Re: How to programmatically highlight region?

[Perry Smith]

On Nov 15, 2006, at 4:48 PM, David Abrahams wrote:

Perry Smith <pedz@easesoftware.com> writes:

On Nov 15, 2006, at 2:10 PM, David Abrahams wrote:

    Hi,

    Could someone tell me how to get the effect of an "activated mark" in

    transient mark mode from within elisp?  In other words, I'd like to be

    able to set up the point and mark, and when my elisp completes, see

    the region highlighted.  Seems like it should be simple, but nothing I

    do seems to work.

You might be asking how transient mark mode works.  

I don't think that's what I'm asking.

It seems to be just a variable that commands look at.  But this

works for me:

(defun dog-test ()

 (interactive)

 (transient-mark-mode 1)

 (set-mark (point))

 (forward-char 20))

execute dog-test from the minibuffer and the current point plus 20

characters are highlighted

Not for me. :(

Thanks for responding.

I felt challenged :-)

You make a face.  Put the attributes that you want in it.  Then use put-text-property to apply that face to the region.

(make-face 'my-blue-face)

(set-face-attribute 'my-blue-face nil :background "blue")

(defun dog-test3 ()

  (interactive)

  (put-text-property (point) (mark) 'face 'my-blue-face))

Set your mark and point, then do M-x dog-test3

There is something I don't understand though.  If you have font-lock-mode set, then it does not work.  I'm not sure what is happening in that case.  I'm curious to see if others reply.

Hope this help...

Perry Smith

Ease Software, Inc.

pedz@easesoftware.com

http://www.easesoftware.com

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