get more accurate TLW sizing by using a window decorations cache

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@48646 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/taskbar.cpp

@@ -14,6 +14,9 @@
 
 #if wxUSE_TASKBARICON
 
+#include <gtk/gtkversion.h>
+#if GTK_CHECK_VERSION(2, 1, 0)
+
 #include "wx/gtk/taskbarpriv.h"
 
 #ifndef WX_PRECOMP
@@ -22,14 +25,9 @@
     #include "wx/menu.h"
 #endif
 
+#include <gtk/gtk.h>
 #include <gdk/gdkx.h>
 
-#ifdef __WXGTK20__
-#include <gtk/gtkversion.h>
-#if GTK_CHECK_VERSION(2, 1, 0)
-
-#include "gtk/gtk.h"
-
 #include "eggtrayicon.h"
 
 wxTaskBarIconAreaBase::wxTaskBarIconAreaBase()
@@ -73,6 +71,13 @@ bool wxTaskBarIconAreaBase::IsProtocolSupported()
     return (bool)s_supported;
 }
 
+bool wxTaskBarIconAreaBase::IsDecorCacheable() const
+{
+    // Apparently, WM frame extents extend to full width of screen when window
+    // is in the tray. Don't cache, it's not useful for other windows.
+    return false;
+}
+
 //-----------------------------------------------------------------------------
 // Pop-up menu stuff
 //-----------------------------------------------------------------------------
@@ -143,9 +148,7 @@ bool wxTaskBarIconAreaBase::DoPopupMenu( wxMenu *menu, int x, int y )
 
     return true;
 }
+
 #endif // wxUSE_MENUS_NATIVE
-
-#endif // __WXGTK20__
 #endif // GTK_CHECK_VERSION(2, 1, 0)
-
 #endif // wxUSE_TASKBARICON