ListView: use checked subtraction between focus and scroll index
@@ -294,6 +294,7 @@ impl View for ListView {
.unwrap_or(0);
if self.children.len() > req.y {
+ // Include a scroll bar
Vec2::new(label_width + 1 + view_size + 2, req.y)
} else {
Vec2::new(label_width + 1 + view_size, self.children.len())
@@ -372,13 +373,18 @@ impl View for ListView {
// Send the event to the focused child.
let labels_width = self.labels_width();
if let ListChild::Row(_, ref mut view) = self.children[self.focus] {
- let y = self.focus - self.scrollbase.start_line;
+
+ // If self.focus < self.scrollbase.start_line, it means the focus is not
+ // in view. Something's fishy, so don't send the event.
+ if let Some(y) = self.focus.checked_sub(self.scrollbase.start_line) {
+
let offset = (labels_width + 1, y);
let result = view.on_event(event.relativized(offset));
if result.is_consumed() {
return result;
}
}
+ }
// If the child ignored this event, change the focus.
match event {
