I have a problem with 'togglebutton' in MATLAB 2012a GUI

Hello everyone;

Let us say we have a text file that contains a number. we need to continuously read the file and print that number on the screen. (Obviously we will need some kind of loop)

Note that reading process should start only when a toggle button is pressed, and stop once the button is pressed again (i.e. released).

My problem is that every time I run the program, it fall in an infinite loop! I assumed that the function will monitor the button state since I include the 'get' function in the loop.

Here is the code: (I have replaced the reading commands with a simple addition statement to simplify the work)

    function tbtn1_Callback(hObject,eventData)
    % 
        isPressed = get(hObject,'Value');  % read the button state
        if isPressed
            set(hObject,'String','Stop');
        else
            set(hObject,'String','Start');
        end

        ii = 0;
        while isPressed
           ii = ii+1  %instead of reading the text file
           isPressed = get(hObject,'Value'); % check if the button released
        end

    end

Hope you can help! Thanks in advanced.

Answer 1

[Sean de Wolski]

Put a drawnow inside of the while-loop before you get(hObject,'Value').

This forces MATLAB to flush the event queue before continuing the loop which may have some queued up events (i.e. pushing the button).

[Sadi Altamimi]

Nice and cool :)

Thanks