1 files changed, 32 insertions, 17 deletions

diff --git a/tui/widget/list/scrolllist.ha b/tui/widget/list/scrolllist.ha
index d08c7d7..fed58a5 100644
--- a/tui/widget/list/scrolllist.ha
+++ b/tui/widget/list/scrolllist.ha
@@ -4,12 +4,13 @@ use io;
 use unix::tty;
 use memio;
 use strings;
+use fmt;
 
 export type scrolllist = struct {
 	widget: widget::widget,
 	items: []str,
 	frame: frame,
-	cursor: u16,
+	cursor: int,
 };
 
 // Return an instance of list. out is the tty file, pos the starting position,
@@ -26,9 +27,10 @@ style: (*widget::style | void), items: str...) (scrolllist | tty::error) = {
 	case void =>
 		yield tsz.rows - 1;
 	};
+	let end = end: int;
 
-	if (end > len(items)) {
-		end = len(items): u16;
+	if (end > len(items): int) {
+		end = len(items): int;
 	};
 
 	return scrolllist {
@@ -48,12 +50,16 @@ style: (*widget::style | void), items: str...) (scrolllist | tty::error) = {
 			start = 0,
 			end = end,
 		},
-		cursor = 0u16,
+		cursor = 0,
 	};
 };
 
 fn printscrolllist(widget: *widget::widget) void = {
 	const list = widget: *scrolllist;
+	assert(list.frame.start >= 0);
+	assert(list.frame.end <= len(list.items): int);
+	fmt::errorln(list.frame.start)!;
+	fmt::errorln(list.frame.end)!;
 	list.widget.buf = widget::linesbuf {
 		lines = list.items[list.frame.start..list.frame.end],
 		styles = &stylesscrolllist,
@@ -73,7 +79,7 @@ export fn down(li: *scrolllist) void = {
 	if (li.cursor == li.frame.end - 1) {
 		framedown(li);
 	};
-	if (li.cursor < len(li.items) - 1) {
+	if (li.cursor < len(li.items): int - 1) {
 		li.cursor += 1;
 	};
 };
@@ -95,7 +101,7 @@ export fn frameup(li: *scrolllist) void = {
 };
 
 export fn framedown(li: *scrolllist) void = {
-	if (li.frame.end < len(li.items)) {
+	if (li.frame.end < len(li.items): int) {
 		li.frame.start += 1;
 		li.frame.end += 1;
 	};
@@ -110,12 +116,12 @@ export fn top(li: *scrolllist) void = {
 
 export fn bottom(li: *scrolllist) void = {
 	const sz = li.frame.end - li.frame.start;
-	li.cursor = len(li.items): u16 - 1;
-	li.frame.end = len(li.items): u16;
-	li.frame.start = len(li.items): u16 - sz;
+	li.cursor = len(li.items): int - 1;
+	li.frame.end = len(li.items): int;
+	li.frame.start = len(li.items): int - sz;
 };
 
-export fn setcursor(li: *scrolllist, newpos: u16) void = {
+export fn setcursor(li: *scrolllist, newpos: int) void = {
 	li.cursor = newpos;
 	reframe(li);
 };
@@ -123,19 +129,28 @@ export fn setcursor(li: *scrolllist, newpos: u16) void = {
 fn reframe(li: *scrolllist) void = {
 	if (li.cursor > li.frame.end) {
 		const diff = li.frame.end - li.frame.start;
-		li.frame.start = li.cursor;
-		li.frame.end = li.frame.start + diff;
-	};
-	if (li.cursor < li.frame.start) {
+		li.frame.start = if (li.cursor <= len(li.items): int - diff) li.cursor else len(li.items): int - diff;
+		li.frame.end = if (li.frame.start + diff > len(li.items): int) {
+			yield len(li.items): int;
+		} else {
+			yield li.frame.start + diff;
+		};
+	} else if (li.cursor < li.frame.start) {
 		const diff = li.frame.end - li.frame.start;
-		li.frame.end = li.cursor;
-		li.frame.start = li.frame.end - diff;
+		li.frame.end = if (li.cursor > diff) li.cursor else diff;
+		li.frame.start = if (li.frame.end - diff < 0) {
+			yield 0;
+		} else {
+			yield li.frame.end - diff;
+		};
 	};
+	assert(li.frame.start >= 0);
+	assert(li.frame.end <= len(li.items): int);
 };
 
 fn stylesscrolllist(widget: *widget::widget, txt: str, idx: size) str = {
 	const list = widget: *scrolllist;
-	const idx = idx + list.frame.start;
+	const idx = idx: int + list.frame.start;
 	let st = memio::dynamic();
 	defer io::close(&st)!;
 	if (idx == list.cursor) {