Add clearSystemMessages to IrrlichtDevices (implemented only for Win32 and Linux so far).

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3051 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,5 +1,7 @@
 Changes in 1.7
 
+ - Add clearSystemMessages to devices (implemented only for Linux and Win32 so far).
+ 
  - Fix incorrect cursorpos for resizable windows on Windows Vista (found and patched by buffer)
 
  - Change the beginScene window parameter from void* to SExposedVideoData&. This will allow to manage contexts for OpenGL at some point.

include/IrrlichtDevice.h

@@ -237,6 +237,18 @@ namespace irr
 		virtual bool getGammaRamp(f32 &red, f32 &green, f32 &blue,
 					f32 &brightness, f32 &contrast) =0;
 
+		//! Remove all messages pending in the system message loop
+		/** This function is usually used after messages have been buffered for a longer time, for example
+		when loading a large scene. Clearing the message loop prevents that mouse- or buttonclicks which users
+		have pressed in the meantime will now trigger unexpected actions in the gui. <br>
+		So far the following messages are cleared:<br>
+		Win32: All keyboard and mouse messages<br>
+		Linux: All messages<br>
+		All other devices are not yet supported here.<br>
+		The function is still somewhat experimental, as the kind of messages we clear is based on just a few use-cases.
+		If you think further messages should be cleared, or some messages should not be cleared here, then please tell us. */
+		virtual void clearSystemMessages() = 0;
+
 		//! Get the type of the device.
 		/** This allows the user to check which windowing system is currently being
 		used. */

source/Irrlicht/CIrrDeviceLinux.cpp

@@ -1814,6 +1814,21 @@ void CIrrDeviceLinux::copyToClipboard(const c8* text) const
 #endif
 }
 
+//! Remove all messages pending in the system message loop
+void CIrrDeviceLinux::clearSystemMessages()
+{
+#ifdef _IRR_COMPILE_WITH_X11_
+	if (CreationParams.DriverType != video::EDT_NULL)
+	{
+		XEvent event;
+		while (XPending(display) > 0 )
+		{
+			XNextEvent(display, &event);
+		}
+	}
+#endif //_IRR_COMPILE_WITH_X11_
+}
+
 void CIrrDeviceLinux::initXAtoms()
 {
 #ifdef _IRR_COMPILE_WITH_X11_

source/Irrlicht/CIrrDeviceLinux.h

@@ -116,6 +116,9 @@ namespace irr
 		//! This sets the clipboard selection and _not_ the primary selection which you have on X on the middle mouse button.
 		virtual void copyToClipboard(const c8* text) const;
 
+		//! Remove all messages pending in the system message loop
+		virtual void clearSystemMessages();
+
 		//! Get the device type
 		virtual E_DEVICE_TYPE getType() const
 		{

source/Irrlicht/CIrrDeviceStub.cpp

@@ -352,6 +352,12 @@ u32 CIrrDeviceStub::getDoubleClickTime() const
 	return MouseMultiClicks.DoubleClickTime;
 }
 
+//! Remove all messages pending in the system message loop
+void CIrrDeviceStub::clearSystemMessages()
+{
+}
+
+
 
 } // end namespace irr
 

source/Irrlicht/CIrrDeviceStub.h

@@ -123,6 +123,10 @@ namespace irr
 		//! Get the maximal elapsed time between 2 clicks to generate double- and tripleclicks for the mouse.
 		virtual u32 getDoubleClickTime() const;
 
+		//! Remove all messages pending in the system message loop
+		virtual void clearSystemMessages();
+
+
 	protected:
 
 		void createGUIAndScene();

source/Irrlicht/CIrrDeviceWin32.cpp

@@ -1185,6 +1185,16 @@ bool CIrrDeviceWin32::getGammaRamp( f32 &red, f32 &green, f32 &blue, f32 &bright
 
 }
 
+//! Remove all messages pending in the system message loop
+void CIrrDeviceWin32::clearSystemMessages()
+{
+	MSG msg;
+	while (PeekMessage(&msg, NULL, WM_KEYFIRST, WM_KEYLAST, PM_REMOVE))
+	{}
+	while (PeekMessage(&msg, NULL, WM_MOUSEFIRST, WM_MOUSELAST, PM_REMOVE))
+	{}
+}
+
 // shows last error in a messagebox to help internal debugging.
 void CIrrDeviceWin32::ReportLastWinApiError()
 {

source/Irrlicht/CIrrDeviceWin32.h

@@ -87,6 +87,9 @@ namespace irr
 		//! Get the current Gamma Value for the Display
 		virtual bool getGammaRamp( f32 &red, f32 &green, f32 &blue, f32 &brightness, f32 &contrast );
 
+		//! Remove all messages pending in the system message loop
+		virtual void clearSystemMessages();
+
 		//! Get the device type
 		virtual E_DEVICE_TYPE getType() const
 		{