How to Implement a pause button in appdesigner while frames of video are being displayed in another figure?

I've used this technique in a previous app and had no problems but it is not working in the current one, both made in appdesginer.

One button when pushed is a for loop that does calculations and displayes an image with several notations in a separate figure than the one with the buttons. After the image is plotted the for loop includes the following:

if app.PauseState.Value

waitfor(app.PauseState,'UserData',1);

end

If the user pushes the "Pause" button the PauseStateValueChanged callback is:

if app.PauseState.Value

app.PauseState.UserData = 0;

app.PauseState.Text = 'Resume';

else

app.PauseState.UserData =1;

app.PauseState.Text = 'Pause';

end

drawnow;

In the first app I made, pushing the 'Pause' button causes the for loop to wait to continue plotting until pushing the 'Pause' button again. However the second app the 'Pause' button does nothing until the loop is finished. I looked at teh priority of each button and they say interuptible. Any ideas?

Answer 1

[Voss]

Put a drawnow in the for loop, before checking app.PauseState.Value, i.e.:

drawnow
if app.PauseState.Value
    waitfor(app.PauseState,'UserData',1);
end

(The other drawnow, in PauseStateValueChanged, may be unnecessary.)

[Voss]

Here's a complete piece of code that exhibits the behavior I think you want. You can run it and refer to it to figure out how to apply the same logic to your app (but I think you just need that drawnow in the for loop before checking app.PauseState.Value):

function test_func()

f = uifigure();

b = uibutton(f,'state','Text','Pause','ValueChangedFcn',@cb_btn,'Value',0,'UserData',1);

figure
while true
    plot(rand(1,10))
    drawnow
    if b.Value
        waitfor(b,'UserData',1);
    end
end


function cb_btn(~,~)
    if b.Value
        b.UserData = 0;
        b.Text = 'Resume';
    else
        b.UserData = 1;
        b.Text = 'Pause';
    end
%     drawnow
end

end

[Taylor]

Excellent, thank you it worked.

[Voss]

You're welcome! Any questions, let me know. Otherwise, please "Accept This Answer". Thanks!

[Voss]

@Taylor: Did this answer work for you? If so, please Accept this answer. Thanks!