* Add workaround to Carbon bug 18211 (PaintStruct not initialized)

* Add a dummy AlphaBlend function to Carbon interface

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@1402 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/virtualtreeview-new/branches/4.8/VirtualTrees.pas

@@ -16444,10 +16444,15 @@ begin
   if tsVCLDragging in FStates then
     ImageList_DragShowNolock(False);
   {$endif}
+  //todo: workaround to bug 18211. Remove when fixed.
+  {$ifndef LCLCarbon}
   if csPaintCopy in ControlState then
     FUpdateRect := ClientRect
   else
-    FUpdateRect:=Message.PaintStruct^.rcPaint;
+    FUpdateRect := Message.PaintStruct^.rcPaint;
+  {$else}
+  FUpdateRect := ClientRect;
+  {$endif}
 
   {$ifdef DEBUG_VTV}Logger.Send([lcPaint],'FUpdateRect', FUpdateRect);{$endif}
 

components/virtualtreeview-new/branches/4.8/include/intf/carbon/vtgraphicsi.inc

@@ -0,0 +1,23 @@
+//todo: properly implement
+procedure AlphaBlend(Source, Destination: HDC; const R: TRect; const Target: TPoint; Mode: TBlendMode; ConstantAlpha, Bias: Integer);
+begin
+  case Mode of
+    bmConstantAlpha,
+    bmPerPixelAlpha,
+    bmMasterAlpha,
+    bmConstantAlphaAndColor:
+      begin
+	    BitBlt(Destination, Target.X, Target.Y, R.Right - R.Left, R.Bottom - R.Top, Source, R.Left, R.Right, SRCCOPY); 
+      end;
+  end;
+end;
+
+function CalculateScanline(Bits: Pointer; Width, Height, Row: Integer): Pointer;
+begin
+  Result := nil;
+end;
+
+function GetBitmapBitsFromBitmap(Bitmap: HBITMAP): Pointer;
+begin
+  Result := nil;
+end;