problem with waitbar cancel button

All,

I'm encountering a little problem with a cancel button on a waitbar. I can get the Matlab example in the help file to work perfectly, although for some reason when I try it in my code, it does not seem to acknowledge the callback for the cancel button. Heres what I have:

   hWaitBar = waitbar(0, '',...     
              'Name', 'LOADING IMAGES - PLEASE WAIT...',...     
              'CreateCancelBtn','setappdata(gcbf,''Canceling'',1)'); 
          setappdata(hWaitBar,'Canceling',0) 

for i=3:size(filelist,1)                                

%do stuff here

getappdata(hWaitBar,'Canceling')

       % Check for Cancel button press
      ch = getappdata(hWaitBar, 'Canceling')
      if getappdata(hWaitBar,'Canceling') ==1
          break
      end

              waitbar(i/size(filelist,1),hWaitBar)

      end  

delete(hWaitBar)

The check command 'getappdata(hWaitBar,'Canceling')' inside the loop never returns the value of 1, which it should do from the callback defined in hWaitBar.

The only difference I can think of between the matlab example and my code is that all my above code is located in a set if-else loops (4 deep). Would this be responsible?

Thanks

Jim

Answer 1

[Walter Roberson]

Try adding a drawnow() call inside the loop, so that the callback of canceling the waitbar will have a chance to run.

[Jim O'Doherty]

Thanks for the answer - no luck with the drawnow() command unfortunately. I think the issue is that when I actually press the cancel button, it doesn't change the "Canceling" variable to 1, and hence the callback doesn't run.

Answer 2

[Alexander Kosenkov]

The currently running function must be started from a button/menu, where Interruptible is set to 'on'. Otherwise, currently running calculation (the one that opened the progress bar) can not be interrupted even to set 'Canceling' to 1.

[Ali Yar Khan]

can you share the code how can we set it on from the callee function ?