popupPanel Displays a popup panel with specified content

Syntax:
hPopupPanel = popupPanel(contents, position, highlightedWords)

Description:

popupPanel(CONTENTS) displays Matlab's help popup (available on Matlab releases R2007b onward) with the specified CONTENTS, which is one of:
- Webpage URL (e.g. 'UndocumentedMatlab.com'). Supported in all Matlab releases as of R2020a
- Help topic string (e.g. 'surf' or 'myFunction'). Not supported in R2020a+
- HTML text (e.g. '<b>bold</b> <i>italic</i> text'). Not supported in R2020a+ (you can place the HTML in a file and load the file)
- text filename (e.g. 'my_data.txt'). Supported in all Matlab releases as of R2020a

popupPanel(CONTENTS,POSITION) indicates the panel's position and size in screen-relative regular Matlab format: [x,y,width,height]. If POSITION is empty or unspecified, then [x,y,500,300] is assumed, where (x,y) is the current pointer's location.

popupPanel(CONTENTS,POSITION,HIGHLIGHTEDWORDS) specifies a string term or cell-array of string terms that should be highlighted in the presented panel's CONTENTS. This feature is not supported in R2013a and later.

hPopupPanel = popupPanel(...) returns the Java handle reference of the created panel, allowing access to many useful properties and callbacks. Type "get(hPopupPanel)", "methodsview(hPopupPanel)" for details.

Examples:
popupPanel('UndocumentedMatlab.com'); % display an online webpage
popupPanel('surf'); % display the specified doc page
popupPanel('myFunction'); % display a user-created help topic
popupPanel('myFunction.m'); % display a user-created help topic
popupPanel('<b>bold</b> <i>italic</i> text'); % display HTML text
popupPanel('C:\localTextPage.txt'); % display a local file
popupPanel('localWebPage.html'); % display a local webpage
popupPanel('surf',[200,300,400,500]); % display 400x500 popup at [200,300]
popupPanel('surf',[],'surface'); % display popup, highlight 'surface' terms
popupPanel('surf',[],{'surface','surfc'}); % highlight several terms

Warning:
This code heavily relies on undocumented and unsupported Matlab functionality. It works on Matlab 7.5+ (R2007b+), but use at your own risk!

Bugs and suggestions:
Please send to Yair Altman (altmany at gmail dot com)

Technical details of the implementation can be found at http://undocumentedmatlab.com/blog/customizing-help-popup-contents