CheckBoxTree - Combination of CheckedNodesChangeFcn and SelectionChangedFcn

Hi,

I am wondering about the behavior of the both main callbacks of a checkboxtree (CheckedNodesChangeFcn, SelectionChangedFcn).

I used to define them externaly via an controller class instead of defining directly in app-File (mlapp):

app.OutputTree.CheckedNodesChangedFcn = ...

@(src,event)My_Toolbox_AppControllerClass.checkedChangedFcn(app,src,event);

app.OutputTree.SelectionChangedFcn = ...

@(src,event)My_Toolbox_AppControllerClass.commonValueChangedFcn(app,src,event);

When I do so the behavior when checking a checkbox differs from the direct implementation in the mlapp-File.

Direct Implementation:

Click on a checkbox -> checkbox gets unchecked or checked directly (both callbacks are executed)

External Implementation in Class:

Click on a checkbox -> checkbox stays unchecked or checked (only SelectionChangedFcn is executed)

Click on the same checkbox -> checkbox gets unchecked or checked (only CheckedNodesChangedFcn is executed)

Does anyone know how to deal with this behavior ? I don't want to perform 2 clicks on a checkbox to uncheck/check it and I don't really want to implement the callbacks in the mlapp-File.

Thanks for your held in advance.

Answer 1

[Ravi]

Hi DenS,

I understand that you are facing an issue in defining the callback functions using an external class.

The methods that are defined in the external class should be marked as Static. “SelectionChangedFcn” is called when the user selects a node that is different from the previous one. This is why you would be seeing only “CheckedNodesChangedFcn” executing over and over when the same checkbox is clicked multiple times.

Please find the below sample code for declaring the callbacks in the app and defining the callbacks in the external class.

function startupFcn(app) 
            app.Tree.CheckedNodesChangedFcn = @(src, evt) AppController.checkedChangedFcn(app,src,evt); 
            app.Tree.SelectionChangedFcn = @(src, evt) AppController.commonValueChangedFcn(app,src,evt); 
        end 
 
classdef AppController 
    methods(Static) 
        function checkedChangedFcn(app, src, event) 
            % Handle the checked state change 
            disp('checkedChangedFcn called'); 
        end 
        function commonValueChangedFcn(app, src, event) 
            % Handle the selection change 
            disp('commonValueChangedFcn called'); 
        end 
    end 
end

To learn more about the callback functions, please refer to the following link.

CheckBoxTree Properties - https://www.mathworks.com/help/matlab/ref/matlab.ui.container.checkboxtree-properties.html

I hope this solution resolves the issue you are facing.

Thanks,

Ravi Chandra

[DenS]

Hi Ravi,

thank you very much for your reply. Your solution sounds good to me and I will try it.

kind regards

Daniel