-;;; register.el --- register commands for Emacs
+;;; register.el --- register commands for Emacs -*- lexical-binding: t; -*-
-;; Copyright (C) 1985, 1993-1994, 2001-2013 Free Software Foundation,
+;; Copyright (C) 1985, 1993-1994, 2001-2014 Free Software Foundation,
;; Inc.
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
;; Keywords: internal
;; Package: emacs
:type '(choice (const :tag "None" nil)
(character :tag "Use register" :value ?+)))
+(defcustom register-preview-delay 1
+ "If non-nil, time to wait in seconds before popping up a preview window.
+If nil, do not show register previews, unless `help-char' (or a member of
+`help-event-list') is pressed."
+ :version "24.4"
+ :type '(choice number (const :tag "No preview unless requested" nil))
+ :group 'register)
+
(defun get-register (register)
"Return contents of Emacs register named REGISTER, or nil if none."
(cdr (assq register register-alist)))
(push (cons register value) register-alist))
value))
+(defun register-describe-oneline (c)
+ "One-line description of register C."
+ (let ((d (replace-regexp-in-string
+ "\n[ \t]*" " "
+ (with-output-to-string (describe-register-1 c)))))
+ (if (string-match "Register.+? contains \\(?:an? \\|the \\)?" d)
+ (substring d (match-end 0))
+ d)))
+
+(defun register-preview-default (r)
+ "Default function for the variable `register-preview-function'."
+ (format "%s %s\n"
+ (concat (single-key-description (car r)) ":")
+ (register-describe-oneline (car r))))
+
+(defvar register-preview-function #'register-preview-default
+ "Function to format a register for previewing.
+Takes one argument, a cons (NAME . CONTENTS) as found in `register-alist'.
+Returns a string.")
+
+(defun register-preview (buffer &optional show-empty)
+ "Pop up a window to show register preview in BUFFER.
+If SHOW-EMPTY is non-nil show the window even if no registers.
+Format of each entry is controlled by the variable `register-preview-function'."
+ (when (or show-empty (consp register-alist))
+ (with-temp-buffer-window
+ buffer
+ (cons 'display-buffer-below-selected
+ '((window-height . fit-window-to-buffer)))
+ nil
+ (with-current-buffer standard-output
+ (setq cursor-in-non-selected-windows nil)
+ (insert (mapconcat register-preview-function register-alist ""))))))
+
+(defun register-read-with-preview (prompt)
+ "Read and return a register name, possibly showing existing registers.
+Prompt with the string PROMPT. If `register-alist' and
+`register-preview-delay' are both non-nil, display a window
+listing existing registers after `register-preview-delay' seconds.
+If `help-char' (or a member of `help-event-list') is pressed,
+display such a window regardless."
+ (let* ((buffer "*Register Preview*")
+ (timer (when (numberp register-preview-delay)
+ (run-with-timer register-preview-delay nil
+ (lambda ()
+ (unless (get-buffer-window buffer)
+ (register-preview buffer))))))
+ (help-chars (cl-loop for c in (cons help-char help-event-list)
+ when (not (get-register c))
+ collect c)))
+ (unwind-protect
+ (progn
+ (while (memq (read-event (propertize prompt 'face 'minibuffer-prompt))
+ help-chars)
+ (unless (get-buffer-window buffer)
+ (register-preview buffer 'show-empty)))
+ (if (characterp last-input-event) last-input-event
+ (error "Non-character input-event")))
+ (and (timerp timer) (cancel-timer timer))
+ (let ((w (get-buffer-window buffer)))
+ (and (window-live-p w) (delete-window w)))
+ (and (get-buffer buffer) (kill-buffer buffer)))))
+
(defun point-to-register (register &optional arg)
"Store current location of point in register REGISTER.
With prefix argument, store current frame configuration.
Use \\[jump-to-register] to go to that location or restore that configuration.
-Argument is a character, naming the register."
- (interactive "cPoint to register: \nP")
+Argument is a character, naming the register.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview "Point to register: ")
+ current-prefix-arg))
;; Turn the marker into a file-ref if the buffer is killed.
(add-hook 'kill-buffer-hook 'register-swap-out nil t)
(set-register register
(defun window-configuration-to-register (register &optional _arg)
"Store the window configuration of the selected frame in register REGISTER.
Use \\[jump-to-register] to restore the configuration.
-Argument is a character, naming the register."
- (interactive "cWindow configuration to register: \nP")
+Argument is a character, naming the register.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview
+ "Window configuration to register: ")
+ current-prefix-arg))
;; current-window-configuration does not include the value
;; of point in the current buffer, so record that separately.
(set-register register (list (current-window-configuration) (point-marker))))
+;; It has had the optional arg for ages, but never used it.
+(set-advertised-calling-convention 'window-configuration-to-register
+ '(register) "24.4")
+
(defun frame-configuration-to-register (register &optional _arg)
"Store the window configuration of all frames in register REGISTER.
Use \\[jump-to-register] to restore the configuration.
-Argument is a character, naming the register."
- (interactive "cFrame configuration to register: \nP")
+Argument is a character, naming the register.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview
+ "Frame configuration to register: ")
+ current-prefix-arg))
;; current-frame-configuration does not include the value
;; of point in the current buffer, so record that separately.
(set-register register (list (current-frame-configuration) (point-marker))))
+;; It has had the optional arg for ages, but never used it.
+(set-advertised-calling-convention 'frame-configuration-to-register
+ '(register) "24.4")
+
(defalias 'register-to-point 'jump-to-register)
(defun jump-to-register (register &optional delete)
"Move point to location stored in a register.
If the register contains a file name, find that file.
\(To put a file name in a register, you must use `set-register'.)
-If the register contains a window configuration (one frame) or a frame
-configuration (all frames), restore that frame or all frames accordingly.
+If the register contains a window configuration (one frame) or a frameset
+\(all frames), restore that frame or all frames accordingly.
First argument is a character, naming the register.
Optional second arg non-nil (interactively, prefix argument) says to
-delete any existing frames that the frame configuration doesn't mention.
-\(Otherwise, these frames are iconified.)"
- (interactive "cJump to register: \nP")
+delete any existing frames that the frameset doesn't mention.
+\(Otherwise, these frames are iconified.)
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview "Jump to register: ")
+ current-prefix-arg))
(let ((val (get-register register)))
(cond
((registerv-p val)
Two args, NUMBER and REGISTER (a character, naming the register).
If NUMBER is nil, a decimal number is read from the buffer starting
at point, and point moves to the end of that number.
-Interactively, NUMBER is the prefix arg (none means nil)."
- (interactive "P\ncNumber to register: ")
+Interactively, NUMBER is the prefix arg (none means nil).
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list current-prefix-arg
+ (register-read-with-preview "Number to register: ")))
(set-register register
(if number
(prefix-numeric-value number)
PREFIX to it.
If REGISTER is empty or if it contains text, call
-`append-to-register' with `delete-flag' set to PREFIX."
- (interactive "P\ncIncrement register: ")
+`append-to-register' with `delete-flag' set to PREFIX.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list current-prefix-arg
+ (register-read-with-preview "Increment register: ")))
(let ((register-val (get-register register)))
(cond
((numberp register-val)
(defun view-register (register)
"Display what is contained in register named REGISTER.
-The Lisp value REGISTER is a character."
- (interactive "cView register: ")
+The Lisp value REGISTER is a character.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview "View register: ")))
(let ((val (get-register register)))
(if (null val)
(message "Register %s is empty" (single-key-description register))
(princ (car val))))
((stringp val)
+ (setq val (copy-sequence val))
(if (eq yank-excluded-properties t)
(set-text-properties 0 (length val) nil val)
(remove-list-of-text-properties 0 (length val)
"Insert contents of register REGISTER. (REGISTER is a character.)
Normally puts point before and mark after the inserted text.
If optional second arg is non-nil, puts mark before and point after.
-Interactively, second arg is non-nil if prefix arg is supplied."
- (interactive "*cInsert register: \nP")
+Interactively, second arg is non-nil if prefix arg is supplied.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (progn
+ (barf-if-buffer-read-only)
+ (list (register-read-with-preview "Insert register: ")
+ current-prefix-arg)))
(push-mark)
(let ((val (get-register register)))
(cond
(error "Register does not contain text"))))
(if (not arg) (exchange-point-and-mark)))
-(defun copy-to-register (register start end &optional delete-flag)
+(defun copy-to-register (register start end &optional delete-flag region)
"Copy region into register REGISTER.
With prefix arg, delete as well.
Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
-START and END are buffer positions indicating what to copy."
- (interactive "cCopy to register: \nr\nP")
- (set-register register (filter-buffer-substring start end))
+START and END are buffer positions indicating what to copy.
+The optional argument REGION if non-nil, indicates that we're not just copying
+some text between START and END, but we're copying the region.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview "Copy to register: ")
+ (region-beginning)
+ (region-end)
+ current-prefix-arg
+ t))
+ (set-register register (if region
+ (funcall region-extract-function delete-flag)
+ (prog1 (filter-buffer-substring start end)
+ (if delete-flag (delete-region start end)))))
(setq deactivate-mark t)
- (cond (delete-flag
- (delete-region start end))
+ (cond (delete-flag)
((called-interactively-p 'interactive)
(indicate-copied-region))))
"Append region to text in register REGISTER.
With prefix arg, delete as well.
Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
-START and END are buffer positions indicating what to append."
- (interactive "cAppend to register: \nr\nP")
+START and END are buffer positions indicating what to append.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview "Append to register: ")
+ (region-beginning)
+ (region-end)
+ current-prefix-arg))
(let ((reg (get-register register))
(text (filter-buffer-substring start end))
(separator (and register-separator (get-register register-separator))))
"Prepend region to text in register REGISTER.
With prefix arg, delete as well.
Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
-START and END are buffer positions indicating what to prepend."
- (interactive "cPrepend to register: \nr\nP")
+START and END are buffer positions indicating what to prepend.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview "Prepend to register: ")
+ (region-beginning)
+ (region-end)
+ current-prefix-arg))
(let ((reg (get-register register))
(text (filter-buffer-substring start end))
(separator (and register-separator (get-register register-separator))))
To insert this register in the buffer, use \\[insert-register].
Called from a program, takes four args: REGISTER, START, END and DELETE-FLAG.
-START and END are buffer positions giving two corners of rectangle."
- (interactive "cCopy rectangle to register: \nr\nP")
+START and END are buffer positions giving two corners of rectangle.
+
+Interactively, reads the register using `register-read-with-preview'."
+ (interactive (list (register-read-with-preview
+ "Copy rectangle to register: ")
+ (region-beginning)
+ (region-end)
+ current-prefix-arg))
(let ((rectangle (if delete-flag
(delete-extract-rectangle start end)
(extract-rectangle start end))))
(setq deactivate-mark t)
(indicate-copied-region (length (car rectangle))))))
-
(provide 'register)
;;; register.el ends here