When using checkbox, how do I cancel the last check?

checkbox3_value=get(handles.checkbox3, 'Value');
if checkbox3_value == 1
     a = [0:10]';
     b = num2str(a); c = cellstr(b);
     text(Nodelocation(:,2), Nodelocation(:,3), c);
else

end

How to not display text when else?

I tried delete and visible but it just doesn't work.

Answer 1

[Deepak]

Hi @han han,

This issue can be resolved by implementing a “persistent” variable to store the handles of the text objects, allowing for efficient management of their visibility. When the checkbox is “checked”, the text is created, and its handles are stored. If the checkbox is “unchecked”, the stored text handles are used to delete the text objects, ensuring they are removed from the plot.

This approach ensures that text annotations are only displayed when needed and are reliably cleared when not, maintaining a clean and responsive user interface.

Here is the sample MATLAB code to achieve the same:

% Create a figure 
hFig = figure('Position', [100, 100, 400, 300]); 

% Create an axes 
hAxes = axes('Parent', hFig, 'Position', [0.1, 0.3, 0.8, 0.6]); 

% Create a checkbox 
hCheckbox = uicontrol('Style', 'checkbox', 'String', 'Show Text', ... 
    'Position', [150, 50, 100, 30], ... 
    'Callback', @checkboxCallback); 

% Sample Nodelocation data 
Nodelocation = [0:10; 0:10; 0:10]'; 

% Store Nodelocation in the figure's app data 
setappdata(hFig, 'Nodelocation', Nodelocation); 

% Callback function for the checkbox 
function checkboxCallback(hObject, ~) 
checkbox3_value = get(hObject, 'Value'); 

% Access Nodelocation from the figure's app data 
Nodelocation = getappdata(hFig, 'Nodelocation'); 

persistent textHandles; 

if checkbox3_value == 1 
    a = [0:10]'; 
    b = num2str(a);  
    c = cellstr(b); 
    % Display text and store the handles 
    textHandles = text(Nodelocation(:,2), Nodelocation(:,3), c, 'Parent', hAxes); 
else 
    % Check if textHandles is not empty and delete the text objects 
    if ~isempty(textHandles) 
        delete(textHandles); 
        textHandles = []; 
    end 
end 
end 

For more information on the functions used refer to the following documentation:

uicontrol: www.mathworks.com/help/matlab/ref/uicontrol.html

persistent: www.mathworks.com/help/matlab/ref/persistent.html

I hope this helps in resolving the issue.