zed/crates/gpui/src/elements/list.rs
Max Brunsfeld 94209d2b6d Rename rpc_client -> client
Co-Authored-By: Nathan Sobo <nathan@zed.dev>
2021-10-04 17:14:21 -07:00

891 lines
30 KiB
Rust

use crate::{
geometry::{
rect::RectF,
vector::{vec2f, Vector2F},
},
json::json,
DebugContext, Element, ElementBox, ElementRc, Event, EventContext, LayoutContext, PaintContext,
SizeConstraint,
};
use std::{cell::RefCell, collections::VecDeque, ops::Range, rc::Rc};
use sum_tree::{Bias, SumTree};
pub struct List {
state: ListState,
invalidated_elements: Vec<ElementRc>,
}
#[derive(Clone)]
pub struct ListState(Rc<RefCell<StateInner>>);
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum Orientation {
Top,
Bottom,
}
struct StateInner {
last_layout_width: Option<f32>,
render_item: Box<dyn FnMut(usize, &mut LayoutContext) -> ElementBox>,
rendered_range: Range<usize>,
items: SumTree<ListItem>,
logical_scroll_top: Option<ListOffset>,
orientation: Orientation,
overdraw: f32,
scroll_handler: Option<Box<dyn FnMut(Range<usize>, &mut EventContext)>>,
}
#[derive(Clone, Copy, Debug, Default, PartialEq)]
pub struct ListOffset {
item_ix: usize,
offset_in_item: f32,
}
#[derive(Clone)]
enum ListItem {
Unrendered,
Rendered(ElementRc),
Removed(f32),
}
impl std::fmt::Debug for ListItem {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
Self::Unrendered => write!(f, "Unrendered"),
Self::Rendered(_) => f.debug_tuple("Rendered").finish(),
Self::Removed(height) => f.debug_tuple("Removed").field(height).finish(),
}
}
}
#[derive(Clone, Debug, Default, PartialEq)]
struct ListItemSummary {
count: usize,
rendered_count: usize,
unrendered_count: usize,
height: f32,
}
#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
struct Count(usize);
#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
struct RenderedCount(usize);
#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
struct UnrenderedCount(usize);
#[derive(Clone, Debug, Default)]
struct Height(f32);
impl List {
pub fn new(state: ListState) -> Self {
Self {
state,
invalidated_elements: Default::default(),
}
}
}
impl Element for List {
type LayoutState = ListOffset;
type PaintState = ();
fn layout(
&mut self,
constraint: SizeConstraint,
cx: &mut LayoutContext,
) -> (Vector2F, Self::LayoutState) {
let state = &mut *self.state.0.borrow_mut();
let size = constraint.max;
let mut item_constraint = constraint;
item_constraint.min.set_y(0.);
item_constraint.max.set_y(f32::INFINITY);
if cx.refreshing || state.last_layout_width != Some(size.x()) {
state.rendered_range = 0..0;
state.items = SumTree::from_iter(
(0..state.items.summary().count).map(|_| ListItem::Unrendered),
&(),
)
}
let old_items = state.items.clone();
let mut new_items = SumTree::new();
let mut rendered_items = VecDeque::new();
let mut rendered_height = 0.;
let mut scroll_top = state
.logical_scroll_top
.unwrap_or_else(|| match state.orientation {
Orientation::Top => ListOffset {
item_ix: 0,
offset_in_item: 0.,
},
Orientation::Bottom => ListOffset {
item_ix: state.items.summary().count,
offset_in_item: 0.,
},
});
// Render items after the scroll top, including those in the trailing overdraw.
let mut cursor = old_items.cursor::<Count>();
cursor.seek(&Count(scroll_top.item_ix), Bias::Right, &());
for (ix, item) in cursor.by_ref().enumerate() {
if rendered_height - scroll_top.offset_in_item >= size.y() + state.overdraw {
break;
}
let element = state.render_item(scroll_top.item_ix + ix, item, item_constraint, cx);
rendered_height += element.size().y();
rendered_items.push_back(ListItem::Rendered(element));
}
// Prepare to start walking upward from the item at the scroll top.
cursor.seek(&Count(scroll_top.item_ix), Bias::Right, &());
// If the rendered items do not fill the visible region, then adjust
// the scroll top upward.
if rendered_height - scroll_top.offset_in_item < size.y() {
while rendered_height < size.y() {
cursor.prev(&());
if let Some(item) = cursor.item() {
let element = state.render_item(cursor.start().0, item, item_constraint, cx);
rendered_height += element.size().y();
rendered_items.push_front(ListItem::Rendered(element));
} else {
break;
}
}
scroll_top = ListOffset {
item_ix: cursor.start().0,
offset_in_item: rendered_height - size.y(),
};
match state.orientation {
Orientation::Top => {
scroll_top.offset_in_item = scroll_top.offset_in_item.max(0.);
state.logical_scroll_top = Some(scroll_top);
}
Orientation::Bottom => {
scroll_top = ListOffset {
item_ix: cursor.start().0,
offset_in_item: rendered_height - size.y(),
};
state.logical_scroll_top = None;
}
};
}
// Render items in the leading overdraw.
let mut leading_overdraw = scroll_top.offset_in_item;
while leading_overdraw < state.overdraw {
cursor.prev(&());
if let Some(item) = cursor.item() {
let element = state.render_item(cursor.start().0, item, item_constraint, cx);
leading_overdraw += element.size().y();
rendered_items.push_front(ListItem::Rendered(element));
} else {
break;
}
}
let new_rendered_range = cursor.start().0..(cursor.start().0 + rendered_items.len());
let mut cursor = old_items.cursor::<Count>();
if state.rendered_range.start < new_rendered_range.start {
new_items.push_tree(
cursor.slice(&Count(state.rendered_range.start), Bias::Right, &()),
&(),
);
let remove_to = state.rendered_range.end.min(new_rendered_range.start);
while cursor.start().0 < remove_to {
new_items.push(cursor.item().unwrap().remove(), &());
cursor.next(&());
}
}
new_items.push_tree(
cursor.slice(&Count(new_rendered_range.start), Bias::Right, &()),
&(),
);
new_items.extend(rendered_items, &());
cursor.seek(&Count(new_rendered_range.end), Bias::Right, &());
if new_rendered_range.end < state.rendered_range.start {
new_items.push_tree(
cursor.slice(&Count(state.rendered_range.start), Bias::Right, &()),
&(),
);
}
while cursor.start().0 < state.rendered_range.end {
new_items.push(cursor.item().unwrap().remove(), &());
cursor.next(&());
}
new_items.push_tree(cursor.suffix(&()), &());
state.items = new_items;
state.rendered_range = new_rendered_range;
state.last_layout_width = Some(size.x());
(size, scroll_top)
}
fn paint(
&mut self,
bounds: RectF,
visible_bounds: RectF,
scroll_top: &mut ListOffset,
cx: &mut PaintContext,
) {
cx.scene.push_layer(Some(bounds));
let state = &mut *self.state.0.borrow_mut();
for (mut element, origin) in state.visible_elements(bounds, scroll_top) {
element.paint(origin, visible_bounds, cx);
}
cx.scene.pop_layer();
}
fn dispatch_event(
&mut self,
event: &Event,
bounds: RectF,
scroll_top: &mut ListOffset,
_: &mut (),
cx: &mut EventContext,
) -> bool {
let mut handled = false;
let mut state = self.state.0.borrow_mut();
let mut item_origin = bounds.origin() - vec2f(0., scroll_top.offset_in_item);
let mut cursor = state.items.cursor::<Count>();
let mut new_items = cursor.slice(&Count(scroll_top.item_ix), Bias::Right, &());
while let Some(item) = cursor.item() {
if item_origin.y() > bounds.max_y() {
break;
}
if let ListItem::Rendered(element) = item {
let prev_notify_count = cx.notify_count();
let mut element = element.clone();
handled = element.dispatch_event(event, cx) || handled;
item_origin.set_y(item_origin.y() + element.size().y());
if cx.notify_count() > prev_notify_count {
new_items.push(ListItem::Unrendered, &());
self.invalidated_elements.push(element);
} else {
new_items.push(item.clone(), &());
}
cursor.next(&());
} else {
unreachable!();
}
}
new_items.push_tree(cursor.suffix(&()), &());
drop(cursor);
state.items = new_items;
match event {
Event::ScrollWheel {
position,
delta,
precise,
} => {
if bounds.contains_point(*position) {
if state.scroll(scroll_top, bounds.height(), *delta, *precise, cx) {
handled = true;
}
}
}
_ => {}
}
handled
}
fn debug(
&self,
bounds: RectF,
scroll_top: &Self::LayoutState,
_: &(),
cx: &DebugContext,
) -> serde_json::Value {
let state = self.state.0.borrow_mut();
let visible_elements = state
.visible_elements(bounds, scroll_top)
.map(|e| e.0.debug(cx))
.collect::<Vec<_>>();
let visible_range = scroll_top.item_ix..(scroll_top.item_ix + visible_elements.len());
json!({
"visible_range": visible_range,
"visible_elements": visible_elements,
"scroll_top": state.logical_scroll_top.map(|top| (top.item_ix, top.offset_in_item)),
})
}
}
impl ListState {
pub fn new<F>(
element_count: usize,
orientation: Orientation,
overdraw: f32,
render_item: F,
) -> Self
where
F: 'static + FnMut(usize, &mut LayoutContext) -> ElementBox,
{
let mut items = SumTree::new();
items.extend((0..element_count).map(|_| ListItem::Unrendered), &());
Self(Rc::new(RefCell::new(StateInner {
last_layout_width: None,
render_item: Box::new(render_item),
rendered_range: 0..0,
items,
logical_scroll_top: None,
orientation,
overdraw,
scroll_handler: None,
})))
}
pub fn reset(&self, element_count: usize) {
let state = &mut *self.0.borrow_mut();
state.rendered_range = 0..0;
state.logical_scroll_top = None;
state.items = SumTree::new();
state
.items
.extend((0..element_count).map(|_| ListItem::Unrendered), &());
}
pub fn splice(&self, old_range: Range<usize>, count: usize) {
let state = &mut *self.0.borrow_mut();
if let Some(ListOffset {
item_ix,
offset_in_item,
}) = state.logical_scroll_top.as_mut()
{
if old_range.contains(item_ix) {
*item_ix = old_range.start;
*offset_in_item = 0.;
} else if old_range.end <= *item_ix {
*item_ix = *item_ix - (old_range.end - old_range.start) + count;
}
}
let new_end = old_range.start + count;
if old_range.start < state.rendered_range.start {
state.rendered_range.start =
new_end + state.rendered_range.start.saturating_sub(old_range.end);
}
if old_range.start < state.rendered_range.end {
state.rendered_range.end =
new_end + state.rendered_range.end.saturating_sub(old_range.end);
}
let mut old_heights = state.items.cursor::<Count>();
let mut new_heights = old_heights.slice(&Count(old_range.start), Bias::Right, &());
old_heights.seek_forward(&Count(old_range.end), Bias::Right, &());
new_heights.extend((0..count).map(|_| ListItem::Unrendered), &());
new_heights.push_tree(old_heights.suffix(&()), &());
drop(old_heights);
state.items = new_heights;
}
pub fn set_scroll_handler(
&mut self,
handler: impl FnMut(Range<usize>, &mut EventContext) + 'static,
) {
self.0.borrow_mut().scroll_handler = Some(Box::new(handler))
}
}
impl StateInner {
fn render_item(
&mut self,
ix: usize,
existing_item: &ListItem,
constraint: SizeConstraint,
cx: &mut LayoutContext,
) -> ElementRc {
if let ListItem::Rendered(element) = existing_item {
element.clone()
} else {
let mut element = (self.render_item)(ix, cx);
element.layout(constraint, cx);
element.into()
}
}
fn visible_range(&self, height: f32, scroll_top: &ListOffset) -> Range<usize> {
let mut cursor = self.items.cursor::<ListItemSummary>();
cursor.seek(&Count(scroll_top.item_ix), Bias::Right, &());
let start_y = cursor.start().height + scroll_top.offset_in_item;
cursor.seek_forward(&Height(start_y + height), Bias::Left, &());
scroll_top.item_ix..cursor.start().count + 1
}
fn visible_elements<'a>(
&'a self,
bounds: RectF,
scroll_top: &ListOffset,
) -> impl Iterator<Item = (ElementRc, Vector2F)> + 'a {
let mut item_origin = bounds.origin() - vec2f(0., scroll_top.offset_in_item);
let mut cursor = self.items.cursor::<Count>();
cursor.seek(&Count(scroll_top.item_ix), Bias::Right, &());
std::iter::from_fn(move || {
while let Some(item) = cursor.item() {
if item_origin.y() > bounds.max_y() {
break;
}
if let ListItem::Rendered(element) = item {
let result = (element.clone(), item_origin);
item_origin.set_y(item_origin.y() + element.size().y());
cursor.next(&());
return Some(result);
}
cursor.next(&());
}
None
})
}
fn scroll(
&mut self,
scroll_top: &ListOffset,
height: f32,
mut delta: Vector2F,
precise: bool,
cx: &mut EventContext,
) -> bool {
if !precise {
delta *= 20.;
}
let scroll_max = (self.items.summary().height - height).max(0.);
let new_scroll_top = (self.scroll_top(scroll_top) - delta.y())
.max(0.)
.min(scroll_max);
if self.orientation == Orientation::Bottom && new_scroll_top == scroll_max {
self.logical_scroll_top = None;
} else {
let mut cursor = self.items.cursor::<ListItemSummary>();
cursor.seek(&Height(new_scroll_top), Bias::Right, &());
let item_ix = cursor.start().count;
let offset_in_item = new_scroll_top - cursor.start().height;
self.logical_scroll_top = Some(ListOffset {
item_ix,
offset_in_item,
});
}
if self.scroll_handler.is_some() {
let visible_range = self.visible_range(height, scroll_top);
self.scroll_handler.as_mut().unwrap()(visible_range, cx);
}
cx.notify();
true
}
fn scroll_top(&self, logical_scroll_top: &ListOffset) -> f32 {
let mut cursor = self.items.cursor::<ListItemSummary>();
cursor.seek(&Count(logical_scroll_top.item_ix), Bias::Right, &());
cursor.start().height + logical_scroll_top.offset_in_item
}
}
impl ListItem {
fn remove(&self) -> Self {
match self {
ListItem::Unrendered => ListItem::Unrendered,
ListItem::Rendered(element) => ListItem::Removed(element.size().y()),
ListItem::Removed(height) => ListItem::Removed(*height),
}
}
}
impl sum_tree::Item for ListItem {
type Summary = ListItemSummary;
fn summary(&self) -> Self::Summary {
match self {
ListItem::Unrendered => ListItemSummary {
count: 1,
rendered_count: 0,
unrendered_count: 1,
height: 0.,
},
ListItem::Rendered(element) => ListItemSummary {
count: 1,
rendered_count: 1,
unrendered_count: 0,
height: element.size().y(),
},
ListItem::Removed(height) => ListItemSummary {
count: 1,
rendered_count: 0,
unrendered_count: 1,
height: *height,
},
}
}
}
impl sum_tree::Summary for ListItemSummary {
type Context = ();
fn add_summary(&mut self, summary: &Self, _: &()) {
self.count += summary.count;
self.rendered_count += summary.rendered_count;
self.unrendered_count += summary.unrendered_count;
self.height += summary.height;
}
}
impl<'a> sum_tree::Dimension<'a, ListItemSummary> for Count {
fn add_summary(&mut self, summary: &'a ListItemSummary, _: &()) {
self.0 += summary.count;
}
}
impl<'a> sum_tree::Dimension<'a, ListItemSummary> for RenderedCount {
fn add_summary(&mut self, summary: &'a ListItemSummary, _: &()) {
self.0 += summary.rendered_count;
}
}
impl<'a> sum_tree::Dimension<'a, ListItemSummary> for UnrenderedCount {
fn add_summary(&mut self, summary: &'a ListItemSummary, _: &()) {
self.0 += summary.unrendered_count;
}
}
impl<'a> sum_tree::Dimension<'a, ListItemSummary> for Height {
fn add_summary(&mut self, summary: &'a ListItemSummary, _: &()) {
self.0 += summary.height;
}
}
impl<'a> sum_tree::SeekTarget<'a, ListItemSummary, ListItemSummary> for Count {
fn cmp(&self, other: &ListItemSummary, _: &()) -> std::cmp::Ordering {
self.0.partial_cmp(&other.count).unwrap()
}
}
impl<'a> sum_tree::SeekTarget<'a, ListItemSummary, ListItemSummary> for Height {
fn cmp(&self, other: &ListItemSummary, _: &()) -> std::cmp::Ordering {
self.0.partial_cmp(&other.height).unwrap()
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::geometry::vector::vec2f;
use rand::prelude::*;
use std::env;
#[crate::test(self)]
fn test_layout(cx: &mut crate::MutableAppContext) {
let mut presenter = cx.build_presenter(0, 0.);
let constraint = SizeConstraint::new(vec2f(0., 0.), vec2f(100., 40.));
let elements = Rc::new(RefCell::new(vec![(0, 20.), (1, 30.), (2, 100.)]));
let state = ListState::new(elements.borrow().len(), Orientation::Top, 1000.0, {
let elements = elements.clone();
move |ix, _| {
let (id, height) = elements.borrow()[ix];
TestElement::new(id, height).boxed()
}
});
let mut list = List::new(state.clone());
let (size, _) = list.layout(constraint, &mut presenter.build_layout_context(false, cx));
assert_eq!(size, vec2f(100., 40.));
assert_eq!(
state.0.borrow().items.summary(),
ListItemSummary {
count: 3,
rendered_count: 3,
unrendered_count: 0,
height: 150.
}
);
state.0.borrow_mut().scroll(
&ListOffset {
item_ix: 0,
offset_in_item: 0.,
},
40.,
vec2f(0., -54.),
true,
&mut presenter.build_event_context(cx),
);
let (_, logical_scroll_top) =
list.layout(constraint, &mut presenter.build_layout_context(false, cx));
assert_eq!(
logical_scroll_top,
ListOffset {
item_ix: 2,
offset_in_item: 4.
}
);
assert_eq!(state.0.borrow().scroll_top(&logical_scroll_top), 54.);
elements.borrow_mut().splice(1..2, vec![(3, 40.), (4, 50.)]);
elements.borrow_mut().push((5, 60.));
state.splice(1..2, 2);
state.splice(4..4, 1);
assert_eq!(
state.0.borrow().items.summary(),
ListItemSummary {
count: 5,
rendered_count: 2,
unrendered_count: 3,
height: 120.
}
);
let (size, logical_scroll_top) =
list.layout(constraint, &mut presenter.build_layout_context(false, cx));
assert_eq!(size, vec2f(100., 40.));
assert_eq!(
state.0.borrow().items.summary(),
ListItemSummary {
count: 5,
rendered_count: 5,
unrendered_count: 0,
height: 270.
}
);
assert_eq!(
logical_scroll_top,
ListOffset {
item_ix: 3,
offset_in_item: 4.
}
);
assert_eq!(state.0.borrow().scroll_top(&logical_scroll_top), 114.);
}
#[crate::test(self, iterations = 10, 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"))
.unwrap_or(10);
let mut presenter = cx.build_presenter(0, 0.);
let mut next_id = 0;
let elements = Rc::new(RefCell::new(
(0..rng.gen_range(0..=20))
.map(|_| {
let id = next_id;
next_id += 1;
(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..=100) as f32;
let state = ListState::new(elements.borrow().len(), orientation, overdraw, {
let elements = elements.clone();
move |ix, _| {
let (id, height) = elements.borrow()[ix];
TestElement::new(id, height).boxed()
}
});
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());
log::info!("size: ({:?}, {:?})", width, height);
log::info!("==================");
let mut last_logical_scroll_top = None;
for _ in 0..operations {
match rng.gen_range(0..=100) {
0..=29 if last_logical_scroll_top.is_some() => {
let delta = vec2f(0., rng.gen_range(-overdraw..=overdraw));
log::info!(
"Scrolling by {:?}, previous scroll top: {:?}",
delta,
last_logical_scroll_top.unwrap()
);
state.0.borrow_mut().scroll(
last_logical_scroll_top.as_ref().unwrap(),
height,
delta,
true,
&mut presenter.build_event_context(cx),
);
}
30..=34 => {
width = rng.gen_range(0..=2000) as f32 / 2.;
log::info!("changing width: {:?}", width);
}
35..=54 => {
height = rng.gen_range(0..=1000) as f32 / 2.;
log::info!("changing height: {:?}", height);
}
_ => {
let mut elements = elements.borrow_mut();
let end_ix = rng.gen_range(0..=elements.len());
let start_ix = rng.gen_range(0..=end_ix);
let new_elements = (0..rng.gen_range(0..10))
.map(|_| {
let id = next_id;
next_id += 1;
(id, rng.gen_range(0..=200) as f32 / 2.)
})
.collect::<Vec<_>>();
log::info!("splice({:?}, {:?})", start_ix..end_ix, new_elements);
state.splice(start_ix..end_ix, new_elements.len());
elements.splice(start_ix..end_ix, new_elements);
for (ix, item) in state.0.borrow().items.cursor::<()>().enumerate() {
if let ListItem::Rendered(element) = item {
let (expected_id, _) = elements[ix];
element.with_metadata(|metadata: Option<&usize>| {
assert_eq!(*metadata.unwrap(), expected_id);
});
}
}
}
}
let mut list = List::new(state.clone());
let (size, logical_scroll_top) = list.layout(
SizeConstraint::new(vec2f(0., 0.), vec2f(width, height)),
&mut presenter.build_layout_context(false, cx),
);
assert_eq!(size, vec2f(width, height));
last_logical_scroll_top = Some(logical_scroll_top);
let state = state.0.borrow();
log::info!("items {:?}", state.items.items(&()));
let scroll_top = state.scroll_top(&logical_scroll_top);
let rendered_top = (scroll_top - overdraw).max(0.);
let rendered_bottom = scroll_top + height + overdraw;
let mut item_top = 0.;
log::info!(
"rendered top {:?}, rendered bottom {:?}, scroll top {:?}",
rendered_top,
rendered_bottom,
scroll_top,
);
let mut first_rendered_element_top = None;
let mut last_rendered_element_bottom = None;
assert_eq!(state.items.summary().count, elements.borrow().len());
for (ix, item) in state.items.cursor::<()>().enumerate() {
match item {
ListItem::Unrendered => {
let item_bottom = item_top;
assert!(item_bottom <= rendered_top || item_top >= rendered_bottom);
item_top = item_bottom;
}
ListItem::Removed(height) => {
let (id, expected_height) = elements.borrow()[ix];
assert_eq!(
*height, expected_height,
"element {} height didn't match",
id
);
let item_bottom = item_top + height;
assert!(item_bottom <= rendered_top || item_top >= rendered_bottom);
item_top = item_bottom;
}
ListItem::Rendered(element) => {
let (expected_id, expected_height) = elements.borrow()[ix];
element.with_metadata(|metadata: Option<&usize>| {
assert_eq!(*metadata.unwrap(), expected_id);
});
assert_eq!(element.size().y(), expected_height);
let item_bottom = item_top + element.size().y();
first_rendered_element_top.get_or_insert(item_top);
last_rendered_element_bottom = Some(item_bottom);
assert!(item_bottom > rendered_top || item_top < rendered_bottom);
item_top = item_bottom;
}
}
}
match orientation {
Orientation::Top => {
if let Some(first_rendered_element_top) = first_rendered_element_top {
assert!(first_rendered_element_top <= scroll_top);
}
}
Orientation::Bottom => {
if let Some(last_rendered_element_bottom) = last_rendered_element_bottom {
assert!(last_rendered_element_bottom >= scroll_top + height);
}
}
}
}
}
struct TestElement {
id: usize,
size: Vector2F,
}
impl TestElement {
fn new(id: usize, height: f32) -> Self {
Self {
id,
size: vec2f(100., height),
}
}
}
impl Element for TestElement {
type LayoutState = ();
type PaintState = ();
fn layout(&mut self, _: SizeConstraint, _: &mut LayoutContext) -> (Vector2F, ()) {
(self.size, ())
}
fn paint(&mut self, _: RectF, _: RectF, _: &mut (), _: &mut PaintContext) {
todo!()
}
fn dispatch_event(
&mut self,
_: &Event,
_: RectF,
_: &mut (),
_: &mut (),
_: &mut EventContext,
) -> bool {
todo!()
}
fn debug(&self, _: RectF, _: &(), _: &(), _: &DebugContext) -> serde_json::Value {
self.id.into()
}
fn metadata(&self) -> Option<&dyn std::any::Any> {
Some(&self.id)
}
}
}