«
»

Customizing Matlab labels

Wednesday, November 11th, 2009

As I was deliberating the topic of my weekly article, a new CSSM newsreader thread arrived today to immediately conclude the debate: The CSSM poster asked how Matlab labels can be modified to display non-ASCII characters such as the ∀ or β math symbols.

As you may recall, unlike axes text labels that support Tex/Latex, and unlike other uicontrols like buttons or listboxes that support HTML, text labels (uicontrol(‘Style’,'text’,…)) do not support text formatting or special symbols.

In the above-mentioned thread, Matt Whitaker, a longstanding CSSM contributor and a Matlab-Java veteran gave a solution that shows how seemingly difficult questions sometimes have simple solutions right beneath our noses. His solution was to simply replace the uicontrol label with a Java JLabel:

%show the 'for all' and 'beta' symbols
labelStr = '<html>&#8704;&#946; <b>bold</b> <i><font color="red">label</html>';
jLabel = javaObjectEDT('javax.swing.JLabel',labelStr);
[hcomponent,hcontainer] = javacomponent(jLabel,[100,100,40,20],gcf);

Math symbols and HTML support in a Java JLabel

Math symbols and HTML support in a Java JLabel

Note that the standard Matlab text uicontrol itself is very limited in the amount of customization it supports, even when accessing its underlying Java object using the FindJObj utility. This underlying Java object is a com.mathworks.hg.peer.utils.MultilineLabel extension of Swing’s bland javax.swing.JComponent. In fact, aside from some font and color customizations (also available via the Matlab HG properties), the most useful properties that are accessible only via the Java object are few. These include Border, HorizontalAlignment, VerticalAlignment and LineWrap. This is a very short list compared to the long list of corresponding undocumented properties in the other uicontrols.

Related posts:

  1. Syntax highlighted labels & panels Syntax-highlighted labels and edit-boxes can easily be displayed in Matlab GUI - this article explains how. ...
  2. Customizing listbox & editbox scrollbars Matlab listbox and multi-line editbox uicontrols have pre-configured scrollbars. This article shows how they can be customized....
  3. FindJObj – find a Matlab component’s underlying Java object The FindJObj utility can be used to access and display the internal components of Matlab controls and containers. This article explains its uses and inner mechanism....
  4. Matlab and the Event Dispatch Thread (EDT) The Java Swing Event Dispatch Thread (EDT) is very important for Matlab GUI timings. This article explains the potential pitfalls and their avoidance using undocumented Matlab functionality....
  5. Rich Matlab editbox contents The Matlab editbox uicontrol does not handle HTML contents as do other uicontrols. In this article I show how this limitation can be removed....
  6. Spicing up Matlab uicontrol tooltips Matlab uicontrol tooltips can be spiced-up using HTML and CSS, including fonts, colors, tables and images...

Tags: , , , , , ,

Categories: GUI, Handle graphics, Hidden property, Java, Low risk of breaking in future versions, UI controls

This entry was posted on Wednesday, November 11th, 2009 at 4:06 pm PST
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.

PoorSo-soHelpfulVery helpfulExcellent! (No Ratings Yet)
Loading ... Loading ...
 Bookmark and Share Print Print
If you like this post, please consider buying me a cup of coffee.

2 Responses to “Customizing Matlab labels”

  1. Nick Nick says:
    May 28, 2010 at 7:00 pm

    I don’t know if this is obvious as I don’t know Java, but you can change the gray background of the JLabel by defining a java.awt.Color object and using setBackground:

    mycolor = javaObjectEDT(‘java.awt.Color’, rgb_code)
    setBackground(jLabel, mycolor);

    The rgb_code is an integer that seems to be correspond to RGB as follows:

    256^2*(0-255 red level) + 256*(0-255 green level) + (0-255 blue level)

    So black = 0, and white is 256^2*255 + 256*255 + 255. You can cobble together highlighted sentences using this technique by aligning multiple JLabel objects in the figure.

  2. Yair Altman Yair Altman says:
    May 29, 2010 at 11:12 am

    @Nick – JLabel’s Background and Foreground properties, and their corresponding getXYZ(),setXYZ() accessor methods, are common to all Java Swing components, together with several other basic properties (and their accessor methods).

    In this particular case, java.awt.Color can be constructed in several ways:

    1) Color(int) – the single integer RGB value you have reported in your comment

    2) Color(float,float,float) – accepts three values between 0.0-1.0 (R,G,B)

    3) Color(float,float,float,float) – as #2 above, with an additional 0.0-1.0 value for transparency (alpha)

    4) Color(int, int, int) – as #2 above but the RGB values are specified as integer values between 0-255. There is also a fourth value for alpha, as in #3 above

    5) Color.red etc. – there are several predefined static values: black, blue, cyan, darkGray, gray, green, lightGray, magenta, orange, pink, red, white, and yellow

Leave a Reply


Wrap code fragments inside <pre lang="matlab"> tags, like this: 

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