func (mw *MainWindow) drawStuff(surface *drawing.Surface, updateBounds drawing.Rectangle) os.Error { bmp := createBitmap() defer bmp.Dispose() bounds, err := mw.paintWidget.ClientBounds() panicIfErr(err) rectPen, err := drawing.NewCosmeticPen(drawing.PenSolid, drawing.RGB(255, 0, 0)) panicIfErr(err) defer rectPen.Dispose() panicIfErr(surface.DrawRectangle(rectPen, bounds)) ellipseBrush, err := drawing.NewHatchBrush(drawing.RGB(0, 255, 0), drawing.HatchCross) panicIfErr(err) defer ellipseBrush.Dispose() panicIfErr(surface.FillEllipse(ellipseBrush, bounds)) linesBrush, err := drawing.NewSolidColorBrush(drawing.RGB(0, 0, 255)) panicIfErr(err) defer linesBrush.Dispose() linesPen, err := drawing.NewGeometricPen(drawing.PenDash, 8, linesBrush) panicIfErr(err) defer linesPen.Dispose() panicIfErr(surface.DrawLine(linesPen, drawing.Point{bounds.X, bounds.Y}, drawing.Point{bounds.Width, bounds.Height})) panicIfErr(surface.DrawLine(linesPen, drawing.Point{bounds.X, bounds.Height}, drawing.Point{bounds.Width, bounds.Y})) bmpSize := bmp.Size() panicIfErr(surface.DrawImage(bmp, drawing.Point{bounds.Width/2 - bmpSize.Width/2, bounds.Height/2 - bmpSize.Height/2})) return nil }