how to set controller by keyboard arrows in matlab app designer

I have a problem to set controller by keyboard arrows in matlab app designer. I cant reset my key value when there is no key Pressed. I want to make action only while some key is pressing and stop the action when the key is un pressing

function ControllerUIFigureKeyPress(app, event)

key = event.Key;

switch key

case 'leftarrow'

app.left_icon.Position = [210 98 71 102];

case 'uparrow'

app.up_icon.Position = [285 150 71 102];

case 'rightarrow'

app.right_icon.Position = [360 98 71 102];

case 'downarrow'

app.down_icon.Position = [285 40 71 102];

otherwise

app.down_icon.Position = [285 60 71 102];

app.up_icon.Position = [285 133 71 102];

app.right_icon.Position = [343 98 71 102];

app.left_icon.Position = [225 98 71 102];

end

Answer 1

[Gowtham]

Hello Roye Vadana,

I understand that you want to change the position of arrow icons using keyboard arrows in app designer. To reset the position of the keys, we can use the Key Release callback which is similar to the Key Press callback you have created.

For a sample demonstration of this process, kindly refer to the updated code snippet:

% Callbacks that handle component events
    methods (Access = private)

        % Code that executes after component creation
        function startupFcn(app)
            app.down_icon.Position = [285 60 71 102];
            app.up_icon.Position = [285 133 71 102];
            app.right_icon.Position = [343 98 71 102];
            app.left_icon.Position = [225 98 71 102];
        end

        % Key press function: UIFigure
        function UIFigureKeyPress(app, event)
            key = event.Key;
            switch key
                case 'leftarrow'
                    app.left_icon.Position = [210 98 71 102];
                case 'uparrow'
                    app.up_icon.Position = [285 150 71 102];
                case 'rightarrow'
                    app.right_icon.Position = [360 98 71 102];
                case 'downarrow'
                    app.down_icon.Position = [285 40 71 102];
                otherwise
                    app.down_icon.Position = [285 60 71 102];
                    app.up_icon.Position = [285 133 71 102];
                    app.right_icon.Position = [343 98 71 102];
                    app.left_icon.Position = [225 98 71 102];
            end
        end

        % Key release function: UIFigure
        function UIFigureKeyRelease(app, event)
            key = event.Key;
            % reset positions
            switch key
                case 'leftarrow'
                    app.left_icon.Position = [225 98 71 102];
                case 'uparrow'
                    app.up_icon.Position = [285 133 71 102];
                case 'rightarrow'
                    app.right_icon.Position = [343 98 71 102];
                case 'downarrow'
                    app.down_icon.Position = [285 60 71 102];
            end
        end
    end

Kindly refer to the following documentation for further understanding on callbacks in app designer https://www.mathworks.com/help/matlab/creating_guis/write-callbacks-for-gui-in-app-designer.html

Hope this helps in resolving the issue you were facing.

Regards,

Gowtham