gtk2: get correct primary monitor if we are using gtk2 >= 2.20. issue #32464

git-svn-id: trunk@55913 -

lcl/interfaces/gtk2/gtk2extra.inc

@@ -77,8 +77,11 @@ initialization
     end;
   end;
   gdklibhandle := LoadLibrary(gdklib);
-  if gdklibhandle <> 0
-  then pointer(gdk_window_get_cursor):=GetProcAddress(gdklibhandle,'gdk_window_get_cursor');
+  if gdklibhandle <> 0 then
+  begin
+   pointer(gdk_window_get_cursor) := GetProcAddress(gdklibhandle,'gdk_window_get_cursor');
+   pointer(gdk_screen_get_primary_monitor) := GetProcAddress(gdklibhandle,'gdk_screen_get_primary_monitor');
+  end;
 
 finalization
   if gtkhandle <> 0 then

lcl/interfaces/gtk2/gtk2extrah.inc

@@ -341,6 +341,8 @@ var
   gtk_window_set_opacity: procedure(window: PGtkWindow; opacity: gdouble); cdecl;
   g_object_ref_sink: function(anObject: PGObject): gpointer; cdecl;
   gdk_window_get_cursor: function(window: PGdkWindow): PGdkCursor; cdecl;
+  // since 2.20
+  gdk_screen_get_primary_monitor: function(screen: PGdkScreen): gint; cdecl;
 
   // since 2.10
   gtk_tree_view_set_grid_lines: procedure(tree_view: PGtkTreeView; grid_lines: TGtkTreeViewGridLines); cdecl;

lcl/interfaces/gtk2/gtk2winapi.inc

@@ -4998,11 +4998,21 @@ begin
   else
   {$ENDIF}
   lpmi^.rcWork := lpmi^.rcMonitor;
-  // gtk uses zero position for primary monitor
-  if Monitor = 0 then
-    lpmi^.dwFlags := MONITORINFOF_PRIMARY
-  else
-    lpmi^.dwFlags := 0;
+  // since gtk-2.20 we have correct api to get primary monitor. issue #32464
+  if Assigned(gdk_screen_get_primary_monitor) then
+  begin
+    if (Monitor = gdk_screen_get_primary_monitor(gdk_screen_get_default)) then
+      lpmi^.dwFlags := MONITORINFOF_PRIMARY
+    else
+      lpmi^.dwFlags := 0;
+  end else
+  begin
+    // gtk2 below 2.20
+    if Monitor = 0 then
+      lpmi^.dwFlags := MONITORINFOF_PRIMARY
+    else
+      lpmi^.dwFlags := 0;
+  end;
 end;
 
 {------------------------------------------------------------------------------