class TMrbHelpBrowser: public TNamed

 This class implements a simple HelpBrowser typically used in an interactive
 application where a standard browser like Netscape appears to be too clumpsy
 and takes away too much resources especially space on the screen.
 It does n o t support internet references (e.g. http:) but only file refs.
 It does n o t support display of the Web documentation of ROOT.

It accepts input in HTML format but does not recognize all possible tags.
 urrently only the following tags are recognized (others are just ignored):

<Hn> 					  Heading i.e. highlight line
<B>, <I> 				  bold, italic
<a NAME=xxx> 			  an anchor
<a href=yyy>text</a> 	  a reference (may not be http:)
<img SRC=pict.canvas.gif>  insert a gif picture

The constructor is normally called with the name of a directory containing
html-files to be included into the documention.
NB: A file index.html containing the entry level hrefs should be
    part of this directory.
If the complete documentation is in one htmlfile the name of
this file may be given instead.
Also a ROOT-file containing ready made documentation can be given
(see method ToRootFile below);
More files / directories may be added using the method: AddHtml

It chops text between references (<a href=..) into help items.
Text before the the first anchor gets the name of the the file
as name of the help item. This is useful to construct an index which
works also for a normal browser like netscape.
If a reference is clicked on only the text for this item is displayed.
The window size is adjusted to the number of lines.
It is assumed that the help text is preformatted, so no formatting
is done except optionally breaking lines at fMaxLineLength.
A possible image is displayed in a separate window.

To display the helptext the method: DrawText(anchor_name, xpos, ypos)
should be used.
When help items should be added to a popup menu the method
DrawText(index, xpos, ypos)

As an extension ROOT-files containing canvases may be
defined. If an image with name "pict.canvas.gif" appears
in the documentation a root-file with name "pict.canvas.root"
is searched for in the same directory.
i.e. the convention is to replace the suffix .gif by .root
If not found xv is invoked for the gif-file.
Otherwise the the canvas contained in the root-file is drawn.
This allows a standard browser to be used and still have the possiblity
to exploit the interactive features of root when showing a canvas.

An example (for HistPresent) can be found here.

Use View Page source to see how it is done.