HorizontalSplitting

In modern Emacs versions (at least from Emacs 24 onwards) we have easy customization for this through variables like

    split-height-threshold
    split-width-threshold

For forced vertical positioning of pop-up windows you can set

    (setq split-width-threshold 0)

I (halloleo) personally do the oposite: I want the pop-up windows always horizontally split, so I use

     (setq split-width-threshold 9999)

– halloleo

I prefer having two windows side-by-side in my Emacs, as opposed to two windows, one vertically above each other. No problem, I just use C-x 3 all the time instead of C-x 2. However, Emacs insists that I use vertically positioned windows for its popup windows: for example, when you only have a single window open and you use C-x C-b, or describe-function, or something similar. Here’s how I (with help from bpalmer and bojohan on EmacsChannel) managed to persuade emacs to use horizontally positioned windows instead:

     (defun split-horizontally-not-vertically ()
       "If there's only one window (excluding any possibly active minibuffer), then
     split the current window horizontally."
       (interactive)
       (if (= (length (window-list nil 'dont-include-minibuffer-even-if-active)) 1)
           (split-window-horizontally)))
     (add-hook 'temp-buffer-setup-hook 'split-horizontally-not-vertically)

This works pretty well.

– DavidHouse

Here is my (PeterJones) small adaption of the above function:

    (defun split-horizontally-for-temp-buffers ()
      "Split the window horizontally for temp buffers."
      (when (one-window-p t) 
        (split-window-horizontally)))

    (add-hook 'temp-buffer-setup-hook 'split-horizontally-for-temp-buffers)

I really enjoy the idea of horizontal splitting by default. I improved function a bit - now it correctly handles situation when we are in minibuffer and trying to get list of completions:

     (defun split-horizontally-for-temp-buffers ()
       "Split the window horizontally for temp buffers."
       (when (and (one-window-p t)
     	     (not (active-minibuffer-window)))
         (split-window-horizontally)))    

– KonstantinAntipin

         (defun split-window-prefer-horizonally (window)
           "If there's only one window (excluding any possibly active
         minibuffer), then split the current window horizontally."
           (if (and (one-window-p t)
                    (not (active-minibuffer-window)))
               (let ((split-height-threshold nil))
                 (split-window-sensibly window))
             (split-window-sensibly window)))

         (setq split-window-preferred-function 'split-window-prefer-horizonally)

CategoryWindows