I need help fix a check box in a gui

I have create a gui for a robot maze. When the robot moves through the maze a blue line follows the path the robot took. In my gui I have a check box that is label history when it checked i want it to show the blue line when its unchecked I want it to no show the blue line. I am unsure how to do this.

createRandomMaze

figure;
first_button = uicontrol('style', 'pushbutton');
set(first_button, 'units', 'normalized', 'position', [0.2,0.7, 0.2, 0.2])
set(first_button, 'string', 'turn left')
set(first_button, 'callback', @turnLeft)

second_button = uicontrol('style', 'pushbutton');
set(second_button, 'units', 'normalized', 'position', [0.4, 0.7, 0.2, 0.2])
set(second_button, 'string', 'step')
set(second_button, 'callback', @step)

third_button = uicontrol('style', 'pushbutton');
set(third_button, 'units', 'normalized', 'position', [0.6, 0.7, 0.2, 0.2])
set(third_button, 'string', 'turn right')
set(third_button, 'callback', @turnRight)

fourth_button = uicontrol('style', 'pushbutton');
set(fourth_button, 'units', 'normalized', 'position', [0.2, 0.5, 0.2, 0.2])
set(fourth_button, 'string', 'left')
set(fourth_button, 'callback', @stepLeft)

fifth_button = uicontrol('style', 'pushbutton');
set(fifth_button, 'units', 'normalized', 'position', [0.4, 0.5, 0.2, 0.2])
set(fifth_button, 'string', 'back')
set(fifth_button, 'callback', @stepBack)

sixth_button = uicontrol('style', 'pushbutton');
set(sixth_button, 'units', 'normalized', 'position', [0.6, 0.5, 0.2, 0.2])
set(sixth_button, 'string', 'right')
set(sixth_button, 'callback',@stepRight)

seventh_button = uicontrol ('style','checkbox');
set(seventh_button, 'units', 'normalized', 'position', [0.2, 0.3, 0.2, 0.2])
set(seventh_button, 'string', 'History')
set(seventh_button, 'callback', @toggleHistory)

eighth_button = uicontrol ('style', 'edit');
set(eighth_button, 'units', 'normalized', 'position', [0.4, 0.37, 0.2, 0.05])
set(eighth_button, 'string', '2')

ninth_button = uicontrol('style','pushbutton');
set(ninth_button, 'units', 'normalized', 'position', [0.6, 0.3, 0.2, 0.2])
set(ninth_button, 'string', 'Run!')
set(ninth_button, 'callback', @Run)
ninth_button.Callback = 'number_of_steps = str2num(eighth_button.String); walk(number_of_steps)';

function toggleHistory(sender, eventdata)
if sender.Value == 1
    disp showHistory
else 
    disp hideHistory
end 
end 

 function Run(sender, eventdata)
        step_input = (['eighth_button', 'string']);
        if ~strcmp(step_input, ' ');
            number_of_steps = str2num(step_input);
            walk(number_of_steps);
        end
    end

Answer 1

[Dev]

Hi @Amanda,

We can show/hide the blue line based on the current state of the check box by leveraging the steps below-

• Store a handle to the blue line when you plot it: We can use the “setappdata” function in MATLAB to store the blue line and the “getappdata” function to share this handle among callbacks.

Please refer to an example code snippet below-

figureHandle = gcf;
% After plotting the blue line, store its handle:
blueLine = plot(xPath, yPath, 'b', 'LineWidth', 2); % Example plotting
setappdata(figureHandle, 'blueLineHandle', blueLine);

• Update the “toggleHistory” function: The “toggleHistory” function in the code provided in the question, we can show/hide the line by setting its ‘Visible’ property. The code provided below achieves the same-

fig = ancestor(sender, 'figure');
blueLine = getappdata(fig, 'blueLineHandle');
if isempty(blueLine) || ~isgraphics(blueLine)
    return; % No line to show/hide yet
end
if sender.Value == 1
    set(blueLine, 'Visible', 'on');
else
    set(blueLine, 'Visible', 'off');
end

For more information regarding the usage of the functions mentioned above, kindly refer to the documentation links below-

“setappdata”- https://www.mathworks.com/help/releases/R2024a/matlab/ref/setappdata.html

“getappdata”- https://www.mathworks.com/help/releases/R2024a/matlab/ref/getappdata.html

I hope the above steps help solve your query.