How can I prevent Emacs resizing my windows? - emacs

Question

my Lisp-working-environment has the frame split into two windows, the former for the main coding, the latter for my slime evaluation.
Unfortunately, when I made some mistakes (cause I'm still learning Lisp :P) the slime debugger warns me, and doing this it shows up into the bottom window that is automatically resized.
Just to be more explicit:
BEFORE:
_______
| |
| |
_______
|_____|
AFTER:
_______
| | <- decreased in size!
_______
|_____| <- increased in size!
How can I prevent Emacs resizing my windows? I want Emacs to leave my window sizes the same.
How can I accomplish that?
Thanks! Bye!
Alfredo

Answer 1

You can remember your window configuration using the command M-x window-configuration-to-register (or C-x r w) at the beginning.
After you can always restore your configurations using M-x jump-to-register (or C-x r j).

Answer 2

winner-mode is a lifesaver, but to make pop-to-buffer not resize the window in the first place, do
(setq even-window-heights nil)

Answer 3

Unfortunately the main command pop-to-buffer, which is used by almost every program in emacs to switch to a buffer in a different window, has the side-effect you described.
In adition to all other solutions so far, there is a winner mode to undo/redo any changes in window configuration, at any moment of time.

Answer 4

If some code you call changes the window configuration you can
wrap your code with (save-window-excursion BODY ...)
If it is the debugger that changes the configuration - hit "q" and the old configuration will be resotred.
If you want the debugger not to change size try adding a debugger-mode-hook to restore your window size.

Answer 5

To disable window shrinking, shrink-window-if-larger-than-buffer needs to be a no-op. You could just redefine it to do nothing, but if you advise it, you get the ability to enable and disable it at will.
;; never shrink windows
(defvar allow-window-shrinking nil
"If non-nil, effectively disable shrinking windows by making `shrink-window-if-larger-than-buffer' a no-op.")
(advice-add 'shrink-window-if-larger-than-buffer
:before-while
(lambda (&rest args)
"Do nothing if `allow-window-shrinking' is nil."
allow-window-shrinking))
You can advise other functions that call shrink-window-if-larger-than-buffer to enable or disable shrinking:
(advice-add 'some-function-that-resizes-windows
:around
(lambda (orig &rest args)
"enable shrinkage"
(let ((allow-window-shrinking t))
(apply orig args))))
I had an old piece of code that was essentially the above, and I had ignore-errors wrapped around (apply orig args) for some forgotten reason, but it probably isn't universally needed.
N.B. this uses the new advice API, which was added in Emacs 24.4. The old advice API can do the same thing with different syntax if you need to use an old Emacs version.

Answer 6

Set the 'frame-inhibit-implied-resize' variable to 'true' [1], either via the configuration file (~/.emacs etc.):
(custom-set-variables '(frame-inhibit-implied-resize t))
or via the GUI with:
Options > Customize Emacs > Specific Option > 'frame-inhibit-implied-resize' > Value Menu = 'Always' & Apply and Save
In case of the latter method the 'STATE' in the 'Customize Option: Frame Inhibit Implied Resize' buffer should indicate 'SAVED and set', as opposed to 'STANDARD'.
From [1]:
"If {Frame Inhibit Implied Resize} is nil, setting font, menu bar, tool bar, internal borders, fringes or scroll bars of a specific frame may resize the frame in order to preserve the number of columns or lines it displays. If this option is t, no such resizing is done. (..)"