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author | Noam Postavsky <npostavs@gmail.com> | 2016-08-28 16:38:04 -0400 |
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committer | Noam Postavsky <npostavs@gmail.com> | 2017-02-02 21:19:52 -0500 |
commit | d17e92da064cabf376597f5de2a8d5a6484bfea6 (patch) | |
tree | b608581cb4e883357a753c12e4526cac53066427 /src/window.c | |
parent | 53c16c75a57aa486dfc1f46ef5aa538264e6ad47 (diff) | |
download | emacs-d17e92da064cabf376597f5de2a8d5a6484bfea6.tar.gz |
Refactor uses of scroll_margin to a function
Its effective range needs to be clamped between 0 and (window height /
4), so it's better to have this constraint in a single place.
* src/window.c (window_scroll_margin): New function.
(window_scroll_pixel_based, window_scroll_line_based):
(Frecenter, Fmove_to_window_line):
* src/xdisp.c (try_scrolling, try_cursor_movement):
(redisplay_window, try_window, try_window_id): Use it.
Diffstat (limited to 'src/window.c')
-rw-r--r-- | src/window.c | 44 |
1 files changed, 28 insertions, 16 deletions
diff --git a/src/window.c b/src/window.c index bc3f488f37f..1c83d989aa8 100644 --- a/src/window.c +++ b/src/window.c @@ -4790,6 +4790,29 @@ window_scroll (Lisp_Object window, EMACS_INT n, bool whole, bool noerror) XWINDOW (window)->window_end_valid = false; } +/* Compute scroll margin for WINDOW. + We scroll when point is within this distance from the top or bottom + of the window. The result is measured in lines or in pixels + depending on the second parameter. */ +int +window_scroll_margin (struct window *window, enum margin_unit unit) +{ + if (scroll_margin > 0) + { + int frame_line_height = default_line_pixel_height (window); + int window_total_lines + = window->total_lines * WINDOW_FRAME_LINE_HEIGHT (window) + / frame_line_height; + int margin = min (scroll_margin, window_total_lines / 4); + if (unit == MARGIN_IN_PIXELS) + return margin * frame_line_height; + else + return margin; + } + else + return 0; +} + /* Implementation of window_scroll that works based on pixel line heights. See the comment of window_scroll for parameter @@ -4806,7 +4829,6 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, bool noerror) bool vscrolled = false; int x, y, rtop, rbot, rowh, vpos; void *itdata = NULL; - int window_total_lines; int frame_line_height = default_line_pixel_height (w); bool adjust_old_pointm = !NILP (Fequal (Fwindow_point (window), Fwindow_old_point (window))); @@ -5062,12 +5084,7 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, bool noerror) /* Move PT out of scroll margins. This code wants current_y to be zero at the window start position even if there is a header line. */ - window_total_lines - = w->total_lines * WINDOW_FRAME_LINE_HEIGHT (w) / frame_line_height; - this_scroll_margin = max (0, scroll_margin); - this_scroll_margin - = min (this_scroll_margin, window_total_lines / 4); - this_scroll_margin *= frame_line_height; + this_scroll_margin = window_scroll_margin (w, MARGIN_IN_PIXELS); if (n > 0) { @@ -5290,9 +5307,7 @@ window_scroll_line_based (Lisp_Object window, int n, bool whole, bool noerror) if (pos < ZV) { - /* Don't use a scroll margin that is negative or too large. */ - int this_scroll_margin = - max (0, min (scroll_margin, w->total_lines / 4)); + int this_scroll_margin = window_scroll_margin (w, MARGIN_IN_LINES); set_marker_restricted_both (w->start, w->contents, pos, pos_byte); w->start_at_line_beg = !NILP (bolp); @@ -5722,8 +5737,7 @@ and redisplay normally--don't erase and redraw the frame. */) /* Do this after making BUF current in case scroll_margin is buffer-local. */ - this_scroll_margin - = max (0, min (scroll_margin, w->total_lines / 4)); + this_scroll_margin = window_scroll_margin (w, MARGIN_IN_LINES); /* Don't use redisplay code for initial frames, as the necessary data structures might not be set up yet then. */ @@ -5962,10 +5976,6 @@ from the top of the window. */) lines = displayed_window_lines (w); -#if false - this_scroll_margin = max (0, min (scroll_margin, lines / 4)); -#endif - if (NILP (arg)) XSETFASTINT (arg, lines / 2); else @@ -5981,6 +5991,8 @@ from the top of the window. */) it is probably better not to install it. However, it is here inside #if false so as not to lose it. -- rms. */ + this_scroll_margin = window_scroll_margin (w, MARGIN_IN_LINES); + /* Don't let it get into the margin at either top or bottom. */ iarg = max (iarg, this_scroll_margin); iarg = min (iarg, lines - this_scroll_margin - 1); |