How to change to different colors for a button in MATLAB in the middle of the program execution.

I want to change the color of a gui button in MATLAb in middle of the execution of the button that is I want to continously change the color of a button in program until a user presses it so that it is being highligted and the user will easily understand that a particular button has to be clicked.

[Stephen23]

See the "eval" button (graphics object handle eUiH) used in maxdistcolor_view here:

https://www.mathworks.com/matlabcentral/fileexchange/70215-maximally-distinct-color-generator

[SUMAN DUTTA]

Sorry but I couldn't understand the method and it didn't help me.

[DGM]

Uicontrol buttons have 'foregroundcolor' and 'backgroundcolor' properties. You can just set them however you see fit.

myfavoritecolor = [0.9 0.2 0.2];
set(mybuttonhandle,'backgroundcolor',myfavoritecolor);

When and how you set it is up to you and your code which nobody has seen. You can set it in the callback when the button is pressed or in some other function when the color needs to be reset to prompt the user. If you want it to change color continuously when idle, you'll need to write a function that does that and decide how you want to manage its execution.

[dpb]

And you may need a drawnow to make the display refresh...ran into that in App Designer just recently when disabling/changing color on a button during execution of the associated code...

[Adam Danz]

@SUMAN DUTTA The solution in my answer isn't too much different than then one you commented on earlier. That one changes the visible property, this one changes the BackgroundColor property.

Answer 1

[Adam Danz]

> I want to continously change the color of a button in program until a user presses it

An efficient method that will work in the background and will not interfere with ongoing processes or user interaction is to use a timer object.

The two demos below create a figure with a uibutton. It's a state button but can easily be adapted to work with any app component.

The timer changes the background color of the button every 0.2 seconds (200 ms). That period can easily be changed in the timer function. You can also alternate between a pre-defined list of colors instead of flashing random colors (demo #2).

When the button is pressed (state change from 0 to 1), the button background is set to default (gray). When the button is pressed again (state change from 0 to 1) the randomized colors start again.

You can start and stop the random colors any time you want using start(app.uibTimer) and stop(app.uibTimer).

% Create app with 1 button
app.uifigure = uifigure();
app.uibutton = uibutton(app.uifigure,'state',...
    'Text','Stop the madness',...
    'Value',false, ...
    'Position', [100 100 150 80], ...
    'FontSize', 16, ...
    'FontWeight','bold');

% Create timer to set the button color to random colors every 200ms
app.uibTimer = timer('Period',.2, 'ExecutionMode','fixedDelay',...
    'TimerFcn',@(~,~)set(app.uibutton, 'BackgroundColor', rand(1,3)));

% Define other functions 
app.uibutton.DeleteFcn = @(~,~)delete(app.uibTimer); 
app.uibutton.ValueChangedFcn = @(btn,evt)stateButtonPressed(app,btn,evt); % After creating timer!
start(app.uibTimer)

% Function that responds to button press 
function stateButtonPressed(app, btnHandle, event)
    if event.Value 
        % Button is TRUE: set color to default
        btnHandle.BackgroundColor = [.96 .96 .96]; % default color
        stop(app.uibTimer)
    else
        % Button is FALSE: Turn on random colors
        start(app.uibTimer)
    end
end

Demo 2: alternates between two colors

Choose a base color and the timer will alternate between the base and it's opposite defined by 1-rgb where rgb is the 1x3 color value of the base color.

% Create app with 1 button
app.uifigure = uifigure();
app.uibutton = uibutton(app.uifigure,'state',...
    'Text','Stop the madness',...
    'Value',false, ...
    'Position', [100 100 150 80], ...
    'FontSize', 16, ...
    'FontWeight','bold');

% Define the base color (1x3 vector) and create timer to 
% set the button color to alternative the base and its 
% opposite color every 200ms
app.uibutton.BackgroundColor = [1 1 0];
app.uibTimer = timer('Period',.2, 'ExecutionMode','fixedDelay',...
    'TimerFcn',@(~,~)set(app.uibutton, 'BackgroundColor', 1-app.uibutton.BackgroundColor));

% Define other functions 
app.uibutton.DeleteFcn = @(~,~)delete(app.uibTimer); 
app.uibutton.ValueChangedFcn = @(btn,evt)stateButtonPressed(app,btn,evt); % After creating timer!
start(app.uibTimer)

% Function that responds to button press 
function stateButtonPressed(app, btnHandle, event)
    if event.Value 
        % Button is TRUE: set color to default
        btnHandle.BackgroundColor = [.96 .96 .96]; % default color
        stop(app.uibTimer)
    else
        % Button is FALSE: Turn on flashing colors
         btnHandle.BackgroundColor = [1 1 0]; %base color 
        start(app.uibTimer)
    end
end