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diff --git a/lisp/smooth-scrolling.el b/lisp/smooth-scrolling.el deleted file mode 100644 index 98df30e..0000000 --- a/lisp/smooth-scrolling.el +++ /dev/null @@ -1,327 +0,0 @@ -;;; smooth-scrolling.el --- Make emacs scroll smoothly -;; -;; Copyright (c) 2007-2016 Adam Spiers -;; -;; Filename: smooth-scrolling.el -;; Description: Make emacs scroll smoothly -;; Author: Adam Spiers <emacs-ss@adamspiers.org> -;; Jeremy Bondeson <jbondeson@gmail.com> -;; Ryan C. Thompson <rct+github@thompsonclan.org> -;; Maintainer: Adam Spiers <emacs-ss@adamspiers.org> -;; Homepage: http://github.com/aspiers/smooth-scrolling/ -;; Version: 2.0.0 -;; Keywords: convenience -;; GitHub: http://github.com/aspiers/smooth-scrolling/ - -;; This file is not part of GNU Emacs - -;;; License: -;; -;; 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 -;; of the License, 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; if not, write to the Free Software -;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. - -;;; Commentary: - -;; To interactively toggle the mode on / off: -;; -;; M-x smooth-scrolling-mode -;; -;; To make the mode permanent, put this in your .emacs: -;; -;; (require 'smooth-scrolling) -;; (smooth-scrolling-mode 1) -;; -;; This package offers a global minor mode which make emacs scroll -;; smoothly. It keeps the point away from the top and bottom of the -;; current buffer's window in order to keep lines of context around -;; the point visible as much as possible, whilst minimising the -;; frequency of sudden scroll jumps which are visually confusing. -;; -;; This is a nice alternative to all the native `scroll-*` custom -;; variables, which unfortunately cannot provide this functionality -;; perfectly. For example, when using the built-in variables, clicking -;; with the mouse in the margin will immediately scroll the window to -;; maintain the margin, so the text that you clicked on will no longer be -;; under the mouse. This can be disorienting. In contrast, this mode -;; will not do any scrolling until you actually move up or down a line. -;; -;; Also, the built-in margin code does not interact well with small -;; windows. If the margin is more than half the window height, you get -;; some weird behavior, because the point is always hitting both the top -;; and bottom margins. This package auto-adjusts the margin in each -;; buffer to never exceed half the window height, so the top and bottom -;; margins never overlap. - -;; See the README.md for more details. - -;;; Change Log: -;; 27 Feb 2016 -- v2.0.0 -;; * Converted to global minor mode "smooth-scrolling-mode". This -;; means that simply loading the file no longer enables smooth -;; scrolling; you must also enable the mode. -;; * Internal code restructuring that should improve some edge -;; cases, but otherwise have no user-visible effects. -;; 19 Dec 2013 -- v1.0.4 -;; * Disabled scrolling while a keyboard macro is executing in -;; order to prevent a premature termination of the macro by -;; the mode throwing an error such as "End of Buffer" -;; 02 Jun 2013 -- v1.0.3 -;; * Fixed Issue #3 where bounds checking was not being performed -;; prior to calls to 'count-lines' and 'count-screen-lines' -;; functions. -;; 14 Apr 2013 -- v1.0.2 -;; * Adam Spiers GitHub account now houses the canonical -;; repository. -;; 06 Dec 2011 -- v1.0.1 -;; * Altered structure to conform to package.el standards. -;; * Restructured code to group settings changes -;; * Set "redisplay-dont-pause" to true. -;; ?? ??? 2007 -- v1.0.0 -;; * Original version from Adam Spiers - -;;; Code: - -;;;_ + internal variables -(defvar smooth-scroll-orig-scroll-margin nil) - -;;;_ + defcustoms - -(defgroup smooth-scrolling nil - "Make emacs scroll smoothly" - :group 'convenience) - -;;;###autoload -(define-minor-mode smooth-scrolling-mode - "Make emacs scroll smoothly" - :init-value nil - :global t - :group 'smooth-scrolling - (if smooth-scrolling-mode - (setq smooth-scroll-orig-scroll-margin scroll-margin - scroll-margin 0) - (setq scroll-margin smooth-scroll-orig-scroll-margin - smooth-scroll-orig-scroll-margin nil))) - -;;;###autoload -(defcustom smooth-scroll-margin 10 - "Number of lines of visible margin at the top and bottom of a window. -If the point is within these margins, then scrolling will occur -smoothly for `previous-line' at the top of the window, and for -`next-line' at the bottom. - -This is very similar in its goal to `scroll-margin'. However, it -is implemented by activating `smooth-scroll-down' and -`smooth-scroll-up' advise via `defadvice' for `previous-line' and -`next-line' respectively. As a result it avoids problems -afflicting `scroll-margin', such as a sudden jump and unexpected -highlighting of a region when the mouse is clicked in the margin. - -Scrolling only occurs when the point is closer to the window -boundary it is heading for (top or bottom) than the middle of the -window. This is to intelligently handle the case where the -margins cover the whole buffer (e.g. `smooth-scroll-margin' set -to 5 and `window-height' returning 10 or less). - -See also `smooth-scroll-strict-margins'." - :type 'integer - :group 'smooth-scrolling) - -;;;###autoload -(defcustom smooth-scroll-strict-margins t - "If true, the advice code supporting `smooth-scroll-margin' -will use `count-screen-lines' to determine the number of -*visible* lines between the point and the window top/bottom, -rather than `count-lines' which obtains the number of actual -newlines. This is because there might be extra newlines hidden -by a mode such as folding-mode, outline-mode, org-mode etc., or -fewer due to very long lines being displayed wrapped when -`truncate-lines' is nil. - -However, using `count-screen-lines' can supposedly cause -performance issues in buffers with extremely long lines. Setting -`cache-long-line-scans' may be able to address this; -alternatively you can set this variable to nil so that the advice -code uses `count-lines', and put up with the fact that sometimes -the point will be allowed to stray into the margin." - :type 'boolean - :group 'smooth-scrolling) - -;;;_ + helper functions -(defmacro smooth-scroll-ignore-scroll-errors (&rest body) - "Like `progn', but ignores beginning/end of line errors. - -If BODY encounters such an error, further evaluation is stopped -and this form returns nil. Any other error is raised as normal." - (declare (indent 0)) - `(condition-case err - (progn ,@body) - (end-of-buffer nil) - (beginning-of-buffer nil) - (error (signal (car err) (cdr err))))) - -(defun smooth-scroll-line-beginning-position () - "Return position at beginning of (logical/visual) line. - -If `smooth-scroll-strict-margins' is non-nil, this looks to the -beginning of the visual line. Otherwise it uses the beginning of -the logical line." - (save-excursion - ;; Cannot use `line-beginning-position' here because there is no - ;; visual-line equivalent. - (funcall (if smooth-scroll-strict-margins - #'beginning-of-visual-line - #'beginning-of-line)) - (point))) - -(defun smooth-scroll-count-lines (start end) - "Return number of (logical/visual) lines between START and END. - -If `smooth-scroll-strict-margins' is non-nil, this counts visual -lines. Otherwise it counts logical lines. - -If END is less than START, this returns zero, so it is important -to pass them in order." - (if (< end start) - 0 - (funcall (if smooth-scroll-strict-margins - #'count-screen-lines - #'count-lines) - start end))) - -(defun smooth-scroll-lines-above-point () - "Return the number of lines in window above point. - -This does not include the line that point is on." - (smooth-scroll-count-lines (window-start) - (smooth-scroll-line-beginning-position))) - -(defun smooth-scroll-lines-below-point () - "Return the number of lines in window above point. - -This does not include the line that point is on." - ;; We don't rely on `window-end' because if we are scrolled near the - ;; end of the buffer, it will only give the number of lines - ;; remaining in the file, not the number of lines to the bottom of - ;; the window. - (- (window-height) 2 (smooth-scroll-lines-above-point))) - -(defun smooth-scroll-window-allowed-margin () - "Return the maximum allowed margin above or below point. - -This only matters for windows whose height is -`smooth-scroll-margin' * 2 lines or less." - ;; We subtract 1 for the modeline, which is counted in - ;; `window-height', and one more for the line that point is on. Then - ;; we divide by 2, rouding down. - (/ (- (window-height) 2) 2)) - -(defsubst window-is-at-bob-p () - "Returns non-nil if `(window-start)' is 1 (or less)." - (<= (window-start) 1)) - -;;;_ + main function -(defun do-smooth-scroll () - "Ensure that point is not to close to window edges. - -This function scrolls the window until there are at least -`smooth-scroll-margin' lines between the point and both the top -and bottom of the window. If this is not possible because the -window is too small, th window is scrolled such that the point is -roughly centered within the window." - (interactive) - (when smooth-scrolling-mode - (let* ((desired-margin - ;; For short windows, we reduce `smooth-scroll-margin' to - ;; half the window height minus 1. - (min (smooth-scroll-window-allowed-margin) - smooth-scroll-margin)) - (upper-margin (smooth-scroll-lines-above-point)) - (lower-margin (smooth-scroll-lines-below-point))) - (smooth-scroll-ignore-scroll-errors - (cond - ((< upper-margin desired-margin) - (save-excursion - (dotimes (i (- desired-margin upper-margin)) - (scroll-down 1)))) - ((< lower-margin desired-margin) - (save-excursion - (dotimes (i (- desired-margin lower-margin)) - (scroll-up 1))))))))) - -;;;_ + advice setup - -;;;###autoload -(defmacro enable-smooth-scroll-for-function (func) - "Define advice on FUNC to do smooth scrolling. - -This adds after advice with name `smooth-scroll' to FUNC. - -Note that the advice will not have an effect unless -`smooth-scrolling-mode' is enabled." - `(defadvice ,func (after smooth-scroll activate) - "Do smooth scrolling after command finishes. - -This advice only has an effect when `smooth-scrolling-mode' is -enabled. See `smooth-scrolling-mode' for details. To remove this -advice, use `disable-smooth-scroll-for-function'." - (do-smooth-scroll))) - -(defmacro enable-smooth-scroll-for-function-conditionally (func cond) - "Define advice on FUNC to do smooth scrolling conditionally. - -This adds after advice with name `smooth-scroll' to FUNC. The -advice runs smooth scrolling if expression COND evaluates to -true. COND is included within the advice and therefore has access -to all of FUNC's arguments. - -Note that the advice will not have an effect unless -`smooth-scrolling-mode' is enabled." - (declare (indent 1)) - `(defadvice ,func (after smooth-scroll activate) - ,(format "Do smooth scrolling conditionally after command finishes. - -Smooth sccrolling will only be performed if the following -expression evaluates to true after the function has run: - -%s -This advice only has an effect when `smooth-scrolling-mode' is -enabled. See `smooth-scrolling-mode' for details. To remove this -advice, use `disable-smooth-scroll-for-function'." - (pp-to-string cond)) - (when ,cond - (do-smooth-scroll)))) - -(defmacro disable-smooth-scroll-for-function (func) - "Delete smooth-scroll advice for FUNC." - ;; This doesn't actually need to be a macro, but it is one for - ;; consistency with the enabling macro. Errors are ignored in case - ;; the advice has already been removed. - `(ignore-errors - (ad-remove-advice ',func 'after 'smooth-scroll) - (ad-activate ',func))) - -(progn - (enable-smooth-scroll-for-function previous-line) - (enable-smooth-scroll-for-function next-line) - (enable-smooth-scroll-for-function dired-previous-line) - (enable-smooth-scroll-for-function dired-next-line) - (enable-smooth-scroll-for-function isearch-repeat) - (enable-smooth-scroll-for-function-conditionally scroll-up-command - (not (window-is-at-bob-p))) - (enable-smooth-scroll-for-function-conditionally scroll-down-command - (not (window-is-at-bob-p)))) - -;;;_ + provide -(provide 'smooth-scrolling) -;;; smooth-scrolling.el ends here |