;;; ruler-mode.el --- display a ruler in the header line ;; Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, ;; 2007 Free Software Foundation, Inc. ;; Author: David Ponce ;; Maintainer: David Ponce ;; Created: 24 Mar 2001 ;; Version: 1.6 ;; Keywords: convenience ;; This file is part of GNU Emacs. ;; This program 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 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. ;; You should have received a copy of the GNU General Public License ;; along with this program; see the file COPYING. If not, write to ;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, ;; Boston, MA 02110-1301, USA. ;;; Commentary: ;; This library provides a minor mode to display a ruler in the header ;; line. It works only on Emacs 21. ;; ;; You can use the mouse to change the `fill-column' `comment-column', ;; `goal-column', `window-margins' and `tab-stop-list' settings: ;; ;; [header-line (shift down-mouse-1)] set left margin end to the ruler ;; graduation where the mouse pointer is on. ;; ;; [header-line (shift down-mouse-3)] set right margin beginning to ;; the ruler graduation where the mouse pointer is on. ;; ;; [header-line down-mouse-2] Drag the `fill-column', `comment-column' ;; or `goal-column' to a ruler graduation. ;; ;; [header-line (control down-mouse-1)] add a tab stop to the ruler ;; graduation where the mouse pointer is on. ;; ;; [header-line (control down-mouse-3)] remove the tab stop at the ;; ruler graduation where the mouse pointer is on. ;; ;; [header-line (control down-mouse-2)] or M-x ;; `ruler-mode-toggle-show-tab-stops' toggle showing and visually ;; editing `tab-stop-list' setting. The `ruler-mode-show-tab-stops' ;; option controls if the ruler shows tab stops by default. ;; ;; In the ruler the character `ruler-mode-current-column-char' shows ;; the `current-column' location, `ruler-mode-fill-column-char' shows ;; the `fill-column' location, `ruler-mode-comment-column-char' shows ;; the `comment-column' location, `ruler-mode-goal-column-char' shows ;; the `goal-column' and `ruler-mode-tab-stop-char' shows tab stop ;; locations. Graduations in `window-margins' and `window-fringes' ;; areas are shown with a different foreground color. ;; ;; It is also possible to customize the following characters: ;; ;; - `ruler-mode-basic-graduation-char' character used for basic ;; graduations ('.' by default). ;; - `ruler-mode-inter-graduation-char' character used for ;; intermediate graduations ('!' by default). ;; ;; The following faces are customizable: ;; ;; - `ruler-mode-default' the ruler default face. ;; - `ruler-mode-fill-column' the face used to highlight the ;; `fill-column' character. ;; - `ruler-mode-comment-column' the face used to highlight the ;; `comment-column' character. ;; - `ruler-mode-goal-column' the face used to highlight the ;; `goal-column' character. ;; - `ruler-mode-current-column' the face used to highlight the ;; `current-column' character. ;; - `ruler-mode-tab-stop' the face used to highlight tab stop ;; characters. ;; - `ruler-mode-margins' the face used to highlight graduations ;; in the `window-margins' areas. ;; - `ruler-mode-fringes' the face used to highlight graduations ;; in the `window-fringes' areas. ;; - `ruler-mode-column-number' the face used to highlight the ;; numbered graduations. ;; ;; `ruler-mode-default' inherits from the built-in `default' face. ;; All `ruler-mode' faces inherit from `ruler-mode-default'. ;; ;; WARNING: To keep ruler graduations aligned on text columns it is ;; important to use the same font family and size for ruler and text ;; areas. ;; ;; You can override the ruler format by defining an appropriate ;; function as the buffer-local value of `ruler-mode-ruler-function'. ;; Installation ;; ;; To automatically display the ruler in specific major modes use: ;; ;; (add-hook '-hook 'ruler-mode) ;; ;;; History: ;; ;;; Code: (eval-when-compile (require 'wid-edit)) (require 'scroll-bar) (require 'fringe) (defgroup ruler-mode nil "Display a ruler in the header line." :version "22.1" :group 'convenience) (defcustom ruler-mode-show-tab-stops nil "*If non-nil the ruler shows tab stop positions. Also allowing to visually change `tab-stop-list' setting using and on the ruler to respectively add or remove a tab stop. \\[ruler-mode-toggle-show-tab-stops] or on the ruler toggles showing/editing of tab stops." :group 'ruler-mode :type 'boolean) ;; IMPORTANT: This function must be defined before the following ;; defcustoms because it is used in their :validate clause. (defun ruler-mode-character-validate (widget) "Ensure WIDGET value is a valid character value." (save-excursion (let ((value (widget-value widget))) (if (char-valid-p value) nil (widget-put widget :error (format "Invalid character value: %S" value)) widget)))) (defcustom ruler-mode-fill-column-char (if (char-displayable-p ?¶) ?\¶ ?\|) "*Character used at the `fill-column' location." :group 'ruler-mode :type '(choice (character :tag "Character") (integer :tag "Integer char value" :validate ruler-mode-character-validate))) (defcustom ruler-mode-comment-column-char ?\# "*Character used at the `comment-column' location." :group 'ruler-mode :type '(choice (character :tag "Character") (integer :tag "Integer char value" :validate ruler-mode-character-validate))) (defcustom ruler-mode-goal-column-char ?G "*Character used at the `goal-column' location." :group 'ruler-mode :type '(choice (character :tag "Character") (integer :tag "Integer char value" :validate ruler-mode-character-validate))) (defcustom ruler-mode-current-column-char (if (char-displayable-p ?¦) ?\¦ ?\@) "*Character used at the `current-column' location." :group 'ruler-mode :type '(choice (character :tag "Character") (integer :tag "Integer char value" :validate ruler-mode-character-validate))) (defcustom ruler-mode-tab-stop-char ?\T "*Character used at `tab-stop-list' locations." :group 'ruler-mode :type '(choice (character :tag "Character") (integer :tag "Integer char value" :validate ruler-mode-character-validate))) (defcustom ruler-mode-basic-graduation-char ?\. "*Character used for basic graduations." :group 'ruler-mode :type '(choice (character :tag "Character") (integer :tag "Integer char value" :validate ruler-mode-character-validate))) (defcustom ruler-mode-inter-graduation-char ?\! "*Character used for intermediate graduations." :group 'ruler-mode :type '(choice (character :tag "Character") (integer :tag "Integer char value" :validate ruler-mode-character-validate))) (defcustom ruler-mode-set-goal-column-ding-flag t "*Non-nil means do `ding' when `goal-column' is set." :group 'ruler-mode :type 'boolean) (defface ruler-mode-default '((((type tty)) (:inherit default :background "grey64" :foreground "grey50" )) (t (:inherit default :background "grey76" :foreground "grey64" :box (:color "grey76" :line-width 1 :style released-button) ))) "Default face used by the ruler." :group 'ruler-mode) (defface ruler-mode-pad '((((type tty)) (:inherit ruler-mode-default :background "grey50" )) (t (:inherit ruler-mode-default :background "grey64" ))) "Face used to pad inactive ruler areas." :group 'ruler-mode) (defface ruler-mode-margins '((t (:inherit ruler-mode-default :foreground "white" ))) "Face used to highlight margin areas." :group 'ruler-mode) (defface ruler-mode-fringes '((t (:inherit ruler-mode-default :foreground "green" ))) "Face used to highlight fringes areas." :group 'ruler-mode) (defface ruler-mode-column-number '((t (:inherit ruler-mode-default :foreground "black" ))) "Face used to highlight number graduations." :group 'ruler-mode) (defface ruler-mode-fill-column '((t (:inherit ruler-mode-default :foreground "red" ))) "Face used to highlight the fill column character." :group 'ruler-mode) (defface ruler-mode-comment-column '((t (:inherit ruler-mode-default :foreground "red" ))) "Face used to highlight the comment column character." :group 'ruler-mode) (defface ruler-mode-goal-column '((t (:inherit ruler-mode-default :foreground "red" ))) "Face used to highlight the goal column character." :group 'ruler-mode) (defface ruler-mode-tab-stop '((t (:inherit ruler-mode-default :foreground "steelblue" ))) "Face used to highlight tab stop characters." :group 'ruler-mode) (defface ruler-mode-current-column '((t (:inherit ruler-mode-default :weight bold :foreground "yellow" ))) "Face used to highlight the `current-column' character." :group 'ruler-mode) (defsubst ruler-mode-full-window-width () "Return the full width of the selected window." (let ((edges (window-edges))) (- (nth 2 edges) (nth 0 edges)))) (defsubst ruler-mode-window-col (n) "Return a column number relative to the selected window. N is a column number relative to selected frame." (- n (car (window-edges)) (or (car (window-margins)) 0) (fringe-columns 'left) (scroll-bar-columns 'left))) (defun ruler-mode-mouse-set-left-margin (start-event) "Set left margin end to the graduation where the mouse pointer is on. START-EVENT is the mouse click event." (interactive "e") (let* ((start (event-start start-event)) (end (event-end start-event)) col w lm rm) (when (eq start end) ;; mouse click (save-selected-window (select-window (posn-window start)) (setq col (- (car (posn-col-row start)) (car (window-edges)) (scroll-bar-columns 'left)) w (- (ruler-mode-full-window-width) (scroll-bar-columns 'left) (scroll-bar-columns 'right))) (when (and (>= col 0) (< col w)) (setq lm (window-margins) rm (or (cdr lm) 0) lm (or (car lm) 0)) (message "Left margin set to %d (was %d)" col lm) (set-window-margins nil col rm)))))) (defun ruler-mode-mouse-set-right-margin (start-event) "Set right margin beginning to the graduation where the mouse pointer is on. START-EVENT is the mouse click event." (interactive "e") (let* ((start (event-start start-event)) (end (event-end start-event)) col w lm rm) (when (eq start end) ;; mouse click (save-selected-window (select-window (posn-window start)) (setq col (- (car (posn-col-row start)) (car (window-edges)) (scroll-bar-columns 'left)) w (- (ruler-mode-full-window-width) (scroll-bar-columns 'left) (scroll-bar-columns 'right))) (when (and (>= col 0) (< col w)) (setq lm (window-margins) rm (or (cdr lm) 0) lm (or (car lm) 0) col (- w col 1)) (message "Right margin set to %d (was %d)" col rm) (set-window-margins nil lm col)))))) (defvar ruler-mode-dragged-symbol nil "Column symbol dragged in the ruler. That is `fill-column', `comment-column', `goal-column', or nil when nothing is dragged.") (defun ruler-mode-mouse-grab-any-column (start-event) "Drag a column symbol on the ruler. Start dragging on mouse down event START-EVENT, and update the column symbol value with the current value of the ruler graduation while dragging. See also the variable `ruler-mode-dragged-symbol'." (interactive "e") (setq ruler-mode-dragged-symbol nil) (let* ((start (event-start start-event)) col newc oldc) (save-selected-window (select-window (posn-window start)) (setq col (ruler-mode-window-col (car (posn-col-row start))) newc (+ col (window-hscroll))) (and (>= col 0) (< col (window-width)) (cond ;; Handle the fill column. ((eq newc fill-column) (setq oldc fill-column ruler-mode-dragged-symbol 'fill-column) t) ;; Start dragging ;; Handle the comment column. ((eq newc comment-column) (setq oldc comment-column ruler-mode-dragged-symbol 'comment-column) t) ;; Start dragging ;; Handle the goal column. ;; A. On mouse down on the goal column character on the ruler, ;; update the `goal-column' value while dragging. ;; B. If `goal-column' is nil, set the goal column where the ;; mouse is clicked. ;; C. On mouse click on the goal column character on the ;; ruler, unset the goal column. ((eq newc goal-column) ; A. Drag the goal column. (setq oldc goal-column ruler-mode-dragged-symbol 'goal-column) t) ;; Start dragging ((null goal-column) ; B. Set the goal column. (setq oldc goal-column goal-column newc) ;; mouse-2 coming AFTER drag-mouse-2 invokes `ding'. This ;; `ding' flushes the next messages about setting goal ;; column. So here I force fetch the event(mouse-2) and ;; throw away. (read-event) ;; Ding BEFORE `message' is OK. (when ruler-mode-set-goal-column-ding-flag (ding)) (message "Goal column set to %d (click on %s again to unset it)" newc (propertize (char-to-string ruler-mode-goal-column-char) 'face 'ruler-mode-goal-column)) nil) ;; Don't start dragging. ) (if (eq 'click (ruler-mode-mouse-drag-any-column-iteration (posn-window start))) (when (eq 'goal-column ruler-mode-dragged-symbol) ;; C. Unset the goal column. (set-goal-column t)) ;; At end of dragging, report the updated column symbol. (message "%s is set to %d (was %d)" ruler-mode-dragged-symbol (symbol-value ruler-mode-dragged-symbol) oldc)))))) (defun ruler-mode-mouse-drag-any-column-iteration (window) "Update the ruler while dragging the mouse. WINDOW is the window where occurred the last down-mouse event. Return the symbol `drag' if the mouse has been dragged, or `click' if the mouse has been clicked." (let ((drags 0) event) (track-mouse (while (mouse-movement-p (setq event (read-event))) (setq drags (1+ drags)) (when (eq window (posn-window (event-end event))) (ruler-mode-mouse-drag-any-column event) (force-mode-line-update)))) (if (and (zerop drags) (eq 'click (car (event-modifiers event)))) 'click 'drag))) (defun ruler-mode-mouse-drag-any-column (start-event) "Update the value of the symbol dragged on the ruler. Called on each mouse motion event START-EVENT." (let* ((start (event-start start-event)) (end (event-end start-event)) col newc) (save-selected-window (select-window (posn-window start)) (setq col (ruler-mode-window-col (car (posn-col-row end))) newc (+ col (window-hscroll))) (when (and (>= col 0) (< col (window-width))) (set ruler-mode-dragged-symbol newc))))) (defun ruler-mode-mouse-add-tab-stop (start-event) "Add a tab stop to the graduation where the mouse pointer is on. START-EVENT is the mouse click event." (interactive "e") (when ruler-mode-show-tab-stops (let* ((start (event-start start-event)) (end (event-end start-event)) col ts) (when (eq start end) ;; mouse click (save-selected-window (select-window (posn-window start)) (setq col (ruler-mode-window-col (car (posn-col-row start))) ts (+ col (window-hscroll))) (and (>= col 0) (< col (window-width)) (not (member ts tab-stop-list)) (progn (message "Tab stop set to %d" ts) (setq tab-stop-list (sort (cons ts tab-stop-list) #'<))))))))) (defun ruler-mode-mouse-del-tab-stop (start-event) "Delete tab stop at the graduation where the mouse pointer is on. START-EVENT is the mouse click event." (interactive "e") (when ruler-mode-show-tab-stops (let* ((start (event-start start-event)) (end (event-end start-event)) col ts) (when (eq start end) ;; mouse click (save-selected-window (select-window (posn-window start)) (setq col (ruler-mode-window-col (car (posn-col-row start))) ts (+ col (window-hscroll))) (and (>= col 0) (< col (window-width)) (member ts tab-stop-list) (progn (message "Tab stop at %d deleted" ts) (setq tab-stop-list (delete ts tab-stop-list))))))))) (defun ruler-mode-toggle-show-tab-stops () "Toggle showing of tab stops on the ruler." (interactive) (setq ruler-mode-show-tab-stops (not ruler-mode-show-tab-stops)) (force-mode-line-update)) (defvar ruler-mode-map (let ((km (make-sparse-keymap))) (define-key km [header-line down-mouse-1] #'ignore) (define-key km [header-line down-mouse-3] #'ignore) (define-key km [header-line down-mouse-2] #'ruler-mode-mouse-grab-any-column) (define-key km [header-line (shift down-mouse-1)] #'ruler-mode-mouse-set-left-margin) (define-key km [header-line (shift down-mouse-3)] #'ruler-mode-mouse-set-right-margin) (define-key km [header-line (control down-mouse-1)] #'ruler-mode-mouse-add-tab-stop) (define-key km [header-line (control down-mouse-3)] #'ruler-mode-mouse-del-tab-stop) (define-key km [header-line (control down-mouse-2)] #'ruler-mode-toggle-show-tab-stops) (define-key km [header-line (shift mouse-1)] 'ignore) (define-key km [header-line (shift mouse-3)] 'ignore) (define-key km [header-line (control mouse-1)] 'ignore) (define-key km [header-line (control mouse-3)] 'ignore) (define-key km [header-line (control mouse-2)] 'ignore) km) "Keymap for ruler minor mode.") (defvar ruler-mode-header-line-format-old nil "Hold previous value of `header-line-format'.") (defvar ruler-mode-ruler-function 'ruler-mode-ruler "Function to call to return ruler header line format. This variable is expected to be made buffer-local by modes.") (defconst ruler-mode-header-line-format '(:eval (funcall ruler-mode-ruler-function)) "`header-line-format' used in ruler mode. Call `ruler-mode-ruler-function' to compute the ruler value.") ;;;###autoload (define-minor-mode ruler-mode "Display a ruler in the header line if ARG > 0." nil nil ruler-mode-map :group 'ruler-mode (if ruler-mode (progn ;; When `ruler-mode' is on save previous header line format ;; and install the ruler header line format. (when (local-variable-p 'header-line-format) (set (make-local-variable 'ruler-mode-header-line-format-old) header-line-format)) (setq header-line-format ruler-mode-header-line-format) (add-hook 'post-command-hook 'force-mode-line-update nil t)) ;; When `ruler-mode' is off restore previous header line format if ;; the current one is the ruler header line format. (when (eq header-line-format ruler-mode-header-line-format) (kill-local-variable 'header-line-format) (when (local-variable-p 'ruler-mode-header-line-format-old) (setq header-line-format ruler-mode-header-line-format-old) (kill-local-variable 'ruler-mode-header-line-format-old))) (remove-hook 'post-command-hook 'force-mode-line-update t))) ;; Add ruler-mode to the minor mode menu in the mode line (define-key mode-line-mode-menu [ruler-mode] `(menu-item "Ruler" ruler-mode :button (:toggle . ruler-mode))) (defconst ruler-mode-ruler-help-echo "\ S-mouse-1/3: set L/R margin, \ mouse-2: set goal column, \ C-mouse-2: show tabs" "Help string shown when mouse is over the ruler. `ruler-mode-show-tab-stops' is nil.") (defconst ruler-mode-ruler-help-echo-when-goal-column "\ S-mouse-1/3: set L/R margin, \ C-mouse-2: show tabs" "Help string shown when mouse is over the ruler. `goal-column' is set and `ruler-mode-show-tab-stops' is nil.") (defconst ruler-mode-ruler-help-echo-when-tab-stops "\ C-mouse1/3: set/unset tab, \ C-mouse-2: hide tabs" "Help string shown when mouse is over the ruler. `ruler-mode-show-tab-stops' is non-nil.") (defconst ruler-mode-fill-column-help-echo "drag-mouse-2: set fill column" "Help string shown when mouse is on the fill column character.") (defconst ruler-mode-comment-column-help-echo "drag-mouse-2: set comment column" "Help string shown when mouse is on the comment column character.") (defconst ruler-mode-goal-column-help-echo "\ drag-mouse-2: set goal column, \ mouse-2: unset goal column" "Help string shown when mouse is on the goal column character.") (defconst ruler-mode-margin-help-echo "%s margin %S" "Help string shown when mouse is over a margin area.") (defconst ruler-mode-fringe-help-echo "%s fringe %S" "Help string shown when mouse is over a fringe area.") (defsubst ruler-mode-space (width &rest props) "Return a single space string of WIDTH times the normal character width. Optional argument PROPS specifies other text properties to apply." (apply 'propertize " " 'display (list 'space :width width) props)) (defun ruler-mode-ruler () "Compute and return a header line ruler." (let* ((w (window-width)) (m (window-margins)) (f (window-fringes)) (i 0) (j (window-hscroll)) ;; Setup the scrollbar, fringes, and margins areas. (lf (ruler-mode-space 'left-fringe 'face 'ruler-mode-fringes 'help-echo (format ruler-mode-fringe-help-echo "Left" (or (car f) 0)))) (rf (ruler-mode-space 'right-fringe 'face 'ruler-mode-fringes 'help-echo (format ruler-mode-fringe-help-echo "Right" (or (cadr f) 0)))) (lm (ruler-mode-space 'left-margin 'face 'ruler-mode-margins 'help-echo (format ruler-mode-margin-help-echo "Left" (or (car m) 0)))) (rm (ruler-mode-space 'right-margin 'face 'ruler-mode-margins 'help-echo (format ruler-mode-margin-help-echo "Right" (or (cdr m) 0)))) (sb (ruler-mode-space 'scroll-bar 'face 'ruler-mode-pad)) ;; Remember the scrollbar vertical type. (sbvt (car (window-current-scroll-bars))) ;; Create an "clean" ruler. (ruler (propertize (make-string w ruler-mode-basic-graduation-char) 'face 'ruler-mode-default 'local-map ruler-mode-map 'help-echo (cond (ruler-mode-show-tab-stops ruler-mode-ruler-help-echo-when-tab-stops) (goal-column ruler-mode-ruler-help-echo-when-goal-column) (ruler-mode-ruler-help-echo)))) k c) ;; Setup the active area. (while (< i w) ;; Graduations. (cond ;; Show a number graduation. ((= (mod j 10) 0) (setq c (number-to-string (/ j 10)) m (length c) k i) (put-text-property i (1+ i) 'face 'ruler-mode-column-number ruler) (while (and (> m 0) (>= k 0)) (aset ruler k (aref c (setq m (1- m)))) (setq k (1- k)))) ;; Show an intermediate graduation. ((= (mod j 5) 0) (aset ruler i ruler-mode-inter-graduation-char))) ;; Special columns. (cond ;; Show the `current-column' marker. ((= j (current-column)) (aset ruler i ruler-mode-current-column-char) (put-text-property i (1+ i) 'face 'ruler-mode-current-column ruler)) ;; Show the `goal-column' marker. ((and goal-column (= j goal-column)) (aset ruler i ruler-mode-goal-column-char) (put-text-property i (1+ i) 'face 'ruler-mode-goal-column ruler) (put-text-property i (1+ i) 'mouse-face 'mode-line-highlight ruler) (put-text-property i (1+ i) 'help-echo ruler-mode-goal-column-help-echo ruler)) ;; Show the `comment-column' marker. ((= j comment-column) (aset ruler i ruler-mode-comment-column-char) (put-text-property i (1+ i) 'face 'ruler-mode-comment-column ruler) (put-text-property i (1+ i) 'mouse-face 'mode-line-highlight ruler) (put-text-property i (1+ i) 'help-echo ruler-mode-comment-column-help-echo ruler)) ;; Show the `fill-column' marker. ((= j fill-column) (aset ruler i ruler-mode-fill-column-char) (put-text-property i (1+ i) 'face 'ruler-mode-fill-column ruler) (put-text-property i (1+ i) 'mouse-face 'mode-line-highlight ruler) (put-text-property i (1+ i) 'help-echo ruler-mode-fill-column-help-echo ruler)) ;; Show the `tab-stop-list' markers. ((and ruler-mode-show-tab-stops (member j tab-stop-list)) (aset ruler i ruler-mode-tab-stop-char) (put-text-property i (1+ i) 'face 'ruler-mode-tab-stop ruler))) (setq i (1+ i) j (1+ j))) ;; Return the ruler propertized string. Using list here, ;; instead of concat visually separate the different areas. (if (nth 2 (window-fringes)) ;; fringes outside margins. (list "" (and (eq 'left sbvt) sb) lf lm ruler rm rf (and (eq 'right sbvt) sb)) ;; fringes inside margins. (list "" (and (eq 'left sbvt) sb) lm lf ruler rf rm (and (eq 'right sbvt) sb))))) (provide 'ruler-mode) ;; Local Variables: ;; coding: iso-latin-1 ;; End: ;;; arch-tag: b2f24546-5605-44c4-b67b-c9a4eeba3ee8 ;;; ruler-mode.el ends here