- Undocumented Matlab - https://undocumentedmatlab.com -

Panel-level uicontrols

Posted By Yair Altman On November 24, 2010 | 17 Comments

In one of my larger Matlab applications – Integration-lab Debriefing System (IDS, which shall be described in a future dedicated article) – I wanted to present a panel-level checkbox that applies to the entire panel contents. In my particular case, the IDS uipanel contained a Java table (another future topic) with multiple selectable rows, and I needed a global checkbox that selects all (or none) of them at once:

Panel-level ("Objects") checkbox
Panel-level ("Objects") checkbox

One way to do this is to calculate the checkbox’s desired position relative to the uipanel and place a regular checkbox-style uicontrol there. The checkbox can even be made a child of the uipanel with ‘normalized’ units, thereby moving and resizing it together with its uipanel parent when the later is moved or resized.
But there’s a much simpler method that want to share. It relies on the undocumented fact that the uipanel‘s title label is a simple hidden uicontrol child of the uipanel handle. This uicontrol handle can be found and simply transformed from a ‘style’=’text’ control into a ‘style’=’checkbox’ control, as follows:

% Prepare the panel
hPanel = uipanel('position',[0.2,0.2,0.4,0.4], 'title','Objects');
% Get the title label's handle
warning off MATLAB:Uipanel:HiddenImplementation  % turn off warning
hTitle = setdiff(findall(hPanel),hPanel);  % retrieve title handle
hTitle = get(hPanel,'TitleHandle');  % alternative, uses hidden prop
% Modify the uicontrol style; add 20 pixel space for the checkbox
newPos = get(hTitle,'position') + [0,0,20,0];  % in pixels
set(hTitle, 'style','checkbox', 'value',1, 'pos',newPos);

Panel-level checkbox
Panel-level checkbox

Note that we can retrieve the title handle using either the uipanel‘s hidden property TitleHandle, or by scanning the panel’s children using findall. I prefer the TitleHandle approach because it does not require modification (minor as it might be) when the panel already contains other children.
The down-side is that since TitleHandle is an undocumented hidden property, it may change its name, its behavior or even be removed in some future Matlab release. In fact, there’s even a Matlab warning about this, unless you turn it off using:

warning off MATLAB:Uipanel:HiddenImplementation

We can use this approach for more complex options panels, as the following example illustrates. Here, we set radio-button controls rather than a checkbox control, and also modify the title color to blue:

% Main panel and basic alternative control
hPanelMain = uipanel('pos',[.1,.1,.8,.8], 'Title','Main', 'units','norm');
hAlt1 = uicontrol('parent',hPanelMain, 'units','norm', 'pos',[.1,.8,.5,.1], 'style','radio', 'string','Alternative #1');
% Alternative options panel #2
hAlt2 = uipanel('parent',hPanelMain, 'units','norm', 'pos',[.07,.4,.5,.35], 'title','Alternative #2');
hAlt2Title = get(hAlt2, 'TitleHandle');
newPos = get(hAlt2Title,'position') + [0,0,20,0];  % in pixels
set(hAlt2Title, 'style','radio', 'pos',newPos);
hAlt2a = uicontrol('parent',hAlt2, 'units','norm', 'pos',[.2,.6,.7,.3], 'style','checkbox', 'string','Option 1');
hAlt2b = uicontrol('parent',hAlt2, 'units','norm', 'pos',[.2,.2,.7,.3], 'style','checkbox', 'string','Option 2');
% Alternative options panel #3
hAlt3 = uipanel('parent',hPanelMain, 'units','norm', 'pos',[.07,.05,.5,.3], 'title','Alternative #3');
hAlt3Title = get(hAlt3, 'TitleHandle');
newPos = get(hAlt3Title,'position') + [0,0,20,0];  % in pixels
set(hAlt3Title, 'style','radio', 'pos',newPos, 'ForegroundColor','blue');
hAlt3a = uicontrol('parent',hAlt3, 'units','norm', 'pos',[.2,.5,.7,.3], 'style','popup', 'string',{'Option 3a','Option 3b','Option 3c'});

Advanced panel-level controls
Advanced panel-level controls

Note that since the hAlt2Title and hAlt3Title radio-buttons are children of their respective uipanel parents, we cannot use a simple uibuttongroup to group them in a mutual-exclusion group. Instead, we must use a dedicated callback function. This is actually quite easy:

% Set the callback for all relevant radio-buttons
hButtonGroup = [hAlt1, hAlt2Title, hAlt3Title];
set(hButtonGroup, 'Callback', {@SelectionCb, hButtonGroup});
% This is the callback function that manages mutual exclusion
function SelectionCb(hSrc,hEvent,hButtonGroup)
   otherButtons = setdiff(hButtonGroup,hSrc);
   set(hSrc,'value',1);  % needed to prevent de-selection

Categories: GUI, Handle graphics, Hidden property, Low risk of breaking in future versions, Stock Matlab function, UI controls

17 Comments (Open | Close)

17 Comments To "Panel-level uicontrols"

#1 Comment By Alex On November 25, 2010 @ 02:20

In the first image in this article, how did you achieve the horizontal line under the tabs that are not active?

#2 Comment By Yair Altman On November 25, 2010 @ 09:20

Alex – The uitab control (explained [7], with additional articles earlier this month that showed how to customize the tab appearance and behavior), hides the separator line in its internal implementation. In the example on this page I used a Java JTabbedPane directly, and this preserves the separator line. Here’s a simple example:

[jTabbedPane, hContainer] = javacomponent('javax.swing.JTabbedPane', [20,50,200,200], gcf);
jTabbedPane.addTab('tab #1',javax.swing.JPanel);
jTabbedPane.addTab('tab #2',javax.swing.JPanel);

#3 Comment By Alex On November 26, 2010 @ 01:30

Thanks, that’s exactly what I was looking for. Can you give ma an example how to add a Matlab uicontrol and axes to a tab? Can I set the ‘parent’ property to an uicontrol or is there another way now?

#4 Comment By Yair Altman On November 30, 2010 @ 15:26

Alex – Matlab uicontrols and axes cannot be added to Java containers (well, at least not without a herculean effort).

This is why MathWorks implemented uitab so that uicontrols/axes are not added directly to the tabs but rather to invisible Matlab containers that are handled by the tab callbacks.

Under the hood, uitab is a simple JTabbedPane that has no containers, only tabs. So, fixing it such that the missing separator line appears should be a simple enough exercise for you.

Please post the necessary changes to the uitab.m file (or its relatives) here if and when you succeed.

#5 Comment By Alex On December 1, 2010 @ 03:40

Is it in the schema.m? I tried to modify the line

jpanel = javax.swing.JPanel(java.awt.BorderLayout);
[comp2, h.HgContainer] = javacomponent(jpanel,[1 1 1 1], h.parent);

but I couldn’t see the effect.
I’m new to Java, so could you please give me more hints?

#6 Comment By Alex On December 9, 2010 @ 06:42

I looked at jTabGroup using


is there a property to make the separator line appear?

#7 Pingback By Using Java 7 in Matlab R2013a and earlier | Undocumented Matlab On June 19, 2013 @ 12:11

[…] Notice that the panel names are still missing. So far no solution for this has been found. Perhaps this can be overcome using the fact that uipanel titles are simply hidden children of the panel object. […]

#8 Comment By Ninad kubal On February 25, 2014 @ 22:44

Can i add callback on any property change of matlab uipanel or uicontrol?

#9 Comment By Yair Altman On February 26, 2014 @ 00:30

@Ninad – you can try to use [8].

#10 Comment By Patrick Holland On June 11, 2014 @ 06:31

Hello Mr. Altman,
I don’t know where exactly to ask, so I ask here.
I found in the internet one respond from you

[jPanel,hPanel] = javacomponent(javax.swing.JPanel);
set(hPanel, 'units','normalized','position',[.1,.1,.8,.8]);
hControl = uicontrol('style','pushbutton', 'parent',hPanel, 'string','click me');

I have tried this code with Matlab 2013b and the Panel is empty somehow. I don’t know why.
But my question IS… I want to add an undetermined amount of editboxes and labels to a panel. It can be 1 or 32 or even more.
I don’t want to resize them according to the space because then they would be extremely too small. So i need a Scrollbar.

I thought to use a JPanel and put it in a JScrollpane, but i failed at the first step up there. The jPanel is empty.
Do you know what’s wrong?


#11 Comment By Yair Altman On June 11, 2014 @ 06:46

@Patrick – you used javacomponent incorrectly. Read about the correct usage here: [9]

If you’d like my consulting help with setting up a scroll-panel and other such advanced GUI stuff, please contact me offline – my email link is at the top-right of this page.

#12 Comment By Patrick Holland On June 11, 2014 @ 06:49

Hello Mr. Altman,
i don’t understand. It’s from your own post here.


#13 Comment By Yair Altman On June 11, 2014 @ 06:54

@Patrick – just do as I suggested, read the link I provided.

#14 Comment By Kusi On February 23, 2015 @ 04:38

In R2014b, it seems like the TitleHandle property is gone. Is there another way to have panel-level check boxes?

#15 Comment By Yair Altman On February 23, 2015 @ 05:33

@Kusi – no: in HG2 (R2014b) the Matlab uipanel is (finally!) implemented as a true Java Swing component (deriving from JPanel), and the title is implemented as a standard Java titled-border. In other words, it is no longer a separate uicontrol.

Instead, you can simply place a dedicated checkbox uicontrol on top of the panel, you just need to ensure the position is correct and normalized so that it moves with the panel when it changes its size/position.

#16 Comment By Garuve On May 2, 2017 @ 10:52

@Yair: Could you provide an example of doing this (in HG2)? I can’t get it to work (i.e. I don’t know how to put a checkbox uicontrol ‘on top of’ the panel?
Very much appreciated!

#17 Comment By Matt On May 3, 2017 @ 02:35

Garuve, one easy way to put a control on top of a panel simply put the panel as the parent.

exampleFigure = figure;
hp = uipanel('Title','Main Panel','FontSize',12,...
             'Position',[.25 .1 .67 .67],...
             'Units', 'Normalized');
cb = uicontrol(hp,'style','checkbox','position',[100,100, 20,20])

Article printed from Undocumented Matlab: https://undocumentedmatlab.com

URL to article: https://undocumentedmatlab.com/articles/panel-level-uicontrols

URLs in this post:

[1] Rich-contents log panel : https://undocumentedmatlab.com/articles/rich-contents-log-panel

[2] GUI integrated HTML panel : https://undocumentedmatlab.com/articles/gui-integrated-html-panel

[3] Images in Matlab uicontrols & labels : https://undocumentedmatlab.com/articles/images-in-matlab-uicontrols-and-labels

[4] Icon images & text in Matlab uicontrols : https://undocumentedmatlab.com/articles/icon-images-in-matlab-uicontrols

[5] Transparency in uicontrols : https://undocumentedmatlab.com/articles/transparency-in-uicontrols

[6] Transparent uipanels : https://undocumentedmatlab.com/articles/transparent-uipanels

[7] : https://undocumentedmatlab.com/blog/tab-panels-uitab-and-relatives/

[8] : https://undocumentedmatlab.com/blog/continuous-slider-callback/#Property_Listener

[9] : https://undocumentedmatlab.com/blog/javacomponent

[10] : https://www.mathworks.com/matlabcentral/newsreader/view_thread/148636

Copyright © Yair Altman - Undocumented Matlab. All rights reserved.