Stop a infinite while loop pressing a key in Matlab

Question

I have a while loop, infinite, and I want to stop it when I press a keyboard key.

Pseudocode:

While(1)
    do stuff;

    listening for key;
    if key is pressed
        break;
    end
end

The function waitforbuttonpress makes me press the key, so no luck.

I've found no option on the web.

Check this link out: http://undocumentedmatlab.com/blog/waiting-for-asynchronous-events . Look at the section where you want to set a timeout for `waitfor`. — rayryeng, May 21 '14 at 16:57

score 3 · Answer 1 · answered Jan 16 '15 at 18:42

OK, I know this is a bit late but, I found a solution after a long hunt. When a figure window is focused, you can do this:

set(gcf,'currentchar',' ')         % set a dummy character
while get(gcf,'currentchar')==' '  % which gets changed when key is pressed
   do_stuff()
end

When a key is pressed while focus is in a figure, it sets the property 'currentchar'. Tested in R2010b.

score 3 · Answer 2 · answered Mar 17 '16 at 17:50

3

GUI based solution I found in Matlab central

dialogBox = uicontrol('Style', 'PushButton', 'String', 'Break','Callback', 'delete(gcbf)');
while (ishandle(dialogBox))
    statements....
end

answered Mar 17 '16 at 17:50

Shan

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1

it works but you have to add a "drawnow" command in statements – jamk Jun 12 '18 at 15:36

score 1 · Accepted Answer · answered May 21 '14 at 17:00

I suppose if you don't want to resort to multithreading (one thread doing the computation in the while loop, another one waiting for input and setting a global sentinel value to break the while loop) you can try to implement breaking the loop on catching a keyboard-interrupt (ctrl-c). This should be possible, albeit in a kinda hackish way.

Stop a infinite while loop pressing a key in Matlab

3 Answers3

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