No, I do not need #1.  This is not a question about highlighting.
I most sincerely regret ever using the word "highlight", because
it has sent you off chasing a massive red herring.

Let's just pretend I never said I wanted them to highlight.
I want them to squeak audibly, like mice.  OK?  I will figure out
how to make that happen.  By myself.

My question is #2, and your solution does not work.  Emacs does
not send any notifications when the mouse moves unless track-mouse
is on.  This is what is called, in the vulgar parlance, a Catch-22.

Stefan already understands my question and has given me a
very satisfactory answer, which is, in short:  go ahead and implement
it.  That is what I was hoping to hear.

Before I start, I need to go poke fun at Stephen for acting like
a user on a Mac OS X forum and telling me in great detail that I
don't really want to do what I specifically said I want to do.

-steve

On Fri, Jul 31, 2009 at 5:56 PM, Drew Adams <drew.adams@oracle.com> wrote:

>        The mode decorates the source with various text properties to
>        facilitate navigation, outlining, folding, etc.  My goal is to link
>        together all the references to each local variable, so they light
>        up when you mouse over any of them.
>
> Sounds like you need two things:
>
> 1. A way to highlight all text that has some property with a given value.
> 2. A way to know when the mouse is over any such text.
>
> For #2 I dunno. Maybe you can put something on `post-command-hook' (or you
> might
> need to do mouse-tracking). A function on `post-command-hook' could perhaps
> check whether the last event was a mouse event, and if so get the mouse
> position
> and then the value of the property at that position. That could be costly,
> but
> it might get you started.
>
> For #1, I just added a command to highlight.el that does that. It should
> give
> you something that works while you look for something more appropriate, if
> it
> isn't exactly what you want.
>
> The new command is `hlt-highlight-property-with-value'. You give it the
> property
> and value to highlight. You can give it a list of possible values - if the
> property has any of them, then the text is highlighted.
>
> You can also give it start and end limits, the highlighting face, the
> highlighting type (overlay or text property or both), and whether the
> highlighting should be with property `face' or `mouse-face'. All of these
> args
> are optional.
>
> To test the command:
>
> 1. Add a property to some text. For a quick test, you could add property
> `mouse-face' with value `highlight' (e.g. just as a test) using `C-u M-x
> hlt-highlight-regexp-region'.
>
> 2. Highlight all text that has a given property value. `M-x
> hlt-highlight-property-with-value'. You are prompted for the property and
> the
> value. E.g., enter `mouse-face' for the property and `highlight' for its
> value.
> All text (in the region or buffer) that has property `mouse-face' with
> value
> `highlight' is highlighted. (See the file for how to unhighlight etc.)
>
> http://www.emacswiki.org/emacs/highlight.el
>
> HTH.
>
>