Customizing listbox & editbox scrollbars

February 1, 2010 54 Comments

A few days ago, a CSSM forum reader asked how to modify Matlab’s listbox scrollbars. Another user asked how to configure line-wrapping. I thought this is a good opportunity to describe how listbox and editbox scrollbars can be customized. The timing is particularly opportune, after I have recently described how the Matlab Editbox can be customized by accessing its underlying Java object using the FindJObj utility.
Both the listbox and the multi-line editbox uicontrols share a similar design: a multi-line Java control embedded within a JViewport within a JScrollPane (note that for historical reasons, the Java view-port class is called JViewport rather than the more standard camel-cased JViewPort). In addition to the view-port, the containing scroll-pane also contains two scrollbars (horizontal and vertical), as expected from standard Java scroll-panes.

Scrollbar policies

Control of the scroll-pane’s scrollbar behavior is done via the JScrollPane’s VerticalScrollBarPolicy and HorizontalScrollBarPolicy properties.
VerticalScrollBarPolicy accepts the self-explanatory values of:

VERTICAL_SCROLLBAR_ALWAYS (=22)
VERTICAL_SCROLLBAR_NEVER (=21)
and VERTICAL_SCROLLBAR_AS_NEEDED (=20)

HorizontalScrollBarPolicy accepts:

HORIZONTAL_SCROLLBAR_ALWAYS (=32)
HORIZONTAL_SCROLLBAR_NEVER (=31)
and HORIZONTAL_SCROLLBAR_AS_NEEDED (=30)

All these properties are static enumerated constants that can be referred using either their Java notation (e.g., JScrollPane.VERTICAL_SCROLLBAR_ALWAYS) or their equivalent numeric values. Using the non-numeric format is better, since it is more readable and the numeric values may change, but the choice is yours.
By default, Matlab implements a VerticalScrollBarPolicy of VERTICAL_SCROLLBAR_ALWAYS for sufficiently tall uicontrols (>20-25 pixels, which practically means always) and VERTICAL_SCROLLBAR_NEVER for shorter uicontrols.
For the horizontal scrollbar, Matlab implements a HorizontalScrollBarPolicy of HORIZONTAL_SCROLLBAR_NEVER for all editboxes and for narrow listboxes (<35 pixels), and HORIZONTAL_SCROLLBAR_AS_NEEDED for wide listboxes.
These settings are generally satisfactory. However, in some cases users may wish to modify the settings. For example, the default VerticalScrollBarPolicy setting of VERTICAL_SCROLLBAR_ALWAYS causes the vertical scrollbar to appear even when unneeded (the entire editbox content is visible). Also, we may wish to have a horizontal scrollbar on narrow listboxes and editboxes, something that the standard HORIZONTAL_SCROLLBAR_NEVER prevents. In both cases, a *_SCROLLBAR_AS_NEEDED policy might be more appropriate.
To modify these settings, we simply need to get the uicontrol’s underlying Java reference handle (using the FindJObj utility), and modify the appropriate property. For example:

% Create a multi-line (Max>1) editbox uicontrol
hEditbox = uicontrol('style','edit', 'max',5, ...);
% Get the Java scroll-pane container reference
jScrollPane = findjobj(hEditbox);
% Modify the scroll-pane's scrollbar policies
% (note the equivalent alternative methods used below)
set(jScrollPane,'VerticalScrollBarPolicy',20);  % or: jScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED
jScrollPane.setHorizontalScrollBarPolicy(30);  % or: jScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED

default scrollbars (VERTICAL_SCROLLBAR_ALWAYS)

non-default scrollbars (VERTICAL_SCROLLBAR_AS_NEEDED)

Note that updating the uicontrol handle (hEditbox)’s Position property has the side-effect of automatically reverting the scrollbar policies to their default values (HORIZONTAL_SCROLLBAR_NEVER and VERTICAL_SCROLLBAR_ALWAYS/NEVER). This also happens whenever the uicontrol is resized interactively (by resizing its container figure window, for example). It is therefore advisable to set jScrollPane’s ComponentResizedCallback property to “unrevert” the policies:

cbStr = sprintf('set(gcbo,''VerticalScrollBarPolicy'',%d)', ...
                jScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
hjScrollPane = handle(jScrollPane,'CallbackProperties');
set(hjScrollPane,'ComponentResizedCallback',cbStr);

Line-wrapping

By default, line-wrapping is turned on, effectively disabling horizontal scrolling (which is why Matlab set the HorizontalScrollBarPolicy to HORIZONTAL_SCROLLBAR_NEVER. However, in some cases it may be more useful to turn line-wrapping off and horizontal scrolling on using the TextArea’s setWrapping() method. Here’s a usage example:

jViewPort = jScrollPane.getViewport;
jEditbox = jViewPort.getComponent(0);
jEditbox.setWrapping(false);  % do *NOT* use set(...)!!!
newPolicy = jScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED;
set(jScrollPane,'HorizontalScrollBarPolicy',newPolicy);

Notes:

setWrapping() only works for the default EditorKit, and fails for HTMLEditorKit – This is due to HTML’s inherent wrapping behavior, as can easily be seen in any browser webpage.
while setWrapping() may seem like a regular setter method for a Wrapping property, in reality it is not. Actually, set(jEditbox,’wrapping’,flag) may crash Matlab. So, always use the setWrapping(flag) method variant, which is entirely safe.

54 Responses

Carrie Kimbel February 10, 2010 at 08:45 Reply

I’m trying to turn off the ‘always on’ behavior of the vertical scrollbar in an edit control when I’ve made it multiline.

d.DirNameEdit = uicontrol(d.RunDlg, 'style', 'edit', ...
                        'position', [10 y(3) 260 20], ...
                        'BackgroundColor', [1 1 1], ...
                        'HorizontalAlignment', 'left', ...
                        'string', pwd);
jScrollPane = findjobj(d.DirNameEdit);
set(jScrollPane, 'VerticalScrollBarPolicy', 21);

I also tried jScrollPane.VERTICAL_SCROLLBAR_NEVER in place of the 21, but am getting this error:

??? There is no ‘VerticalScrollBarPolicy’ property in the
‘com.mathworks.hg.peer.EditTextPeer$hgTextField’ class.

Any suggestions? I downloaded and added findjobj to my path. Is there some other m-file I’m missing?

Yair Altman February 10, 2010 at 09:04 Reply

EditTextPeer$hgTextField is the single-line edit-box component, which does not have scrollbars. This is expected, since you ran findjobj immediately after creating your editbox as a single-line control. To turn the control to multi-line, you need to set the control’s Max property to a value greater than 1. If you now run findjobj you’ll see EditTextPeer$hgTextEditMultiline, which does indeed contain scrollbars.

Carrie Kimbel February 10, 2010 at 09:32
Found the answer. Well, first I was trying to do this on the wrong edit control in my code – needed to do it on a multiline edit control.

Second, when using the findjobj, it returned a 1×2 matrix of objects. Turned out the UIScrollPane was the second object in the matrix, so to set the scrollbar, I did:
set(set(jScrollPane(2), 'VerticalScrollBarPolicy', 21);
set(set(jScrollPane(2), 'VerticalScrollBarPolicy', 21);
Of note, Matlab said “No appropriate method, property, or field … when I tried to use jScrollPane(2).VERTICAL_SCROLLBAR_AS_NEVER instead of 21.
Carrie Kimbel February 10, 2010 at 09:50

Thanks Yair. Sorry I didn’t see your post before I posted my final solution. I didn’t mean to seem ungrateful for your response.
Yair Altman February 10, 2010 at 09:50

@Carrie – it’s VERTICAL_SCROLLBAR_NEVER (without the “_AS_”). Only VERTICAL_SCROLLBAR_AS_NEEDED has an “_AS_”.
Carrie Kimbel February 10, 2010 at 10:30

Sorry. Just a typo in my post. I tried …AS_NEEDED and …_NEVER in my code – no luck, but the numbers work great. Thanks.

camilo April 23, 2010 at 08:21 Reply

i tryed this code, for horizontal scrollbar,

jViewPort = jScrollPane.getViewport;
jEditbox = jViewPort.getComponent(0);
jEditbox.setWrapping(false);  % do *NOT* use set(...)!!!
newPolicy = jScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED;
set(jScrollPane,'HorizontalScrollBarPolicy',newPolicy);

but am getting this error:
?? No appropriate method, property, or field HORIZONTAL_SCROLLBAR_AS_NEEDED for class javahandle_withcallbacks.com.mathworks.hg.peer.utils.UIScrollPane.

Error in ==> blblblb at 8
newPolicy = jScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED;

Yair Altman April 24, 2010 at 11:03 Reply

@Camilo – it would help to know which Matlab version, Java version and OS you have – in short, the output of the ver function in your Matlab command prompt.

In the meantime, you can try Carrie’s solution above – simply use the number 30 instead of jScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED

Jeroen Boschma May 12, 2010 at 06:27 Reply

Hi Yair,

It works only half for me, hopefully you can point me in the correct direction. Currently working with :

———————————————————————————–
MATLAB Version 7.4.0.287 (R2007a)
Operating System: Microsoft Windows XP Version 5.1 (Build 2600: Service Pack 3)
Java VM Version: Java 1.5.0_07 with Sun Microsystems Inc. Java HotSpot(TM) Client VM mixed mode
———————————————————————————–

For testing I put a button and edit on a figure in GUIDE, I have a function to change the properties of the edit:

function r = set_edit_props(varargin)
 
r = true;
try
    h           = findobj('Tag', 'edit2');
    jScrollPane = findjobj(h);
    jViewPort   = jScrollPane.getViewport;
    jEditbox    = jViewPort.getComponent(0);
    %set(jScrollPane,'HorizontalScrollBarPolicy', jScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
    %set(jScrollPane,'VerticalScrollBarPolicy', jScrollPane.VERTICAL_SCROLLBAR_NEVER);
    set(jScrollPane,'HorizontalScrollBarPolicy', 32);
    set(jScrollPane,'VerticalScrollBarPolicy', 21);
    jEditbox.setWrapping(false);
catch
    disp(lasterr)
    r = false;
end

I used the integer-values for the scrollbars because the named constants are not part of the Java object.

Problem: when I call the above function from the button-callback, then it works. But this is not what I want, I want that when the figure is made visible, the scrollbars are automatically OK. So what I tried:

1) call ‘set_edit_props’ from edit create-callback:

jScrollPane =

handle: 0-by-0

No appropriate method or public field getViewport for class handle.handle.

2) call ‘set_edit_props’ after a 2 secs delay (timer-object) started within edit create-callback (try to let everything become visible before access is requested):

jScrollPane =

handle: 1-by-0

No appropriate method or public field getViewport for class handle.handle.

3) call ‘set_edit_props’ from OpeningFcn: result as with 2)

4) call ‘set_edit_props’ via timer from OpeningFcn: result as with 1) (!)

Nothing works. Maybe you have some ideas….

Regards,

Jeroen

Yair Altman May 12, 2010 at 07:51 Reply

@Jeroen – It doesn’t work in your creation callbacks because the figure is not yet visible at that point and findjobj requires a visible figure to find the underlying Java handles. This is why you see an empty handle list. This is also the reason it doesn’t work in your _OpeningFcn() function. Instead, place your code in the _OutputFcn() function, which is called immediately after the figure becomes visible.

Yair Altman June 18, 2010 at 08:08 Reply
@Carrie, @Camilo and others: If you get an error when you try to use the enumerated (non-numeric) policy values, then you can simply cast the Matlab handle() of the Java reference back into a Java reference. For example:
jScrollPane.java.HORIZONTAL_SCROLLBAR_AS_NEEDED
jScrollPane.java.HORIZONTAL_SCROLLBAR_AS_NEEDED
Alternately, as mentioned above, you can always use the numeric values of these enumerated policies. They are less readable/maintainable, but they always work 🙂
Gonzalo March 24, 2012 at 04:12 Reply

Hello Yair,

I show three edit text boxes. I want that when you move the first one`s slider( so you get the text from the line 12, for example) the other two show the text from the same line as the first one.

Do you know any way to do so?

Thanks,
Gonzalo

Yair Altman March 24, 2012 at 09:43 Reply

@Gonzalo – you can do this in the callback function for the slider. If you need help in this development (for a fee), then contact me offline using the email link at the top-left of this page.

Adeel May 12, 2012 at 23:18 Reply

I want maintain the scroll bar with respect to my matching text .For example in my page if there is Adeel in first existance than the scroll bar set on this Index. Please help me out
charan January 26, 2013 at 13:22 Reply

Hi Sir,
I am using Matlab 7.6.0(R2008a). When i used the same code for multiline edit, i am getting the following error:
??? Undefined function or method ‘findjobj’ for input arguments of type ‘double’.
I sincerely request your help to get rid of this problem.
And also how to make the display window to span across the entire screen?
Thank you.

Yair Altman January 26, 2013 at 13:26 Reply

@Charan – you need to download the findjobj utility from the Matlab File exchange (link). See a detailed explanation here.

Regarding window maximization, read here.

charan January 26, 2013 at 15:20

Hi Sir,
Thanks a lot for your “jet” reply.
I downloaded findjobj and now working fine. I am able to maximize the figure window also.
But still there persists a small problem.
The horizontal scroll bar is getting visible only after i press “Maximize” button in the control box (located on the top right hand corner); otherwise it is not visible, eventhough the text is crossing.
Thank you
Charan

Ben Kirollos March 22, 2013 at 08:29 Reply

Hi Yair,

I would like to stop a uitable from automatically scrolling back to the top after a cell has been edited in the table – instead staying at the same viewing position.

How would I go about doing this?

Many thanks,
Ben

Yair Altman March 23, 2013 at 10:24 Reply

By updating the cell at the Java level rather than updating the uitable’s Data property
Peter Borda December 17, 2014 at 05:49 Reply

“By updating the cell at the Java level rather than updating the uitable’s Data property”

How do you do that?

Yair Altman December 17, 2014 at 05:55

By using findjobj and the table’s setValueAt() method. The specifics depend on your Matlab release. Read my uitable customization report or section 4.1 in my Matlab-Java programming book for details.

mafap August 12, 2013 at 13:32 Reply

Hi Yair,
Can you give me some help? I’m not understanding how can I implement this in a GUI using GUIDE.
I have this Callback, there are no errors but it’s not working because the Horizontal Scrollbar is still appearing.

function message_list_Callback(hObject, eventdata, handles)
% hObject    handle to message_list (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
 
  % Get the Java scroll-pane container reference
  jScrollPane = findjobj(message_list);
 
  % Modify the scroll-pane's scrollbar policies
  set(jScrollPane,'VerticalScrollBarPolicy',20);  % VERTICAL_SCROLLBAR_AS_NEEDED
  set(jScrollPane,'HorizontalScrollBarPolicy',31);  % HORIZONTAL_SCROLLBAR_NEVER

Thanks

Yair Altman August 12, 2013 at 15:47 Reply

your message_list variable is not defined in your function, so obviously the function errors out
mafap August 12, 2013 at 16:07 Reply
Do you mean this?
% Create a multi-line (Max>1) editbox uicontrol message_list = uicontrol('style','edit', 'max',5, ...);
% Create a multi-line (Max>1) editbox uicontrol message_list = uicontrol('style','edit', 'max',5, ...);
I don’t get it because in GUIDE the editbox is self-created

Yair Altman August 12, 2013 at 16:16

You need to use the control’s handle, which is probably handles.message_list in your case. I’m afraid this is very basic HG programming, and this blog is for programmers who already have experience with Matlab programming. This is not a general-purpose Matlab blog. You may find the Matlab newsgroup or forum more suitable for your skill level.

mafap August 12, 2013 at 16:21 Reply

Thanks Yair, I will take a look.
mafap August 13, 2013 at 09:14 Reply

Hi Yair,
Actually I already had searched in some foruns including Matlab, what bring me here.
It looks like this doens’t work with GUIDEs or maybe I’m confused with a simple thing.

I get this error:
« The name ‘VerticalScrollBarPolicy’ is not an accessible property for an instance of class
‘com.mathworks.hg.peer.ListboxPeer$UicontrolList’. »

Yair Altman August 13, 2013 at 10:00

Findjobj works perfectly with GUIDE-generated GUI. I’m sorry but this starts to get beyond my ability to support in a public blog. Please contact me offline (via the email link at the top of this page) for a private 1-on-1 consulting session.

Dan September 2, 2013 at 16:56 Reply

What is the best way to retrieve and set the position of the viewport? I would like to record the current view of an uitable, and then reset it after Data is updated.

Yair Altman September 2, 2013 at 23:56 Reply

@Dan –

% Note: the following also works with Matlab listboxes and editboxes
hTable = uitable(...);
jScrollPane = findjobj(hTable);
jViewport = jScrollPane.getViewport;
originalPos = jViewport.getViewPosition;  % java.awt.Point[x=150,y=54]
...
jViewport.setViewPosition(originalPos);          jScrollPane.repaint
jViewport.setViewPosition(java.awt.Point(0,0));  jScrollPane.repaint  % move to top-left position

John Wilson June 25, 2014 at 11:59 Reply

Yair, thank you so much for your prolific and open sharing – this is valuable stuff. Your code snippet to set the scroll position helped me significantly today!

Just a quick comment on the following line:

jScrollPane = findjobj(hTable);

What I found in my case is that 2 handles were returned from findjobj(hTable). Here is what MATLAB’s “class” function returned for the 2 handles:

javahandle_withcallbacks.com.mathworks.hg.peer.HeavyweightLightweightContainerFactory$UIComponentLightweightContainer
javahandle_withcallbacks.com.mathworks.hg.peer.utils.UIScrollPane

So what I did is just filter through these as follows:

% The original scroll position for the table
tableHandles = findjobj(hObject);
jScrollPane = [];
jViewport = [];
origScrollPos = [];
if length(tableHandles) == 1
    jScrollPane = tableHandles;
else
    % Find the handle which corresponds to the scroll pane
    for i=1:length(tableHandles)
        classStr = lower(class(tableHandles(i)));
        idx = strfind(classStr,'scrollpane');
        if ~isempty(idx)
            jScrollPane = tableHandles(i);
            break;
        end
    end
end
if ~isempty(jScrollPane)
    jViewport = jScrollPane.getViewport;
    origScrollPos = jViewport.getViewPosition;
end

Thanks again for your help!

John

Variables Editor scrolling | Undocumented Matlab January 8, 2014 at 11:08 Reply

[…] desired position using the scrollCellToVisible() method.Note that the Matlab object builds on the javax.swing.JViewport and provides a convenient interface as in the case of the scrolling function, since its java […]
Knut J February 6, 2014 at 05:00 Reply

Yair,

These functions are extremely valuable. I have an issue in uitable when updating single cells at the java level instead of reloading the entire Data.

I have a long uitable-list with e.g. 100 rows and 5 columns. When updating a single cell (or multiple cells) that is not in the current view, the jtable.setValueAt-function hangs the entire program, and have to be force-quit. Example: Viewport is at (0,0) top left, and I ask that cells with checkboxes in row 90 to 100 is set false by a for-loop, without scrolling down.

It works like a charm if the edited cells are in the current view. Is this a limitation in java-tables?

Knut

Matlab 2013a.

Yair Altman February 6, 2014 at 05:08 Reply

@Knut – more likely it is a bug in Matlab’s implementation of uitable (which is a wrapper around Java’s JTable), and not a limitation of the underlying JTable. Try setting the table visibility off just for the duration of the update, maybe this will work. Otherwise, you can temporarily scroll to make the selected cell visible, and/or use a real JTable or JIDE table rather than uitable.

Knut J February 7, 2014 at 14:30 Reply

Thanks for your tips.

Just turning off visibility did not do the trick. My solution was to get the viewport position (using some of your other code snippets), setting the entire Data to the table, and then jumping to the original scroll position. Thank you for the inspiration.

This works:

% Get selected row numbers
myTable = findjobj(h.Table);
rows = myTable.getComponent(0).getComponent(0).getSelectedRows+1;
cols = myTable.getComponent(0).getComponent(0).getSelectedColumns+1;
 
% Get scroll position
jViewport = myTable.getViewport;
%jtable = jViewport.getView;
originalPos = jViewport.getViewPosition;
 
% Set table visible off
set(h.myTable,'Visible', 'off');
 
% Change myData
myData(x,y) = false;
 
% Set data to table
set(h.Table,'Data', myData);
 
% Change viewport position
jViewport.setViewPosition(originalPos);
 
% Set visibility on again
set(h.myTable,'Visible', 'on');

Knut

Raj March 12, 2014 at 01:38 Reply

Hey,
how can i get access to the row header? If it works, i would like to use it to display the line numbers of the editbox. There are lots of useful links on google for java purpose but i can’t figure out how to implement them on matlab.

lumina April 25, 2014 at 08:59 Reply

I tried this:

hTable = uitable(...);
jscroll = findjobj(hTable);
jVScroll = jscroll(2).getVerticalScrollBar;
max = jVScroll.getMaximum;
%jVScroll.setValue(max);
jViewport = jscroll(2).getViewport;
jViewport.setViewPosition(java.awt.Point(0,max));

if I put a break point after the last line, i can see the scrollbar goes down to the bottom.
if I dont use break point, the scrollbar stays at the original position.
If I use jVScroll.setValue(max); it displays error message.

how to solve this problem?
Thanks

Yair Altman April 27, 2014 at 03:37 Reply

@Lumina – this appears like yet another instance of EDT effects. Try using javaMethodEDT and/or drawnow; pause(0.05);

Joe August 11, 2014 at 08:05 Reply

I am developing a GUI that creates multiple detached figures. I have been using the MATLAB ‘Figures’ container to manage all these figures because it provides so much useful functionality, rather than spend a lot of time creating a less slick and time-costing multi-figure container on my own. I am trying to set the horizontalscrollbarpolicy and have run into a couple problems for which someone might have some insight.

One thing I have noticed is that findjobj cannot find any figure objects when the figure is docked to the MATLAB ‘Figures’ container. Perhaps there is a code workaround for that? As a simpler workaround, I undock the figure and then set the horizontalscrollbarpolicy to allow horizontal scrolling (which works). If I dock the figure back to the MATLAB ‘Figures’ container, the scrollbar is reset and no longer allows horizontal scrolling. Is there any way to make persistent the java settings on the GUI objects as they are docked to the ‘Figures’ container?
Thanks

Xiaolong Ma October 6, 2014 at 06:53 Reply

Horizontal bar disappeared after upgrading to R2014b. The same code works fine in R2013a.

jScrollPane = findjobj(handles.edit1);
set(jScrollPane,'VerticalScrollBarPolicy',20);  % or: jScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED
jScrollPane.setHorizontalScrollBarPolicy(30);  % or: jScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED
jViewPort = jScrollPane.getViewport;
jEditbox = jViewPort.getComponent(0);
jEditbox.setWrapping(false);  % do *NOT* use set(...)!!!

Thanks!

Adam October 8, 2014 at 04:26 Reply

This is an issue of the new graphics system in R2014b so far as I can see (I also have a similar problem). An editbox is now a matlab.ui.control.UIControl object rather than just a numeric handle and findjobj doesn’t know about these of course since they are totally new. I am having a look at findjobj with respect to this for my own similar problem but it is an area I am totally unfamiliar with so I’m not sure I’ll find a solution other than no longer using it. If I do I’ll add a further comment if Yair has not already responded.

Yair Altman October 8, 2014 at 05:26
@Adam – I’ve updated findjobj over a year ago to process handle (in addition to numeric) objects. It behaves well in both HG1 (up to R2014a) and HG2 (R2014b). If it cannot find your specific handle then you might be using it incorrectly.

@Xialong – in 14b, you simply need to have Matlab repaint the component in order for the scroll changes to be visible. This can easily be done programmatically:
jEditbox.revalidate
jEditbox.revalidate

Adam October 8, 2014 at 05:35 Reply

Ah yes, sorry! I jumped the gun on that one, it must be a different aspect of the R2014b upgrade that has broken my functionality and caused findjobj to return no component (uitable in my case).

Christian Beuschel November 25, 2014 at 07:19 Reply

Dear Mr. Altman,
i got a problem with the setWrapping Function. It does not work.
My Versions are:
MATLAB Version: 8.2.0.701 (R2013b)
Java Version: Java 1.7.0_11-b21

When i check the component then there is “Wrapping off” but when i resize my figure the text breaks into multiple lines. I have of course used the componentresizecallback too. Everything should be okay, but my text breaks into multiple lines after resizing my figure.

Am i doing something wrong?
Here a sample code. The only code that worked for me.

    jScrollPane = findjobj(hEditorFeld);
    jViewPort = jScrollPane.getViewport;
    jEditbox = jViewPort.getComponent(0);
    jEditbox.setWrapping(false);
    jScrollPane.setHorizontalScrollBarPolicy(30);
    cbStr = sprintf('set(gcbo,''HorizontalScrollBarPolicy'',%d)',30);
    set(jScrollPane,'ComponentResizedCallback',cbStr);

Thanks Mr. Altman

Christian Beuschel November 26, 2014 at 00:54 Reply

Here a screenshot to show my problem a little better. I am attaching a small textarea to the jHandle of the editfield to see the number of lines. but when i resize the window, the text breaks into more lines…
http://fs1.directupload.net/images/141126/56nang4l.jpg

Greetings

Yair Altman November 26, 2014 at 03:09

@Christian – when you resize a component, Matlab resets its internal Java properties, so your Java customizations are forgotten and need to be re-applied. Specifically, you need to call setWrapping(false) once again, it’s not enough to just re-update the scrollbar policies.

Christian Beuschel November 26, 2014 at 08:54 Reply

Hello,
unfortunately it’s not true. I just tried by opening my programm directly with smaller figure width. I did not resize it after. The text is immediately wrapped :-/ I think that setWrapping doesn’t work as it should.
Christian Beuschel November 26, 2014 at 10:02 Reply

I guess that my manipulation of the rowHeader by attaching a textarea, destroys everything. 🙁 Before manipulation my object has Wrapping off. After manipulation there is no Wrapping anymore, neither on or off.. it’s like it’s an another object

Andres Roid April 26, 2017 at 17:06 Reply

Hi,

I’m trying scroll to a specific position in a GUI table. But when I load the value an exception appears.

I do this, it’s okay?

jTable = findjobj(handles.ranking); %% Ranking is a GUI table
jScrollPane = jTable.getComponent(0);
scrollPos = jScrollPane.getViewPosition;
set(jScrollPane,'ViewPosition',[0,69]); %% for exaple, x = 0, y = 69 position.

The error is this,

Exception in thread "AWT-EventQueue-0" java.util.ConcurrentModificationException
	at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
	at java.util.AbstractList$Itr.next(Unknown Source)
	at com.jidesoft.grid.CellStyleTable.configureRendererComponent(Unknown Source)
	at com.jidesoft.grid.CellStyleTable.prepareRenderer(Unknown Source)
	at com.jidesoft.grid.CellSpanTable.prepareRenderer(Unknown Source)
	at com.jidesoft.grid.PropertyTable.prepareRenderer(Unknown Source)
	at com.mathworks.mlwidgets.inspector.JidePropertyViewTable.prepareRenderer(JidePropertyViewTable.java:90)
	at com.jidesoft.plaf.basic.BasicJideTableUI.paintCell(Unknown Source)
	at com.jidesoft.plaf.basic.BasicCellSpanTableUI.c(Unknown Source)
	at com.jidesoft.plaf.basic.BasicCellSpanTableUI.paint(Unknown Source)
	at javax.swing.plaf.ComponentUI.update(Unknown Source)
	at javax.swing.JComponent.paintComponent(Unknown Source)
	at javax.swing.JComponent.paint(Unknown Source)
	at javax.swing.JComponent.paintToOffscreen(Unknown Source)
	at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(Unknown Source)
	at javax.swing.RepaintManager$PaintManager.paint(Unknown Source)
	at javax.swing.BufferStrategyPaintManager.paint(Unknown Source)
	at javax.swing.RepaintManager.paint(Unknown Source)
	at javax.swing.JComponent._paintImmediately(Unknown Source)
	at javax.swing.JComponent.paintImmediately(Unknown Source)
	at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
	at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
	at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
	at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
	at java.awt.event.InvocationEvent.dispatch(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)

Exception in thread "AWT-EventQueue-0" java.util.ConcurrentModificationException at java.util.AbstractList$Itr.checkForComodification(Unknown Source) at java.util.AbstractList$Itr.next(Unknown Source) at com.jidesoft.grid.CellStyleTable.configureRendererComponent(Unknown Source) at com.jidesoft.grid.CellStyleTable.prepareRenderer(Unknown Source) at com.jidesoft.grid.CellSpanTable.prepareRenderer(Unknown Source) at com.jidesoft.grid.PropertyTable.prepareRenderer(Unknown Source) at com.mathworks.mlwidgets.inspector.JidePropertyViewTable.prepareRenderer(JidePropertyViewTable.java:90) at com.jidesoft.plaf.basic.BasicJideTableUI.paintCell(Unknown Source) at com.jidesoft.plaf.basic.BasicCellSpanTableUI.c(Unknown Source) at com.jidesoft.plaf.basic.BasicCellSpanTableUI.paint(Unknown Source) at javax.swing.plaf.ComponentUI.update(Unknown Source) at javax.swing.JComponent.paintComponent(Unknown Source) at javax.swing.JComponent.paint(Unknown Source) at javax.swing.JComponent.paintToOffscreen(Unknown Source) at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(Unknown Source) at javax.swing.RepaintManager$PaintManager.paint(Unknown Source) at javax.swing.BufferStrategyPaintManager.paint(Unknown Source) at javax.swing.RepaintManager.paint(Unknown Source) at javax.swing.JComponent._paintImmediately(Unknown Source) at javax.swing.JComponent.paintImmediately(Unknown Source) at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source) at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source) at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source) at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source)

I am using Matlab 2009a

Xiangrui Li April 26, 2017 at 18:51 Reply

This seems related to the post at https://undocumentedmatlab.com/blog/handling-red-java-console-errors
Peter November 2, 2021 at 14:10 Reply

Hello Mr. Atlmann,
is it possible to change the width of the scrollbar? I use my app on a touch display and its hard to impossible to hit the scrollbar with the finger, so i would like to change the width of the scrollbar. If thats not possible, what other solutions would there be?
Thanks, Peter.

Yair Altman November 7, 2021 at 12:20 Reply

@Peter – you can modify the scrollbars by accessing them directly. For example:

% Create a multi-line (Max>1) editbox uicontrol
hEditbox = uicontrol('style','edit', 'max',5, ...);
% Get the Java scroll-pane container reference
jScrollPane = findjobj(hEditbox);
% Update the scrollbar handles
jSize = java.awt.Dimension(40,40);
jScrollPane.getHorizontalScrollBar.setPreferredSize(jSize);
jScrollPane.getVerticalScrollBar.setPreferredSize(jSize);
% Repaint the scrollpane on-screen
jScrollPane.revalidate

A more advanced solution could be to modify Matlab’s default Look-&-Feel (javax.swing.UIManager.put('ScrollBar.width',40);) so that all scrollbars created from now on (in the current Matlab session) will have a width of 40 pixels.

dani June 9, 2022 at 14:54 Reply

hi!! how i can set the horizontal scrollbar to the leftside when appearing! now it set to right side of text

Yair Altman June 10, 2022 at 10:24 Reply

Dani – You can use jViewport.setViewPosition(java.awt.Point(0,0)) as I showed in earlier comments here

HTML tags such as <b> or <i> are accepted.
Wrap code fragments inside <pre lang="matlab"> tags, like this:

<pre lang="matlab">
a = magic(3);
disp(sum(a))
</pre>

I reserve the right to edit/delete comments (read the site policies).
Not all comments will be answered. You can always email me (altmany at gmail) for private consulting.

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Iñigo (2 days 2 hours ago): Thanks Yair. I didn’t realize it was posted just above. It would be great to know about a solution soon
Yair Altman (3 days 10 hours ago): @Iñigo – your query is related to Seth’s question above. We can access the currently-browsed URL in JavaScript (for example: jBrowserPanel.executeScript...
Iñigo (5 days 1 hour ago): I am looking for setting a UI that allows following process: opening a web site, navigate inside this web site and at some specific moments (i.e. when the figure is closed or a button...
Nicholas (12 days 7 hours ago): Yair, this works wonderfully! I can’t thank you enough!
Collin (14 days 11 hours ago): Seth Good point, I am using 2022b, mathworks seems to have started using CEF browsers from 2019a, best I can tell. take a look at the package com.mathworks.toolbox.matla...
Seth (15 days 3 hours ago): Collin, What version of MATLAB are you using?
Collin (20 days 9 hours ago): Seth, I have had some success executing javascript that requires no return value by executing it directly (sort of) on the org.cef.browser.CefBrowser that a...
Coo Coo (22 days 4 hours ago): FFT-based convolution is circular whereas MATLAB’s conv functions have several options (‘valid’, ‘same’, ‘full’) but unfortunately not...
Seth (22 days 7 hours ago): No luck with removing the space.
Seth (22 days 9 hours ago): The javascript code works fine running the application from the 2019b desktop version and the 2016b deployed version.
Seth (22 days 9 hours ago): I have been using this browser functionality in 2016b because it works fully in deployed applications in that version. However, because of Java 7 being flagged as a security risk, I...
Yair Altman (22 days 9 hours ago): I’ve never tested javascript callbacks, but perhaps you should try removing the extra space after the “matlab:” protocol specifier. Does it make any difference?
Seth (22 days 9 hours ago): I have been using this functionality in 2016b since it works in deployed applications and have not had a reason to need to upgrade but with java 7 being flagged as a security risk I am...
KEVIN (42 days 10 hours ago): I apologize, I intended my response to fall under ‘T’ but did not seem to work. I was referring to the bit of code posted by ‘T’ regarding the toolgroup and...
Yair Altman (42 days 10 hours ago): It is not clear from your comment which code exactly you are referring to and what you see differently in 19b vs. 20b, so I cannot assist with your specific query. In general I...

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