RAD Studio Athens

1.64

Description

The following example uses the CopyMode of an image's canvas to whiten and empty the image when the user chooses the Cut menu item. This example requires a Main Menu with a Copy and a Cut menu item that have their OnClick error handlers populated. Note: CopyMode and CopyRect are members of the destination canvas.

Code

procedure TForm1.Copy1Click(Sender: TObject);
var
  DstRect, SrcRect: TRect;

begin
  with Image2.Canvas do
  begin
    CopyMode := cmSrcCopy;
    DstRect := Rect(0, 0, Image2.Width, Image2.Height);
    SrcRect := Rect(0, 0, Image1.Width, Image1.Height);
    CopyRect(DstRect, Image1.Canvas, SrcRect);
  end;
end;

procedure TForm1.Cut1Click(Sender: TObject);
var
  ARect: TRect;

begin
  Copy1Click(Sender); { Do the same thing as the copy menu item. }
  with Image1.Canvas do
  begin
    CopyMode := cmWhiteness;
    ARect := Rect(0, 0, Image1.Width, Image1.Height);
    CopyRect(ARect, Image1.Canvas, ARect);
    CopyMode := cmSrcCopy; { Restore the copy mode. }
  end;
end;

Uses