This page describes package Lisp:blank-mode.el, by ViniciusJoseLatorre. : .:: ''v9.1'' :: ''part of GNU Emacs'' ::. : It runs on Emacs 21, 22 and 23. : **Note:** //This package was replaced by// WhiteSpace. == Screenshot == The screenshots below show when BlankMode is turned on using the default setting. * /Light background/ : :: [[image:BlankModeOn]] * /Dark background/ : :: [[image:BlankModeOnDark]] == About blank-mode == This package is a minor mode to visualize blanks (TAB, (HARD) SPACE and NEWLINE). BlankMode uses two ways to visualize blanks: [[Face]]s and display table. * [[Face]]s are used to highlight the background with a color. BlankMode uses font-lock to highlight blank characters. * Display table changes the way a character is displayed, that is, it provides a visual mark for characters, for example, at the end of line (##?\xB6##), at SPACEs (##?\xB7##) and at TABs (##?\xBB##). The `blank-style' and `blank-chars' variables are used to select which way should be used to visualize blanks. Note that when BlankMode is turned on, BlankMode saves the font-lock state, that is, if font-lock is on or off. And BlankMode restores the font-lock state when it is turned off. So, if BlankMode is turned on and font-lock is off, BlankMode also turns on the font-lock to highlight blanks, but the font-lock will be turned off when BlankMode is turned off. Thus, turn on font-lock before BlankMode is on, if you want that font-lock continues on after BlankMode is turned off. When BlankMode is on, it takes care of highlighting some special characters over the default mechanism of `nobreak-char-display' (which see) and `show-trailing-whitespace' (which see). There are two ways of using BlankMode: local and global. * Local BlankMode affects only the current buffer. * Global BlankMode affects all current and future buffers. That is, if you turn on global BlankMode and then create a new buffer, the new buffer will also have BlankMode on. The `blank-global-modes' variable controls which major-mode will be automagically turned on. You can mix the local and global usage without any conflict. But local BlankMode has priority over global BlankMode. BlankMode is active in a buffer if you have enabled it in that buffer or if you have enabled it globally. When global and local BlankMode are on: * if local BlankMode is turned off, BlankMode is turned off for the current buffer only. * if global BlankMode is turned off, BlankMode continues on only in the buffers in which local BlankMode is on. To use BlankMode, insert in your ##~/.emacs##: (require 'blank-mode) Or autoload at least one of the commands`blank-mode', `blank-toggle-options', `global-blank-mode' or `global-blank-toggle-options'. For example: (autoload 'blank-mode "blank-mode" "Toggle blank visualization." t) (autoload 'blank-toggle-options "blank-mode" "Toggle local `blank-mode' options." t) BlankMode was inspired by: : ##whitespace.el## -- Rajesh Vaidheeswarran <_rv_@_gnu_._org_> :: Warn about and clean bogus whitespaces in the file :: (inspired the idea to warn and clean some blanks) : ##show-whitespace-mode.el## -- Aurélien Tisné <_aurelien_._tisne_@_free_._fr_> :: Simple mode to highlight whitespaces :: (inspired the idea to use font-lock) : ##whitespace-mode.el## -- LawrenceMitchell :: Major mode for editing Whitespace :: (inspired the idea to use display table) : ##visws.el## -- MilesBader :: Make whitespace visible :: (handle display table, his code was modified, but the main idea was kept) For good performance, be sure to byte-compile BlankMode, e.g. M-x byte-compile-file This will generate blank-mode.elc, which will be loaded instead of Lisp:blank-mode.el. BlankMode was tested with GNU Emacs 22 and 23. == Using blank-mode == There is no problem if you mix local and global minor mode usage. LOCAL BlankMode: : To toggle BlankMode options locally, type: :: ##M-x blank-toggle-options RET## [new] : To activate BlankMode locally, type: :: ##C-u 1 M-x blank-mode RET## [new] : To deactivate BlankMode locally, type: :: ##C-u 0 M-x blank-mode RET## [new] : To toggle BlankMode locally, type: :: ##M-x blank-mode RET## [new] GLOBAL BlankMode: : To toggle BlankMode options globally, type: :: ##M-x global-blank-toggle-options RET## [new] : To activate BlankMode globally, type: :: ##C-u 1 M-x global-blank-mode RET## [new] : To deactivate BlankMode globally, type: :: ##C-u 0 M-x global-blank-mode RET## [new] : To toggle BlankMode globally, type: :: ##M-x global-blank-mode RET## [new] You can also bind `blank-mode', `global-blank-mode', `blank-toggle-options' and `global-blank-toggle-options' to some key, like: (global-set-key "\C-c_b" 'blank-mode) (global-set-key "\C-c_t" 'blank-toggle-options) (global-set-key "\C-c=b" 'global-blank-mode) (global-set-key "\C-c=t" 'global-blank-toggle-options) There are also the following useful commands: ; `blank-cleanup' : Cleanup some blank problems in all buffer or at region. ; `blank-cleanup-region' : Cleanup some blank problems at region. The problems, which are cleaned up, are: : 1. empty lines at beginning of buffer. : 2. empty lines at end of buffer. :: If `blank-chars' has `empty' as an element, remove all empty lines at beginning and/or end of buffer. : 3. 8 or more SPACEs at beginning of line. :: If `blank-chars' has `indentation' as an element, replace 8 or more SPACEs at beginning of line by TABs. : 4. SPACEs before TAB. :: If `blank-chars' has `space-before-tab' as an element, replace SPACEs by TABs. : 5. SPACEs or TABs at end of line. :: If `blank-chars' has `trailing' as an element, remove all SPACEs or TABs at end of line." : 6. 8 or more SPACEs after TAB. :: If `blank-chars' has `space-after-tab' as an element, replace SPACEs by TABs. == Hooks == BlankMode has the following hook variables: ; `blank-mode-hook' : It is evaluated always when BlankMode is turned on. ; `global-blank-mode-hook' : It is evaluated always when BlankMode is turned on globally. ; `blank-load-hook' : It is evaluated after BlankMode package is loaded. == Options == Below it's shown a brief description of BlankMode options, please, see the options declaration in the code for a long documentation. ; `blank-style' : Specify the visualization style. ; `blank-chars' : Specify which kind of blank is visualized. ; `blank-space' : [[Face]] used to visualize SPACE. ; `blank-hspace' : [[Face]] used to visualize HARD SPACE. ; `blank-tab' : [[Face]] used to visualize TAB. ; `blank-newline' : [[Face]] used to visualize NEWLINE char mapping. ; `blank-trailing' : [[Face]] used to visualize trailing blanks. ; `blank-line' : [[Face]] used to visualize "long" lines. ; `blank-space-before-tab' : [[Face]] used to visualize SPACEs before TAB. ; `blank-indentation' : [[Face]] used to visualize 8 or more SPACEs at beginning of line. ; `blank-empty' : [[Face]] used to visualize empty lines at beginning and/or end of buffer. ; `blank-space-after-tab' : [[Face]] used to visualize 8 or more SPACEs after TAB. ; `blank-space-regexp' : Specify SPACE characters regexp. ; `blank-hspace-regexp' : Specify HARD SPACE characters regexp. ; `blank-tab-regexp' : Specify TAB characters regexp. ; `blank-trailing-regexp' : Specify trailing characters regexp. ; `blank-space-before-tab-regexp' : Specify SPACEs before TAB regexp. ; `blank-indentation-regexp' : Specify regexp for 8 or more SPACEs at beginning of line. ; `blank-empty-at-bob-regexp' : Specify regexp for empty lines at beginning of buffer. ; `blank-empty-at-eob-regexp' : Specify regexp for empty lines at end of buffer. ; `blank-space-after-tab-regexp' : Specify regexp for 8 or more SPACEs after TAB. ; `blank-line-column' : Specify column beyond which the line is highlighted. ; `blank-display-mappings' : Specify an alist of mappings for displaying characters. ; `blank-global-modes' : Modes for which global BlankMode is automagically turned on. To set the above options you may: [new] a. insert the code in your ##~/.emacs##, like: (setq blank-space 'underline) This way always keep your default settings when you enter a new Emacs session. [new] b. or use `set-variable' in your Emacs session, like: M-x set-variable RET blank-space RET underline RET This way keep your settings only during the current Emacs session. [new] c. or use customization, for example: In Emacs 21 or lower: # click on MenuBar ##Help## option, # then click on ##Customize##, # then click on ##Browse Customization Groups##, # expand ##Data## group, # expand ##Blank## group # and then customize BlankMode options. In Emacs 22 or higher: # click on MenuBar ##Options## option, # then click on ##Customize Emacs##, # then click on ##Browse Customization Groups##, # expand ##Data## group, # expand ##Blank## group # and then customize BlankMode options. Through this way, you may choose if the settings are kept or not when you leave out the current Emacs session. [new] d. or see the option value: C-h v blank-space RET and click the ##customize## hypertext button. Through this way, you may choose if the settings are kept or not when you leave out the current Emacs session. == Acknowledgements == Thanks to [[nschum]] for the idea about highlight "long" lines tail. See EightyColumnRule. Thanks to JuriLinkov for suggesting: * `define-minor-mode'. * `global-blank-*' name for global commands. Thanks to Robert J. Chassell <_bob_@_gnu_._org_> for doc fix and testing. Thanks to DrewAdams for toggle commands suggestion. Thanks to Antti Kaihola <_antti_._kaihola_@_linux-aktivaattori_._org_> for helping to fix `find-file-hooks' reference. Thanks to Andreas Roehler <_andreas_._roehler_@_easy-emacs_._de_> for indicating defface byte-compilation warnings. Thanks to TimOCallaghan for the idea about highlight "long" lines. See EightyColumnRule. Thanks to Yanghui Bian <_yanghuibian_@_gmail_._com_> for indicating a new newline character mapping. Thanks to Pete Forman <_pete_._forman_@_westgeo_._com_> for indicating ##whitespace-mode## on XEmacs. Thanks to: : Rajesh Vaidheeswarran <_rv_@_gnu_._org_> -- ##whitespace.el## : Aurélien Tisné <_aurelien_._tisne_@_free_._fr_> -- ##show-whitespace-mode.el## (ShowWhitespaceMode) : LawrenceMitchell -- ##whitespace-mode.el## (WhitespaceMode) : MilesBader -- ##visws.el## (Emacs 21) And to all people who contributed with them. == TAB & Display Table == When BlankMode is on and a ##TAB## occupies exactly one column, it will display the character ##?\xBB## at that column followed by a ##TAB## which goes to the next ##TAB## column. This is due the way the Emacs display engine works. The situation above is illustrated by the following images: : [[image:BlankModeOffTab]] [[image:BlankModeOnTab]] There are the following possibilities to deal with the situation above: * Insert in your ##~/.emacs## file: (setq blank-display-mappings '((?\ [?\xB7] [?.]) ; space (?\xA0 [?\xA4] [?_]) ; hard space (?\n [?\xB6 ?\n] [?$ ?\n]) ; end-of-line )) : The setting above doesn't have any ##TAB## mapping. * Comment the ##TAB## mapping line in the ##blank-mode.el## file: (defcustom blank-display-mappings '((?\ [?\xB7] [?.]) ; space (?\xA0 [?\xA4] [?_]) ; hard space (?\n [?\xB6 ?\n] [?$ ?\n]) ; end-of-line ;; WARNING: the mapping below has a problem. ;; When a TAB occupies exactly one column, it will display the character ;; ?\xBB at that column followed by a TAB which goes to the next TAB ;; column. ;; If this is a problem for you, please, comment the line below. ;;(?\t [?\xBB ?\t] [?\\ ?\t]) ; tab ) ...... * Set ##blank-style## variable to ##color##: (setq blank-style '(color)) : That is, don't use display table. * Just live with it. :) == See Also == * WhiteSpace * ShowWhiteSpace * ShowWhitespaceMode * WhitespaceMode * EightyColumnRule * [[Easymacs]] ---- == Inbox == [new] I have a question about this mode running under XEmacs, in case anyone has solved it: * When I turn BlankMode on, only the visible part of the buffer is highlighted. Is this normal? Thanks, -- BillBarnard [new] just use whitespace-mode (WhitespaceMode) on XEmacs -- ClausBrunzema [new] Use whitespace-visual-mode for recent releases of the text-modes ([http://www.xemacs.org/Develop/packages.html#text-modes sources]) XEmacs package ([http://www.xemacs.org/Documentation/packageGuide.html Quickstart Package Guide]) -- AdrianAichner '''See also:''' ShowWhiteSpace for several other ways to do what blank-mode does. [new:ViniciusJoseLatorre:] Well, BlankMode does not run on XEmacs. It is welcome any help from anyone who knows XEmacs. -- ViniciusJoseLatorre [new] The :stipple face attribute can do some cool things (defface blank-tab `((t (:stipple ;; 88 = 8 * (frame-char-width) ;; 18 = (frame-char-height) (88 18 , (string 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 #b01000000 0 0 0 0 0 0 0 0 0 0 #b10000000 0 0 0 0 0 0 0 0 0 0 #b11111100 #x01 #x01 #x08 #x40 #x00 #x02 #x10 #x80 #x00 #x04 #b10000000 0 0 0 0 0 0 0 0 0 0 #b01000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0)) :foreground "cyan4"))) "") [[image:bojohan-stippled-tab]] -- [[bojohan]] [new:ViniciusJoseLatorre:] Cool! It doesn't have the ##TAB## problem which display table has. :-) But ##:stipple## depends on your current ##(frame-char-width)## and ##(frame-char-height)##. :-( : From my Emacs session: :: ##(frame-char-width)## = 6 :: ##(frame-char-height)## = 13 : -- ViniciusJoseLatorre [new] I have been successfully using blank-mode.el and whitespace.el for a while now on Windows-based GNU Emacs, including 22.3. I appreciate it very much. Thank you! I just tried using blank-mode.el on x86-64 Fedora 9-based GNU Emacs 22.3. It behaves as if it is not loaded at all, except that BL and/or bl appears in the modeline, depending on whether I have it in global-blank-mode and/or blank-mode. AFAIK, I have it installed and configured and loaded via .emacs the same way as I have successfully used on my Windows-based GNU Emacs 22.3. (I am having a different problem with whitespace.el that I have described over on that wikipage.) -- Dan'l Miller [new:ViniciusJoseLatorre:2009-07-19 00:21 UTC] : Well, I answered in the WhiteSpace page. -- ViniciusJoseLatorre ---- CategoryCode, CategoryModes, CategoryFaces