StratoSDK is a framework with a declarative approach similar to Flutter/React, written and designed entirely for Rust.
| 1 | use pathfinder_geometry::vector::Vector2F; |
| 2 | |
| 3 | use super::Point; |
| 4 | use crate::{ |
| 5 | event::DispatchedEvent, AfterLayoutContext, AppContext, ClipBounds, Element, EventContext, |
| 6 | LayoutContext, PaintContext, SizeConstraint, |
| 7 | }; |
| 8 | use std::any::Any; |
| 9 | |
| 10 | /// Element that clips a child to its bounds |
| 11 | pub struct Clipped { |
| 12 | origin: Option<Point>, |
| 13 | size: Option<Vector2F>, |
| 14 | child: Box<dyn Element>, |
| 15 | } |
| 16 | |
| 17 | impl Clipped { |
| 18 | pub fn new(child: Box<dyn Element>) -> Self { |
| 19 | Self { |
| 20 | origin: None, |
| 21 | size: None, |
| 22 | child, |
| 23 | } |
| 24 | } |
| 25 | |
| 26 | pub fn sized(child: Box<dyn Element>, size: Vector2F) -> Self { |
| 27 | Self { |
| 28 | origin: None, |
| 29 | size: Some(size), |
| 30 | child, |
| 31 | } |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | impl Element for Clipped { |
| 36 | fn layout( |
| 37 | &mut self, |
| 38 | constraint: SizeConstraint, |
| 39 | ctx: &mut LayoutContext, |
| 40 | app: &AppContext, |
| 41 | ) -> Vector2F { |
| 42 | self.child.layout(constraint, ctx, app) |
| 43 | } |
| 44 | |
| 45 | fn after_layout(&mut self, ctx: &mut AfterLayoutContext, app: &AppContext) { |
| 46 | self.child.after_layout(ctx, app); |
| 47 | } |
| 48 | |
| 49 | fn paint(&mut self, origin: Vector2F, ctx: &mut PaintContext, app: &AppContext) { |
| 50 | let origin_point = Point::from_vec2f(origin, ctx.scene.z_index()); |
| 51 | self.origin = Some(origin_point); |
| 52 | |
| 53 | // Get current clip bounds (if any) to ensure that the next layer respects them. |
| 54 | let current_bounds = ctx.scene.visible_rect( |
| 55 | origin_point, |
| 56 | self.size() |
| 57 | .expect("Clipped element should have a size at time of paint"), |
| 58 | ); |
| 59 | |
| 60 | // Clipping works by creating a separate layer for an element with clip bounds. |
| 61 | // If current_bounds is None, this means that we shouldn't paint anything. |
| 62 | if let Some(bounds) = current_bounds { |
| 63 | ctx.scene.start_layer(ClipBounds::BoundedBy(bounds)); |
| 64 | self.child.paint(origin, ctx, app); |
| 65 | ctx.scene.stop_layer(); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | fn dispatch_event( |
| 70 | &mut self, |
| 71 | event: &DispatchedEvent, |
| 72 | ctx: &mut EventContext, |
| 73 | app: &AppContext, |
| 74 | ) -> bool { |
| 75 | // Only dispatch the event to the child if it has been painted. |
| 76 | self.child.origin().is_some() && self.child.dispatch_event(event, ctx, app) |
| 77 | } |
| 78 | |
| 79 | fn size(&self) -> Option<Vector2F> { |
| 80 | self.size.or_else(|| self.child.size()) |
| 81 | } |
| 82 | |
| 83 | fn origin(&self) -> Option<Point> { |
| 84 | self.origin |
| 85 | } |
| 86 | |
| 87 | fn parent_data(&self) -> Option<&dyn Any> { |
| 88 | self.child.parent_data() |
| 89 | } |
| 90 | |
| 91 | #[cfg(any(test, feature = "test-util"))] |
| 92 | fn debug_text_content(&self) -> Option<String> { |
| 93 | self.child.debug_text_content() |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | #[cfg(test)] |
| 98 | #[path = "clipped_test.rs"] |
| 99 | mod tests; |
| 100 |