Hello Lazarus-List, Thursday, March 4, 2010, 12:34:56 AM, you wrote:
AK> Yes, TChart do draw over the control from MouseMove event. AK> However, there is no "bitmap" for TChart, it is a TCustomControl descendant. AK> Does that mean that I have to call Invalidate from inside MouseMove AK> to repaint the chart every time? That would have serious performance impact. No the invalidaterect is not needed in your case (I think). I'll explain my case: I have a bitmap (TImage) which is strenched and I must paint a selection box over it so I can not paint in the bitmap because the selection box will be also draw strenched too, so I paint over the control: TImage.Canvas.DrawFocusRect(...); This procedure is not working on QT, I do not know actually if the problem is known by the QT maintainer(s), or maybe it is regression as I do not have experience with the QT widgetset. In you case as you are already drawing the content, drawing in the same way the selectionbox using a XOR pen should solve the problem at least partially. -- Best regards, JoshyFun -- _______________________________________________ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
