Zoom

This minor mode takes care of managing the window sizes by enforcing a fixed and automatic balanced layout where the currently selected window is resized according to zoom-size which can be an absolute value in lines/columns, a ratio between the selected window and frame size or even a custom callback.

Installation

MELPA package

M-x package-install RET zoom

Local package

M-x package-install-file RET /path/to/zoom.el

Manual

(require 'zoom "/path/to/zoom.el")

Usage

Enable Zoom with M-x zoom-mode otherwise use M-x zoom to manually rearrange windows just once.

Load it automatically with:

(custom-set-variables
 '(zoom-mode t))

See the FAQ.

Example configurations

For a complete reference see M-x customize-group RET zoom.

---

Resize the selected window using the golden ratio:

(custom-set-variables
 '(zoom-size '(0.618 . 0.618)))

---

Resize the selected window according to the frame width, for example:

• 90 columns and 75% of the frame height if the frame width is larger than 1024 pixels;
• half the frame size otherwise.

(defun size-callback ()
  (cond ((> (frame-pixel-width) 1280) '(90 . 0.75))
        (t                            '(0.5 . 0.5))))

(custom-set-variables
 '(zoom-size 'size-callback))

---

Override the key binding of balance-windows:

(global-set-key (kbd "C-x +") 'zoom)

---

Prevent some windows from being resized, for example:

• dired and markdown major modes;
• zoom.el init.el buffer names;
• calculator-related windows;
• any buffer containing less than 20 lines.

(custom-set-variables
 '(zoom-ignored-major-modes '(dired-mode markdown-mode))
 '(zoom-ignored-buffer-names '("zoom.el" "init.el"))
 '(zoom-ignored-buffer-name-regexps '("^*calc"))
 '(zoom-ignore-predicates '((lambda () (> (count-lines (point-min) (point-max)) 20)))))

(Please note that ignored windows are not resized when selected but all the windows are nevertheless arranged with balance-windows.)

FAQ

What about golden-ratio.el?

I have been a more or less happy golden-ratio.el user for some time when I stared noticing some bugs and sadly I discovered that it is apparently a dead project now, so I decided to write a new and improved minor mode from scratch that implements the same basic idea of automatic window layout as my first attempt at Emacs mode development.

Why when there are several horizontal splits the completions buffer is very small?

This happens when zoom-minibuffer-preserve-layout is non-nil (the default) because most of the space is probably occupied by the zoomed window. The solution (apart from setting the aforementioned variable to nil) is to enable the temp-buffer-resize-mode minor mode:

(custom-set-variables
 '(temp-buffer-resize-mode t))

Why windows are resized even when they are ignored?

When a window is ignored it is simply not resized when the user selects it.

In order to maintain a stable layout, windows are always balanced, then the selected window, unless ignored, is zoomed according to the user preference.

This may cause weird layouts with windows that are designed to be small, e.g., imenu-list. Unfortunately there is no universal solution to this.

The workaround is to set window-size-fixed to t for the buffers whose window must preserve the current size, for example the following fixes the size of the imenu-list window to 30 columns:

(defun my/fix-imenu-size ()
  (with-selected-window (get-buffer-window "*Ilist*")
    (setq window-size-fixed t)
    (window-resize (selected-window) (- 30 (window-total-width)) t t)))

(add-hook 'imenu-list-update-hook 'my/fix-imenu-size)