--- /dev/null
+;;; smart-yank.el --- A different approach of yank pointer handling -*- lexical-binding: t -*-
+
+;; Copyright (C) 2016 Free Software Foundation, Inc
+
+;; Author: Michael Heerdegen <michael_heerdegen@web.de>
+;; Maintainer: Michael Heerdegen <michael_heerdegen@web.de>
+;; Created: 14 May 2016
+;; Keywords: convenience
+;; Compatibility: GNU Emacs 24
+;; Version: 0.1
+;; Package-Requires: ((emacs "24"))
+
+
+;; This file is not part of GNU Emacs.
+
+;; GNU Emacs 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 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs 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.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
+
+
+;;; Commentary:
+;;
+;; Introduction
+;; ============
+;;
+;; This library implements the global minor mode `smart-yank-mode'
+;; that changes the way Emacs handles the `kill-ring-yank-pointer' in
+;; a way that some people prefer over the default behavior.
+;;
+;; Normally, only a kill command resets the yank pointer. With
+;; `smart-yank-mode' enabled, any command except yank commands resets
+;; it.
+;;
+;; In addition, when yanking any "older" element from the kill-ring
+;; with yank-pop (and not replacing it with a subsequent yank-pop), it
+;; is automatically moved to the "first position" so `yank' invoked
+;; later will yank this element again.
+;;
+;; Finally, `yank-pop' (normally bound to M-y) is replaced with
+;; `smart-yank-yank-pop' that is a bit more sophisticated:
+;;
+;; - When _not_ called after a `yank', instead of raising an error
+;; like `yank-pop', yank the next-to-the-last kill.
+;;
+;; - Hit M-y twice in fast succession (delay < 0.2 secs by default)
+;; when you got lost. This will remove the yanked text. If you
+;; bind a command to `smart-yank-browse-kill-ring-command', this
+;; command will be called too (typically something like
+;; `browse-kill-ring').
+;;
+;;
+;; Example: you want to manually replace some words in some buffer
+;; with a new word "foo". With `smart-yank-mode' enabled, you can do
+;; it like this:
+;;
+;; 1. Put "foo" into the kill ring.
+;; 2. Move to the next word to be replaced.
+;; 3. M-d M-y
+;; 4. Back to 2, iterate.
+;;
+;;
+;; Setup
+;; =====
+;;
+;; Just enable `smart-yank-mode' and you are done.
+
+
+
+;;; Code:
+
+;;;; Configuration stuff
+
+(defgroup smart-yank nil
+ "A different approach of yank pointer handling."
+ :group 'killing)
+
+(defcustom smart-yank-yank-pop-multikey-delay .2
+ "Max delay between two \\[smart-yank-yank-pop] invocations revealing special behavior.
+See `smart-yank-yank-pop' for details."
+ :type 'number)
+
+(defcustom smart-yank-browse-kill-ring-command nil
+ "Command to invoke when hitting \\[smart-yank-yank-pop] twice (fast)."
+ :type '(choice (const :tag "None" nil)
+ (const browse-kill-ring)
+ (const helm-show-kill-ring)
+ (function :tag "Other Function")))
+
+(defvar smart-yank-map
+ (let ((map (make-sparse-keymap)))
+ (define-key map [remap yank-pop] #'smart-yank-yank-pop)
+ map)
+ "Map used by `smart-yank-mode'.")
+
+
+;;;; Internals
+
+(defun smart-yank--stopwatch ()
+ "Return a fresh stopwatch.
+This is a function accepting zero arguments that upon each call
+will return the time difference from its last call in seconds.
+When called the first time it will return nil."
+ (let ((last-invocation nil))
+ (lambda ()
+ (prog1 (and last-invocation
+ (time-to-seconds (time-subtract (current-time) last-invocation)))
+ (setq last-invocation (current-time))))))
+
+(defun smart-yank-reset-yank-pointer ()
+ (unless (eq last-command #'yank)
+ (setq kill-ring-yank-pointer kill-ring)))
+
+(defun smart-yank--before-ad (&rest _args)
+ "Before advice function for `yank'.
+
+Reset `kill-ring-yank-pointer'. For yank-pop, move the really
+yanked text \"to the beginning\" of the kill ring."
+ (unless (eq kill-ring kill-ring-yank-pointer)
+ (let ((last-yank (car kill-ring-yank-pointer)))
+ (when last-yank
+ (setq kill-ring (cons last-yank (delete last-yank kill-ring)))
+ (smart-yank-reset-yank-pointer)))))
+
+(let ((r (smart-yank--stopwatch)))
+ (defun smart-yank-yank-pop (&optional arg)
+ "\"smart-yank\"'s private version of `yank-pop'.
+
+When called directly after a `yank' command (including itself),
+call `yank-pop'.
+
+If its key was hit two times in fast succession - i.e. with a
+delay less than `smart-yank-yank-pop-multikey-delay' - delete any
+yanked text; in addition call
+`smart-yank-browse-kill-ring-command' when set.
+
+When not called after a yank, yank the next-to-the-last
+`kill-ring' entry; with prefix arg, call the
+`smart-yank-browse-kill-ring-command'."
+ (interactive "P")
+ (let ((diff (funcall r)))
+ (cond
+ ((not (eq last-command 'yank)) (if arg (call-interactively smart-yank-browse-kill-ring-command)
+ (rotate-yank-pointer 1)
+ (yank)))
+ ((or (not diff)
+ (> diff smart-yank-yank-pop-multikey-delay))
+ (call-interactively #'yank-pop))
+ (t (funcall (or yank-undo-function #'delete-region)
+ (region-beginning) (region-end))
+ (when smart-yank-browse-kill-ring-command
+ (call-interactively smart-yank-browse-kill-ring-command)))))))
+
+(declare-function smart-yank-yank-pop 'smart-yank)
+
+
+;;;; User stuff
+
+;;;###autoload
+(define-minor-mode smart-yank-mode
+ "Alter the behavior of yank commands in several ways.
+
+Turning on this mode has the following effects:
+
+ - Makes any command except yank commands reset the
+ `kill-ring-yank-pointer', instead of only killing commands.
+
+ - Remaps `yank-pop' to `smart-yank-yank-pop'.
+
+ - When yanking an older element from the `kill-ring' with
+ \\[smart-yank-yank-pop] (and not replacing it with a subsequent \\[smart-yank-yank-pop]), the
+ element is automatically \"moved to the first position\" of
+ the `kill-ring' so that `yank' invoked later will again yank
+ this element."
+ :global t :keymap smart-yank-map
+ (if smart-yank-mode
+ (advice-add 'yank :before #'smart-yank--before-ad)
+ (advice-remove 'yank #'smart-yank--before-ad)))
+
+
+(provide 'smart-yank)
+
+;;; smart-yank.el ends here