From fbda3883e067c274d82e5a1a9b1dc4189cc05767 Mon Sep 17 00:00:00 2001 From: Gregory Heytings Date: Tue, 5 Jul 2022 12:07:07 +0000 Subject: [PATCH] Actually fix the long lines display bug (bug#56393). * lisp/files.el (auto-narrow-mode): New minor mode. (auto-narrow-pre-command-function, auto-narrow-post-command-function): New auxiliary functions for the minor mode. (auto-narrow-display-length, auto-narrow-widen-automatically): New defcustoms for the minor mode. (auto-narrow--widen-automatically, auto-narrow--isearch-widen-automatically, auto-narrow--initialized): New internal variables for the minor mode. * src/buffer.h (struct buffer): New internal variable for the minor mode. * src/buffer.c (init_buffer_once, syms_of_buffer): New internal variable for the minor mode. * src/fileio.c (Finsert_file_contents): Automatically enter the minor mode when appropriate. (syms_of_fileio): New defcustom for the minor mode. * src/keyboard.c (syms_of_keyboard): New hook functions for the minor mode. (command_loop_1): Execute the hook functions. * src/xdisp.c (decode_mode_spec): Indicate when the minor mode is active in the modeline. * lisp/isearch.el (isearch-widen-automatically): New defcustom. (isearch-search): Use the new defcustom. * lisp/bindings.el (mode-line-modes): Do not propertize the indication in the modeline when the new minor mode is active. * etc/NEWS: Announce the new minor mode, and remove the unobsoletion indication for 'longlines-mode'. * lisp/longlines.el: Reobsolete longlines-mode. * doc/emacs/display.texi (Auto-Narrowing): New section, describing the new minor mode. (Display): Entry for the new section. * doc/emacs/trouble.texi (Long Lines): Remove the section. (Lossage): Remove the entry for the Long Lines section. * doc/emacs/emacs.texi (Top): Remove the entry for the Long Lines section. --- doc/emacs/display.texi | 25 +++++++++ doc/emacs/emacs.texi | 1 - doc/emacs/trouble.texi | 59 -------------------- etc/NEWS | 15 ++++-- lisp/bindings.el | 12 +++-- lisp/files.el | 92 ++++++++++++++++++++++++++++++++ lisp/isearch.el | 32 +++++++---- lisp/{ => obsolete}/longlines.el | 1 + src/buffer.c | 5 ++ src/buffer.h | 3 ++ src/fileio.c | 22 ++++++++ src/keyboard.c | 28 ++++++++++ src/xdisp.c | 7 ++- 13 files changed, 223 insertions(+), 79 deletions(-) rename lisp/{ => obsolete}/longlines.el (99%) diff --git a/doc/emacs/display.texi b/doc/emacs/display.texi index cadac7e453..9fe9533e88 100644 --- a/doc/emacs/display.texi +++ b/doc/emacs/display.texi @@ -19,6 +19,8 @@ Display * Horizontal Scrolling:: Moving text left and right in a window. * Narrowing:: Restricting display and editing to a portion of the buffer. +* Auto-Narrowing:: Automatically restrict display to a portion of + the buffer. * View Mode:: Viewing read-only buffers. * Follow Mode:: Follow mode lets two windows scroll as one. * Faces:: How to change the display style using faces. @@ -467,6 +469,29 @@ Narrowing if you enable the command, confirmation will no longer be required for it. @xref{Disabling}. +@node Auto-Narrowing +@findex auto-narrow-mode +@vindex auto-narrow-long-line-threshold +@vindex auto-narrow-display-length +@vindex auto-narrow-widen-automatically + + When a file with extremely long lines is opened or inserted in a +buffer, Emacs automatically enters auto-narrow mode, and the word +@samp{Auto-Narrow} appears in the mode line. This means that Emacs +restricts display, but not editing, to a portion of the buffer above +and below point. All editing commands, including narrowing commands, +remain available, and they act on the whole buffer. For example, +@kbd{M->} moves point to the end of the buffer, and not, as would +happen with ordinary narrowing, to the end of the portion of the +buffer to which display is currently restricted. + + The behavior of auto-narrow mode is controlled by three variables: +@code{auto-narrow-long-line-threshold} is the line length above which +auto-narrow move is entered, @code{auto-narrow-display-length} is the +number of characters to which display is restricted, and +@code{auto-narrow-widen-automatically} is a list of commands for which +display is widened before they are executed. + @node View Mode @section View Mode @cindex View mode diff --git a/doc/emacs/emacs.texi b/doc/emacs/emacs.texi index 5e72699bbe..b43c966f87 100644 --- a/doc/emacs/emacs.texi +++ b/doc/emacs/emacs.texi @@ -1190,7 +1190,6 @@ Top * Crashing:: What Emacs does when it crashes. * After a Crash:: Recovering editing in an Emacs session that crashed. * Emergency Escape:: What to do if Emacs stops responding. -* Long Lines:: Mitigating slowness due to extremely long lines. * DEL Does Not Delete:: What to do if @key{DEL} doesn't delete. Reporting Bugs diff --git a/doc/emacs/trouble.texi b/doc/emacs/trouble.texi index f06b93759d..887e5c6170 100644 --- a/doc/emacs/trouble.texi +++ b/doc/emacs/trouble.texi @@ -158,7 +158,6 @@ Lossage * Crashing:: What Emacs does when it crashes. * After a Crash:: Recovering editing in an Emacs session that crashed. * Emergency Escape:: What to do if Emacs stops responding. -* Long Lines:: Mitigating slowness due to extremely long lines. * DEL Does Not Delete:: What to do if @key{DEL} doesn't delete. @end menu @@ -433,64 +432,6 @@ Emergency Escape emergency escape---but there are cases where it won't work, when a system call hangs or when Emacs is stuck in a tight loop in C code. -@node Long Lines -@subsection Long Lines -@cindex long lines - - For a variety of reasons (some of which are fundamental to the Emacs -redisplay code and the complex range of possibilities it handles; -others of which are due to modes and features which do not scale well -in unusual circumstances), Emacs can perform poorly when extremely -long lines are present (where ``extremely long'' usually means at -least many thousands of characters). - -@cindex @code{so-long} mode -@findex global-so-long-mode -@vindex so-long-action - A particular problem is that Emacs may ``hang'' for a long time at -the point of visiting a file with extremely long lines. This can be -mitigated by enabling the @file{so-long} library, which detects when a -visited file contains abnormally long lines, and takes steps to -disable features which are liable to cause slowness in that situation. -To enable this library, type @kbd{M-x global-so-long-mode @key{RET}}, -or turn on the @code{global-so-long-mode} in your init file -(@pxref{Init File}), or customize the @code{global-so-long-mode} -option. You can tailor this mode's operation by customizing the -variable @code{so-long-action}. - - The @file{so-long} library can also significantly improve -performance when moving and editing in a buffer with long lines. -Performance is still likely to degrade as you get deeper into the long -lines, but the improvements from using this library can nevertheless -be substantial. - -@findex so-long-commentary - Use @kbd{M-x so-long-commentary} to view the documentation for this -library and learn more about how to enable and configure it. - -@vindex max-redisplay-ticks - If even @code{so-long-mode} doesn't help making Emacs responsive -enough, or if you'd rather not disable the display-related features -that @code{so-long-mode} turns off, you can instead customize the -variable @code{max-redisplay-ticks} to a non-zero value. Then Emacs -will abort redisplay of a window and commands, like @kbd{C-n} and -@kbd{M-v}, which use the display code to do their job, if processing a -window needs more low-level display operations than the value of this -variable. The display of the offending window will then remain -outdated, and possibly incomplete, on the screen, but Emacs should -otherwise be responsive, and you could then switch to another buffer, -or kill the problematic buffer, or turn on @code{so-long-mode} or -@code{so-long-minor-mode} in that buffer. When the display of a -window is aborted due to this reason, the buffer shown in that window -will not have any of its windows redisplayed until the buffer is -modified or until you type @kbd{C-l} (@pxref{Recentering}) in one of -that buffer's windows. - - If you decide to customize this variable to a non-zero value, we -recommend to use a value between 100,000 and 1,000,000, depending on -your patience and the speed of your system. The default value is -zero, which disables this feature. - @node DEL Does Not Delete @subsection If @key{DEL} Fails to Delete @cindex @key{DEL} vs @key{BACKSPACE} diff --git a/etc/NEWS b/etc/NEWS index 7967190c6e..30c71e7f0c 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -324,9 +324,6 @@ startup. Previously, these functions ignored * Changes in Emacs 29.1 ---- -** 'longlines-mode' is no longer obsolete. - +++ ** New command to change the font size globally. To increase the font size, type 'C-x C-M-+' or 'C-x C-M-='; to @@ -901,6 +898,18 @@ Formerly it invoked 'just-one-space'. The actions performed by 'cycle-spacing' and their order can now be customized via the user option 'cycle-spacing-actions'. ++++ +** Emacs is now capable of editing files with arbitarily long lines. +When a file with long lines is opened or inserted in a buffer, Emacs +automatically enters auto-narrow mode. This means that Emacs +restricts display, but not editing, to a portion of the buffer above +and below point. All editing commands, including narrowing commands, +remain available, and they act on the whole buffer. The behavior of +that mode is controlled by three variables: +auto-narrow-long-line-threshold, auto-narrow-display-length and +auto-narrow-widen-automatically. To disable that feature, set +auto-narrow-long-line-threshold to nil in your init file. + --- ** 'zap-to-char' and 'zap-up-to-char' are case-sensitive for upper-case chars. These commands now behave as case-sensitive for interactive calls when diff --git a/lisp/bindings.el b/lisp/bindings.el index 0cf1834a4f..fa5040776d 100644 --- a/lisp/bindings.el +++ b/lisp/bindings.el @@ -400,10 +400,14 @@ mode-line-modes mouse-2: Show help for minor mode\n\ mouse-3: Toggle minor modes" local-map ,mode-line-minor-mode-keymap) - (propertize "%n" 'help-echo "mouse-2: Remove narrowing from buffer" - 'mouse-face 'mode-line-highlight - 'local-map (make-mode-line-mouse-map - 'mouse-2 #'mode-line-widen)) + '(:eval + (if (not (eq auto-narrow--narrowing 'auto)) + (propertize "%n" + 'help-echo "mouse-2: Remove narrowing from buffer" + 'mouse-face 'mode-line-highlight + 'local-map (make-mode-line-mouse-map + 'mouse-2 #'mode-line-widen)) + "%n")) ")" (propertize "%]" 'help-echo recursive-edit-help-echo) " ")) diff --git a/lisp/files.el b/lisp/files.el index 8812175014..abdeea7a80 100644 --- a/lisp/files.el +++ b/lisp/files.el @@ -2648,6 +2648,98 @@ find-file-literally (confirm-nonexistent-file-or-buffer)))) (switch-to-buffer (find-file-noselect filename nil t))) +(defcustom auto-narrow-display-length 30000 + "Number of characters to which display is restricted in `auto-narrow-mode'." + :group 'files + :group 'find-file + :version "29.1" + :type 'integer) + +(defcustom auto-narrow-widen-automatically + '( move-beginning-of-line move-end-of-line backward-sentence forward-sentence + backward-sexp forward-sexp beginning-of-defun end-of-defun + beginning-of-buffer end-of-buffer goto-char goto-line + mark-sexp mark-defun mark-paragraph mark-whole-buffer mark-page + exchange-point-and-mark pop-global-mark set-mark-command jump-to-register + bookmark-jump) + "Commands for which display is automatically widened in `auto-narrow-mode'." + :group 'files + :group 'find-file + :version "29.1" + :type '(repeat function)) + +(defvar-local auto-narrow--widen-automatically nil + "Internal variable used by `auto-narrow-mode'.") + +(defvar-local auto-narrow--isearch-widen-automatically nil + "Internal variable used by `auto-narrow-mode'.") + +(defvar-local auto-narrow--initialized nil + "Internal variable used by `auto-narrow-mode'.") + +(defun auto-narrow-pre-command-function () + "Conditionally widen display when `auto-narrow-mode' is in effect." + (when auto-narrow-mode + (unless auto-narrow--initialized + (setq auto-narrow--widen-automatically widen-automatically + auto-narrow--isearch-widen-automatically isearch-widen-automatically + auto-narrow--narrowing 'auto + auto-narrow--initialized t)) + (setq-local widen-automatically t + isearch-widen-automatically t) + (if (memq this-command '(narrow-to-region narrow-to-defun narrow-to-page)) + (setq auto-narrow--narrowing 'explicit + widen-automatically auto-narrow--widen-automatically + isearch-widen-automatically auto-narrow--isearch-widen-automatically)) + (if (eq this-command 'widen) + (setq auto-narrow--narrowing 'auto)) + (when (and (not (eq auto-narrow--narrowing 'explicit)) + (memq this-command auto-narrow-widen-automatically)) + (widen)))) + +(defun auto-narrow-post-command-function () + "Update display narrowing when `auto-narrow-mode' is in effect." + (when (and auto-narrow-mode + (not (eq auto-narrow--narrowing 'explicit))) + (unless auto-narrow--initialized + (setq auto-narrow--narrowing 'auto)) + (let (point cur-point-min buf-point-min buf-point-max size) + (setq point (point) cur-point-min (point-min) + size (/ auto-narrow-display-length 3)) + (save-restriction + (widen) + (setq buf-point-min (point-min) buf-point-max (point-max))) + (let* ((pos (* (min (max (/ point size) 1) + (1- (/ buf-point-max size))) + size)) + (begin (max (- pos size) buf-point-min)) + (end (min (+ begin (* 3 size)) buf-point-max))) + (when (or (not (buffer-narrowed-p)) + (not (= begin cur-point-min))) + (narrow-to-region begin end)))))) + +(setq auto-narrow-long-line-threshold 30000 + auto-narrow-pre-command-function #'auto-narrow-pre-command-function + auto-narrow-post-command-function #'auto-narrow-post-command-function) + +(define-minor-mode auto-narrow-mode + "Automatically narrow the display of a buffer above and below point. + +This mode is automatically entered when a file with one or more lines +longer than `auto-narrow-long-line-threshold' is opened or inserted +in a buffer. It restricts display, but not editing, to +`auto-narrow-display-length' characters. Display is widened before +executing any of the commands listed in `auto-narrow-widen-automatically'." + :group 'files + :version "29.1" + :after-hook (progn (put 'auto-narrow-mode 'permanent-local t) + (put 'auto-narrow--narrowing 'permanent-local t)) + (if auto-narrow-mode + (auto-narrow-post-command-function) + (when (not (eq auto-narrow--narrowing 'explicit)) + (widen)) + (setq auto-narrow--narrowing nil))) + (defun after-find-file (&optional error warn noauto _after-find-file-from-revert-buffer nomodes) diff --git a/lisp/isearch.el b/lisp/isearch.el index db7b53c014..a6e034df6b 100644 --- a/lisp/isearch.el +++ b/lisp/isearch.el @@ -3037,6 +3037,13 @@ isearch-allow-prefix :type 'boolean :group 'isearch) +(defcustom isearch-widen-automatically nil + "Whether a narrowed buffer can be widened when isearch fails. +This option has no effect when `widen-automatically' is nil." + :version "29.1" + :type 'boolean + :group 'isearch) + (defun isearch-string-out-of-window (isearch-point) "Test whether the search string is currently outside of the window. Return nil if it's completely visible, or if point is visible, @@ -3649,17 +3656,20 @@ isearch-search (while retry (setq isearch-success (isearch-search-string isearch-string nil t)) - ;; Clear RETRY unless the search predicate says - ;; to skip this search hit. - (if (or (not isearch-success) - (funcall isearch-filter-predicate - (match-beginning 0) (match-end 0))) - (setq retry nil) - ;; Advance point on empty matches before retrying - (when (= (match-beginning 0) (match-end 0)) - (if (if isearch-forward (eobp) (bobp)) - (setq retry nil isearch-success nil) - (forward-char (if isearch-forward 1 -1)))))) + (if (and (not isearch-success) (buffer-narrowed-p) + isearch-widen-automatically widen-automatically) + (widen) + ;; Clear RETRY unless the search predicate says + ;; to skip this search hit. + (if (or (not isearch-success) + (funcall isearch-filter-predicate + (match-beginning 0) (match-end 0))) + (setq retry nil) + ;; Advance point on empty matches before retrying + (when (= (match-beginning 0) (match-end 0)) + (if (if isearch-forward (eobp) (bobp)) + (setq retry nil isearch-success nil) + (forward-char (if isearch-forward 1 -1))))))) (setq isearch-just-started nil) (when isearch-success (setq isearch-other-end diff --git a/lisp/longlines.el b/lisp/obsolete/longlines.el similarity index 99% rename from lisp/longlines.el rename to lisp/obsolete/longlines.el index a6cf93a039..d44a634e2e 100644 --- a/lisp/longlines.el +++ b/lisp/obsolete/longlines.el @@ -6,6 +6,7 @@ ;; Alex Schroeder ;; Chong Yidong ;; Maintainer: emacs-devel@gnu.org +;; Obsolete-since: 24.4 ;; Keywords: convenience, wp ;; This file is part of GNU Emacs. diff --git a/src/buffer.c b/src/buffer.c index 509ce51b55..cbc246067d 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -5276,6 +5276,7 @@ init_buffer_once (void) XSETFASTINT (BVAR (&buffer_local_flags, tab_line_format), idx); ++idx; XSETFASTINT (BVAR (&buffer_local_flags, cursor_type), idx); ++idx; XSETFASTINT (BVAR (&buffer_local_flags, extra_line_spacing), idx); ++idx; + XSETFASTINT (BVAR (&buffer_local_flags, auto_narrow__narrowing), idx); ++idx; XSETFASTINT (BVAR (&buffer_local_flags, cursor_in_non_selected_windows), idx); ++idx; /* buffer_local_flags contains no pointers, so it's safe to treat it @@ -6363,6 +6364,10 @@ from (abs POSITION). If POSITION is positive, point was at the front If value is a floating point number, it specifies the spacing relative to the default frame line height. A value of nil means add no extra space. */); + DEFVAR_PER_BUFFER ("auto-narrow--narrowing", + &BVAR (current_buffer, auto_narrow__narrowing), Qnil, + doc: /* Internal variable used by `auto-narrow-mode'. */); + DEFVAR_PER_BUFFER ("cursor-in-non-selected-windows", &BVAR (current_buffer, cursor_in_non_selected_windows), Qnil, doc: /* Non-nil means show a cursor in non-selected windows. diff --git a/src/buffer.h b/src/buffer.h index 135eaf72d3..a6abc6ece8 100644 --- a/src/buffer.h +++ b/src/buffer.h @@ -561,6 +561,9 @@ #define BVAR(buf, field) ((buf)->field ## _) in the display of this buffer. */ Lisp_Object extra_line_spacing_; + /* Narrowing type when auto-narrow mode is in effect. */ + Lisp_Object auto_narrow__narrowing_; + /* Cursor type to display in non-selected windows. t means to use hollow box cursor. See `cursor-type' for other values. */ diff --git a/src/fileio.c b/src/fileio.c index 10d4b8bc15..e6c51da0d9 100644 --- a/src/fileio.c +++ b/src/fileio.c @@ -4997,6 +4997,17 @@ because (1) it preserves some marker positions (in unchanged portions Otherwise start with an empty undo_list. */ bset_undo_list (current_buffer, EQ (old_undo, Qt) ? Qt : Qnil); + if (!noninteractive + && !NILP (Vauto_narrow_long_line_threshold) + && !NILP (CALLN + (Fgtr, + Fcar (Fcdr (Fbuffer_line_statistics (Fcurrent_buffer ()))), + Vauto_narrow_long_line_threshold))) + { + safe_call (1, Qauto_narrow_mode); + message1 ("Auto-Narrow mode enabled in current buffer"); + } + unbind_to (count1, Qnil); } @@ -6638,6 +6649,17 @@ do (file-exists-p FILENAME) and FILENAME is handled by HANDLER, then /* Lisp function for recursively deleting directories. */ DEFSYM (Qdelete_directory, "delete-directory"); + DEFVAR_LISP ("auto-narrow-long-line-threshold", + Vauto_narrow_long_line_threshold, + doc: /* Line length above which `auto-narrow-mode' is entered. +When non-nil, and when a file with one or more lines longer than +`auto-narrow-long-line-threshold' is opened or inserted in a buffer, +`auto-narrow-mode' is automatically enabled. +When nil, `auto-narrow-mode' is not entered automatically. */); + Vauto_narrow_long_line_threshold = Qnil; + + DEFSYM (Qauto_narrow_mode, "auto-narrow-mode"); + DEFSYM (Qsubstitute_env_in_file_name, "substitute-env-in-file-name"); DEFSYM (Qget_buffer_window_list, "get-buffer-window-list"); diff --git a/src/keyboard.c b/src/keyboard.c index bed8307b6f..38aa64774d 100644 --- a/src/keyboard.c +++ b/src/keyboard.c @@ -1290,6 +1290,9 @@ command_loop_1 (void) if (NILP (Vmemory_full)) { + if (!NILP (Vauto_narrow_post_command_function) && !NILP (Vrun_hooks)) + safe_run_hooks (Qauto_narrow_post_command_function); + /* Make sure this hook runs after commands that get errors and throw to top level. */ /* Note that the value cell will never directly contain nil @@ -1472,6 +1475,8 @@ command_loop_1 (void) Vreal_this_command = cmd; safe_run_hooks (Qpre_command_hook); + safe_run_hooks (Qauto_narrow_pre_command_function); + already_adjusted = 0; if (NILP (Vthis_command)) @@ -1522,6 +1527,8 @@ command_loop_1 (void) } kset_last_prefix_arg (current_kboard, Vcurrent_prefix_arg); + safe_run_hooks (Qauto_narrow_post_command_function); + safe_run_hooks (Qpost_command_hook); /* If displaying a message, resize the echo area window to fit @@ -12040,6 +12047,11 @@ syms_of_keyboard (void) DEFSYM (Qpre_command_hook, "pre-command-hook"); DEFSYM (Qpost_command_hook, "post-command-hook"); + DEFSYM (Qauto_narrow_pre_command_function, + "auto-narrow-pre-command-function"); + DEFSYM (Qauto_narrow_post_command_function, + "auto-narrow-post-command-function"); + DEFSYM (Qundo_auto__add_boundary, "undo-auto--add-boundary"); DEFSYM (Qundo_auto__undoably_changed_buffers, "undo-auto--undoably-changed-buffers"); @@ -12604,6 +12616,22 @@ syms_of_keyboard (void) See also `pre-command-hook'. */); Vpost_command_hook = Qnil; + DEFVAR_LISP ("auto-narrow-pre-command-function", + Vauto_narrow_pre_command_function, + doc: /* Function executed before each command is executed in `auto-narrow-mode'. +If non-nil, and `auto-narrow-mode' is enabled, the function is +called before each command is executed, after `pre-command-hook'. +It is called without arguments. */); + Vauto_narrow_pre_command_function = Qnil; + + DEFVAR_LISP ("auto-narrow-post-command-function", + Vauto_narrow_post_command_function, + doc: /* Function executed after each command is executed in `auto-narrow-mode'. +If non-nil, and `auto-narrow-mode' is enabled, the function is +called after each command is executed, before `post-command-hook'. +It is called without arguments. */); + Vauto_narrow_post_command_function = Qnil; + #if 0 DEFVAR_LISP ("echo-area-clear-hook", ..., doc: /* Normal hook run when clearing the echo area. */); diff --git a/src/xdisp.c b/src/xdisp.c index 4089525e10..d782659b92 100644 --- a/src/xdisp.c +++ b/src/xdisp.c @@ -27667,7 +27667,12 @@ decode_mode_spec (struct window *w, register int c, int field_width, case 'n': if (BUF_BEGV (b) > BUF_BEG (b) || BUF_ZV (b) < BUF_Z (b)) - return " Narrow"; + { + if (EQ (BVAR (current_buffer, auto_narrow__narrowing), intern ("auto"))) + return " Auto-Narrow"; + else + return " Narrow"; + } break; /* Display the "degree of travel" of the window through the buffer. */ -- 2.35.1