[lazarus] Get button state

[Mattias Gaertner]

On Tue, 16 Dec 2003 14:47:35 +0000  Sebastian Kraft <sebastian_kraft at gmx.de>
wrote:

> Hi all,
> 
> I have a window with 2 buttons. One Start and one Stop. When clicking on
> start the program begins to write some lines to the commandline. How can I
> find out when the button stop is pressed? Seems the event isn't handled
> when the Program is still hanging in the start-button event...
> 
> Should look kind of that...
> 
> procedure TTestwin.startClicked(Sender: TObject);
> begin
>  repeat writeln('xxx') until "button stop pressed";
> end;
> 
> But I've no idea who to build that in Pascal code...
> 
> Can anyone help?

You have to give the LCL event queue some processing time.

procedure TTestwin.startClicked(Sender: TObject);
begin
  ButtonStopPressed:=false;
  repeat 
    writeln('xxx');
    Application.ProcessMessages;
  until ButtonStopPressed;
end;

procedure TTestwin.stopClicked(Sender: TObject);
begin
  ButtonStopPressed:=true;
end;


OR:
Put your writeln in an Application.OnIdle event.


Mattias