Eclipse with Emacs keybindings: rebind Ctrl+J to end line and indent? - eclipse

I need to use Eclipse to edit a language that doesn't have a good major mode in Emacs. I'm using what it advertises as "Emacs keybinding scheme", but it has several distinctions, some of them just happen too often and are really annoying when they happen.
One such keybinding is the Ctrl+J, or in a more Emacs-friendly format: C-j. This combination is typically bound to insertion of new line and indentation before the caret (unlike Enter or RET, which just inserts a line ending character).
So, I went to the Preferences panel, the keys settings, but I can't find anything that would simply insert a newline character. I.e. I can unbind the C-j combination, but I don't seem to be able to assign it to do the insertion. Is there any way to do it? I only found "Insert Line (Above / Below) Current Line" command, but no analogue to self-insert-command etc.

This was one of the more important keybindings for me from emacs, so I really needed to get this to work.
Go to preferences->keys, choose emacs as the scheme, search for ctrl+j, and unbind it. It's set to incremental search by default, so I changed it to ctrl+s. Once it's unbound, it just works as it should. This has worked for me from eclipse 3.x to Juno.

Related

How do I use Latex/Tex-inspired keybindings in Dr. Racket?

The Racket Docs say that to use a Latex/Tex-inspired keybinding like
\Downarrow for ⇓ that we should do something with C-\ M-\ c:x;l:
C-\ M-\ c:x;l : traces backwards from the insertion point, looking for a backslash followed by a LaTeX macro name or a prefix of such a name. If a macro name is found, it replaces the backslash and the name with the corresponding key in the table below ...
The parts that confuse me are:
What does C-\ M-\ c:x;l mean? I suspect the C-\ M-\ c:x;l is Ctrl, followed by Option, followed by something.
I'm not sure I follow the business about tracing backwards. If I have my hands on the keyboard and I want to type an arrow, what do I actually do?
I think that the documentation you refer to is showing three likely bindings, but the DrRacket docs say that the final word on keybindings is to be found by consulting the Show Active Keybindings menu item from the Edit menu. When I check Show Active Keybindings on my DrRacket installation, I see as one of the options: TeX compress (~c:m:\), which is equivalent to M-\, i.e., pressing Meta-\ together. Entering \Downarrow followed by Meta-\ in the interactions area, I am greeted with the expected character: ⇓.

Netbeans unindent (Shift+Tab) not working when cursor is inside the line (no selection)?

In Neatbeans, unindent works as expected when multiple lines are selected. But consider the following, where the pipe character | symbolizes the cursor position in the editor:
(a) Cursor at start of line (no selection)
|hello world!
(b) Cursor inside of line (no selection)
hell|o world!
In Netbeans, when I hit Shift+Tab on version (a) then the indentation is removed. This is what I expect.
However, when I hit Shift+Tab on version (b) then nothing happens. This is different from the code editors that I am used to. I would expect the indentation to be removed, or that the cursor moves to the start of the line, such that the next Shift+Tab will remove the indentation.
Is there a config in Netbeans that makes unindent via Shift+Tab work when the cursor is inside the line?
To shift the line to the left, regardless of the cursor position you can use the "Shift line left" editor action. In the default NetBeans mapping this is assigned to Alt+Shift+KP_LEFT and Alt+Shift-LEFT
Just open the keymap options page and search for the action "shift line"
It's not exactly what you are asking, but you could try to remap that action to "Shift-Tab" and see if it works.
TLDR: There seems to be a bug in the way NetBeans handles indenting/unindenting.
I would expect the indentation to be removed
I don't see any formal documentation on how unindenting is supposed to work in NetBeans, but it appears to move the text to the right of the cursor to the left, as long as there is only whitespace to the left of the cursor. While that is different to how unindenting works in other code editors such as Intellij IDEA and Eclipse, where the entire line is shifted to the left even when the cursor is poitioned within the text, it's not necessarily incorrect.
If you want to unindent in NetBeans there are two simple alternatives: either position the cursor at the start of the line, or select some text - anything at all! - on that line before unindenting.
Some comments in the NetBeans Bug Report Bug 212353 - Shift+Tab (Delete tab) shortcut does not work in editor may be relevant:
Please note that those actions should be inverse - I mean when you
select a block and you hit <TAB> <TAB> <Shift-TAB> <Shift-TAB> you
should always end up with the same text. The same should be true if
you change the order to <Shift-TAB> <Shift-TAB> <TAB> <TAB> you
should end up with the same text.
That said, NetBeans is not adhering to that standard. Using your second example, pressing <TAB><TAB> works fine, but subsequently pressing <SHIFT><TAB> does nothing, so it is not possible to "end up with the same text". That looks like a bug (in Apache NetBeans 11.2 at least). You can raise a bug report here.
It's also worth noting that <Shift> + <Tab> is actually defined as the keymap for "Delete TAB" rather "unindenting".
Is there a config in Netbeans that makes unindent via Shift+Tab work
when the cursor is inside the line?
I don't think so. All you can do, using Tools > Options > Keymap, is to change the shortcut keys from <Shift> + <Tab> to something else, but that won't change the behavior.

Some shortcuts don't work on emacs beginning with C-c

In Haskell-mode, the shortcut C-c C-= is defined to do something.
Trying this shortcut, I realized that emacs do not recognize the shortcut C-c C-=.
Indeed, when I try the shortcut on emacs, the buffer write C-c = is not defined although I pressed C- C-=. I have the same problem with some other symbols like '.' or '§'. But shortcuts like C-c C-l or C-c C-c work.
I try to remove my .emacs but I have the same problem.
a friend have the same problem as me.
Both we are on ArchLinux (64 bits) and we use emacs in console. The keyboard is an azerty.
The problem come from emacs ? Arch Linux ?
Your terminal can't send Emacs C-= so you can't use that key sequence. (Emacs would recognise it if it received it, but that won't happen.)
Your options are:
Run GUI Emacs.
Use M-x name-of-command RET (for whatever command is bound to the key sequence you're not able to use). Use C-hm to see the major mode's bindings, or C-hb to see all current bindings, in order to learn what those command names are.
Create new custom keybindings for the commands in question (i.e. bindings which your terminal can send to Emacs).
Find a different terminal emulator with enhanced key sequence abilities. The vast majority of them will be no better than what you have, because they're all adhering to the limitations of the terminals they're emulating. The most capable one I know of is http://invisible-island.net/xterm/xterm.html but you may need to compile it yourself, and then expect to spend lots of time configuring it. (It's not a trivial solution, though, and xterm requires a GUI environment, so running GUI Emacs is much simpler.)
Use C-x#c<key> instead of C-<key>.
With that last option, you can use a sequence your terminal can send to fake a sequence that it can't send.
C-cC-= would become C-cC-x#c=
If you really wanted to use that last option, you can set a custom binding to simplify the sequence (may be necessary in some instances to avoid conflicting with existing sequences). See the end of https://stackoverflow.com/a/24804434/324105 for more information.
To add to phils' post - another option is an Emacs package (which I wrote), which can teach Emacs and terminals how to properly recognize all PC keyboard keys and modifier key combinations:
https://github.com/CyberShadow/term-keys
The default configuration already includes encoding key combinations like Ctrl=, as well as similar variations.

How to preserve keybindings when using multi-term.el in line mode?

In emacs (ver. 24.3), I have my forward-paragraph and backward-paragraph mapped to M-p and M-n instead of M-{ and M-}. It is easier for me to remember and use fluidly with C-p and C-n. I've recently started using multi-term to run most of my terminal work. However, when I switch to line-mode my custom bindings for forward and backward paragraph no longer work. It says 'empty input ring'. Oddly when I'm in char-mode, the C-p and C-n do what they are supposed to do (bringing up previous prompt entries), but my paragraph movements work.
So in short, my custom forward and backward paragraph bindings work in char-mode (where I don't really need them), but not in line-mode. Any ideas?
See term-bind-key-alist, which includes C-p, C-n, M-p, and M-n by default. See also these passages from the EmacsWiki page MultiTerm. The second especially seems relevant to your problem. These do not mention term-line-mode or term-char-mode, but I think they might give you a place to start.
Note 1
‘term-unbind-key-list’ is a list of keys which emacs keeps for itself. By default it contains (“C-z” “C-c” “C-x” “C-h” “C-y” “”)
‘term-bind-key-alist’ is a list of keys and functions which you can use, for example to use Emacs style cursor movement to the multi-terminal. The default is long, so I’ll let you look it up yourself.
Note 2
Because C-r is default keystroke for isearch-backward, for avoid conflict with C-r, i binding M-r to send “C-r” character to shell.
You can use option term-bind-key-alist/term-unbind-key-list to binding/unbinding special keystroke in multi-term.el, and don’t use term-mode-hook. ☺ –- AndyStewart
Also, I don't see term-line-mode anywhere in multi-term.el. It looks as if it makes use only of term-char-mode. See, for instance, multi-term-keystroke-setup.

Emacs tab not working

I have installed Emacs on my FreeBSD 8.2 box. Everything works fine but I cannot use tabs. When I am editing a file with emacs and hit tab, nothing happens.
What could be causing this?
If you're new to Emacs, you might expect pressing TAB to insert a literal \T. For various reasons, that's not the way most Emacs modes work. Most editing modes auto-indent your code as needed (<tab> is bound toindent-for-tab-command rather than self-insert). If the line you're TABbing on is already at the correct indentation level, it might seem that nothing happened.
Auto-indenting like this is easier and more consistent than manually indenting, but doesn't give you as much flexibility when it comes to deciding exactly how much whitespace is going to be present at the beginning of each line (and it also causes some problems when you want to, for example, tab-separate some fields). You can auto-indent a region using C-M-\ (that's Ctrl + Alt + \).
If you absolutely, positively must insert a literal \T into your code somewhere, you can do so using C-q TAB (press and release Ctrl + q and then press TAB). Typically, this is done to align columns in other editors; if that's what you're doing, it's probably a better idea to use align-regexp rather than tab literals.
In fundamental and text-mode I use C-<TAB>. I do not know which other modes this works in, but with few exceptions, plain text is the only time I need an actual \t character.