display-line-number.el (emacs中显示行号)

;;; display-line-number.el --- line number mode for Emacs

;; Copyright (C) 2004 Free Software Foundation, Inc.

;; Author: ChunYe Wang

;; Keywords: tools

;; 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 2, or (at your option)

;; any later version.

;; This file 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; see the file COPYING. If not, write to

;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,

;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; Installation:

;; put the display-line-number.el in your load-path

;; (require 'display-line-number)

;; M-x display-line-number-mode

;; M-x display-line-number-mode-on

;; M-x display-line-number-mode-off

;;; Code:

(defvar display-line-number-mode nil

"Non-nil if display-line-number-mode is active in the current buffer.")

(make-variable-buffer-local 'display-line-number-mode)

(defvar display-line-number-face 'font-lock-keyword-face)

(defvar global-display-line-number-mode nil

"Non-nil if display-line-number-mode is active in the all buffer.")

(defvar display-line-number-format "%5d "

"String suitable for `format' that will generate a line number string.

`format' will be called with this string and one other argument

which will be an integer, the line number.")

(defun display-line-number-mode (&optional arg)

"Toggle display-line-number-mode.

With prefix argument, turn display-line-number-mode on if argument is positive.

When display-line-number-mode is enabled, a line number will appear at the left

margin of each line."

(interactive "P")

(if (null arg) (setq arg 0)

(setq arg (prefix-numeric-value arg)))

(cond

((> arg 0) (setq display-line-number-mode t))

((= arg 0) (setq display-line-number-mode

(not display-line-number-mode)))

((< arg 0) (setq display-line-number-mode nil)))

(if display-line-number-mode

(display-line-number-mode-on)

(display-line-number-mode-off)))

(defun global-display-line-number-mode (&optional arg)

"Toggle display-line-number-mode.

With prefix argument, turn display-line-number-mode on if argument is positive.

When display-line-number-mode is enabled, a line number will appear at the left

margin of each line."

(interactive "P")

(if (null arg) (setq arg 0)

(setq arg (prefix-numeric-value arg)))

(cond

((> arg 0) (setq global-display-line-number-mode t))

((= arg 0) (setq global-display-line-number-mode

(not global-display-line-number-mode)))

((< arg 0) (setq global-display-line-number-mode nil)))

(if global-display-line-number-mode

(add-hook 'find-file-hooks

'display-line-number-mode-on)

(remove-hook 'find-file-hooks

'display-line-number-mode-on))

(message "global display line number mode is %s" (if global-display-line-number-mode "on" "off")))

;; (global-display-line-number-mode (if global-display-line-number-mode 1 0))

(defun display-line-number-mode-on()

(interactive)

(setq display-line-number-mode t)

(dln-undisplay)

(dln-display)

(make-local-variable 'after-change-functions)

(make-local-variable 'window-scroll-functions)

(make-local-variable 'window-configuration-change-hook)

(add-to-list 'after-change-functions

'dln-after-change-function)

(add-to-list 'window-configuration-change-hook

'dln-window-configuration-change-function)

(add-to-list 'window-scroll-functions

'dln-window-scroll-function))

(defun display-line-number-mode-off()

(interactive)

(dln-undisplay)

(setq after-change-functions (remq

'dln-after-change-function

after-change-functions))

(setq window-configuration-change-hook (remq

'dln-window-configuration-change-function

window-configuration-change-hook))

(setq window-scroll-functions (remq

'dln-window-scroll-function

window-scroll-functions)))

(defun dln-core (start end str)

(let ((e (make-overlay start end)))

(overlay-put e 'before-string (propertize str 'face display-line-number-face))

(overlay-put e 'name 'dln-core)))

(defun dln-display ( &optional arg)

(interactive "p")

;; (setq left-margin-width 5)

;; (set-window-margins (selected-window) 5 0)

(let ((line-number 1)

(start (window-start (selected-window)))

(end (window-end (selected-window) t))

(n 0)

(flag 0))

(save-excursion

(save-restriction

(widen)

(goto-char start)

(beginning-of-line)

(setq n (count-lines 1 (point)))

(while (= flag 0)

(setq n (1+ n))

(dln-core (line-beginning-position)

(line-end-position)

(format display-line-number-format n

))

(forward-line 1)

(if (or (>= (point) end)

(>= (point) (point-max))

(not (equal (point) (line-beginning-position))))

(setq flag 1)))))))

(defun dln-undisplay ()

(interactive)

(save-excursion

(save-restriction

(widen)

(let ((es (overlays-in 1 (1+ (point-max)))))

(mapc (lambda (e)

(if (eq (overlay-get e 'name) 'dln-core)

(delete-overlay e)))

es)))))

(defun dln-after-change-function (&optional start end length)

(dln-undisplay)

(dln-display))

(defun dln-window-scroll-function (&optional win pos)

(dln-undisplay)

(dln-display))

(defun dln-window-configuration-change-function (&optional win pos)

(dln-undisplay)

(dln-display))

(provide 'display-line-number)

;;; display-line-number.el ends here