Comments on: Uicontrol callbacks

By: Matlab-Java memory leaks, performance | Undocumented Matlab

Matlab-Java memory leaks, performance | Undocumented Matlab — Fri, 20 Jan 2012 11:52:29 +0000

[...] a Matlab callback that gets invoked multiple times per second by a Java object (see related articles here and here). Each time the Matlab callback function is invoked, it reads the event information [...]

By: Yair Altman

Yair Altman — Thu, 05 Jan 2012 10:05:52 +0000

@Dave – this is correct. Matlab callbacks always send the originating object (in your case, a button which is actually an MJButton control) as the first parameter, and an eventData object as the second parameter. in eventData you can find information regarding the event, for example whether the button was clicked or right-clicked etc.

By: Dave

Dave — Tue, 03 Jan 2012 15:35:01 +0000

Yair, your knowledge is incredible, thank you for sharing.
Please excuse my lack of understanding but it seems that whenever I try to use a callback it sends javahandle_withcallbacks.com.mathworks.mwswing.MJButton as the first parameter.

function badprogrammingpractice
 
hFig = figure('position', [300 300 600 400]);
jbt = com.mathworks.mwswing.MJButton('click me');
jbt.setBorder([])
jbt.setBackground(java.awt.Color.white);
jbt.setCursor(java.awt.Cursor.getPredefinedCursor(java.awt.Cursor.HAND_CURSOR));
jbt.setFlyOverAppearance(1);
bob = [1 2 3]
jbtPosition = [0.1 0.1 0.3 0.3]
[dummy,btContainer] = javacomponent(jbt,[0 0 1 1],hFig);
set(btContainer, 'Units','Norm', 'Position',jbtPosition);
hbt = handle(jbt,'CallbackProperties');
set(hbt,'ActionPerformedCallback',@dosomething);
 
function [mean,stdev] = dosomething(x,y)
x

output:

bob =
1 2 3
jbtPosition =
0.1000 0.1000 0.3000 0.3000
x =
javahandle_withcallbacks.com.mathworks.mwswing.MJButton
>>

By: Janos Marki

Janos Marki — Sun, 30 Jan 2011 14:27:16 +0000

Update to previous: it now works. I think the problem was with the callback getting overwritten for some reason (only possible culprit: pcolor function). By inserting the callback handle again, it works without a hitch. Sorry for the hassle.

Janos

figure(a111)
set(gcf,'WindowKeyPressFcn',@scalSet)
waitfor(a111,'UserData','Done');

By: Janos Marki

Janos Marki — Sun, 30 Jan 2011 12:12:49 +0000

Hi,

I have a problem that I can’t seem to solve, and I can’t find the info.

I execute a number of commands culminating in a plot. At this point, I need to intervene manually, which I thought of doing via the WindowKeyPressFcn callback of the figure I plotted in. Once done, I would like script execution to resume.

However, whatever way I use to stop keyboard execution (keyboard, waitfor(figHand), no matter what I do, instead of the figure’s callback (scalSet.m) activating, the pressed key appears in the command window (i.e. I cannot make the figure the “active” object so the pressed key goes into it). It seems to me like this goes against the notion of having ready code, running the GUI, and then interacting with it (as interaction would already start whilst the script is run). Is this me trying to use Matlab in ways it has not been intended to work? Can it be done, or should I just do it differently?

a111=figure('WindowKeyPressFcn',@scalSet); 
waitfor(a111,'UserData','Done');

…and the idea was to have one key (d) for the “Done” state in the callback function (waitfor would let the script carry on once this is triggered), which looks like this:

function scalSet(src,eventdata)
%function scalSet(src,eventdata)
%
%Function used to set scales with the mouse manually on plots with a colorbar
%Press 'r' to narrow the scale by clicking two values on the
%colorbar with the mouse
%
%Press 'w' to double the range
%
%enter set(gcf,'WindowKeyPressFcn',@scalSet) to add it to figures a
%posteriori
 
%we want to make the colorbar scaling smaller
if strcmp(eventdata.Character,'r')
   scval=ginput(2);
   chs=get(src,'Children');
   for k=1:length(chs)
       nu=get(chs(k),'Type');
       if strcmp(nu,'axes')
         nu2=get(chs(k),'Tag');
           if ~strcmp(nu2,'Colorbar')
               caxis(chs(k),[sort(scval(:,2))'])
           end
       end
   end   
end
 
%we want to widen it
if strcmp(eventdata.Character,'w')
   scval=caxis;
   wid=scval(2)-scval(1);
   caxis([scval(1)-wid scval(2)+wid])
end
 
%we are done
if strcmp(eventdata.Character,'d')
   set(src,'UserData','Done') 
end

Thanks!
Janos

By: Yair Altman

Yair Altman — Tue, 07 Dec 2010 19:59:06 +0000

@Sean – take a look at: http://undocumentedmatlab.com/blog/modifying-default-toolbar-menubar-actions/

- Yair

By: Sean Larkin

Sean Larkin — Tue, 07 Dec 2010 19:12:07 +0000

I’m trying to use findjobj to get the java handle for a toolbar uitogglebutton. It does not find the handles for the button. When I call the function like this:
findjobj;

it finds the toolbar button. Why is this and is there a way I can modify findjobj to directly find toolbar buttons?

By: iroln

iroln — Wed, 10 Nov 2010 21:11:15 +0000

Thanks, Yair Altman!

By: Yair Altman

Yair Altman — Sun, 07 Nov 2010 22:40:23 +0000

@iroln and Donn – apparently all mouse actions are delegated to the AxisCanvas component, so simply set your callback on that component. It works for me on R2010b. Here’s the complete code snippet:

function TestMouseCallbacks()
  hFig = figure();
  warning('off','MATLAB:HandleGraphics:ObsoletedProperty:JavaFrame');
  drawnow;
  jh = get(hFig, 'JavaFrame');
  jf = jh.fFigureClient.getAxisComponent;  % note the change
  jbh = handle(jf, 'CallbackProperties');
  set(jbh, 'MouseWheelMovedCallback', @MousePressed)
end
 
function MousePressed(jObject, jEventData)
  disp('Pressed')
end

By: Donn Shull

Donn Shull — Fri, 05 Nov 2010 15:53:09 +0000

@iroln – I am using windows 7 32 bit and the code you just sent works as you described