Inserting a timer in standalone application.

I have created a standalone application in Matlab using guide feature and Matlab Compiler. I need to insert a timer to get the time for which the application was used every time. How can I implement this in my application ?

[Jan]

What should the "timer" do? Display the elapsed time every second or store the used time on the disk, when the application is closed? What does "which the application was used every time" exactly mean?

[sanchit ingale]

Hi Jan,

The timer should just be displayed during the application is running. And it should increment by 1 second.

Answer 1

[Walter Roberson]

First ensure that you have a uicontrol style 'text' with tag 'timer_display' .

In the figure CreateFcn callback,

fig = hObject;
start_time = now();
txtbox = findobj(fig, 'tag', 'timer_display');
timer_obj = timer('Period', 1, 'TimerFcn', @(hobject, event) set(txtbox, 'string', datestr(now-start_time, 'HH:MM:SS')));
set(fig, 'UserData', timer_obj);    %do not let it get deleted
start(timer_obj);

Note: this timer will not get updated at all during some long-running computations. For example if you use the mldivide operator for large matrices then a high performance library is called that does not support timers.

Note: with the form of the code given here, the text box will get updated during graphics callbacks, but the display might not get updated immediately. To have the text updated immediately, you need to add in a drawnow() call, which unfortunately would require that you create a real function to be called-back (anonymous functions cannot chain calls that do not produce output.)

[sanchit ingale]

Thanks for the input. The timer is appearing, however there is no increment. Timer stays at '00:00:00'. There is no error on running the GUI application.