App Designer get element in focus

Hi there,

I switched from GUIDE to the App Designer some time ago, and find that a lot of important functionalities are now missing. One particular feature is the possibility to get a handle to the current GUI element in focus. In my particular example, I have 2 ListBox elements in my application and I want to add a shortcut to them for modification. The KeyPress function is only possible on the uifigure level, so I need a way to distinguish between the two ListBox elements.

Is this possible in some way or does this feature not exist at the moment.

Thanks, Rasmus

[Quy]

Looking for an answer for this question as well.

[Isak Idrizi]

me too.

Answer 1

[Suraj Kumar]

Hi,

I understand that you are facing difficulty in getting the handle of the current GUI element which is in focus. As a workaround you can track the focus manually by setting up callbacks for each interactive component and storing the handle of the currently focused component in a property.

Consider adding a private property to store focussed component as shown below:

properties (Access = private) 
   FocusedComponent   
end 

Then implement the “onKeyPress” callback to handle key press events based on which “ListBox” is currently focussed.

You can refer to the code below for better understanding:

function onKeyPress(app, event)
    if isempty(app.FocusedComponent)
        return;
    end
    switch app.FocusedComponent
     case app.ListBox1
        % Handle key press for ListBox1
        disp('Key pressed in ListBox1');
     case app.ListBox2
        % Handle key press for ListBox2
        disp('Key pressed in ListBox2');
    end
end

Please refer to the following documentation link on “callbacks” in App Designer :

• https://www.mathworks.com/help/matlab/creating_guis/write-callbacks-for-gui-in-app-designer.html

Hope this helps!