only draw visible lines

1 files changed, 13 insertions, 1 deletions

diff --git a/ui.c b/ui.c
index 6080f13..e4d2c30 100644
--- a/ui.c
+++ b/ui.c
@@ -158,7 +158,19 @@ ui_draw(Str input, int inpi, int seli, UiOpts o)
 
 	XSetFont(dsp, gc, freg->fid);
 	int y = 64;
-	for (int i = 0; i < o.n; i++) {
+
+	int lines = (attr.height - 32) / 24;
+	int tline = lines / 2;
+	int bline = lines - tline;
+	int scroll = seli;
+	if (scroll > o.n - bline) scroll = o.n - bline;
+	if (scroll < tline) scroll = tline;
+	int top = scroll - tline;
+	int bot = scroll + bline;
+	if (top < 0) top = 0;
+	if (bot > o.n) bot = o.n;
+
+	for (int i = top; i < bot; i++) {
 		if (i == seli) {
 			int w = XTextWidth(freg, o.v[i].s, o.v[i].n);
 			XFillRectangle(dsp, win, gc,