Emacs: Preventing gud & pdb from controlling windows - emacs

I'm using pdb to debug Python programs and am unhappy with it's behaviour.
I have the screen divided into multiple emacs windows, and when I execute pdb, it (randomly?) replaces one of the windows with the output of the *gud* debugger.
Also, when a breakpoint is encountered, even if the debugging buffer is already visible in a window, it usually puts this buffer into another window, and replaces another of my windows with the contents of the source file. (incidentally I like that it jumps to the correct line in the source file)
How can I disable gud/pdb from managing my windows for me? Is it possible in emacs to prevent all programattic manipulation of windows & screen layout?
Edit: I found the answer that partially solves this in another post: toggle dedicated windows

I tried all these approaches without success on Emacs 24.
If you are still interested I reverted to the old gdb behavior using 'gud-gdb' which implements the old behavior of gdb/emacs interaction (no dedicated-windows and no I/O buffer). If you don't want to call M-x gud-gdb when you use it, you can define an alias for M-x gdb

Look into sticky windows.

I have a solution that prevents the gdb from stealing windows. It works with Emacs 24.4 (2014-07-18 snapshot) and does not require dedicating buffers. The benefit over other answers is you won't have to bother dedicating and undedicating buffers whenever you change buffers, which quickly becomes tedious.
Place this advice in your .emacs:
(defadvice gdb-inferior-filter
(around gdb-inferior-filter-without-stealing)
(with-current-buffer (gdb-get-buffer-create 'gdb-inferior-io)
(comint-output-filter proc string)))
(ad-activate 'gdb-inferior-filter)
This effectively replaces this function as defined in gdb-mi.el and removes the branch that calls gdb-display-buffer, which is the cause of the window thievery.

You should use Sticky Windows to make your windows and buffers stick where they are but Sticky Windows won't stop gud/pdb from trying to steal your windows. When gud/pdb can't steal your source code window, it opens a new Emacs Frame even if there is another window on the current frame.
This comes from the fact that the function that tries to jump to the gud-pdb buffer (py-pdbtrack-track-stack-file) calls function pop-to-buffer with argument OTHER-WINDOW set to t.
To circumvent this behavior for all libraries that calls pop-to-buffer, you could cancel the role of OTHER-WINDOW by defining an advice on pop-to-buffer (in your .emacs) :
(defadvice pop-to-buffer (before cancel-other-window first)
(ad-set-arg 1 nil))
(ad-activate 'pop-to-buffer)
You should also customize variable pop-up-windows to nil in order to force display-buffer (the low-level routine used to display a particular buffer on windows and frames) to not create a new window.

Related

Emacs switch to buffer in different frame

I'm currently programming away in emacs. I have a function defined in my .emacs that saves all my work and executes the interpreter to run my work in the currently open shell buffer. Typically I'll be editing in one or more frames and have the shell open in a separate frame. The problem I have is when I run my save and execute function, everything is saved but the shell buffer then gets displayed in the frame I'm currently editing. So I have two frames showing the shell buffer and I can't see the source code I was just editing. Quite often when I'm programming, I'd immediately like to compare the output of the code with the code I've just written. It's a bit annoying to have to switch back to my code buffer and then go to the end of the other shell buffer to look at the output while referencing the just written code.
(defun execute-script ()
"Switch to shell buffer and re-execute the last command."
(interactive)
(save-some-buffers)
(switch-to-buffer "*shell*")
(end-of-buffer)
(comint-previous-input 0)
(comint-send-input))
As you can see my function is rather primitive at the moment, just re-executing the most recently used command in the shell.
I know that Emacs has the functionality to switch to a buffer in a different frame, as the ido buffer switcher code does this. Does anybody have any pointers as to what I need to replace my call to switch-to-buffer with to get the desired effect?
Regards Giles.
Exchange
(switch-to-buffer "*shell*")
for
(switch-to-buffer-other-window "*shell*")
This will enforce a two window layout with your previous buffer on the left side and the shell buffer on the right side.
Edit: If you're using a multiple frame layout and not a multiple window layout you can use
(switch-to-buffer-other-frame "*shell*")
You can also use pop-to-buffer which will later let you customize exactly how that behaves, e.g. via display-buffer-reuse-frame, or display-buffer-alist, or special-display-regexp.

in emacs how to control which windows to show compile result?

I have used emacs for erlang programming. According to http://emacswiki.org/emacs/CompileCommand, I have configure c-c c for recompile.
In the emacs frame, 6 windows are open, top 3 are for erlang source code reading and writing.
In the below windows, one is supposed for the compie window.
But when different windows is active and recompile, the compile window will switch randomly. How to fix it in one perticular window?
If you start reading at C-hf display-buffer RET (or in the manual at M-: (info "(elisp) Choosing Window") RET), you'll find a bunch of ways in which you can modify the behaviour.
It can get a little complex, but something like this might be all you need in your recompile function:
(let ((display-buffer-overriding-action
'(display-buffer-reuse-window)))
(compile))
I always use dedicated windows when I want to keep things in the one place, so you might also find that useful to look into:
M-: (info "(elisp) Dedicated Windows") RET
I use the toggle-window-dedicated function from Pin Emacs buffers to windows (for cscope) (see also How do I make this Emacs frame keep its buffer and not get resized?)

How can I more easily switch between buffers in Emacs?

I've recently started using emacs and I'm enjoying using it for the most part. The only thing I'm not enjoying, is switching between buffers. I often have a few buffers open and I've grown tired of using C-x b and C-x C-b, are there any packages that make switching between buffers easier? I've looked into emacs wiki on switching buffers and I'd appreciate insight/feedback on what are are using/enjoying. Thanks.
UPDATE: iswitchb-mode is obsolete in Emacs >= 24.4, replaced by ido.
All of the features of iswitchdb are now provided by ido. Ross provided a link to the documentation in his answer. You can activate with the following in your .emacs (or use the customization interface as Ross suggests):
(require 'ido)
(ido-mode 'buffers) ;; only use this line to turn off ido for file names!
(setq ido-ignore-buffers '("^ " "*Completions*" "*Shell Command Output*"
"*Messages*" "Async Shell Command"))
By default, ido provides completions for buffer names and file names. If you only want to replace the features of iswitchb, the second line turns off this feature for file names. ido will ignore any buffers that match the regexps listed in ido-ignore-buffers.
The behaviour described below for iswitchb-mode applies equally to ido for switching buffers.
iswitchb-mode (Emacs < 24.4)
iswitchb-mode replaces the default C-x b behaviour with a very intuitive buffer-switching-with-completion system. There are more sophisticated options, but I've never needed more than this.
After you hit C-x b, you are presented with a list of all buffers. Start typing the name of the buffer you want (or part of its name), and the list is narrowed until only one buffer matches. You don't need to complete the name, though, as soon as the buffer you want is highlighted hitting enter will move you to it. You can also use C-s and C-r to move through the list in order.
You can turn it on by default with this in your .emacs:
(iswitchb-mode 1)
You can also tell it to ignore certain buffers that you never (or very rarely) need to switch to:
(setq iswitchb-buffer-ignore '("^ " "*Completions*" "*Shell Command Output*"
"*Messages*" "Async Shell Command"))
You can use C-x <right> (next-buffer) and C-x <left> (previous-buffer) to cycle around in the buffer ring. You could bind S-<right> and S-<left> to these functions. (S is the "super-key" or windows-key). This way you can save some keystrokes.
Moreover, note that C-x b has a default entry, i.e. it displays a standard value (most of the time this is the previously viewed buffer), so that you don't always need to enter the buffer name explicitly.
Another nice trick is to open separate windows using C-x 2 and C-x 3. This displays several buffers simultaneously. Then you can bind C-<tab> to other-window and get something similar to tabbed browsing.
M-x customize-group ido then set Ido Mode to Turn on both buffer and file and set Ido Everywhere to on. Then click the Save for future sessions button at the top and enjoy ido magic for both files and buffers. Read the docs to get a sense of how to use ido.
Also, take a look at smex.
ido-mode provides an efficient way to switch buffers.
ibuffer is best for managing all opened buffers.
anything is good for selecting an interested thing from different
sources. (for eg: a single key can be used to switch to another
buffer or to open recently closed file or to open a file residing
in the same directory or ... anything you want ... )
If you've looked at the Emacs Wiki, you probably have all this information already, but here are a few other relevant Q&As:
Emacs: help me understand file/buffer management
Buffer switching in Emacs
How to invoke the buffer list in Emacs
My toolkit consists of ibuffer, windmove+framemove, winner-mode, and a custom binding to make C-xleft/right and C-cleft/right less of a hassle to use.
I have mapped the "§"-key to 'buffer-list and I find it to be very efficient.
I've started using anything for a couple of days and I'm really liking it: http://www.emacswiki.org/emacs/Anything .
Emacs-fu has an good intro to anything: http://emacs-fu.blogspot.com/2011/09/finding-just-about-anything.html
My favourite function for this is helm-mini which is part of helm.
As other helm functions, it allows incremental narrowing of the selection. It also searches your recently visited buffers, which is a really nice way to re-open a buffer. Helm can be a little surprising at first and as a new Emacs user, I found it visually overwhelming and I preferred ido or ibuffer which have been suggested in other replies. But now I absolutely love it and use it all the time for countless things.
Something that I realized by accident and that can be useful:
mouse-buffer-menu is by default bound to <C-mouse-1> (Control key + mouse left click) and opens a popup with a list of the current buffers.

Emacs C-x C-c overriding save-buffers-kill-terminal if within last open frame

I have setup emacs -daemon to run on login to Gnome and associated emacsclient with .cpp and .py files that I work with in Eclipse in order that emacs is used as my default editor for these files when selected within Eclipse. This way I can get a good work flow combining the editing capabilities of emacs and the project/build management and debugging facilities of Eclipse.
Anyhoo... I want to prevent C-x C-c from closing the Emacs frame I am currently editing in if it is the only Emacs frame remaining visible at any given moment.
Is there a way of querying the daemon Emacs process in order to find out how many frames are open and override the default C-x C-c behaviour to do nothing (if only 1 frame remaining) thereby ensuring there is always at least one visible frame open at all times?
Some elisp that implements this behaviour and that can be added to my .emacs would be great.
Bonus Points :¬)
I have aliases that map vi, emacs etc... to "emacsclient -c", so I get emacs frames coming and going all the time in general. A further enhancement would be for Eclipse to send files that I want to edit directly to a specific frame e.g. the 1st frame opened with emacsclient -c.
Make emacs immortal (what ever the way you've started it) :
(defadvice kill-emacs (around emacs-immortal) nil)
(ad-activate 'kill-emacs)
Use ad-deactivate to deactivate this trick.
Within emacs-clients, save-buffers-kill-terminal only calls server-save-buffers-kill-terminal, so you might want to install an advice onto that to not affect non-client frames. The frame-list function cal be used to introspect the currently existing frames. It apparently always includes one entry for the daemon process itself, and then one for each open frame.
(defadvice server-save-buffers-kill-terminal (around dont-kill-last-client-frame activate)
(when (< 2 (length (frame-list)))
ad-do-it))

Restore Emacs Session/Desktop

I've been searching for how to restore an emacs session, with no luck. I'm looking to restore all previously open buffers, some of which might contain erc, shells, directory listings, files, etc.
Every time I open emacs, I spend a considerable amount of time arranging my buffers; splitting them into rows and columns, opening a shell, arranging irc channels. It takes a while to get onto work.
I've tried adding the following to my init.el
(desktop-save-mode 1)
And then using M-x desktop-save. This only seems to restore files that are open, not shells or anything else running within buffers.
I've also checked the following questions:
Session management in emacs using Desktop library
Emacs session / projects / window management
Emacs: reopen buffers from last session on startup?
And read through:
DeskTop and EmacsSession at emacsWiki.org
Here's a screenshot example of my emacs session.
A simple answer would be to just focus on real work :P
I'd suggest a simple solution - create a function that sets up your preferred layout. For example I like to have some IRC channels in the second half of my screen in separate windows, so that I may have a look at them from time to time, while coding for instance in another window. So I've written some simple code to take care of the window splitting and arrange my buffers as I wish:
;; show some buffers
(defun show-some-buffers (buffer-list)
(split-window-horizontally)
(other-window 1)
(dolist (buffer buffer-list)
(split-window-vertically)
(switch-to-buffer (get-buffer buffer))
(other-window 1))
;; at the end we have one extra window we need to delete
(delete-window)
(balance-windows))
;; show some erc buffers
(defun show-erc-buffers ()
(interactive)
(show-some-buffers '("#emacs" "#clojure")))
The code is fairly simple and features no error checking, but it will give you a hint about what I mean.
You might want to consider using registers as well to store some window configurations.
As you've found, desktop.el and session.el are a good start, but they don't restore the window layouts.
However, using revive.el you can save/restore arbitrary window configurations, which are remembered between restarts.
Also check out these hints relating to window layouts, which cover winner-mode and the trick of saving window configurations into registers.
In addition to #Bozhidar's excellent answer on automating your window layout (which I do myself), you may also want to look into using GNU Screen which can be used to retain an arbitrary set of processes across log ins. There's a pretty good tutorial here, and since you'll be using emacs you'll also want to give this a read.