@@ -181,27 +181,47 @@ impl Element for List {
}
rendered_items.reverse();
+ let mut adjust_scroll_top = (rendered_height - scroll_top.offset_in_item) < size.y();
+
new_rendered_start_ix = scroll_top.item_ix;
cursor.seek(&Count(scroll_top.item_ix), Bias::Right, &());
cursor.prev(&());
let mut remaining_overdraw = overdraw - scroll_top.offset_in_item;
+
+ if adjust_scroll_top && rendered_height >= size.y() {
+ let offset_in_item = rendered_height - size.y();
+ stored_scroll_top = Some(ScrollTop {
+ item_ix: new_rendered_start_ix,
+ offset_in_item,
+ });
+ remaining_overdraw = overdraw - offset_in_item;
+ adjust_scroll_top = false;
+ }
+
while let Some(item) = cursor.item() {
let element = render_item(cursor.seek_start().0, item);
- if rendered_height < size.y() && rendered_height + element.size().y() >= size.y() {
- let new_scroll_top = ScrollTop {
- item_ix: cursor.seek_start().0,
- offset_in_item: rendered_height + element.size().y() - size.y(),
- };
- stored_scroll_top = Some(new_scroll_top);
- remaining_overdraw = overdraw + (size.y() - rendered_height);
- } else if rendered_height >= size.y() && remaining_overdraw <= 0. {
+ let next_rendered_height = rendered_height + element.size().y();
+
+ if adjust_scroll_top && next_rendered_height >= size.y() {
+ let offset_in_item = next_rendered_height - size.y();
+ stored_scroll_top = Some(ScrollTop {
+ item_ix: new_rendered_start_ix - 1,
+ offset_in_item,
+ });
+ remaining_overdraw = overdraw + (element.size().y() - offset_in_item);
+ adjust_scroll_top = false;
+ }
+
+ if !adjust_scroll_top && remaining_overdraw <= 0. {
break;
}
- rendered_height += element.size().y();
+ rendered_height = next_rendered_height;
remaining_overdraw -= element.size().y();
rendered_items.push(ListItem::Rendered(element));
+
new_rendered_start_ix -= 1;
+
cursor.prev(&());
}
rendered_items.reverse();
@@ -492,7 +512,9 @@ impl StateInner {
{
let mut cursor = self.items.cursor::<Count, Height>();
cursor.seek(&Count(item_ix), Bias::Right, &());
- (cursor.sum_start().0 + offset_in_item).min(scroll_max)
+ let scroll_top = cursor.sum_start().0 + offset_in_item;
+ assert!(scroll_top <= scroll_max);
+ scroll_top
} else {
match self.orientation {
Orientation::Top => 0.,
@@ -680,7 +702,7 @@ mod tests {
assert_eq!(state.0.borrow().scroll_top(size.y()), 114.);
}
- #[crate::test(self, iterations = 10000)]
+ #[crate::test(self, iterations = 10000, seed = 0)]
fn test_random(cx: &mut crate::MutableAppContext, mut rng: StdRng) {
let operations = env::var("OPERATIONS")
.map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
@@ -693,14 +715,14 @@ mod tests {
.map(|_| {
let id = next_id;
next_id += 1;
- (id, rng.gen_range(0_f32..=100_f32))
+ (id, rng.gen_range(0..=200) as f32 / 2.0)
})
.collect::<Vec<_>>(),
));
let orientation = *[Orientation::Top, Orientation::Bottom]
.choose(&mut rng)
.unwrap();
- let overdraw = rng.gen_range(1_f32..=100_f32);
+ let overdraw = rng.gen_range(1..=100) as f32;
let state = ListState::new(elements.borrow().len(), orientation, overdraw, {
let elements = elements.clone();
move |ix, _| {
@@ -709,8 +731,8 @@ mod tests {
}
});
- let mut width = rng.gen_range(0_f32..=1000_f32);
- let mut height = rng.gen_range(0_f32..=1000_f32);
+ let mut width = rng.gen_range(0..=2000) as f32 / 2.;
+ let mut height = rng.gen_range(0..=2000) as f32 / 2.;
log::info!("orientation: {:?}", orientation);
log::info!("overdraw: {}", overdraw);
log::info!("elements: {:?}", elements.borrow());
@@ -736,11 +758,11 @@ mod tests {
);
}
30..=34 => {
- width = rng.gen_range(0_f32..=1000_f32);
+ width = rng.gen_range(0..=2000) as f32 / 2.;
log::info!("changing width: {:?}", width);
}
35..=54 => {
- height = rng.gen_range(0_f32..=1000_f32);
+ height = rng.gen_range(0..=1000) as f32 / 2.;
log::info!("changing height: {:?}", height);
}
_ => {
@@ -751,7 +773,7 @@ mod tests {
.map(|_| {
let id = next_id;
next_id += 1;
- (id, rng.gen_range(0_f32..=100_f32))
+ (id, rng.gen_range(0..=200) as f32 / 2.)
})
.collect::<Vec<_>>();
log::info!("splice({:?}, {:?})", start_ix..end_ix, new_elements);
@@ -777,15 +799,18 @@ mod tests {
scroll_top = Some(new_scroll_top);
let state = state.0.borrow();
+ log::info!("items {:?}", state.items.items(&()));
+
let rendered_top = (state.scroll_top(height) - overdraw).max(0.);
let rendered_bottom = state.scroll_top(height) + height + overdraw;
let mut item_top = 0.;
+
log::info!(
"rendered top {:?}, rendered bottom {:?}",
rendered_top,
rendered_bottom
);
- log::info!("items {:?}", state.items.items(&()));
+
assert_eq!(state.items.summary().count, elements.borrow().len());
for (ix, item) in state.items.cursor::<(), ()>().enumerate() {
match item {