static builds had used the shared folders (thx @ gerdb for reporting)
 - Add ITexture::getSource which can be used to check where the last IVideoDriver::getTexture call found the texture.
 - Add IMeshTextureLoader interface and replace texture-loading algorithms in most meshloaders.
-- CGUICheckBox no longer gives up focus on EMIE_LMOUSE_LEFT_UP (thx @Demre for reporting)
+- CGUICheckBox no longer gives up focus on EMIE_LMOUSE_LEFT_UP (thx @Demre and @REDDemon for reporting)
 - Bugfix: IGUIElement::addChild now prevents setting an element as it's own child.
 - GUI editor improvements (prevent crash, improve UI)
 - Add IrrlichtDevice::setWindowSize. 

include/IEventReceiver.h

@@ -315,7 +315,7 @@ struct SEvent
 	//! Any kind of keyboard event.
 	struct SKeyInput
 	{
-		//! Character corresponding to the key (0, if not a character)
+		//! Character corresponding to the key (0, if not a character, value undefined in key releases)
 		wchar_t Char;
 
 		//! Key which has been pressed or released

source/Irrlicht/CIrrDeviceLinux.h

@@ -157,6 +157,12 @@ namespace irr
 
 		bool switchToFullscreen(bool reset=false);
 	
+#ifdef _IRR_COMPILE_WITH_X11_	
+		bool createInputContext();
+		void destroyInputContext();
+		EKEY_CODE getKeyCode(XEvent &event);
+#endif	
+
 		//! Implementation of the linux cursor control
 		class CCursorControl : public gui::ICursorControl
 		{
@@ -394,6 +400,8 @@ namespace irr
 		XSetWindowAttributes attributes;
 		XSizeHints* StdHints;
 		XImage* SoftwareImage;
+		XIM XInputMethod;
+		XIC XInputContext;
 		mutable core::stringc Clipboard;
 		#ifdef _IRR_LINUX_X11_VIDMODE_
 		XF86VidModeModeInfo oldVideoMode;