unofficial mirror of emacs-devel@gnu.org 
 help / color / mirror / code / Atom feed
blob ef7dfcb61d2dd7f976c98a7c2abd26ecae101b48 18025 bytes (raw)
name: lisp/scroll-bar.el 	 # note: path name is non-authoritative(*)

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
 
;;; scroll-bar.el --- window system-independent scroll bar support

;; Copyright (C) 1993-1995, 1999-2020 Free Software Foundation, Inc.

;; Maintainer: emacs-devel@gnu.org
;; Keywords: hardware
;; Package: emacs

;; 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 3 of the License, 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.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; Window-system-independent bindings of mouse clicks on the scroll bar.
;; Presently emulates the scroll-bar behavior of xterm.

;;; Code:

(require 'mouse)
(eval-when-compile (require 'cl-lib))

\f
;;;; Utilities.

(defun scroll-bar-event-ratio (event)
  "Given a scroll bar event EVENT, return the scroll bar position as a ratio.
The value is a cons cell (PORTION . WHOLE) containing two integers
whose ratio gives the event's vertical position in the scroll bar, with 0
referring to the top and 1 to the bottom."
  (nth 2 event))

(defun scroll-bar-scale (num-denom whole)
  "Given a pair (NUM . DENOM) and WHOLE, return (/ (* NUM WHOLE) DENOM).
This is handy for scaling a position on a scroll bar into real units,
like buffer positions.  If SCROLL-BAR-POS is the (PORTION . WHOLE) pair
from a scroll bar event, then (scroll-bar-scale SCROLL-BAR-POS
\(buffer-size)) is the position in the current buffer corresponding to
that scroll bar position."
  ;; We multiply before we divide to maintain precision.
  (truncate (* (car num-denom) whole) (cdr num-denom)))

(defun scroll-bar-columns (side)
  "Return the width, measured in columns, of the vertical scrollbar on SIDE.
SIDE must be the symbol `left' or `right'."
  (let* ((wsb   (window-scroll-bars))
         (vtype (nth 2 wsb))
         (cols  (nth 1 wsb)))
    (cond
     ((not (memq side '(left right)))
      (error "`left' or `right' expected instead of %S" side))
     ((and (eq vtype side) cols))
     ((eq (frame-parameter nil 'vertical-scroll-bars) side)
      ;; nil means it's a non-toolkit scroll bar, and its width in
      ;; columns is 14 pixels rounded up.
      (ceiling (or (frame-parameter nil 'scroll-bar-width) 14)
               (frame-char-width)))
     (0))))

(defun scroll-bar-lines ()
  "Return the height, measured in lines, of the horizontal scrollbar."
  (let* ((wsb   (window-scroll-bars))
         (htype (nth 5 wsb))
         (lines  (nth 4 wsb)))
    (cond
     (htype lines)
     ((frame-parameter nil 'horizontal-scroll-bars)
      ;; nil means it's a non-toolkit scroll bar (which is currently
      ;; impossible), and its height in lines is 14 pixels rounded up.
      (ceiling (or (frame-parameter nil 'scroll-bar-height) 14)
               (frame-char-width)))
     (0))))

\f
;;;; Helpful functions for enabling and disabling scroll bars.

(defvar scroll-bar-mode)
(defvar horizontal-scroll-bar-mode)
(defvar previous-scroll-bar-mode nil)

(defvar scroll-bar-mode-explicit nil
  "Non-nil means `set-scroll-bar-mode' should really do something.
This is nil while loading `scroll-bar.el', and t afterward.")

(defun set-scroll-bar-mode (value)
  "Set the scroll bar mode to VALUE and put the new value into effect.
See the `scroll-bar-mode' variable for possible values to use."
  (if scroll-bar-mode
      (setq previous-scroll-bar-mode scroll-bar-mode))

  (setq scroll-bar-mode value)

  (when scroll-bar-mode-explicit
    (modify-all-frames-parameters (list (cons 'vertical-scroll-bars
					      scroll-bar-mode)))))

(defcustom scroll-bar-mode default-frame-scroll-bars
  "Specify whether to have vertical scroll bars, and on which side.
Possible values are nil (no scroll bars), `left' (scroll bars on left)
and `right' (scroll bars on right).
To set this variable in a Lisp program, use `set-scroll-bar-mode'
to make it take real effect.
Setting the variable with a customization buffer also takes effect."
  :type '(choice (const :tag "none (nil)" nil)
		 (const left)
		 (const right))
  :group 'frames
  ;; The default value for :initialize would try to use :set
  ;; when processing the file in cus-dep.el.
  :initialize 'custom-initialize-default
  :set (lambda (_sym val) (set-scroll-bar-mode val)))

;; We just set scroll-bar-mode, but that was the default.
;; If it is set again, that is for real.
(setq scroll-bar-mode-explicit t)

(defun get-scroll-bar-mode ()
  (declare (gv-setter set-scroll-bar-mode))
  scroll-bar-mode)

(define-minor-mode scroll-bar-mode
  "Toggle vertical scroll bars on all frames (Scroll Bar mode).

This command applies to all frames that exist and frames to be
created in the future."
  :variable ((get-scroll-bar-mode)
             . (lambda (v) (set-scroll-bar-mode
			    (if v (or previous-scroll-bar-mode
				      default-frame-scroll-bars))))))

(defun horizontal-scroll-bars-available-p ()
  "Return non-nil when horizontal scroll bars are available on this system."
  (and (display-graphic-p)
       (boundp 'x-toolkit-scroll-bars)
       x-toolkit-scroll-bars))

(define-minor-mode horizontal-scroll-bar-mode
  "Toggle horizontal scroll bars on all frames (Horizontal Scroll Bar mode).

This command applies to all frames that exist and frames to be
created in the future."
  :init-value nil
  :global t
  :group 'frames
  (if (and horizontal-scroll-bar-mode
	   (not (horizontal-scroll-bars-available-p)))
      (progn
	(setq horizontal-scroll-bar-mode nil)
	(message "Horizontal scroll bars are not implemented on this system"))
    (dolist (frame (frame-list))
      (set-frame-parameter
       frame 'horizontal-scroll-bars horizontal-scroll-bar-mode))
    ;; Handle `default-frame-alist' entry.
    (setq default-frame-alist
	  (cons (cons 'horizontal-scroll-bars horizontal-scroll-bar-mode)
		(assq-delete-all 'horizontal-scroll-bars
				 default-frame-alist)))))

(defun toggle-scroll-bar (arg)
  "Toggle whether or not the selected frame has vertical scroll bars.
With ARG, turn vertical scroll bars on if and only if ARG is positive.
The variable `scroll-bar-mode' controls which side the scroll bars are on
when they are turned on; if it is nil, they go on the left."
  (interactive "P")
  (if (null arg)
      (setq arg
	    (if (frame-parameter nil 'vertical-scroll-bars) -1 1))
    (setq arg (prefix-numeric-value arg)))
  (modify-frame-parameters
   (selected-frame)
   (list (cons 'vertical-scroll-bars
	       (if (> arg 0)
		   (or scroll-bar-mode default-frame-scroll-bars))))))

(defun toggle-horizontal-scroll-bar (arg)
  "Toggle whether or not the selected frame has horizontal scroll bars.
With ARG, turn vertical scroll bars on if and only if ARG is positive."
  (interactive "P")
  (if (null arg)
      (setq arg
	    (if (frame-parameter nil 'horizontal-scroll-bars) -1 1))
    (setq arg (prefix-numeric-value arg)))
  (modify-frame-parameters
   (selected-frame)
   (list (cons 'horizontal-scroll-bars
	       (when (> arg 0) 'bottom)))))
\f
;;;; Buffer navigation using the scroll bar.

;; This was used for up-events on button 2, but no longer.
(defun scroll-bar-set-window-start (event)
  "Set the window start according to where the scroll bar is dragged.
EVENT should be a scroll bar click or drag event."
  (interactive "e")
  (let* ((end-position (event-end event))
	 (window (nth 0 end-position))
	 (portion-whole (nth 2 end-position)))
    (with-current-buffer (window-buffer window)
      (save-excursion
	(goto-char (+ (point-min)
		      (scroll-bar-scale portion-whole
					(- (point-max) (point-min)))))
	(beginning-of-line)
	(set-window-start window (point))))))

(defun scroll-bar-drag-position (portion-whole)
  "Calculate new window start for drag event."
  (save-excursion
    (goto-char (+ (point-min)
		  (scroll-bar-scale portion-whole
				    (- (point-max) (point-min)))))
    (beginning-of-line)
    (point)))

(defun scroll-bar-maybe-set-window-start (event)
  "Set the window start according to where the scroll bar is dragged.
Only change window start if the new start is substantially different.
EVENT should be a scroll bar click or drag event."
  (interactive "e")
  (let* ((end-position (event-end event))
	 (window (nth 0 end-position))
	 (portion-whole (nth 2 end-position))
	 (next-portion-whole (cons (1+ (car portion-whole))
				   (cdr portion-whole)))
	 portion-start
	 next-portion-start
	 (current-start (window-start window)))
    (with-current-buffer (window-buffer window)
      (setq portion-start (scroll-bar-drag-position portion-whole))
      (setq next-portion-start (max
				(scroll-bar-drag-position next-portion-whole)
				(1+ portion-start)))
      (if (or (>= current-start next-portion-start)
	      (< current-start portion-start))
	  (set-window-start window portion-start)
	;; Always set window start, to ensure scroll bar position is updated.
	(set-window-start window current-start)))))

;; Scroll the window to the proper position for EVENT.
(defun scroll-bar-drag-1 (event)
  (let* ((start-position (event-start event))
	 (window (nth 0 start-position))
	 (portion-whole (nth 2 start-position)))
    ;; With 'scroll-bar-adjust-thumb-portion' nil and 'portion-whole'
    ;; indicating that the buffer is fully visible, do not scroll the
    ;; window since that might make it impossible to scroll it back
    ;; with GTK's thumb (Bug#32002).
    (when (or scroll-bar-adjust-thumb-portion
              (not (numberp (car portion-whole)))
              (not (numberp (cdr portion-whole)))
              (/= (car portion-whole) (cdr portion-whole)))
      (save-excursion
        (with-current-buffer (window-buffer window)
	  ;; Calculate position relative to the accessible part of the buffer.
	  (goto-char (+ (point-min)
		        (scroll-bar-scale portion-whole
					  (- (point-max) (point-min)))))
	  (vertical-motion 0 window)
	  (set-window-start window (point)))))))

(defun scroll-bar-drag (event)
  "Scroll the window by dragging the scroll bar slider.
If you click outside the slider, the window scrolls to bring the slider there."
  (interactive "e")
  (let* (done
	 (echo-keystrokes 0)
	 (end-position (event-end event))
	 (window (nth 0 end-position))
	 (before-scroll))
    (with-current-buffer (window-buffer window)
      (setq before-scroll point-before-scroll))
    (save-selected-window
      (select-window window 'mark-for-redisplay)
      (setq before-scroll
	    (or before-scroll (point))))
    (scroll-bar-drag-1 event)
    (track-mouse
      (while (not done)
	(setq event (read-event))
	(if (eq (car-safe event) 'mouse-movement)
	    (setq event (read-event)))
	(cond ((eq (car-safe event) 'scroll-bar-movement)
	       (scroll-bar-drag-1 event))
	      (t
	       ;; Exit when we get the drag event; ignore that event.
	       (setq done t)))))
    (sit-for 0)
    (with-current-buffer (window-buffer window)
      (setq point-before-scroll before-scroll))))

;; Scroll the window to the proper position for EVENT.
(defun scroll-bar-horizontal-drag-1 (event)
  (let* ((start-position (event-start event))
	 (window (nth 0 start-position))
	 (portion-whole (nth 2 start-position))
	 (unit (frame-char-width (window-frame window))))
    (if (eq (current-bidi-paragraph-direction (window-buffer window))
	    'left-to-right)
	(set-window-hscroll
	 window (/ (+ (car portion-whole) (1- unit)) unit))
      (set-window-hscroll
       window (/ (+ (- (cdr portion-whole) (car portion-whole))
		    (1- unit))
		 unit)))))

(defun scroll-bar-horizontal-drag (event)
  "Scroll the window horizontally by dragging the scroll bar slider.
If you click outside the slider, the window scrolls to bring the slider there."
  (interactive "e")
  (let* (done
	 (echo-keystrokes 0)
	 (end-position (event-end event))
	 (window (nth 0 end-position))
	 (before-scroll))
    (with-current-buffer (window-buffer window)
      (setq before-scroll point-before-scroll))
    (save-selected-window
      (select-window window 'mark-for-redisplay)
      (setq before-scroll
	    (or before-scroll (point))))
    (scroll-bar-horizontal-drag-1 event)
    (track-mouse
      (while (not done)
	(setq event (read-event))
	(if (eq (car-safe event) 'mouse-movement)
	    (setq event (read-event)))
	(cond ((eq (car-safe event) 'scroll-bar-movement)
	       (scroll-bar-horizontal-drag-1 event))
	      (t
	       ;; Exit when we get the drag event; ignore that event.
	       (setq done t)))))
    (sit-for 0)
    (with-current-buffer (window-buffer window)
      (setq point-before-scroll before-scroll))))

(defun scroll-bar-scroll-down (event)
  "Scroll the window's top line down to the location of the scroll bar click.
EVENT should be a scroll bar click."
  (interactive "e")
  (let* ((end-position (event-end event))
	 (window (nth 0 end-position))
	 (before-scroll))
    (with-current-buffer (window-buffer window)
      (setq before-scroll point-before-scroll))
    (unwind-protect
	(save-selected-window
	  (let ((portion-whole (nth 2 end-position)))
	    (select-window window 'mark-for-redisplay)
	    (setq before-scroll
		  (or before-scroll (point)))
	    (scroll-down
	     (scroll-bar-scale portion-whole (1- (window-height)))))
	  (sit-for 0))
      (with-current-buffer (window-buffer window)
	(setq point-before-scroll before-scroll)))))

(defun scroll-bar-scroll-up (event)
  "Scroll the line next to the scroll bar click to the top of the window.
EVENT should be a scroll bar click."
  (interactive "e")
  (let* ((end-position (event-end event))
	 (window (nth 0 end-position))
	 (before-scroll))
    (with-current-buffer (window-buffer window)
      (setq before-scroll point-before-scroll))
    (unwind-protect
	(save-selected-window
	  (let ((portion-whole (nth 2 end-position)))
	    (select-window window 'mark-for-redisplay)
	    (setq before-scroll
		  (or before-scroll (point)))
	    (scroll-up
	     (scroll-bar-scale portion-whole (1- (window-height)))))
	  (sit-for 0))
      (with-current-buffer (window-buffer window)
	(setq point-before-scroll before-scroll)))))

\f
;;; Tookit scroll bars.

(defun scroll-bar-toolkit-scroll (event)
  "Handle event EVENT on vertical scroll bar."
  (interactive "e")
  (let* ((end-position (event-end event))
	 (window (nth 0 end-position))
	 (part (nth 4 end-position))
	 before-scroll)
    (cond
     ((eq part 'end-scroll))
     (t
      (with-current-buffer (window-buffer window)
	(setq before-scroll point-before-scroll))
      (save-selected-window
	(select-window window 'mark-for-redisplay)
	(setq before-scroll (or before-scroll (point)))
	(cond
	 ((eq part 'above-handle)
	  (scroll-up '-))
	 ((eq part 'below-handle)
	  (scroll-up nil))
	 ((eq part 'ratio)
	  (let* ((portion-whole (nth 2 end-position))
		 (lines (scroll-bar-scale portion-whole
					  (1- (window-height)))))
	    (scroll-up (cond ((not (zerop lines)) lines)
			     ((< (car portion-whole) 0) -1)
			     (t 1)))))
	 ((eq part 'up)
	  (scroll-up -1))
	 ((eq part 'down)
	  (scroll-up 1))
	 ((eq part 'top)
	  (set-window-start window (point-min)))
	 ((eq part 'bottom)
	  (goto-char (point-max))
	  (recenter))
	 ((eq part 'handle)
	  (scroll-bar-drag-1 event))))
      (when (not (featurep 'pgtk))
        (sit-for 0))
      (with-current-buffer (window-buffer window)
	(setq point-before-scroll before-scroll))))))

(defun scroll-bar-toolkit-horizontal-scroll (event)
  "Handle event EVENT on horizontal scroll bar."
  (interactive "e")
  (let* ((end-position (event-end event))
	 (window (nth 0 end-position))
	 (part (nth 4 end-position))
	 (bidi-factor
	  (if (eq (current-bidi-paragraph-direction (window-buffer window))
		  'left-to-right)
	      1
	    -1))
	 before-scroll)
    (cond
     ((eq part 'end-scroll))
     (t
      (with-current-buffer (window-buffer window)
	(setq before-scroll point-before-scroll))
      (save-selected-window
	(select-window window 'mark-for-redisplay)
	(setq before-scroll (or before-scroll (point)))
	(cond
	 ((eq part 'before-handle)
	  (scroll-right (* bidi-factor 4)))
	 ((eq part 'after-handle)
	  (scroll-left (* bidi-factor 4)))
	 ((eq part 'ratio)
	  (let* ((portion-whole (nth 2 end-position))
		 (columns (scroll-bar-scale portion-whole
					    (1- (window-width)))))
	    (scroll-right
	     (* (cond
		 ((not (zerop columns))
		  columns)
		 ((< (car portion-whole) 0) -1)
		 (t 1))
		bidi-factor))))
	 ((eq part 'left)
	  (scroll-right (* bidi-factor 1)))
	 ((eq part 'right)
	  (scroll-left (* bidi-factor 1)))
	 ((eq part 'leftmost)
	  (goto-char (if (eq bidi-factor 1)
			 (line-beginning-position)
		       (line-end-position))))
	 ((eq part 'rightmost)
	  (goto-char (if (eq bidi-factor 1)
			 (line-end-position)
		       (line-beginning-position))))
	 ((eq part 'horizontal-handle)
	  (scroll-bar-horizontal-drag-1 event))))
      (sit-for 0)
      (with-current-buffer (window-buffer window)
	(setq point-before-scroll before-scroll))))))
\f
;;;; Bindings.

;; For now, we'll set things up to work like xterm.
(cond ((and (boundp 'x-toolkit-scroll-bars) x-toolkit-scroll-bars)
       (global-set-key [vertical-scroll-bar mouse-1]
		       'scroll-bar-toolkit-scroll)
       (global-set-key [horizontal-scroll-bar mouse-1]
		       'scroll-bar-toolkit-horizontal-scroll))
      (t
       (global-set-key [vertical-scroll-bar mouse-1]
		       'scroll-bar-scroll-up)
       (global-set-key [vertical-scroll-bar drag-mouse-1]
		       'scroll-bar-scroll-up)
       (global-set-key [vertical-scroll-bar down-mouse-2]
		       'scroll-bar-drag)
       (global-set-key [vertical-scroll-bar mouse-3]
		       'scroll-bar-scroll-down)
       (global-set-key [vertical-scroll-bar drag-mouse-3]
		       'scroll-bar-scroll-down)))

\f
(provide 'scroll-bar)

;;; scroll-bar.el ends here

debug log:

solving ef7dfcb61d ...
found ef7dfcb61d in https://yhetil.org/emacs-devel/87zhaxjpea.fsf@yahoo.com/
found 5b82934579 in https://git.savannah.gnu.org/cgit/emacs.git
preparing index
index prepared:
100644 5b8293457950fffb475f74e527debddc379cbba9	lisp/scroll-bar.el

applying [1/1] https://yhetil.org/emacs-devel/87zhaxjpea.fsf@yahoo.com/
diff --git a/lisp/scroll-bar.el b/lisp/scroll-bar.el
index 5b82934579..ef7dfcb61d 100644

Checking patch lisp/scroll-bar.el...
Applied patch lisp/scroll-bar.el cleanly.

index at:
100644 ef7dfcb61d2dd7f976c98a7c2abd26ecae101b48	lisp/scroll-bar.el

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).