Obey line length while scrolling - scroll - scrollbackbuffer program for st
(HTM) git clone git://git.suckless.org/scroll
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---
(DIR) commit 247a9b042655291ab64aa9c43f9e89d820e932ee
(DIR) parent 6d1a3bbbb870a303b47f790ba76146e61a4c7b6a
(HTM) Author: Jochen Sprickerhof <git@jochen.sprickerhof.de>
Date: Wed, 29 Apr 2020 23:46:11 +0200
Obey line length while scrolling
Diffstat:
M scroll.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
---
(DIR) diff --git a/scroll.c b/scroll.c
@@ -295,7 +295,7 @@ redraw()
void
scrollup(int n)
{
- int rows = 2, x, y;
+ int rows = 2, x, y, extra = 0;
struct line *scrollend = bottom;
if (bottom == NULL)
@@ -306,18 +306,24 @@ scrollup(int n)
if (n < 0) /* scroll by fraction of ws.ws_row, but at least one line */
n = ws.ws_row > (-n) ? ws.ws_row / (-n) : 1;
- /* wind back scrollend pointer by one page plus n */
- for (; TAILQ_NEXT(scrollend, entries) != NULL &&
- rows < y + n; rows++)
+ /* wind back scrollend pointer by the current screen */
+ while (rows < y && TAILQ_NEXT(scrollend, entries) != NULL) {
scrollend = TAILQ_NEXT(scrollend, entries);
-
- rows -= y;
+ rows += (scrollend->len - 1) / ws.ws_col + 1;
+ }
if (rows <= 0)
return;
+ /* wind back scrollend pointer n lines */
+ for (rows = 0; rows + extra < n &&
+ TAILQ_NEXT(scrollend, entries) != NULL; rows++) {
+ scrollend = TAILQ_NEXT(scrollend, entries);
+ extra += (scrollend->len - 1) / ws.ws_col;
+ }
+
/* move the text in terminal rows lines down */
- dprintf(STDOUT_FILENO, "\033[%dT", rows);
+ dprintf(STDOUT_FILENO, "\033[%dT", n);
/* set cursor position to upper left corner */
write(STDOUT_FILENO, "\033[0;0H", 6);
/* hide cursor */
@@ -357,9 +363,10 @@ scrolldown(char *buf, size_t size, int n)
bottom = TAILQ_PREV(bottom, tailhead, entries);
/* print n lines */
- for (; n > 0 && bottom != NULL && bottom != TAILQ_FIRST(&head); n--) {
+ while (n > 0 && bottom != NULL && bottom != TAILQ_FIRST(&head)) {
bottom = TAILQ_PREV(bottom, tailhead, entries);
write(STDOUT_FILENO, bottom->buf, bottom->size);
+ n -= (bottom->len - 1) / ws.ws_col + 1;
}
if (n > 0 && bottom == TAILQ_FIRST(&head)) {
write(STDOUT_FILENO, "\033[?25h", 6); /* show cursor */