emacs: highlight all code within matching parenthesis off screen - emacs

I have the following two lines in my emacs config file which work perfectly for me:
(show-paren-mode 1);;highlight matching paranthesis
(setq show-paren-style 'expression) ; highlight entire bracket expression
except..when the function is too large to be displayed on one screen. When I scroll down to see the matching close braces , it stops highlighting as soon as the open braces goes offscreen.
How do I get emacs to highlight expressions within a set of matching braces even if I scroll down , as long as my cursor is on a braces?

Related

VSCode: Create two whitespaces between curly braces in CSS with cursor in the middle

Sublime had that default behaviour that in the context of a CSS file when writing { it is autocompleted to {|} (the pipe only indicates the position of the cursor and is not an actual pipe-charakter).
Upon hitting the spacebar {|} was further autocompleted to { | } (the pipe again being the cursor).
How do I get this exact behaviour in VSCode? ....and only for the context of CSS files?
I don't want snippets or any other workaround. I want, with my cursor inside of two empty curly braces, to hit the spacebar and get two spaces between the braces and the cursor to end up right in the middle.

Show line of matching brace for Java in Eclipse

So, let's say I select a closing brace. I want eclipse to not only highlight the matching opening brace, I want it to show me its whole line on the top of my editor, no matter how higher up it is. I'm sure I've seen it on some other IDE, is it possible to do on Eclipse? For example, if it's a closing brace for an if statement, I want to see the opening of this if to see its condition. This could also apply to methods, loops, etc.
If not showing the whole line, I would at least like to highlight the whole line with a color that stands out, so that I can find it easier through scrolling. I know I can jump there with Ctrl+Shift+P, but it's not always practical.

Emacs highlighting: how to deal with highlighting messed up by unusual usage of special characters?

Problem:
In Emacs configuration modes (e.g. conf-xdefaults-mode or conf-space-mode), some special characters are used in unusual ways, for instance when they define keybindings. This messes up the highlighting for the rest of the buffer.
Example:
The ranger rc.conf file uses conf-space-mode which greatly helps its readability. But lines such as:
map # console shell -p%space
map "<any> tag_toggle tag=%any
mess up the highlighting since # usually defines a comment and is followed by font-lock-comment-face until the end of the line and " defines the beginning of a string and is followed by font-lock-string-face until it encounters a closing quote.
Escaping those characters is not an option because it would prevent them from defining the keybindings.
Possible solution:
The best solution I can think of is to fiddle with font lock settings for those configuration modes to remove the highlighting after those special characters. But I will then loose the proper highlighting after those characters when it is suitable.
A compromise could be to keep highlighting after # since this only messes up one line and there are a lot of comments in those configuration files, while removing the highlighting after single and double quotes since those mess up the entire rest of the buffer and strings are not so common in configuration files.
Question:
What is the proper way to deal with these situations?
Is there a way to reset the highlighting at a point in the buffer? or to insert a character which would affect the highlighting (to fix it) without affecting the code? or is there a way to "escape" some characters for the highlighting only without affecting the code?
The easy way
It's probably easiest to just live with it but keep things constrained. Here, I took ranger's default rc.conf and re-arranged some of the font-lock errors.
Let's ignore the blue "map" for now. We have two visible font-lock errors. The map #... is font-locking as a comment, and the map "... font-locking as a string to the end of the buffer. The first error is self-constrained. Comments end at the end of the line. The second error we constrain by adding a comment. (I don't know if ranger would accept comments in the middle of the line, so I'm only using beginning-of-line comments here.)
The second error is now constrained to one line, but a couple more errors have popped up. Quickly adjusting these we get.
This is something that I could live with, as I'm not in conf files all day long (as opposed to say, source code.) It would be even neater if our new "comments" could be included on the same line.
The hard way
You'll want to use Emacs font-lock-add-keywords. Let's get back to that blue map in the first image. It's rendering blue because conf-space-mode thinks that a string, followed by any amount of whitespace, followed by an opening brace should be rendered in font-lock-type-face (the actually regexp that triggers this is ^[_space__tab_]*\\(.+?\\)[_space__tab_\n]*{[^{}]*?$ where _space_ and _tab_ are actual space and tab characters.)
We can override this in a simple fashion by evaluating
(font-lock-remove-keywords
'conf-space-mode
'(("^\\<\\(map\\)\\>" 1 font-lock-variable-name-face)))
and reloading the buffer with C-x C-v RET. Now, every time that the word "map" appears at the beginning of a line it's rendered as font-lock-variable-name-face (yellow in our example.)
You can make this change permanent by adding a hook to your init file.
(add-hook 'conf-space-mode-hook (lambda ()
(font-lock-remove-keywords
nil
'(("^\\<\\(map\\)\\>" 1 font-lock-variable-name-face)))))
This method doesn't appear to work for your comment (#) and string (' ") delimiters as they're defined in the syntax table. Modifying the syntax table to provide special cases is probably more effort than it's worth.

Display consecutive whitespace as dots in Emacs

This answer nicely provides a way to display characters rather than tabs (in the example it suggests ">", but I confirmed it works for ".").
It uses setting the active window display table to do it.
Now my goal is to display 4 spaces as 4 dots. Using the font-face and a regular expression, I am confident that I can display it nicely. I am aware that I could have Emacs automatically use tab characters rather than whitespaces, but I always prefer to have whitespace characters in my files.
I've also looked at whitespace mode, but I tweaked many parameters and in the end I never get the simple dots (with a face that makes it a little less "jump" out).
So: how can I, rather than display tab characters as dots, display 4 spaces elegantly as dots in Emacs?
OK, here's how to mark 4 or more spaces at beginning of line
(setq whitespace-space-regexp "^\\( \\{4,\\}\\)")
And here's how to get rid of the centered dot character for space:
(setq whitespace-display-mappings
'((space-mark ?\ [?\ ] [?.])
(space-mark ?\xA0 [?\ ] [?_])
(newline-mark ?\n [?$ ?\n])
(tab-mark ?\t [?\u00BB ?\t] [?\\ ?\t])))
The changes take effect not immediately but when you revert-buffer or
close it and open again with customizations above already set.

Collapsing the current outline in Emacs org-mode

Say I am in org-mode in a document with the following structure:
* First headline
* Second headline
** Section A
Here is one line
Here is another line
blah, blah
** Section B
Say the cursor is on the line that reads Here is another line. I would like to collapse ** Section A from this location with a keyboard shortcut.
If I press <TAB> it does not collapse ** Section A, as I would need the cursor to be on the stars for this to work.
If I press <Shift-TAB> it collapses all outlines, and not the current one.
Is there any way to cycle through the collapsing of the outline in scope (i.e. the "current outline")?
You can customize the behaviour of the org-cycle command (which is bound to <TAB>) by changing the value of org-cycle-emulate-tab.
To get it to collapse ** Section A when your cursor is on Here is another line add the following line to your .emacs file:
(setq org-cycle-emulate-tab 'white)
The white will allow you to still use <TAB> to indent in empty lines. From org-mode Github:
org-cycle-emulate-tab's value is t
Documentation:
Where should `org-cycle' emulate TAB.
nil Never
white Only in completely white lines
whitestart Only at the beginning of lines, before the first non-white char
t Everywhere except in headlines
exc-hl-bol Everywhere except at the start of a headline
If you don't mind doing this in two steps:
C-c C-p: move the cursor to the previous heading (** Section A in your example)
TAB: fold the section
This method doesn't require any configuration, as long as you get used to it.