[Emacs-diffs] Changes to emacs/lisp/emulation/tpu-extras.el [lexbind]

[Miles Bader]

Index: emacs/lisp/emulation/tpu-extras.el
diff -c /dev/null emacs/lisp/emulation/tpu-extras.el:1.14.8.1
*** /dev/null   Tue Oct 14 19:42:21 2003
--- emacs/lisp/emulation/tpu-extras.el  Tue Oct 14 19:42:12 2003
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*** 0 ****
--- 1,484 ----
+ ;;; tpu-extras.el --- scroll margins and free cursor mode for TPU-edt
+ 
+ ;; Copyright (C) 1993, 1994, 1995, 2000 Free Software Foundation, Inc.
+ 
+ ;; Author: Rob Riepel <address@hidden>
+ ;; Maintainer: Rob Riepel <address@hidden>
+ ;; Keywords: emulations
+ 
+ ;; This file is part of GNU Emacs.
+ 
+ ;; GNU Emacs 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.
+ 
+ ;; GNU Emacs 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:
+ 
+ ;;  Use the functions defined here to customize TPU-edt to your tastes by
+ ;;  setting scroll margins and/or turning on free cursor mode.  Here's an
+ ;;  example for your .emacs file.
+ 
+ ;;     (tpu-set-cursor-free)                   ; Set cursor free.
+ ;;     (tpu-set-scroll-margins "10%" "15%")    ; Set scroll margins.
+ 
+ ;;  Scroll margins and cursor binding can be changed from within emacs using
+ ;;  the following commands:
+ 
+ ;;     tpu-set-scroll-margins  or   set scroll margins
+ ;;     tpu-set-cursor-bound    or   set cursor bound
+ ;;     tpu-set-cursor-free     or   set cursor free
+ 
+ ;;  Additionally, Gold-F toggles between bound and free cursor modes.
+ 
+ ;;  Note that switching out of free cursor mode or exiting TPU-edt while in
+ ;;  free cursor mode strips trailing whitespace from every line in the file.
+ 
+ 
+ ;;; Details:
+ 
+ ;;  The functions contained in this file implement scroll margins and free
+ ;;  cursor mode.  The following keys and commands are affected.
+ 
+ ;;       key/command   function                        scroll   cursor
+ 
+ ;;       Up-Arrow      previous line                     x        x
+ ;;       Down-Arrow    next line                         x        x
+ ;;       Right-Arrow   next character                             x
+ ;;       Left-Arrow    previous character                         x
+ ;;       KP0           next or previous line             x
+ ;;       KP7           next or previous page             x
+ ;;       KP8           next or previous screen           x
+ ;;       KP2           next or previous end-of-line      x        x
+ ;;       Control-e     current end-of-line                        x
+ ;;       Control-h     previous beginning-of-line        x
+ ;;       Next Scr      next screen                       x
+ ;;       Prev Scr      previous screen                   x
+ ;;       Search        find a string                     x
+ ;;       Replace       find and replace a string         x
+ ;;       Newline       insert a newline                  x
+ ;;       Paragraph     next or previous paragraph        x
+ ;;       Auto-Fill     break lines on spaces             x
+ 
+ ;;  These functions are not part of the base TPU-edt for the following
+ ;;  reasons:
+ 
+ ;;  Free cursor mode is implemented with the emacs picture-mode functions.
+ ;;  These functions support moving the cursor all over the screen, however,
+ ;;  when the cursor is moved past the end of a line, spaces or tabs are
+ ;;  appended to the line - even if no text is entered in that area.  In
+ ;;  order for a free cursor mode to work exactly like TPU/edt, this trailing
+ ;;  whitespace needs to be dealt with in every function that might encounter
+ ;;  it.  Such global changes are impractical, however, free cursor mode is
+ ;;  too valuable to abandon completely, so it has been implemented in those
+ ;;  functions where it serves best.
+ 
+ ;;  The implementation of scroll margins adds overhead to previously
+ ;;  simple and often used commands.  These commands are now responsible
+ ;;  for their normal operation and part of the display function.  There
+ ;;  is a possibility that this display overhead could adversely affect the
+ ;;  performance of TPU-edt on slower computers.  In order to support the
+ ;;  widest range of computers, scroll margin support is optional.
+ 
+ ;;  It's actually not known whether the overhead associated with scroll
+ ;;  margin support is significant.  If you find that it is, please send
+ ;;  a note describing the extent of the performance degradation.  Be sure
+ ;;  to include a description of the platform where you're running TPU-edt.
+ ;;  Send your note to the address provided by Gold-V.
+ 
+ ;;  Even with these differences and limitations, these functions implement
+ ;;  important aspects of the real TPU/edt.  Those who miss free cursor mode
+ ;;  and/or scroll margins will appreciate these implementations.
+ 
+ ;;; Code:
+ 
+ 
+ ;;;  Gotta have tpu-edt
+ 
+ (require 'tpu-edt)
+ 
+ 
+ ;;;  Customization variables
+ 
+ (defcustom tpu-top-scroll-margin 0
+   "*Scroll margin at the top of the screen.
+ Interpreted as a percent of the current window size."
+   :type 'integer
+   :group 'tpu)
+ (defcustom tpu-bottom-scroll-margin 0
+   "*Scroll margin at the bottom of the screen.
+ Interpreted as a percent of the current window size."
+   :type 'integer
+   :group 'tpu)
+ 
+ (defcustom tpu-backward-char-like-tpu t
+   "*If non-nil, in free cursor mode backward-char (left-arrow) works
+ just like TPU/edt.  Otherwise, backward-char will move to the end of
+ the previous line when starting from a line beginning."
+   :type 'boolean
+   :group 'tpu)
+ 
+ 
+ ;;;  Global variables
+ 
+ (defvar tpu-cursor-free nil
+   "If non-nil, let the cursor roam free.")
+ 
+ 
+ ;;;  Hooks  --  Set cursor free in picture mode.
+ ;;;             Clean up when writing a file from cursor free mode.
+ 
+ (add-hook 'picture-mode-hook 'tpu-set-cursor-free)
+ 
+ (defun tpu-write-file-hook nil
+   "Eliminate whitespace at ends of lines, if the cursor is free."
+   (if (and (buffer-modified-p) tpu-cursor-free) (tpu-trim-line-ends)))
+ 
+ (or (memq 'tpu-write-file-hook write-file-hooks)
+     (setq write-file-hooks
+         (cons 'tpu-write-file-hook write-file-hooks)))
+ 
+ 
+ ;;;  Utility routines for implementing scroll margins
+ 
+ (defun tpu-top-check (beg lines)
+   "Enforce scroll margin at the top of screen."
+   (let ((margin        (/ (* (window-height) tpu-top-scroll-margin) 100)))
+     (cond ((< beg margin) (recenter beg))
+         ((< (- beg lines) margin) (recenter margin)))))
+ 
+ (defun tpu-bottom-check (beg lines)
+   "Enforce scroll margin at the bottom of screen."
+   (let* ((height (window-height))
+        (margin (+ 1 (/ (* height tpu-bottom-scroll-margin) 100)))
+        ;; subtract 1 from height because it includes mode line
+        (difference (- height margin 1)))
+     (cond ((> beg difference) (recenter beg))
+         ((> (+ beg lines) difference) (recenter (- margin))))))
+ 
+ 
+ ;;;  Movement by character
+ 
+ (defun tpu-forward-char (num)
+   "Move right ARG characters (left if ARG is negative)."
+   (interactive "p")
+   (if tpu-cursor-free (picture-forward-column num) (forward-char num)))
+ 
+ (defun tpu-backward-char (num)
+   "Move left ARG characters (right if ARG is negative)."
+   (interactive "p")
+   (cond ((not tpu-cursor-free)
+        (backward-char num))
+       (tpu-backward-char-like-tpu
+        (picture-backward-column num))
+       ((bolp)
+        (backward-char 1)
+        (picture-end-of-line)
+        (picture-backward-column (1- num)))
+       (t
+        (picture-backward-column num))))
+ 
+ 
+ ;;;  Movement by line
+ 
+ (defun tpu-next-line (num)
+   "Move to next line.
+ Prefix argument serves as a repeat count."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (if tpu-cursor-free (or (eobp) (picture-move-down num))
+       (next-line-internal num))
+     (tpu-bottom-check beg num)
+     (setq this-command 'next-line)))
+ 
+ (defun tpu-previous-line (num)
+   "Move to previous line.
+ Prefix argument serves as a repeat count."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (if tpu-cursor-free (picture-move-up num) (next-line-internal (- num)))
+     (tpu-top-check beg num)
+     (setq this-command 'previous-line)))
+ 
+ (defun tpu-next-beginning-of-line (num)
+   "Move to beginning of line; if at beginning, move to beginning of next line.
+ Accepts a prefix argument for the number of lines to move."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (backward-char 1)
+     (forward-visible-line (- 1 num))
+     (tpu-top-check beg num)))
+ 
+ (defun tpu-next-end-of-line (num)
+   "Move to end of line; if at end, move to end of next line.
+ Accepts a prefix argument for the number of lines to move."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (cond (tpu-cursor-free
+          (let ((beg (point)))
+            (if (< 1 num) (forward-line num))
+            (picture-end-of-line)
+            (if (<= (point) beg) (progn (forward-line) 
(picture-end-of-line)))))
+         (t
+          (forward-char)
+          (end-of-line num)))
+     (tpu-bottom-check beg num)))
+ 
+ (defun tpu-previous-end-of-line (num)
+   "Move EOL upward.
+ Accepts a prefix argument for the number of lines to move."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (cond (tpu-cursor-free
+          (picture-end-of-line (- 1 num)))
+         (t
+          (end-of-line (- 1 num))))
+     (tpu-top-check beg num)))
+ 
+ (defun tpu-current-end-of-line nil
+   "Move point to end of current line."
+   (interactive)
+   (let ((beg (point)))
+     (if tpu-cursor-free (picture-end-of-line) (end-of-line))
+     (if (= beg (point)) (message "You are already at the end of a line."))))
+ 
+ (defun tpu-forward-line (num)
+   "Move to beginning of next line.
+ Prefix argument serves as a repeat count."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (next-line-internal num)
+     (tpu-bottom-check beg num)
+     (beginning-of-line)))
+ 
+ (defun tpu-backward-line (num)
+   "Move to beginning of previous line.
+ Prefix argument serves as repeat count."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (or (bolp) (>= 0 num) (setq num (- num 1)))
+     (next-line-internal (- num))
+     (tpu-top-check beg num)
+     (beginning-of-line)))
+ 
+ 
+ ;;;  Movement by paragraph
+ 
+ (defun tpu-paragraph (num)
+   "Move to the next paragraph in the current direction.
+ A repeat count means move that many paragraphs."
+   (interactive "p")
+   (let* ((left nil)
+        (beg (tpu-current-line))
+        (height (window-height))
+        (top-percent
+         (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin))
+        (bottom-percent
+         (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin))
+        (top-margin (/ (* height top-percent) 100))
+        (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100)))
+        (bottom-margin (max beg (- height bottom-up-margin 1)))
+        (top (save-excursion (move-to-window-line top-margin) (point)))
+        (bottom (save-excursion (move-to-window-line bottom-margin) (point)))
+        (far (save-excursion
+               (goto-char bottom) (forward-line (- height 2)) (point))))
+     (cond (tpu-advance
+          (tpu-next-paragraph num)
+          (cond((> (point) far)
+                (setq left (save-excursion (forward-line height)))
+                (if (= 0 left) (recenter top-margin)
+                  (recenter (- left bottom-up-margin))))
+               (t
+                (and (> (point) bottom) (recenter bottom-margin)))))
+         (t
+          (tpu-previous-paragraph num)
+          (and (< (point) top) (recenter (min beg top-margin)))))))
+ 
+ 
+ ;;;  Movement by page
+ 
+ (defun tpu-page (num)
+   "Move to the next page in the current direction.
+ A repeat count means move that many pages."
+   (interactive "p")
+   (let* ((left nil)
+        (beg (tpu-current-line))
+        (height (window-height))
+        (top-percent
+         (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin))
+        (bottom-percent
+         (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin))
+        (top-margin (/ (* height top-percent) 100))
+        (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100)))
+        (bottom-margin (max beg (- height bottom-up-margin 1)))
+        (top (save-excursion (move-to-window-line top-margin) (point)))
+        (bottom (save-excursion (move-to-window-line bottom-margin) (point)))
+        (far (save-excursion
+               (goto-char bottom) (forward-line (- height 2)) (point))))
+     (cond (tpu-advance
+          (forward-page num)
+          (cond((> (point) far)
+                (setq left (save-excursion (forward-line height)))
+                (if (= 0 left) (recenter top-margin)
+                  (recenter (- left bottom-up-margin))))
+               (t
+                (and (> (point) bottom) (recenter bottom-margin)))))
+         (t
+          (backward-page num)
+          (and (< (point) top) (recenter (min beg top-margin)))))))
+ 
+ 
+ ;;;  Scrolling
+ 
+ (defun tpu-scroll-window-down (num)
+   "Scroll the display down to the next section.
+ A repeat count means scroll that many sections."
+   (interactive "p")
+   (let* ((beg (tpu-current-line))
+        (height (1- (window-height)))
+        (lines (* num (/ (* height tpu-percent-scroll) 100))))
+     (next-line-internal (- lines))
+     (tpu-top-check beg lines)))
+ 
+ (defun tpu-scroll-window-up (num)
+   "Scroll the display up to the next section.
+ A repeat count means scroll that many sections."
+   (interactive "p")
+   (let* ((beg (tpu-current-line))
+        (height (1- (window-height)))
+        (lines (* num (/ (* height tpu-percent-scroll) 100))))
+     (next-line-internal lines)
+     (tpu-bottom-check beg lines)))
+ 
+ 
+ ;;;  Replace the TPU-edt internal search function
+ 
+ (defun tpu-search-internal (pat &optional quiet)
+   "Search for a string or regular expression."
+   (let* ((left nil)
+        (beg (tpu-current-line))
+        (height (window-height))
+        (top-percent
+         (if (= 0 tpu-top-scroll-margin) 10 tpu-top-scroll-margin))
+        (bottom-percent
+         (if (= 0 tpu-bottom-scroll-margin) 15 tpu-bottom-scroll-margin))
+        (top-margin (/ (* height top-percent) 100))
+        (bottom-up-margin (+ 1 (/ (* height bottom-percent) 100)))
+        (bottom-margin (max beg (- height bottom-up-margin 1)))
+        (top (save-excursion (move-to-window-line top-margin) (point)))
+        (bottom (save-excursion (move-to-window-line bottom-margin) (point)))
+        (far (save-excursion
+               (goto-char bottom) (forward-line (- height 2)) (point))))
+     (tpu-search-internal-core pat quiet)
+     (if tpu-searching-forward
+       (cond((> (point) far)
+             (setq left (save-excursion (forward-line height)))
+             (if (= 0 left) (recenter top-margin)
+               (recenter (- left bottom-up-margin))))
+            (t
+             (and (> (point) bottom) (recenter bottom-margin))))
+       (and (< (point) top) (recenter (min beg top-margin))))))
+ 
+ 
+ 
+ ;;;  Replace the newline, newline-and-indent, and do-auto-fill functions
+ 
+ (or (fboundp 'tpu-old-newline)
+     (fset 'tpu-old-newline (symbol-function 'newline)))
+ (or (fboundp 'tpu-old-do-auto-fill)
+     (fset 'tpu-old-do-auto-fill (symbol-function 'do-auto-fill)))
+ (or (fboundp 'tpu-old-newline-and-indent)
+     (fset 'tpu-old-newline-and-indent (symbol-function 'newline-and-indent)))
+ 
+ (defun newline (&optional num)
+   "Insert a newline.  With arg, insert that many newlines.
+ In Auto Fill mode, can break the preceding line if no numeric arg.
+ This is the TPU-edt version that respects the bottom scroll margin."
+   (interactive "p")
+   (let ((beg (tpu-current-line)))
+     (or num (setq num 1))
+     (tpu-old-newline num)
+     (tpu-bottom-check beg num)))
+ 
+ (defun newline-and-indent nil
+   "Insert a newline, then indent according to major mode.
+ Indentation is done using the current indent-line-function.
+ In programming language modes, this is the same as TAB.
+ In some text modes, where TAB inserts a tab, this indents
+ to the specified left-margin column.  This is the TPU-edt
+ version that respects the bottom scroll margin."
+   (interactive)
+   (let ((beg (tpu-current-line)))
+     (tpu-old-newline-and-indent)
+     (tpu-bottom-check beg 1)))
+ 
+ (defun do-auto-fill nil
+   "TPU-edt version that respects the bottom scroll margin."
+   (let ((beg (tpu-current-line)))
+     (tpu-old-do-auto-fill)
+     (tpu-bottom-check beg 1)))
+ 
+ 
+ ;;;  Function to set scroll margins
+ 
+ ;;;###autoload
+ (defun tpu-set-scroll-margins (top bottom)
+   "Set scroll margins."
+   (interactive
+    "sEnter top scroll margin (N lines or N%% or RETURN for current value): \
+ \nsEnter bottom scroll margin (N lines or N%% or RETURN for current value): ")
+   ;; set top scroll margin
+   (or (string= top "")
+       (if (string= "%" (substring top -1))
+         (setq tpu-top-scroll-margin (string-to-int top))
+       (setq tpu-top-scroll-margin
+             (/ (1- (+ (* (string-to-int top) 100) (window-height)))
+                (window-height)))))
+   ;; set bottom scroll margin
+   (or (string= bottom "")
+       (if (string= "%" (substring bottom -1))
+         (setq tpu-bottom-scroll-margin (string-to-int bottom))
+       (setq tpu-bottom-scroll-margin
+             (/ (1- (+ (* (string-to-int bottom) 100) (window-height)))
+                (window-height)))))
+   ;; report scroll margin settings if running interactively
+   (and (interactive-p)
+        (message "Scroll margins set.  Top = %s%%, Bottom = %s%%"
+               tpu-top-scroll-margin tpu-bottom-scroll-margin)))
+ 
+ 
+ ;;;  Functions to set cursor bound or free
+ 
+ ;;;###autoload
+ (defun tpu-set-cursor-free nil
+   "Allow the cursor to move freely about the screen."
+   (interactive)
+   (setq tpu-cursor-free t)
+   (substitute-key-definition 'tpu-set-cursor-free
+                            'tpu-set-cursor-bound
+                            GOLD-map)
+   (message "The cursor will now move freely about the screen."))
+ 
+ ;;;###autoload
+ (defun tpu-set-cursor-bound nil
+   "Constrain the cursor to the flow of the text."
+   (interactive)
+   (tpu-trim-line-ends)
+   (setq tpu-cursor-free nil)
+   (substitute-key-definition 'tpu-set-cursor-bound
+                            'tpu-set-cursor-free
+                            GOLD-map)
+   (message "The cursor is now bound to the flow of your text."))
+ 
+ ;;; arch-tag: 89676fa4-33ec-48cb-9135-6f3bf230ab1a
+ ;;; tpu-extras.el ends here