Face precedence

Face precedence

[Matthew Calhoun]

Hello,

I'm trying to figure out what determines the order in which faces are 
applied to a block of text. I have highlight face, which is applied to 
whatever line point is on, defined as white text on a dark background. 
But in programming modes I also have some syntax-related faces defined 
with a light background. Strangely, in some of these modes the 
highlight face's light foreground is applied, but not its dark 
background. Instead, the syntax face's light background is displayed, 
resulting in light text on a light background. What I would like to do 
is make sure that highlight face always takes precedence over whatever 
other faces are applied to the text.

I'm sure this is possible, but I haven't been able to find or figure 
out how. Can anyone point me in the right direction?

Thanks,
Matt

Re: Face precedence

[Oliver Scholz]

Matthew Calhoun <calhounm@mac.com> writes:

> Hello,
>
> I'm trying to figure out what determines the order in which faces are
> applied to a block of text.

See (info "(elisp)Merging Faces")

> I have highlight face, which is applied to whatever line point is
> on, defined as white text on a dark background. But in programming
> modes I also have some syntax-related faces defined with a light
> background. Strangely, in some of these modes the highlight face's
> light foreground is applied, but not its dark background. Instead,
> the syntax face's light background is displayed, resulting in light
> text on a light background. What I would like to do is make sure
> that highlight face always takes precedence over whatever other
> faces are applied to the text.

Hm. If the highlighted line is implemented with an overlay and those
"syntax related faces" are implemented via text properties, then the
overlay should actually take precedence.  Hm.

(progn (switch-to-buffer (generate-new-buffer "*tmp*"))
       (font-lock-mode -1)
       (insert (propertize "lirum larum"
                           'face '(face :background "magenta")))
       (overlay-put (make-overlay (point-min) (point-max))
                    'face '(face :background "blue")))

Works here.  How exactly is your highligted line implemented?

    Oliver
-- 
8 Brumaire an 213 de la Révolution
Liberté, Egalité, Fraternité!

Re: Face precedence

[Matthew Calhoun]

Hi Oliver,

Thanks for your reply. I think when I said I was "defining faces" I 
gave you the impression that I was doing something more complicated 
than what I'm actually doing. I'm only setting the attributes of 
existing faces with custom-set-faces, like this:

	(custom-set-faces
		'(mode-line ((((type x w32 mac) (class color)) (:background "white" 
:foreground "black" :weight extra-bold))))
		'(mode-line-inactive ((t (:slant oblique :weight light))))
		'(region ((((class color)) (:background "#b5d5ff"))))
		'(isearch ((t (:inherit region :weight bold))))
		'(isearch-lazy-highlight-face ((((class color) (background light)) 
(:background "#d4d4d4" :foreground "black" :weight bold))))
		'(highlight-changes-face ((((class color)) (:inherit highlight))))
		'(highlight-changes-delete-face ((((class color)) (:box (:line-width 
1 :color "#3d80df")))))
		'(highlight-changes-face-1 ((t (:background "gray80"))) t)
		'(highlight-changes-face-2 ((t (:background "gray90"))) t)
		'(highlight-changes-face-3 ((t (:background "gray95"))) t)
		'(show-paren-match-face ((((class color)) (:foreground "saddle 
brown"))))
		'(show-paren-mismatch-face ((((class color)) (:foreground "red"))))
		'(font-lock-builtin-face ((((class color)) (:foreground "black"))))
		'(font-lock-comment-face ((((class color)) (:foreground "gray50"))))
		'(font-lock-constant-face ((((class color)) (:foreground "black"))))
		'(font-lock-function-name-face ((((class color)) (:foreground "black" 
:weight bold))))
		'(font-lock-keyword-face ((((class color)) (:foreground "black"))))
		'(font-lock-string-face ((((class color)) (:foreground "forest 
green"))))
		'(font-lock-type-face ((((class color)) (:foreground "black"))))
		'(font-lock-variable-name-face ((((class color)) (:foreground 
"blue"))))
		'(font-lock-warning-face ((((class color)) (:foreground "red"))))
		'(html-tag-face ((t (:foreground "dodger blue"))))
		'(html-helper-bold-face ((t (:foreground "black"))))
		'(html-helper-builtin-face ((t (:foreground "black"))))
		'(html-helper-italic-face ((t (:foreground "black"))))
		'(html-helper-underline-face ((t (:foreground "black"))))
		'(cperl-array-face ((((class color) (background light)) (:foreground 
"orange"))))
		'(cperl-hash-face ((((class color) (background light)) (:foreground 
"chocolate4"))))
		'(cperl-nonoverridable-face ((((class color) (background light)) 
nil)))
		'(mmm-default-submode-face ((t (:background "yellow"))))
		'(mmm-cleanup-submode-face ((t (:background "yellow"))))
		'(mmm-code-submode-face ((t (:background "yellow"))))
		'(mmm-comment-submode-face ((t (:background "yellow"))))
		'(mmm-declaration-submode-face ((t (:background "yellow"))))
		'(mmm-output-submode-face ((t (:background "yellow"))))
		'(mmm-special-submode-face ((t (:background "yellow"))))
		'(mmm-init-submode-face ((t (:background "yellow"))))
		'(highlight ((((class color)) (:background "#3d80df" :foreground 
"white"))))
		)

The highlight face I was referring to isn't something I implemented 
myself; it's just an existing face that I've customized. What I'm 
finding confusing is the way in which these faces are applied when more 
than 1 of them is in effect. I would appreciate any light you can shed 
on this subject.

Thanks,
Matt

Re: Face precedence

[Oliver Scholz]

Matthew Calhoun <calhounm@mac.com> writes:

[...]
> Thanks for your reply. I think when I said I was "defining faces" I
> gave you the impression that I was doing something more complicated
> than what I'm actually doing. I'm only setting the attributes of
> existing faces with custom-set-faces, like this:
[...]
> The highlight face I was referring to isn't something I implemented
> myself; it's just an existing face that I've customized.

Well, in that case, I have to change my question: how do you turn that
highlight-line feature on?  Do you use some package which comes with
Emacs or something which you found on the web?  If the latter: what
package is that?

    Oliver
-- 
16 Brumaire an 213 de la Révolution
Liberté, Egalité, Fraternité!

Re: Face precedence

[Matthew Calhoun]

The documentation string for highlight is "Basic face for 
highlighting." When I turn on HL Line mode (which is part of Emacs, I 
believe) with:

	(global-hl-line-mode 1)

this face is used to highlight the line the cursor is on. It sounds 
like it's meant to be used for other purposes as well, but that's the 
only place it shows up under my configuration.

The documentation you pointed out to me seems to indicate that overlay 
priorities are the way to control this, but I haven't been able to 
figure out how to set them, or if it's even possible to set them 
outside of the original source files.

Thanks,
Matt


El Nov 5, 2004, a las 11:01 PM, Oliver Scholz escribió:

> Matthew Calhoun <calhounm@mac.com> writes:
>
> [...]
>> Thanks for your reply. I think when I said I was "defining faces" I
>> gave you the impression that I was doing something more complicated
>> than what I'm actually doing. I'm only setting the attributes of
>> existing faces with custom-set-faces, like this:
> [...]
>> The highlight face I was referring to isn't something I implemented
>> myself; it's just an existing face that I've customized.
>
> Well, in that case, I have to change my question: how do you turn that
> highlight-line feature on?  Do you use some package which comes with
> Emacs or something which you found on the web?  If the latter: what
> package is that?
>
>     Oliver
> -- 
> 16 Brumaire an 213 de la Révolution
> Liberté, Egalité, Fraternité!
> _______________________________________________
> Help-gnu-emacs mailing list
> Help-gnu-emacs@gnu.org
> http://lists.gnu.org/mailman/listinfo/help-gnu-emacs

Re: Face precedence

[Oliver Scholz]

Matthew Calhoun <calhounm@mac.com> writes:

[...]
> 	(global-hl-line-mode 1)

Ah! Yes, `hl-line-mode' is part of Emacs.  It is a buffer-local minor
mode that highlights the line where point is in.  It is implemented
with an overlay.

> this face is used to highlight the line the cursor is on. It sounds
> like it's meant to be used for other purposes as well, but that's the
> only place it shows up under my configuration.

Yes, that face is also used for mouse-highlighting in some places, for
example in *Help* buffers.

> The documentation you pointed out to me seems to indicate that overlay
> priorities are the way to control this [...]

Unless you know more than you told, I would think that this conclusion
is premature.  Maybe there is something going wrong in your setup and
we should figure out what it is.

If I understand you correctly, you have a light background and a dark
foreground for the default face and a dark background and a light
foreground for the highlight face.  You said that in some cases the
dark background of the highlight face does not take effect.  Is that
/everywhere/, where a face other than the default face is in the
buffer?  Or does this apply only for a few faces?  Or only in some
modes?  If the latter: which mode?  

If the former: you can examine the text properties a point with M-x
list-text-properties-at (assuming you are using a released version of
Emacs 21).  Please post that together with a description of what you
see.

Finally, can you reproduce the behaviour you described starting from
emacs -q --no-site-file? Can you set up a small test case so that I can
reproduce that behaviour?

FYI, hl-line-mode works as expected here.


[Please don't top-post.  For people who read or skim hundreds of
netnews postings a day this makes more work in getting the context of
a posting.  Please do rather cut out everything but the most relevant
parts of a quoting and write your answers below.]

    Oliver
-- 
17 Brumaire an 213 de la Révolution
Liberté, Egalité, Fraternité!

Re: Face precedence

[Matthew Calhoun]

El Nov 6, 2004, a las 11:31 PM, Oliver Scholz escribió:

> If I understand you correctly, you have a light background and a dark
> foreground for the default face and a dark background and a light
> foreground for the highlight face.  You said that in some cases the
> dark background of the highlight face does not take effect.

Yes, that's exactly what is happening.

> Is that
> /everywhere/, where a face other than the default face is in the
> buffer?  Or does this apply only for a few faces?  Or only in some
> modes?  If the latter: which mode?

I see this when I'm using mmm-mode (Multiple Major Mode Mode) with 
html-helper and cperl as the two major modes in effect. I use mmm-mode 
to edit HTML files which have Perl embedded in them; giving the Perl 
code a yellow background makes it easy to find. But with hl-line 
enabled, the current line has white text on a yellow background.

I do remember seeing this happen once before, but if I remember 
correctly, whatever caused it wasn't useful enough to spend time trying 
to fix it, so I quit using it. I can't remember what it was at the 
moment.

> If the former: you can examine the text properties a point with M-x
> list-text-properties-at (assuming you are using a released version of
> Emacs 21).  Please post that together with a description of what you
> see.

I'm using a version I built from CVS for Mac OS X Carbon a couple of 
months ago (emacs-version says it's 21.3.50.1). I don't have a 
list-text-properties-at command, but I do have 
describe-text-properties. Here is its output when point is in some Perl 
code in mmm-mode:

	Text content at position 13268:


	There are 2 overlays here:
	 From 13267 to 13316
	  mmm                  t
	  beg-sticky           t
	  end-sticky           t
	  evaporate            t
	  mmm-evap             t
	  priority             1
	  name                 nil
	  display-name         nil
	  mmm-mode             cperl-mode
	  face                 mmm-declaration-submode-face
	  mmm-local-variables  ((font-lock-cache-state nil)
	 (font-lock-cache-position #<marker in no buffer>))

	 From 13268 to 13281
	  window               nil
	  face                 highlight


	There are text properties here:
	  fontified            t

As described above, what I am seeing here is a block of Perl code with 
a yellow background, where the text on the current line is white. What 
I would *like* to see is exactly this, except with a blue background on 
the current line.

Thanks again,
Matt

Re: Face precedence

[Oliver Scholz]

Matthew Calhoun <calhounm@mac.com> writes:

> El Nov 6, 2004, a las 11:31 PM, Oliver Scholz escribió:
>
[hl-line-mode face attributes not properly applied]
>> Is that
>> /everywhere/, where a face other than the default face is in the
>> buffer?  Or does this apply only for a few faces?  Or only in some
>> modes?  If the latter: which mode?
>
> I see this when I'm using mmm-mode (Multiple Major Mode Mode) with
> html-helper and cperl as the two major modes in effect.

You were right. mmm-mode uses overlays and setting overlay priorities
seems to be the way to fix the problem. I can reproduce something
along the lines of what you described, when I specify a mmm-submode
region *after* I turned hl-line-mode on.

Shooting from the hips, this seems to fix it:

(add-hook 'hl-line-mode-hook
          (lambda ()
            (overlay-put hl-line-overlay
                         'priority most-positive-fixnum)))


    Oliver
-- 
18 Brumaire an 213 de la Révolution
Liberté, Egalité, Fraternité!