Question

I’ve got an algorithm. I’d like to pause it at some point and then continue once the user presses a button. How do I do that? I’ve browsed the documentation, and searched the internet, but no luck yet.

Here’s a relevant code snip:

      if A[i]>A[i+1]         then           begin             Zameni(i,i+1);             done:=true;              sleep(pauza);              br:=br+1;           end; 

Right now, I use sleep (pauza is just a constant, means pause in Serbian). Ideally, I’d like to replace that line with a procedure which would sleep for the interval, or wait for a button press based on a configuration setting.

EDIT1: Ah yes, if it wasn’t obvious – it’s a graphics application, not console, so slapping a ‘readln’ won’t work (sadly).

Answer 1

I wouldn’t recommend it as good application design, but if none of the other suggestions are suitable for you, you may prefer this.

Add a ‘Paused: Boolean’ field to your class/form, and a ‘Continue’ button.

When you start the operation, set Paused to False, and Continue.Enabled := False;

When your code reaches the section where you want to pause:

Paused := True; Continue.Enabled := True; while Paused do begin   sleep(100);   Application.ProcessMessages; end; 

In your Continue buttons event handler:

procedure Form1.ContinueClick(Sender: TObject); begin   Paused := False;   Continue.Enabled := False; end; 

As I said before, not pretty, but it should get the job done.