provide WM with hint about splash window's purpose under wxGTK2

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@28238 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/splash.cpp

@@ -22,6 +22,10 @@
 
 #if wxUSE_SPLASH
 
+#ifdef __WXGTK20__
+    #include <gtk/gtk.h>
+#endif
+
 #ifndef WX_PRECOMP
 #include "wx/dcmemory.h"
 #include "wx/dcclient.h"
@@ -29,6 +33,7 @@
 
 #include "wx/splash.h"
 
+
 /*
  * wxSplashScreen
  */
@@ -50,6 +55,11 @@ END_EVENT_TABLE()
 wxSplashScreen::wxSplashScreen(const wxBitmap& bitmap, long splashStyle, int milliseconds, wxWindow* parent, wxWindowID id, const wxPoint& pos, const wxSize& size, long style):
     wxFrame(parent, id, wxEmptyString, wxPoint(0, 0), wxSize(100, 100), style)
 {
+#ifdef __WXGTK20__
+    gtk_window_set_type_hint(GTK_WINDOW(m_widget),
+                             GDK_WINDOW_TYPE_HINT_SPLASHSCREEN);
+#endif
+    
     m_window = NULL;
     m_splashStyle = splashStyle;
     m_milliseconds = milliseconds;