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Adding a context-menu to a uitree

A CSSM poster asked a few days ago whether it was possible to add a context (right-click) menu to uitree nodes. Uitree is an internal, undocumented and unsupported Matlab function, which does not enable easy setting of a uicontextmenu like its uicontrol relatives.

However, using some undocumented Java magic, it is possible to do so. Being undocumented and unsupported, this solution might break in future releases, although this is unlikely since it relies on some very basic Java functionality that is unlikely to be broken soon.

Note that the context-menu in the following example uses HTML formatting. As explained in an earlier post, all Swing components (and by extension, most Matlab uicontrols) support HTML formatting.

% Prepare the context menu (note the use of HTML labels)
menuItem1 = javax.swing.JMenuItem('action #1');
menuItem2 = javax.swing.JMenuItem('<html><b>action #2');
menuItem3 = javax.swing.JMenuItem('<html><i>action #3');

% Set the menu items' callbacks
set(menuItem1,'ActionPerformedCallback',@myFunc1);
set(menuItem2,'ActionPerformedCallback',{@myfunc2,data1,data2});
set(menuItem3,'ActionPerformedCallback','disp ''action #3...'' ');

% Add all menu items to the context menu (with internal separator)
jmenu = javax.swing.JPopupMenu;
jmenu.add(menuItem1);
jmenu.add(menuItem2);
jmenu.addSeparator;
jmenu.add(menuItem3);

% Set the tree mouse-click callback
% Note: MousePressedCallback is better than MouseClickedCallback
%       since it fires immediately when mouse button is pressed,
%       without waiting for its release, as MouseClickedCallback does
set(jtree, 'MousePressedCallback', {@mousePressedCallback,jmenu});

% Set the mouse-press callback
function mousePressedCallback(hTree, eventData, jmenu)
   if eventData.isMetaDown  % right-click is like a Meta-button
      % Get the clicked node
      clickX = eventData.getX;
      clickY = eventData.getY;
      jtree = eventData.getSource;
      treePath = jtree.getPathForLocation(clickX, clickY);
      try
         % Modify the context menu or some other element
         % based on the clicked node. Here is an example:
         node = treePath.getLastPathComponent;
         nodeName = ['Current node: ' char(node.getName)];
         item = jmenu.add(nodeName);

         % remember to call jmenu.remove(item) in item callback
         % or use the timer hack shown here to remove the item:
         timerFcn = {@removeItem,jmenu,item};
         start(timer('TimerFcn',timerFcn,'StartDelay',0.2));
      catch
         % clicked location is NOT on top of any node
         % Note: can also be tested by isempty(treePath)
      end

      % Display the (possibly-modified) context menu
      jmenu.show(jtree, clickX, clickY);
      jmenu.repaint;
   end
end

% Remove the extra context menu item after display
function removeItem(hObj,eventData,jmenu,item)
   jmenu.remove(item);
end

% Menu items callbacks must receive at least 2 args:
% hObject and eventData – user-defined args follow after these two
function myfunc1(hObject, eventData)
   % ... 

function myFunc2(hObject, eventData, myData1, myData2)
    % ...

uitree node-specific context-menu

uitree node-specific context-menu
(note the HTML formatting of menu items)

If the issue of undocumented Matlab interests you, please review the list of future post topics and let me know if you have any preference, or would like to see some other (unlisted) topics.

Yair

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Related posts:

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This entry was posted on Friday, March 27th, 2009 at 4:16 am and is filed under GUI, Java, Low risk of breaking in future versions, UI controls. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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4 Responses to “Adding a context-menu to a uitree”

  1. Darik Gamble Darik Gamble says:
    March 27, 2009 at 7:20 pm

    Yair,

    I’m glad to see you’ve got a blog — I remember learning from your newsgroup posts a couple years ago that I could add custom properties and event listeners to handle graphics objects, and both features have helped me immensely (and made it into the Matlab documention!)

    My votes on your to do list include customizing menus and the two schema topics.

    Cheers,

    dg

  2. Venky Venky says:
    March 31, 2009 at 9:27 pm

    Yair,
    It’s interesting to know that it is possible to add uicontextmenus to uitree.
    Your post saved my time.
    Thanks a lot

  3. Scott Koch Scott Koch says:
    June 9, 2009 at 3:00 pm

    If you have access to the figure handle (stored as User Data for instance) you could also use the click event coordinates to display a GUIDE created context menu:

    ...
if eventData.isMetaDown
  fh = get(hTree,'UserData');%Get figure handle
  cm = findobj(fh,'tag','mycontextmenu');%Get context menu handle.
  tpos = get(hTree,'PixelPosition');
 
  set(cm,'position',[eventData.getX()+tpos(1) (tpos(4)-eventData.getY)+tpos(2)],'Visible','on');
 
...
  4. Setting listbox mouse actions | Undocumented Matlab Setting listbox mouse actions | Undocumented Matlab says:
    September 15, 2009 at 6:30 am

    [...] months ago I explained how to set a context (right-click) menu on a uitree control. I shall now show how to implement a similar dynamic context-menu on a listbox. The code is an [...]

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