I must be stupid, but I just switched to Emacs 24, and holding Shift while moving the point no longer highlights text. Mouse selection works as before. What am I missing? Did I turn it off by chance? Or has Shift selection been deemed unergonomical so we have some other, better keyboard-based selection at hand?
Shift selection is enabled by default in Emacs 24.
You can always run emacs -Q to disable your init file and any other default libraries, in order to determine what Emacs' default behaviour is.
You can also run emacs -q which will disable only your init file (other system-wide init files can be loaded).
If the feature works without your init file and does not work with it, you can then start to narrow down what part of your init file is at fault (often by commenting out functionality until the feature starts working as expected -- note Drew's comment).
In this case I suggest that you firstly verify (using C-hv) that the shift-select-mode variable is non-nil (when running with your normal configuration), as a nil value means that shift selection is disabled.
I also found it useful to look at load-path variable, C-h v load-path, which directed me to the culprits, old elpa packages.
Related
I just finished the Emacs Lisp intro and am getting my feet wet with customization. I've browsed the Emacs FAQ, the Emacs W32 FAQ, and perused the fine manual for drag and drop information. I am using GNU Emacs 24.5.1 for Windows without Cygwin (etc.).
I would like to update the default drag and drop behavior to open such files in read only mode. Through C-h f I've identified the dnd functions. In particular, dnd-open-file may be relevant. By C-h k and then dragging a file into Emacs, I've identified the function w32-drag-n-drop. Also, within the Reference Manual is a section on drag-and-drop which specifies x-dnd-types-alist.
How do I identify which of these items, if any, needs to be modified?
What is a safe way to modify its behavior?
I cannot find documentation on x-dnd-types-alist. Is it a function? A variable?
Is there a resource I've overlooked which I should be looking at?
Partial answers of a general nature - I can't help with your dnd problems,
but I hope these suggestions will be of some use.
Q2. It's a good idea to have a minimal init file, containing whatever is necessary to initialize an environment for testing. You can them invoke emacs like this:
emacs -q -l /path/to/minimal/init/file
bypassing your initialization file (-q) and loading the minimal init file instead. Then if something blows up, you just kill this emacs instance, and start again (possibly with a modified init file).
Q3. It's a variable (as are all alists). An alist (short for association list) is a list of key-value pairs. You can get the docstring of any variable with
C-h v VARNAME RET
e.g.
C-h v x-dnd-types-alist RET
Q4. If all else fails, the source is available...
I would find a way to execute the commands in the file emacs. Emacs and therefore automatically.
For example I often use: highlight-80
So I'm forced to type every time: Meta key + highlight-80 +-fashion
it's the same with linum-mode and plenty of other.
I have been trying to put in the file emacs.:
(highlight-80 +-mode)
But the option is not enabled.
Thank you in advance for your help. I am looking desperately for a moment, emacs is my working tool quotidient.
Regards
Use C-h f or C-h v, and read the Emacs manual about such choices.
Some of them are user options (variables), whose values you can customize, using M-x customize-option, so the default setting becomes what you want.
Others are modes, which you can call/set in your init file (~/.emacs) --- see the Emacs manual for how to do that. Typically, you use a positive number to turn a mode on and a negative number to turn it off. E.g.: (menu-bar-mode -1) in your init file turns off the use of a menu bar.
In sum, the Emacs manual (C-x r) is your friend. Sit down and have a first chat with it.
You seem generally a bit unsure about how customising Emacs works, so reading the manual on this topic should probably be your next step:
http://www.gnu.org/software/emacs/manual/html_node/emacs/Customization.html
If you are not using the current stable release (Emacs 24.3 at the moment), there's a chance that some of that information will not apply. The in-built manual is, of course, always correct for the version you are running:
C-hig (emacs) Customization RET
In Aquamacs 2.2 I could do the following:
1) Set the mark with C-SPACE
2) Click somewhere to set the point
Consequently this would define the region. Since Aquamacs-2.3 this behaviour is gone: A click sets both the mark and the point. Is there a way to customize aquamacs to have the old behaviour?
For Emacs 24, here's what worked for me (and may also apply to Aquamacs): Unset the binding for the <down-mouse-1> event, which is what is setting the mark (but not the point; the point is set by a different binding, for the up-event <mouse-1>).
That seems to provide the behavior you are asking for: clicking the mouse after setting the mark via C-space sets the point, and one can see the corresponding region highlighted.
I determined this by reading the help for the bindings above, by doing:
M-x helpkclick, and reading the *Help* text, which explains that <down-mouse-1> is bound to command mouse-drag-region (which sets the mark).
I then tested the resulting behavior by interactively disabling the binding, by doing:
M-x global-unset-key and then clicking; but it is probably much safer to do it programmatically, e.g. in the scratch buffer, by evaluating:
(global-unset-key [down-mouse-1])
If you like the behavior that results, then just copy the above line into your .emacs
Employing the solution described above does seem to cause mouse-dragging to be a little funky, in that it does not highlight the selected region during the drag (but you still get to see what the region is once you let go, and you can now fine tune its end point via single clicks, which may be useful in some circumstances.)
I've found that terminal emacs does not render the correct colors unless I explicitly set TERM=xterm-256color. I use gnome-terminal, and from what I understand, TERM should be set to gnome-256color. Similarly, I tend to use tmux a lot, which advises against any TERM setting other than screen-256color. Unfortunately, both of those settings (within their respective context - gnome-terminal or tmux) result in emacs having wrong colors, whereas vim displays colors correctly. However, if I export TERM=xterm-256color, the colors work just fine in emacs.
Can anyone explain what's going on, or offer a solution?
Update
Here's what I'm dealing with:
I can get the colors to look correct in the terminal by adding the following to my init.el:
(defun terminal-init-gnome ()
"Terminal initialization function for gnome-terminal."
;; This is a dirty hack that I accidentally stumbled across:
;; initializing "rxvt" first and _then_ "xterm" seems
;; to make the colors work... although I have no idea why.
(tty-run-terminal-initialization (selected-frame) "rxvt")
(tty-run-terminal-initialization (selected-frame) "xterm"))
This feels really, really wrong though. There has to be a logical explanation for this...
P.S.
I have very little knowledge of terminfo and the precise role that $TERM plays in the process of color terminal behavior. If it's safe to always use xterm-256color (even when $TERM "should" be gnome-256color or screen-256color), I'll go with that.
Maybe I'm not understanding something, buy why don't you run emacs like this:
TERM=xterm-256color emacs -nw
This way Emacs has its own TERM setting that you know works. You can also make an alias or wrap this in shell-script.
Terminals are a special type of device. When a process sends special byte sequences (called control sequences) to the terminal, it performs some action (like cursor positioning, change colors, etc).
You can read the ANSI terminal codes to find more detail about control sequences.
But terminals come from 70s, when hardware was limited in its capabilities, and a terminal cannot provide info about its capabilities (ie. which sequences it supports).
$TERM was used to resolve this issue - it allows programs to know what to send to the terminal to get the job done. termcap and terminfo are databases that store info about terminal capabilities for many $TERM names. If your $TERM is not in the db, you must ask an administrator to add it.
All terminal emulators inherit these limitations from old hardware terminals. So they need a properly set $TERM, and the terminfo/termcap DB MUST have data for this terminal. When a virtual terminal starts it sets the $TERM variable for you (and inside programs like bash). If $TERM is not in the terminfo/termcap you can quickly define an alias from $TERM to xterm-256color (you can find examples in the termcap file on how to do that).
This behavior has to do with the logic EMACS uses to determine whether the terminal background is dark or light. Run M-x list-colors-display with TERM set to either xterm-256color or screen-256color and you'll see that the exact same colors are listed. As you pointed out in the comments, the difference in color schemes that you've observed is due to the frame background mode. To see this, with your TERM set to screen-256color, compare the colors in
emacs -Q -nw --eval "(setq frame-background-mode 'light)"
and
emacs -Q -nw --eval "(setq frame-background-mode 'dark)"
The function frame-set-background-mode (in frame.el) checks to see whether the terminal type matches "^\\(xterm\\|\\rxvt\\|dtterm\\|eterm\\)" if it can't deduce the background color otherwise.
Within a running session, you can change the color scheme to 'light by evaluating
(let ((frame-background-mode 'light)) (frame-set-background-mode nil))
I am not that familiar with how emacs handles different terminals exactly. But looking at lisp/term directory in emacs sources, I found out that the existence of a function terminal-init-xxx allows you to add support for different terminals. For example, I've got:
(defun terminal-init-screen ()
"Terminal initialization function for screen."
;; Use the xterm color initialization code.
(xterm-register-default-colors)
(tty-set-up-initial-frame-faces))
in my .emacs, which adds support for screen-256color. You may try defining a similar function for gnome by renaming the above function to terminal-init-gnome.
NOTE: If you are interested, you can try to track down the calls from tty-run-terminal-initialization code. It first gets the terminal type using tty-type function, then looks at certain locations to load a relevant terminal file, then tries to locate the matching terminal-init-xxx function, and finally calls it. It may help you figure out the correct name for gnome-terminal.
It looks like unless your TERM indicates that your terminal has 256 colors, emacs will only use 8. Changing TERM to gnome-256color allowed the color registration functions to work.
There is a way to cheat, after all. When I run gnome-terminal, my terminal is set to xterm by default. Instead of changing TERM variable, it is possible to redirect xterm to another terminal, say, gnome-256color. Simply create the directory $(HOME)/.terminfo/x, then run ln -s /usr/share/terminfo/g/gnome-256color ~/.terminfo/x/xterm. I think this is better than setting TERM manually in .bashrc, because it only redirects a particular terminal to something else. A console login would still leave TERM as linux, and not xterm-256color.
Add this to your ~/.emacs:
(add-to-list 'term-file-aliases
'("st-256color" . "xterm-256color"))
It tells emacs that if it sees TERM=st-256color then it should initialize the terminal as if it had seen TERM=xterm-256color.
Longer answer:
Emacs is showing strange colors because it thinks your terminal can only support 8 colors. In Emacs, run M-x list-colors-display to see the colors it thinks are available. The correct number of colors is detected during terminal-specific initialization. It says, in part:
Each terminal type can have its own Lisp library that Emacs loads when run on that type of terminal.
On my machine, the terminal-specific initialization files are in /usr/local/share/emacs/25.*/lisp/term. It has files for xterm, rxvt, screen, etc. but nothing for st. We need to help Emacs find the right initialization file. The documentation further says:
If there is an entry matching TERM in the term-file-aliases association list, Emacs uses the associated value in place of TERM
So that association list is a recommended way to handle unknown terminals. It works without you having to manually override the TERM environment variable.
On ubuntu 10.04 I too had noticed that running emacs -nw inside byobu/tmux/screen was using different colours from emacs -nw in the regular gnome-terminal.
I found that this is because byobu was setting TERM to screen-bce. Then setting TERM to xterm (for me, in the normal gnome-terminal TERM=xterm) gave me the same syntax highlighting when not running through byobu/screen.
So still not sure what the proper solution is.
See also this post:
Emacs Python-mode syntax highlighting
I have tried emacs on and off for a while now and every time I start emacs, I go through the same routine. Customizing. The first one is binding return to newline-and-indent. (g)Vim does this by default. Showing matching parenthesis is also done by default on (g)Vim. It is grea that I can customize emacs to my heart's content but why doesn't emacs have nice and easy defaults? For reference, I am now using Emacs 23 on a RHEL5 box.
Probably because RMS didn't want it, that and because changing long-standing defaults is just an issue of politics. Like vi, Emacs has a hard-core following and basic changes like these are minefields.
Note: if you saved your customizations, then you wouldn't have to re-do them every time...
To have those nice and easy defaults, install Emacs Starter Kit. It enables by default a bunch of useful and convenient features make even the advanced Emacs users more productive.
Otherwise, as TJ pointed out, Emacs Customization Mode (type M-x customize) allows you to save permanently any of the settings. You can even store them in a separate file from your dotemacs―(setq custom-file "~/.emacs-custom.el")―so you can use it in every computer you work on.
The title of your question doesn't really reflect what your question is (and has been answered by Trey and Torok), but I'll tell you why I like it being bound to just newline: useless whitespace. Say you are nested inside a conditional in a function etc. and hit return a couple times to leave a blank line. The blank line now has a bunch of space chars on it. Yes, you can (and I do) remove trailing whitespace before saving, but I also have visual whitespace mode on and I can see it there taunting me.