Faster findjobj - Undocumented Matlab (2024)

11 Responses

1. 

   SjoerdApril 18, 2016 at 12:17Reply

   Hi Yair

   First off thank you for this post, and all the other articles the are very interesting, and i have learned a lot out of it.

   Today I downloaded this updated findjobj file, and when running it in Matlab R2015A it gave the following error.

   >> findjobjfindjobj: Number of elements in right hand side does not match number requiredby left hand sideError in findjobj (line 278) handles (dataLen+1:end) = [];

   For the moment I simply solved it by commenting this line, but this is maby not the best solution. So I was wondering if you have any tips to solve this? Is not a very important thing but i thought it was good to let you know.

   Sjoerd

2. 

   YaroslavApril 18, 2016 at 19:25Reply

   Hi Yair,

   See Also

   Find graphics objects with specific propertiesFind handle objects - MATLAB - MathWorks ItaliaFind handle objects - MATLAB - MathWorks Deutschland

   Kudos on the good work and on your meticulous maintenance. It helps a lot.

   One small thing though: findjobj still doesn’t accept the groot object. For example (Matlab R2015b),

   >> findjobj(groot)findjobj: The following error occurred converting from matlab.ui.Root to handle:Conversion to handle from matlab.ui.Root is not possible.Error in findjobj/traverseContainer (line 523) handles(thisIdx) = handle(jcontainer,'callbackproperties');Error in findjobj (line 277) traverseContainer(container,0,1);

   Nevertheless, the old syntax still works:

   >> findjobj(0)ans =handle: 1-by-1170

   Cheers

3. 

   MeadeAugust 29, 2016 at 23:29Reply

   Hi Yair,

   I’ve been using your excellent utility in a deployed toolbox for about a year now.
   Anyway, when I updated, I know get the following error

   Java exception occurred:java.lang.ArrayIndexOutOfBoundsException: No such child: 4at java.awt.Container.getComponent(Unknown Source)

   This seems to be related to this call:

   jscroll = findjobj(MyUitable) %get jScroll UI element under Matlab tablerhv = jscroll.getComponent(4);

   This call has worked without issue in an older version of |findjobj| (% $Revision: 1.46 $ $Date: 2015/01/12 13:54:47 $)
   I’m also directed to a MW page about deprecating JFrame support.

   Any thoughts would be most appreciated!
   Best,
   Meade

• 

  Yair AltmanSeptember 6, 2016 at 19:21Reply

  @Meade – as you can see, the error is not in the findjobj call but in your code (jscroll.getComponent(4)). You need to check the jscroll object that findjobj returned and see why there is no 5th component (Java indexes start from 0, so “4” means “5th”). You can do something like this:

  >> jscroll = findjobj(MyUitable)>> jscroll.list

• 

  MeadeSeptember 22, 2016 at 16:21

  @Yair – Thanks so much for the reply.
  I’ve been using your .list tip to dig into this more deeply and it seems that the new findjobj function returns a different (shorter) list of components than the older revision. This seems to be why my subsequent call for

  jscroll.getComponent(4);

  fails.
  For example:

  jscroll = findobj(info);jscroll.list

  yields:

  com.mathworks.hg.peer.utils.UIScrollPane[, 0, 0, 0x0, invalid, ..., viewportBorder = ]javax.swing.JViewport[, 0, 0, 0x0, invalid, ..., scrollUnderway = false]com.mathworks.hg.peer.ui.UITablePeer$23[hInfoTable, 0, 0, 0x0, invalid, ..., showHorizontalLines = true, showVerticalLines = true]javax.swing.CellRendererPane[, 0, 0, 0x0, invalid, hidden]com.mathworks.hg.peer.utils.UIScrollPane$1[, 0, 0, 0x0, invalid, ..., blockIncrement = 10, orientation = VERTICAL, unitIncrement = 1]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 0, 0, 0x0, invalid, ..., defaultCapable = true]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 0, 0, 0x0, invalid, ..., defaultCapable = true]com.mathworks.hg.peer.utils.UIScrollPane$2[, 0, 0, 0x0, invalid, ..., blockIncrement = 10, orientation = HORIZONTAL, unitIncrement = 1]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 0, 0, 0x0, invalid, ..., defaultCapable = true]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 0, 0, 0x0, invalid, ..., defaultCapable = true]

  While

  jscrollOLD = findobjOLD(info);jscrollOLD.list

  yields:

  com.mathworks.hg.peer.utils.UIScrollPane[, 0, 0, 500 x140, invalid, ..., viewportBorder = ]javax.swing.JViewport[, 375, 1, 124 x121, invalid, ..., scrollUnderway = false]com.mathworks.hg.peer.ui.UITablePeer$23[hInfoTable, 0, 0, 397 x120, invalid, ..., showHorizontalLines = true, showVerticalLines = true]javax.swing.CellRendererPane[, 0, 0, 0x0, invalid, hidden]com.mathworks.hg.peer.utils.UIScrollPane$1[, 0, 0, 0x0, invalid, hidden, ..., blockIncrement = 10, orientation = VERTICAL, unitIncrement = 1]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 0, 0, 0x0, invalid, ..., defaultCapable = true]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 0, 0, 0x0, invalid, ..., defaultCapable = true]com.mathworks.hg.peer.utils.UIScrollPane$2[, 375, 122, 124 x17, invalid, ..., blockIncrement = 10, orientation = HORIZONTAL, unitIncrement = 1]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 107, 0, 17 x17, invalid, ..., defaultCapable = true]com.sun.java.swing.plaf.windows.WindowsScrollBarUI$WindowsArrowButton[, 0, 0, 17 x17, invalid, ..., defaultCapable = true]javax.swing.JViewport[, 375, 1, 124 x0, invalid, ..., scrollUnderway = false]javax.swing.JLabel[, 1, 1, 374 x0, invalid, ..., verticalAlignment = CENTER, verticalTextPosition = CENTER]

  I’m sure that I’m missing something obvious, but any insight you have would be greatly appreciated.
  (As a final note, curiously, if I call the older version of findjobj first, then the newer version will successfully find all components. Thus, there is some sort of order dependence?! Weird!

  Thanks so much,
  Meade

• 

  Malcolm LidierthSeptember 23, 2016 at 02:46Reply

  @Meade
  Not sure about this. Are your components on the EDT? Are the components visible? You might try a drawnow() and see if that order dependence disappears. Also see javaObjectEDT.
  ML

• 

  MeadeSeptember 23, 2016 at 17:33

  @Malcolm
  I do not know if they are all on EDT. I’m an absolute java novice, but from reading, I cannot say whether all components are being accessed in the same thread. This seems like a question that Yair might be able to answer since all the calls are being made within the findjobj call.

  I understand this all seems stranges, but I get the errors while literally only changing the version of findjobj that is being used, so the difference must be related to that. I’m happy/willing/excited to make changes since Yair has made such dramatic speed improvements in his utility, I’m just at a loss as where to start.

  Thanks for all the good suggestions.
  Meade

• 

  Malcolm LidierthSeptember 23, 2016 at 22:02Reply

  Meade

  Create your JScrollPane through a call to
  >> jscroll=javaObjectEDT(‘javax.swing.JScrollPane’);

  That on it’s own might(??) fix all your problems as subsequent methods calls to the scroll pane should be despatched via the EDT. If not do post your construction code. Very few Swing methods are inherently thread-safe and this does look like a treading issue.

info = uitable('Parent',hLeft,... 'Data',cell(5,1),... 'ColumnName', [],... 'RowName',infoCell,... 'RowStriping','off',... 'ColumnWidth', {397},... 'ColumnFormat', columnformat,... 'ColumnEditable', false,... 'Position',[30, 10, 500, 140 ],... 'FontSize',10,... 'TooltipString',TTstr.TSVinfo,... 'BackgroundColor',[0.94 0.94 0.94],... 'Tag','hInfoTable');%%% Java voodoo for Info tablejscroll=findjobj(info);

• 

  Malcolm LidierthSeptember 27, 2016 at 02:55Reply

  @Meade

  You can call jscroll methods in the EDT if you can get a reference to it and call javaObjectEDT on the reference:

  jscroll=javaObjectEDT(jscroll)

  If you have problems after a javaObjectEDT you might try

  jscroll.revalidate();% Does layoutjscroll.repaint();% Paints componentdrawnow()

  Revalidate and repaint are both thread-safe and will be run on the EDT by Swing.

  I am on a Mac and all seems to work fine without tweaks (and the same with the latest or older findjobj) so I can’t be much help but here’s what I see anyway:

  >> info = uitable('Parent',figure,... 'Data',cell(5,1),... 'ColumnName', [],... 'RowName',{'1', '2', '3','4','5'},... 'RowStriping','off',... 'ColumnWidth', {397},... 'ColumnEditable', false,... 'Position',[30, 10, 500, 140 ],... 'FontSize',10,... 'BackgroundColor',[0.94 0.94 0.94],... 'Tag','hInfoTable');>> jscroll=findjobj(info)jscroll =javahandle_withcallbacks.com.mathworks.hg.peer.utils.UIScrollPane

  All seems OK to me:

  >> jscroll.getComponents()ans = java.awt.Component[]: [1×1 javax.swing.JViewport ] [1×1 com.mathworks.hg.peer.utils.UIScrollPane$1] [1×1 com.mathworks.hg.peer.utils.UIScrollPane$2] [1×1 javax.swing.JViewport ] [1×1 javax.swing.JViewport ] [1×1 javax.swing.JList ]

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