Comments on: Customizing help popup contents

By: Nathan

Nathan — Thu, 28 Jan 2010 00:08:48 +0000

I am not using GUIDE (as implied by “coding by hand”), but your getClient() method worked for me. Thanks for the quick response and your help. This website is very insightful.

-Nathan

By: Yair Altman

Yair Altman — Wed, 27 Jan 2010 23:40:57 +0000

@Nathan – I assume you haven’t placed this in your GUIDE-generated _OpeningFcn(), as explained elsewhere. Another cause of this might be that when you run the code, jTextArea is still unavailable by the time the javaMethodEDT is called. In step-by-step debugging this is not an issue, since there is plenty of time for jTextArea to be set. It is also possible that there is no FocusOwner in the Desktop (unlike the case of step-by-step debugging) – this can be forced using the commandwindow function. As a final alternative, try using the getClient() approach to getting the Command-window TextArea, as I explained in my recent setPrompt article:

jDesktop = com.mathworks.mde.desk.MLDesktop.getInstance;
try
  cmdWin = jDesktop.getClient('Command Window');
  jTextArea = cmdWin.getComponent(0).getViewport.getComponent(0);
catch
  commandwindow;
  jTextArea = jDesktop.getMainFrame.getFocusOwner;
end

By: Nathan

Nathan — Wed, 27 Jan 2010 23:18:51 +0000

I’m having troubles using this in a GUI that I’m coding by hand.
As a “help” pushbutton callback, I have the following code:

function [] = pb_call5(varargin)
  jDesktop = com.mathworks.mde.desk.MLDesktop.getInstance;
  jClassName = 'com.mathworks.mlwidgets.help.HelpPopup';
  jPosition = java.awt.Rectangle(200,200,650,600);
  jTextArea = jDesktop.getMainFrame.getFocusOwner;
  helpTopic = 'LiqVapGui';
  javaMethodEDT('showHelp',jClassName,jTextArea,[],jPosition,helpTopic);
end

However, I am receiving an error stating that
“??? Error using ==> javaMethodEDT
Java exception occurred:
java.lang.IllegalArgumentException: ‘parent’ cannot be null”

When stepping through the debugger, I find that jTextArea is empty. However, if I re-type that line while in debug mode, it works just fine. Do you know any way that I can fix this problem?

-Nathan

By: Yair Altman

Yair Altman — Tue, 01 Dec 2009 22:13:13 +0000

1. This was due to a change in the way Matlab implemented the internal browser component in R2009. This only has an effect on highlighted words of a doc page, not any other popupPanel functionality. Anyway, I have uploaded a fixed version which should be available for download by tomorrow (depending on MathWorks workload...).2. I don't know a way around using the desktop or m-editor reference.- Yair

By: Dani

Dani — Tue, 01 Dec 2009 15:45:34 +0000

Fantastic – thanks a lot for this!

Two problems:

1. The popupPanel(‘surf’) call leads to the following error on my machine:

??? popupPanel: No appropriate method, property, or field 
getHTMLRenderer for class com.mathworks.mlwidgets.html.HTMLRenderer
 
Error in ==> popupPanel at 127
        contents = browser.getHTMLRenderer.getHtmlText;

Works as expected for all the other ways of calling it.

2. In compiled mode the Matlab desktop is not accessible. So the following lines cause problems:

jDesktop = com.mathworks.mde.desk.MLDesktop.getInstance;
jTextArea = jDesktop.getMainFrame.getFocusOwner;

Is it possible to get around this?

Dani