--- /dev/null
+;;; ace-window.el --- Quickly switch windows. -*- lexical-binding: t -*-
+
+;; Copyright (C) 2014-2015 Oleh Krehel
+
+;; Author: Oleh Krehel <ohwoeowho@gmail.com>
+;; URL: https://github.com/abo-abo/ace-window
+;; Version: 0.8.0
+;; Keywords: window, location
+
+;; This file is not part of GNU Emacs
+
+;; This file is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; For a full copy of the GNU General Public License
+;; see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; The main function, `ace-window' is meant to replace `other-window'.
+;; If fact, when there are only two windows present, `other-window' is
+;; called. If there are more, each window will have its first
+;; character highlighted. Pressing that character will switch to that
+;; window.
+;;
+;; To setup this package, just add to your .emacs:
+;;
+;; (global-set-key (kbd "M-p") 'ace-window)
+;;
+;; replacing "M-p" with an appropriate shortcut.
+;;
+;; Depending on your window usage patterns, you might want to set
+;;
+;; (setq aw-keys '(?a ?s ?d ?f ?g ?h ?j ?k ?l))
+;;
+;; This way they're all on the home row, although the intuitive
+;; ordering is lost.
+;;
+;; If you don't want the gray background that makes the red selection
+;; characters stand out more, set this:
+;;
+;; (setq aw-background nil)
+;;
+;; When prefixed with one `universal-argument', instead of switching
+;; to selected window, the selected window is swapped with current one.
+;;
+;; When prefixed with two `universal-argument', the selected window is
+;; deleted instead.
+
+;;; Code:
+(require 'avy)
+
+;;* Customization
+(defgroup ace-window nil
+ "Quickly switch current window."
+ :group 'convenience
+ :prefix "aw-")
+
+(defcustom aw-keys '(?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9)
+ "Keys for selecting window.")
+
+(defcustom aw-scope 'global
+ "The scope used by `ace-window'."
+ :type '(choice
+ (const :tag "global" global)
+ (const :tag "frame" frame)))
+
+(defcustom aw-ignored-buffers '("*Calc Trail*" "*LV*")
+ "List of buffers to ignore when selecting window."
+ :type '(repeat string))
+
+(defcustom aw-ignore-on t
+ "When t, `ace-window' will ignore `aw-ignored-buffers'.
+Use M-0 `ace-window' to toggle this value."
+ :type 'boolean)
+
+(defcustom aw-background t
+ "When t, `ace-window' will dim out all buffers temporarily when used.'."
+ :type 'boolean)
+
+(defcustom aw-leading-char-style 'char
+ "Style of the leading char overlay."
+ :type '(choice
+ (const :tag "single char" 'char)
+ (const :tag "full path" 'path)))
+
+(defface aw-leading-char-face
+ '((((class color)) (:foreground "red"))
+ (((background dark)) (:foreground "gray100"))
+ (((background light)) (:foreground "gray0"))
+ (t (:foreground "gray100" :underline nil)))
+ "Face for each window's leading char.")
+
+(defface aw-background-face
+ '((t (:foreground "gray40")))
+ "Face for whole window background during selection.")
+
+(defface aw-mode-line-face
+ '((t (:inherit mode-line-buffer-id)))
+ "Face used for displaying the ace window key in the mode-line.")
+
+;;* Implementation
+(defun aw-ignored-p (window)
+ "Return t if WINDOW should be ignored."
+ (and aw-ignore-on
+ (member (buffer-name (window-buffer window))
+ aw-ignored-buffers)))
+
+(defun aw-window-list ()
+ "Return the list of interesting windows."
+ (sort
+ (cl-remove-if
+ (lambda (w)
+ (let ((f (window-frame w))
+ (b (window-buffer w)))
+ (or (not (and (frame-live-p f)
+ (frame-visible-p f)))
+ (string= "initial_terminal" (terminal-name f))
+ (aw-ignored-p w)
+ (with-current-buffer b
+ (and buffer-read-only
+ (= 0 (buffer-size b)))))))
+ (cl-case aw-scope
+ (global
+ (cl-mapcan #'window-list (frame-list)))
+ (frame
+ (window-list))
+ (t
+ (error "Invalid `aw-scope': %S" aw-scope))))
+ 'aw-window<))
+
+(defvar aw-overlays-lead nil
+ "Hold overlays for leading chars.")
+
+(defvar aw-overlays-back nil
+ "Hold overlays for when `aw-background' is t.")
+
+(defvar ace-window-mode nil
+ "Minor mode during the selection process.")
+
+;; register minor mode
+(or (assq 'ace-window-mode minor-mode-alist)
+ (nconc minor-mode-alist
+ (list '(ace-window-mode ace-window-mode))))
+
+(defun aw--done ()
+ "Clean up mode line and overlays."
+ ;; mode line
+ (setq ace-window-mode nil)
+ (force-mode-line-update)
+ ;; background
+ (mapc #'delete-overlay aw-overlays-back)
+ (setq aw-overlays-back nil)
+ (aw--remove-leading-chars))
+
+(defun aw--lead-overlay (path leaf)
+ "Create an overlay using PATH at LEAF.
+LEAF is (PT . WND)."
+ (let* ((pt (car leaf))
+ (wnd (cdr leaf))
+ (ol (make-overlay pt (1+ pt) (window-buffer wnd)))
+ (old-str (with-selected-window wnd
+ (buffer-substring pt (1+ pt))))
+ (new-str
+ (concat
+ (cl-case aw-leading-char-style
+ (char
+ (apply #'string (last path)))
+ (path
+ (apply #'string (reverse path)))
+ (t
+ (error "Bad `aw-leading-char-style': %S"
+ aw-leading-char-style)))
+ (cond ((string-equal old-str "\t")
+ (make-string (1- tab-width) ?\ ))
+ ((string-equal old-str "\n")
+ "\n")
+ (t
+ (make-string
+ (max 0 (1- (string-width old-str)))
+ ?\ ))))))
+ (overlay-put ol 'face 'aw-leading-char-face)
+ (overlay-put ol 'window wnd)
+ (overlay-put ol 'display new-str)
+ (push ol aw-overlays-lead)))
+
+(defun aw--remove-leading-chars ()
+ "Remove leading char overlays."
+ (mapc #'delete-overlay aw-overlays-lead)
+ (setq aw-overlays-lead nil))
+
+(defun aw--make-backgrounds (wnd-list)
+ "Create a dim background overlay for each window on WND-LIST."
+ (when aw-background
+ (setq aw-overlays-back
+ (mapcar (lambda (w)
+ (let ((ol (make-overlay
+ (window-start w)
+ (window-end w)
+ (window-buffer w))))
+ (overlay-put ol 'face 'aw-background-face)
+ ol))
+ wnd-list))))
+
+(defvar aw--flip-keys nil
+ "Pre-processed `aw-flip-keys'.")
+
+(defcustom aw-flip-keys '("n")
+ "Keys which should select the last window."
+ :set (lambda (sym val)
+ (set sym val)
+ (setq aw--flip-keys
+ (mapcar (lambda (x) (aref (kbd x) 0)) val))))
+
+(defun aw-select (mode-line)
+ "Return a selected other window.
+Amend MODE-LINE to the mode line for the duration of the selection."
+ (let ((start-window (selected-window))
+ (next-window-scope (cl-case aw-scope
+ ('global 'visible)
+ ('frame 'frame)))
+ (wnd-list (aw-window-list))
+ final-window)
+ (cl-case (length wnd-list)
+ (0
+ start-window)
+ (1
+ (car wnd-list))
+ (2
+ (setq final-window (next-window nil nil next-window-scope))
+ (while (and (aw-ignored-p final-window)
+ (not (equal final-window start-window)))
+ (setq final-window (next-window final-window nil next-window-scope)))
+ final-window)
+ (t
+ (let ((candidate-list
+ (mapcar (lambda (wnd)
+ ;; can't jump if the buffer is empty
+ (with-current-buffer (window-buffer wnd)
+ (when (= 0 (buffer-size))
+ (insert " ")))
+ (cons (aw-offset wnd) wnd))
+ wnd-list)))
+ (aw--make-backgrounds wnd-list)
+ (setq ace-window-mode mode-line)
+ (force-mode-line-update)
+ ;; turn off helm transient map
+ (remove-hook 'post-command-hook 'helm--maybe-update-keymap)
+ (unwind-protect
+ (condition-case err
+ (or (cdr (avy-read (avy-tree candidate-list aw-keys)
+ #'aw--lead-overlay
+ #'aw--remove-leading-chars))
+ start-window)
+ (error
+ (if (memq (caddr err) aw--flip-keys)
+ (aw--pop-window)
+ (signal (car err) (cdr err)))))
+ (aw--done)))))))
+
+;;* Interactive
+;;;###autoload
+(defun ace-select-window ()
+ "Ace select window."
+ (interactive)
+ (aw-switch-to-window
+ (aw-select " Ace - Window")))
+
+;;;###autoload
+(defun ace-delete-window ()
+ "Ace delete window."
+ (interactive)
+ (aw-delete-window
+ (aw-select " Ace - Delete Window")))
+
+;;;###autoload
+(defun ace-swap-window ()
+ "Ace swap window."
+ (interactive)
+ (aw-swap-window
+ (aw-select " Ace - Swap Window")))
+
+;;;###autoload
+(defun ace-maximize-window ()
+ "Ace maximize window."
+ (interactive)
+ (select-window
+ (aw-select " Ace - Maximize Window"))
+ (delete-other-windows))
+
+;;;###autoload
+(defun ace-window (arg)
+ "Select a window.
+Perform an action based on ARG described below.
+
+By default, behaves like extended `other-window'.
+
+Prefixed with one \\[universal-argument], does a swap between the
+selected window and the current window, so that the selected
+buffer moves to current window (and current buffer moves to
+selected window).
+
+Prefixed with two \\[universal-argument]'s, deletes the selected
+window."
+ (interactive "p")
+ (cl-case arg
+ (0
+ (setq aw-ignore-on
+ (not aw-ignore-on))
+ (ace-select-window))
+ (4 (ace-swap-window))
+ (16 (ace-delete-window))
+ (t (ace-select-window))))
+
+;;* Utility
+(defun aw-window< (wnd1 wnd2)
+ "Return true if WND1 is less than WND2.
+This is determined by their respective window coordinates.
+Windows are numbered top down, left to right."
+ (let ((f1 (window-frame wnd1))
+ (f2 (window-frame wnd2))
+ (e1 (window-edges wnd1))
+ (e2 (window-edges wnd2)))
+ (cond ((string< (frame-parameter f1 'window-id)
+ (frame-parameter f2 'window-id))
+ t)
+ ((< (car e1) (car e2))
+ t)
+ ((> (car e1) (car e2))
+ nil)
+ ((< (cadr e1) (cadr e2))
+ t))))
+
+(defvar aw--window-ring (make-ring 10)
+ "Hold the window switching history.")
+
+(defun aw--push-window (window)
+ "Store WINDOW to `aw--window-ring'."
+ (when (or (zerop (ring-length aw--window-ring))
+ (not (equal
+ (ring-ref aw--window-ring 0)
+ window)))
+ (ring-insert aw--window-ring (selected-window))))
+
+(defun aw--pop-window ()
+ "Return the removed top of `aw--window-ring'."
+ (let (res)
+ (condition-case nil
+ (while (not (window-live-p
+ (setq res (ring-remove aw--window-ring 0)))))
+ (error
+ (error "No previous windows stored")))
+ res))
+
+(defun aw-switch-to-window (window)
+ "Switch to the window WINDOW."
+ (let ((frame (window-frame window)))
+ (when (and (frame-live-p frame)
+ (not (eq frame (selected-frame))))
+ (select-frame-set-input-focus frame))
+ (if (window-live-p window)
+ (progn
+ (aw--push-window (selected-window))
+ (select-window window))
+ (error "Got a dead window %S" window))))
+
+(defun aw-flip-window ()
+ "Switch to the window you were previously in."
+ (interactive)
+ (aw-switch-to-window (aw--pop-window)))
+
+(defun aw-delete-window (window)
+ "Delete window WINDOW."
+ (let ((frame (window-frame window)))
+ (when (and (frame-live-p frame)
+ (not (eq frame (selected-frame))))
+ (select-frame-set-input-focus (window-frame window)))
+ (if (= 1 (length (window-list)))
+ (delete-frame frame)
+ (if (window-live-p window)
+ (delete-window window)
+ (error "Got a dead window %S" window)))))
+
+(defun aw-swap-window (window)
+ "Swap buffers of current window and WINDOW."
+ (cl-labels ((swap-windows (window1 window2)
+ "Swap the buffers of WINDOW1 and WINDOW2."
+ (let ((buffer1 (window-buffer window1))
+ (buffer2 (window-buffer window2)))
+ (set-window-buffer window1 buffer2)
+ (set-window-buffer window2 buffer1)
+ (select-window window2))))
+ (let ((frame (window-frame window))
+ (this-window (selected-window)))
+ (when (and (frame-live-p frame)
+ (not (eq frame (selected-frame))))
+ (select-frame-set-input-focus (window-frame window)))
+ (when (and (window-live-p window)
+ (not (eq window this-window)))
+ (aw--push-window this-window)
+ (swap-windows this-window window)))))
+
+(defun aw-offset (window)
+ "Return point in WINDOW that's closest to top left corner.
+The point is writable, i.e. it's not part of space after newline."
+ (let ((h (window-hscroll window))
+ (beg (window-start window))
+ (end (window-end window))
+ (inhibit-field-text-motion t))
+ (with-current-buffer
+ (window-buffer window)
+ (save-excursion
+ (goto-char beg)
+ (while (and (< (point) end)
+ (< (- (line-end-position)
+ (line-beginning-position))
+ h))
+ (forward-line))
+ (+ (point) h)))))
+
+;;* Mode line
+;;;###autoload
+(define-minor-mode ace-window-display-mode
+ "Minor mode for showing the ace window key in the mode line."
+ :global t
+ (if ace-window-display-mode
+ (progn
+ (aw-update)
+ (set-default
+ 'mode-line-format
+ `((ace-window-display-mode
+ (:eval (window-parameter (selected-window) 'ace-window-path)))
+ ,@(assq-delete-all
+ 'ace-window-display-mode
+ (default-value 'mode-line-format))))
+ (force-mode-line-update t)
+ (add-hook 'window-configuration-change-hook 'aw-update))
+ (set-default
+ 'mode-line-format
+ (assq-delete-all
+ 'ace-window-display-mode
+ (default-value 'mode-line-format)))
+ (remove-hook 'window-configuration-change-hook 'aw-update)))
+
+(defun aw-update ()
+ "Update ace-window-path window parameter for all windows."
+ (avy-traverse
+ (avy-tree (aw-window-list) aw-keys)
+ (lambda (path leaf)
+ (set-window-parameter
+ leaf 'ace-window-path
+ (propertize
+ (apply #'string (reverse path))
+ 'face 'aw-mode-line-face)))))
+
+(provide 'ace-window)
+
+;;; ace-window.el ends here