Can I disable onmousemove when onmousedown is used? 2

[pierrotsc]

I am doing a paint program and when i press the mouse to draw I would like to disable the onmousemove event. Is that possible?
Thanks.
PO

 

[DjangMan]

You can disable an event by setting the handler to nil. Later you can restore the event by setting the handler to the proper procedure.

procedure TForm1.DisableMouseMove;
begin
  Memo.OnMouseMove := nil;
end;

procedure TForm1.EnableMouseMove;
begin
  Memo.OnMouseMove := MemoMouseMove;
end;

procedure TForm1.MemoMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  DisableMouseMove;
end;

procedure TForm1.MemoMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  EnableMouseMove;
end;

procedure TForm1.MemoMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  Self.Caption := inttostr(x) + ':' + inttostr(y);
end;

 

[Duoas]

I presume you are just drawing straight lines from <mouse down> to <mouse up>?

It is easily possible.

procedure Form1.FormMouseDown( ... );
  begin
  Form1.OnMouseMove := nil;
  ...
  end;

procedure Form1.FormMouseUp( ... );
  begin
  ...
  Form1.OnMouseMove := Form1.FormMouseMove
  end;

The other option would be to just have a private flag that indicates whether or not you want to ignore mouse move events:

procedure Form1.FormMouseMove( ... );
  begin
  if F_Is_Ignore_MouseMove then Exit;
  ...
  end;

Hope this helps.