I would like to change the background color of emacs markdown-mode, but only the code sections, mainly because I want them to be easily distinguishable from the rest. I have looked through some colorthemes but can't seem to find the right variable to do this.
I am using the colortheme package with a slightly modified version on 'Andreas' theme. For markdown I'm using markdown-mode and polymode (for Rmd).
Here is a demo Rmd
---
title: "Demo"
author: "me"
date: "08.09.17"
---
# Title
Here is some text. This is inline code `paste("Hello world")`. This is
a code block:
```{r this should be dark gray}
head(iris)
```
And thats it.
The question is, how to customize polymode. It lightens the background slightly for the code chunks.
This, I believe, is the relevant part of polymode-methods.el:
(defun pm--get-adjusted-background (prop)
;; if > lighten on dark backgroun. Oposite on light.
(color-lighten-name (face-background 'default)
(if (eq (frame-parameter nil 'background-mode) 'light)
(- prop) ;; darken
prop)))
It looks like the faces you want to customize are markdown-pre-face (for indented code blocks) and markdown-inline-code-face (for inline code).
Both of these faces can be changed via customize-face if you so choose.
You can figure this out for yourself if you put your cursor inside a code block and run M-x describe-face. The default choice is for the face the cursor is on.
Related
I'm using most of the standard features of org-mode that come with the spacemacs develop branch, but I haven't been able to find a way to disable the automatic indentation for source code blocks on a case by case basis. I use tangle and I'm writing Dockerfile's in the same file that I'm writing groovy code or javascript for example. The Dockerfile's are the only ones I want not to be indented so I can get syntax highlighting. Here's what it looks like without the indentation:
And here's what it looks like with the indentation that automatically happens if I edit the text:
The automatic indentation is fine for groovy for example, so I have no issue with the automatic indentation here. (in fact, if I still got the syntax highlighting for Dockerfile's I probably wouldn't mind too much except the weird word wrapping not respecting the background face). Here's the example with groovy:
As you can see, I tried a :noindent property I found in the org-mode docs that's usually in a #+STARTUP directive. I also searched stack overflow, but I didn't find anything fruitful that didn't disable indenting for all source blocks or for the entire file.
In my practice (I'm not sure it is a good practice or not, just share it to you):
I setup org-src-tab-acts-natively to true for using the language’s major-mode indentation. In your case, it will format the src block with the formatting rules of dockerfile-mode.
I created a new major-mode plain-mode for the content which should not be indented automatically. Personally, I use this mode for something like:
shell outputs
ASCII diagrams
...
#+begin_src plain
this will not
be
auto
indented
#+end_src
Above src block will not be indented when you select them as region, and TAB on them.
In this way, the src blocks will always behavior as expected when formatting them.
Aside, the example code of plain-mode:
(define-derived-mode plain-mode
clean-mode "Plain"
"Major mode for plain text."
;; preserve the auto indentation on line
(setq-local indent-line-function 'indent-relative)
;; disable auto indentation on region
(setq-local indent-region-function (lambda (start end))))
I am using Emacs 24.3 and ESS 13.05 with the theme tangotango.el. While the theme is restful on the eyes, variable names in R don't appear to be highlighted. In tangotango-theme.el I can find the following line:
`(font-lock-variable-name-face ((t (:foreground "tomato"))))
but this doesn't appear to have any effect. For example, in the screenshot below I would expect the variable orl to be highlighted in some shade of red. Instead it is the standard text colour for this theme.
If I delve into ESS there is a file named ess-font-lock.el which contains a few references to the variable name face, like this one:
(set-face-foreground 'font-lock-variable-name-face "Black"))
So it looks as if font-lock-variable-name-face has competing definitions. I don't understand the interaction between Emacs themes and these ESS definitions. Is ESS overriding the tangotango theme and if so, will changing the above line in ess-font-lock.el restore variable name highlighting? Or should I be looking somewhere else entirely?
Edit: note that Cperl mode does seem to respect the font lock:
You are looking in a wrong place. ess-font-lock defines themes. Some 10 years ago that was useful. Now there are generic themes like your tango-tango and ESS doesn't interfere with them.
The issue is that ESS does not define a font lock keyword that you are looking for. The reason is that <- is an assignment operator, and there is no an explisit variable definition statement in R. ESS only treats function definitions. That is, assignment of a function will be highlighted:
foo <- function(){}
Believe me or not, but you really don't want to highlight all your assignments. You can try it though with:
(defvar ess-R-fl-keyword:assign-vars
(cons "\\(\\(?2:\\s\"\\).+\\2\\|\\sw+\\)\\s-*\\(<-\\)"
'(1 font-lock-variable-name-face)))
(add-to-list 'ess-R-font-lock-keywords '(ess-R-fl-keyword:assign-vars . t) t)
ESS implements a flexible font lock customisation mechanism on top of emacs font-lock system. See ESS>font-lock submenu.
Yes, it sounds like it. If you see the problem only in that mode, and that mode explicitly changes the face, then that sounds like the culprit. You should not need to change the source code, however. Just do something like this (untested):
(add-hook 'ess-mode (lambda () (set-face-foreground "tomato")))
(I assume that's the right mode name; if not, correct it.)
But this is an ugly workaround -- you should not need to do that. Consider filing a bug against the ess-mode.el code. It should not trample on user settings such as faces that way. If it wants to change the appearance by default then it should give users a new face that they can customize, instead of simply screwing with an existing face in a hard-coded way.
Update:
Note that this thread does not applyt o recent versions of Emacs (24+). Emacs now comes with it's own powerful color theming system (e.g. see a review here) that does not required loading the external package color-theme .
I have the following code snippet in my .emacs file, where I defined a few aliases that allow me to switch conveniently between a couple of color themes using short extended commands:
(require 'color-theme)
(eval-after-load "color-theme"
'(progn
(color-theme-initialize)
(color-theme-aalto-light)))
;; Aliases to color-themes, e.g. 'M-x a' switches to color-theme-hober
(defalias 'a 'color-theme-hober)
(defalias 'b 'color-theme-aalto-light)
Now, when Emacs loads, it displays the color-theme-aalto-light theme properly, and, when I M-x a to change to color-theme-hober, that works too.
The problem is when I try to change the color theme back again to color-theme-aalto-light. Some color faces remain in the old color-theme while others are changed to the new color theme. I have tried with different color theme combinations with no luck (the color faces are not always fully updated, regardless of the color-themes I switch between). Any thoughts?
This is a known bug in 'color-theme' package. If that feature is important for you, consider upgrading to trunk (future emacs-24.1), it natively supports changing themes (M-x customize-themes).
colour themes are basically just functions, which assign new colours to certain faces. There is nothing special about them, especially faces are not reset before switching colour themes. If one colour theme A sets a colour for a certain face, and another B does not, then B will simply take over the colour defined by A for this face.
This is more or less by design, and there is nothing, you can do about, save modifying the colour themes to cover all defined faces (which is rather tedious, and also quite impossible, because any elisp library can define its own faces).
Suppose I have a few words I would like to highlight, so I want to change the color of those few words only to, say, green.
Is there an easy way to do this in emacs?
Thank you.
This is what I've done, using font-lock-add-keywords. I wanted to highlight the words TODO:, HACK:, and FIXME: in my code.
(defface todo-face
'((t ()))
"Face for highlighting comments like TODO: and HACK:")
(set-face-background 'todo-face cyan-name)
;; Add keywords we want highlighted
(defun add-todo-to-current-mode ()
(font-lock-add-keywords nil
'(("\\(TODO\\|HACK\\|FIXME\\):" 1 'todo-face prepend))
t))
Use library HighLight. You can use overlays or text properties. You can save the highlighting permanently or let it be temporary. You can highlight in many ways (regexp, mouse-drag,...). Lots of possibilities.
The highlight package has hlt-highlight-regexp-region and hlt-highlight-regexp-to-end, which do exactly what you want.
http://www.emacswiki.org/cgi-bin/wiki/highlight.el
Use the function font-lock-add-keywords to define a new matcher for the string in question, binding that matcher to some face you've defined that will display as green. For example:
(font-lock-add-keywords nil
'("\\<foo\\>" 0 my-green-face))
Note that you can specify a particular mode where I wrote nil above, and the matching forms can take on any of six different styles. See the documentation for the variable font-lock-keywords for the rules and a few examples.
If you want them highlighted only temporarily, I find M-x highlight-regexp command very helpful, it is especially nice for looking through log files of sorts. For example you made yourself a logging class that outputs some tracing info like MyClass::function() > when function is run and MyClass::function() < when it exits (can be especially useful sometimes when debugging multithreading issues) then you just ask emacs to highlight some of them green and other red and then you can see how did the execution go.
I use what Dimitri suggested. In particular, I have the following two lines in my .emacs
(global-hi-lock-mode t)
(global-set-key (kbd "C-M-h") 'highlight-regexp)
Every-time I need to highlight a certain word (or regex) in a buffer, I hit "C-M-h", which then prompts me for the word (or regex) I want to be displayed differently and then for a face to display it in.
The Emacs cperl-mode seems to get confused less than perl-mode, but the Skittles effect makes the thing unusable for me. Does anyone have or know of an example of a .emacs block that causes cperl-mode to use the colorization from perl-mode, ideally in a form readable enough that I can go back and turn back on the default colors one element at a time until I reach something I'm comfortable with?
In particular there is a hideously shade of light green used for some builtins that I find quite unreadable, and I prefer my variables to not have the leading $ and $$ and such tinted red along with the variable name. Most of the rest are merely distracting.
Press M-x customize-group RET cperl-faces RET and change coloring to your liking.
With colour themes, the problem is limited to arrays and hashes - and it turns out that that's because cperl-mode defines those faces as being bold-weight, which colour themes don't appear to affect (Solarized doesn't).
In Emacs 23.3 on Mac OS, the following restored the colours to how the colour theme defined them:
(custom-set-faces
'(cperl-array-face ((t (:weight normal))))
'(cperl-hash-face ((t (:weight normal))))
)
You can also use the 'real' perl-mode coloring by overwriting font-lock settings with those of perl-mode.
(require 'perl-mode)
(add-hook 'cperl-mode-hook
(lambda ()
(setq font-lock-defaults
'((perl-font-lock-keywords perl-font-lock-keywords-1 perl-font-lock-keywords-2)
nil nil ((?\_ . "w")) nil
(font-lock-syntactic-face-function . perl-font-lock-syntactic-face-function)))
(font-lock-refresh-defaults)))
You can change the color theme if you don't like the particular default colors.