119aa452b6
Now the Element trait is designed to be wrapped in a Lifecycle enum that gets placed inside an ElementBox. This allows the framework to store data on behalf of the Element implementation, such as sizes, bounds, and also implementation-specific LayoutState and PaintState types. This makes it easier to reason about which data is available in each Element method.
47 lines
987 B
Rust
47 lines
987 B
Rust
use crate::{
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AfterLayoutContext, Element, Event, EventContext, LayoutContext, PaintContext, SizeConstraint,
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};
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use pathfinder_geometry::{rect::RectF, vector::Vector2F};
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pub struct Empty;
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impl Empty {
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pub fn new() -> Self {
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Self
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}
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}
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impl Element for Empty {
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type LayoutState = ();
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type PaintState = ();
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fn layout(
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&mut self,
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constraint: SizeConstraint,
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_: &mut LayoutContext,
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) -> (Vector2F, Self::LayoutState) {
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(constraint.max, ())
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}
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fn after_layout(&mut self, _: Vector2F, _: &mut Self::LayoutState, _: &mut AfterLayoutContext) {
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}
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fn paint(
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&mut self,
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_: RectF,
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_: &mut Self::LayoutState,
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_: &mut PaintContext,
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) -> Self::PaintState {
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}
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fn dispatch_event(
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&mut self,
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_: &Event,
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_: RectF,
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_: &mut Self::LayoutState,
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_: &mut Self::PaintState,
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_: &mut EventContext,
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) -> bool {
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false
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}
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}
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