Qt: reduce getSysColor() overhead by caching colors.

git-svn-id: trunk@17700 -

lcl/interfaces/qt/qtint.pp

@@ -67,6 +67,8 @@ type
     FDockImage: QRubberBandH;
     FDragImageList: QWidgetH;
     FDragHotSpot: TPoint;
+    FCachedColors: Array[0..MAX_SYS_COLORS + 1] of PLongWord;
+    procedure ClearCachedColors;
     procedure SetOverrideCursor(const AValue: TObject);
   protected
     FStockNullBrush: HBRUSH;

lcl/interfaces/qt/qtobject.inc

@@ -29,6 +29,7 @@ begin
   App := QApplication_Create(@argc, argv);
   InitStockItems;
   QtWidgetSet := Self;
+  ClearCachedColors;
   FDockImage := nil;
 end;
 
@@ -55,6 +56,8 @@ begin
   QtDefaultContext.Free;
   QtScreenContext.Free;
 
+  ClearCachedColors;
+
   inherited Destroy;
 end;
 
@@ -290,6 +293,7 @@ var
 begin
   Result := False;
   case QEvent_type(Event) of
+    QEventStyleChange: ClearCachedColors;
     LCLQt_Destroy:
       begin
         AObject := TQtObject(Pointer(QLCLMessageEvent_getWParam(QLCLMessageEventH(Event))));
@@ -641,4 +645,16 @@ begin
   FStockDefaultDC := 0; // app must be initialized
 end;
 
+procedure TQtWidgetSet.ClearCachedColors;
+var
+  i: Integer;
+begin
+  for i := 0 to High(FCachedColors) do
+  begin
+    if FCachedColors[i] <> nil then
+      FreeMem(FCachedColors[i]);
+    FCachedColors[i] := nil;
+  end;
+end;
+
 //------------------------------------------------------------------------

lcl/interfaces/qt/qtwinapi.inc

@@ -2778,6 +2778,8 @@ begin
     exit;
   end;
 
+  if FCachedColors[nIndex] = nil then
+  begin
     case nIndex of
       {$IFDEF USE_QT_44}
       COLOR_SCROLLBAR               : Result:=GetColor(QPaletteActive,   QPaletteButton);
@@ -2833,6 +2835,10 @@ begin
     else
       Result:=0;
     end;
+    FCachedColors[nIndex] := getMem(SizeOf(LongWord));
+    FCachedColors[nIndex]^ := Result;
+  end else
+    Result := FCachedColors[nIndex]^;
 end;
 
 {------------------------------------------------------------------------------