How to wait for another GUI button press in AppDesigner?

So, I have webapp with the following loose structure.

1. User clicks start in the GUI
2. A sound is played
3. User clicks one of several buttons to rate the sound
4. The app waits for response
5. Plays another sound shortly after recieving repsonse etc.

I'm stuck with trying to make the app wait for user response. I tried setting a while loop that would wait for a check variable to become true, and assigning that change in each button, but this didn't work, the buttons are not executable when it is in the while loop.

Documentations suggests "use uiwait" but the UI wait documentation doesn't give any further clue how this would be done when relying on callbacks etc, only when closing like dialogue boxes etc.

If I use uiwait()&uiresume, then it creates a figure external to the app which cannot be disabled as far as I can tell.

Thank you!

Answer 1

[Naman Kaushik]

Hi Huw!

I understand that you wish to make an application which first has a start button which on clicking, plays a sound, and the user then has to rate this. Once rated, the next sound is played and this continues.

One workaround for this is to use a public app property for this. You can define a counter variable as a property (let's call it “x”) (or the sound name, as you prefer). Now whenever, the user clicks the button to rate the sound, you can check the value of the property “x”, play the sound which corresponds to “x”and then update the value of “x” according to the new sound.

Consider the code shown below:

classdef firstApp < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure                 matlab.ui.Figure
        GiveratingButton         matlab.ui.control.Button
        StartButton              matlab.ui.control.Button
        RatethesoundButtonGroup  matlab.ui.container.ButtonGroup
        Button_3                 matlab.ui.control.RadioButton
        Button_2                 matlab.ui.control.RadioButton
        Button                   matlab.ui.control.RadioButton
    end

    
    properties (Access = public)
        counter; % Description
    end
    

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

        % Code that executes after component creation
        function startupFcn(app)
            app.RatethesoundButtonGroup.Visible = "off";
            app.GiveratingButton.Visible = 'off';
            app.counter = 1;
           
        end

        % Button pushed function: StartButton
        function StartButtonPushed(app, event)
            app.RatethesoundButtonGroup.Visible = "on";
            app.GiveratingButton.Visible = 'on';
            app.StartButton.Visible = 'off';
            load train;
            sound(y, Fs);
            app.counter = app.counter+1;
          
        end

        % Button pushed function: GiveratingButton
        function GiveratingButtonPushed(app, event)
            % Can also use string for comparison and the string may be the
            % sound name.
            if(rem(app.counter, 4) ==0)
                rating = app.RatethesoundButtonGroup.SelectedObject.Text;
                % The rating is for the previous sound

                load train;
                sound(y, Fs);
            elseif(rem(app.counter, 4) ==1)
                rating = app.RatethesoundButtonGroup.SelectedObject.Text;
                % The rating is for the previous sound

                load laughter;
                sound(y, Fs);
            elseif(rem(app.counter, 4) == 2)
                rating = app.RatethesoundButtonGroup.SelectedObject.Text;
                % The rating is for the previous sound

                load gong;
                sound(y, Fs);
            elseif(rem(app.counter, 4) == 3)
                rating = app.RatethesoundButtonGroup.SelectedObject.Text;
                % The rating is for the previous sound

                load chirp
                sound(y, Fs);
            end
            app.counter = app.counter+1;
        end
    end

    % Component initialization
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure and hide until all components are created
            app.UIFigure = uifigure('Visible', 'off');
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'MATLAB App';

            % Create RatethesoundButtonGroup
            app.RatethesoundButtonGroup = uibuttongroup(app.UIFigure);
            app.RatethesoundButtonGroup.Title = 'Rate the sound';
            app.RatethesoundButtonGroup.Position = [247 188 123 106];

            % Create Button
            app.Button = uiradiobutton(app.RatethesoundButtonGroup);
            app.Button.Text = '1';
            app.Button.Position = [11 60 58 22];
            app.Button.Value = true;

            % Create Button_2
            app.Button_2 = uiradiobutton(app.RatethesoundButtonGroup);
            app.Button_2.Text = '2';
            app.Button_2.Position = [11 38 65 22];

            % Create Button_3
            app.Button_3 = uiradiobutton(app.RatethesoundButtonGroup);
            app.Button_3.Text = '3';
            app.Button_3.Position = [11 17 65 22];

            % Create StartButton
            app.StartButton = uibutton(app.UIFigure, 'push');
            app.StartButton.ButtonPushedFcn = createCallbackFcn(app, @StartButtonPushed, true);
            app.StartButton.Position = [258 321 100 23];
            app.StartButton.Text = 'Start';

            % Create GiveratingButton
            app.GiveratingButton = uibutton(app.UIFigure, 'push');
            app.GiveratingButton.ButtonPushedFcn = createCallbackFcn(app, @GiveratingButtonPushed, true);
            app.GiveratingButton.Position = [259 146 100 23];
            app.GiveratingButton.Text = 'Give rating';

            % Show the figure after all components are created
            app.UIFigure.Visible = 'on';
        end
    end

    % App creation and deletion
    methods (Access = public)

        % Construct app
        function app = firstApp

            % Create UIFigure and components
            createComponents(app)

            % Register the app with App Designer
            registerApp(app, app.UIFigure)

            % Execute the startup function
            runStartupFcn(app, @startupFcn)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

To learn more about App Designer properties you can refer the following documentation:

https://in.mathworks.com/help/matlab/creating_guis/share-data-across-callbacks-in-app-designer.html

For understanding how to get selected value from a radio button group:

https://in.mathworks.com/matlabcentral/answers/468609-how-to-get-the-value-of-radio-buttons-from-app-designer

To learn about the startup function callback:

https://in.mathworks.com/matlabcentral/answers/487344-matlab-app-designer-how-can-i-hide-few-of-my-app-components-when-i-run-the-app