How can I generate selected number of tabs in tab group with app designer?

I need to generate selected number of tabs within one tab group using app designer. Is there any way to do it?

I tried to make the same as from the answer https://www.mathworks.com/matlabcentral/answers/229411-gui-with-changeable-number-of-tabs

My code:

            app.TabGroup = uitabgroup(app.UIFigure);
            app.TabGroup.Position = [300 300 300 300];
            tab = uitab(app.TabGroup,'Title','Main Tab'); %create the main tab
            
                for x = 1:5 %create the number of tabs entered by the user
                    tab.(['t' num2str(x)]) = uitab(app.TabGroup,'Title',['Tab' num2str(x)]);
                end

But there is only one generated tab (figure below) and error "Unrecognized property 't1' for class 'matlab.ui.container.Tab'."

What can I do? Thanks.

Answer 1

[Adam Danz]

You're treating tab like a structure but it's a tab container object. Store the tab handles in a cell array. Here's a demo you can adapt to your app.

% Create a UI Figure
app.UIFigure = uifigure(); 

% Set up tab group
app.TabGroup = uitabgroup(app.UIFigure);
% app.TabGroup.Position = [300 300 300 300];   % not needed for demo

% Specify the total number of tabs
nTabs = 6; % including MainTab

% Set up the main tab
app.tabs = cell(1,nTabs); 
app.tabs{1} = uitab(app.TabGroup,'Title','Main Tab'); %create the main tab

% Create additional tabs
for i = 2:nTabs %create the number of tabs entered by the user
    app.tabs{i} = uitab(app.TabGroup,'Title',['Tab' num2str(i-1)]);
end

To access tab number 'n',

app.tabs{n}
app.tabs{n}.Title = 'Menu';  % for example

Note: when applying this to AppDesigner you'll need to declare tabs as a private property by following these instructions.

[Mikhail Mikhail]

Thanks! It works. Is this useful for other objects (panels, buttons, etc.)?

[Adam Danz]

If you're using appdesigner, I recommend building app components within the AppDesigner UI. For some (most?) components, you can control which components are visible/enabled from within the code.

To answer your question, yes, you can store handles to objects in this way.

[Mikhail Mikhail]

Understood. Thanks a lot!

[Adam Danz]

@Mikhail Mikhail , I've updated my answer so that tabs is a property of your app rather than a variable. You'll have to declare tabs as a property of your app as I've noted at the end of my answer.

[Will Reeves]

Thanks for this answer. Can you comment on the process for dynamically removing tabs created this way?

delete(app.tabs)

doesn't work obviously, where as:

tab1=uitab(app.TabGroup,'Title','Tab1');

then

delete(tab1) 

does work, but you can't delete properties from an app.

[Will Reeves]

Actually... is it just OK to "copy" the "handle" to a local variable and delete it? It seems to work - as in the tab disappears from the GUI, but is it "clean"?

for i=1:length(app.tabs)
    a=app.tabs{i};
    delete(a);
end

[Adam Danz]

@Will Reeves sorry for the delay, I was out on vacation for a while.

> is it just OK to "copy" the "handle" to a local variable and delete it

Yes. When you copy a variable containing a handle to another variable, you are making a semantic copy. Both variables are referencing the same object and if you make changes to properties using one variable, those properties will correctly be represented in the second variable.

For a deeper dive, see this blog post:

https://blogs.mathworks.com/loren/2020/07/31/the-value-of-value-semantics/#0899c115-423b-4230-a1de-0cfa46f1e0ac