when i do
jTabGroup = findjobj(hTabGroup,'class','MJTabbedPane');

I get an object of class
javahandle_withcallbacks.com.mathworks.mwswing.MJTabbedPane

But when I call e.g.
jTabGroup.setForegroundAt(0,java.awt.Color(1.0,1,1));

on it, I just get
“Incorrect number or types of inputs or outputs for function setForegroundAt.”

It’s working! THANK YOU!!

@Peter – tab heights are set by the Operating System’s Look and Feel. You can either change the Look-and-Feel used by Matlab, or use the much larger tabs in the GUI Layout Toolbox (GUILT).

@Michi – in recent Matlab releases Matlab no longer stores the Java handle in the tab-group’s ApplicationData property, so using getappdata() returns an empty array, causing the error that you see. Instead of using getappdata, us the findjobj utility:

jTabGroup = findjobj(hTabGroup,'class','MJTabbedPane');

% Prevent an annoying warning msg
warning off MATLAB:uitabgroup:OldVersion
 
% Prepare a tab-group consisting of two tabs
hTabGroup = uitabgroup; drawnow;
tab1 = uitab(hTabGroup, 'title','Panel 1');
a = axes('parent', tab1); surf(peaks);
tab2 = uitab(hTabGroup, 'title','Panel 2');
uicontrol(tab2, 'String','Close', 'Callback','close(gcbf)');
 
% Get the underlying Java reference (use hidden property)
jTabGroup = getappdata(handle(hTabGroup),'JTabbedPane');

% Equivalent manners to set a red tab foreground:
jTabGroup.setForegroundAt(1,java.awt.Color(1.0,0,0)); % tab #1
jTabGroup.setTitleAt(1,'Panel 2');
jTabGroup.setForeground(java.awt.Color.red);

% Equivalent manners to set a yellow tab background:
jTabGroup.setTitleAt(0,'Panel 1');
jTabGroup.setTitleAt(0,'Panel 1');

the following error shows up:
Dot indexing is not supported for variables of this type.

Executing your code line by line indicates that the error is prompted for the first time when executing
jTabGroup.setForegroundAt(1,java.awt.Color(1.0,0,0)); % tab #1

I am using MATLAB Version: 9.5.0.1033004 (R2018b) Update 2.

Many thanks for your help!

when I run your code:

figure 
% Prepare a tab-group consisting of two tabs
hTabGroup = uitabgroup; drawnow;
tab1 = uitab(hTabGroup, 'title','Panel 1');
a = axes('parent', tab1); surf(peaks);
tab2 = uitab(hTabGroup, 'title','Panel 2');
uicontrol(tab2, 'String','Close', 'Callback','close(gcbf)');
 
% Get the underlying Java reference (use hidden property)
jTabGroup = getappdata(handle(hTabGroup),'JTabbedPane');
 
% Add an icon to tab #1 (=second tab)
icon = javax.swing.ImageIcon('Find.gif');
jLabel = javax.swing.JLabel('Tab #2');
jLabel.setIcon(icon);
jTabGroup.setTabComponentAt(1,jLabel);	% Tab #1 = second tab
 
% Note: both label & icon automatically grayed when disabled
jTabGroup.setEnabledAt(1,false);  % disable only tab #1

I get the following error message. Can you tell me what’s wrong? or Would you please send me your code that works fine?

Thanks,
Maz

@Eric – HTML alignments only work within the area that the control allocates for the contents. It so happens that Java Swing allocates a tightly-fitting area for controls, so we basically have 3 options:

• Use a fixed-width font and right-pad with spaces
• Get the underlying Java handle of the tab-group and modify the Java properties (this became very difficult in recent Matlab releases)
• Enlarge the allocated area dynamically via pure Matlab and HTML: We first get the width of the tabs, then we set the tab’s title to be a left-aligned table having the same fixed width as the tab (minus a bit due to the margins):

  pos = getpixelposition(tab1);
  tab1.Title = sprintf('Tab #1', pos(1)-4);
  

hTabGroup2 = uitabgroup;
tab1 = uitab(hTabGroup2,'title','Tab #1');
tab2 = uitab(hTabGroup2,'title','This is a very long tab');
tab3 = uitab(hTabGroup2,'title','Tab #3');
set(hTabGroup2,'TabLocation','left')

set(tab1,'Title','Tab #1')

@Dani – it works fine for me – perhaps your specific GUI has a problem that causes a problem for findjobj to find the underlying java handle:

jHandles = findjobj(hTabGroup);
jTabbedPane = jHandles(end);