move component into gpui

crates/gpui/src/elements/component.rs

@@ -0,0 +1,87 @@
+use std::marker::PhantomData;
+
+use pathfinder_geometry::{rect::RectF, vector::Vector2F};
+
+use crate::{
+    AnyElement, Element, LayoutContext, PaintContext, SceneBuilder, SizeConstraint, View,
+    ViewContext,
+};
+
+pub trait Component<V: View> {
+    fn render(self, v: &mut V, cx: &mut ViewContext<V>) -> AnyElement<V>;
+
+    fn into_element(self) -> ComponentAdapter<V, Self>
+    where
+        Self: Sized,
+    {
+        ComponentAdapter::new(self)
+    }
+}
+
+pub struct ComponentAdapter<V, E> {
+    component: Option<E>,
+    phantom: PhantomData<V>,
+}
+
+impl<E, V> ComponentAdapter<V, E> {
+    pub fn new(e: E) -> Self {
+        Self {
+            component: Some(e),
+            phantom: PhantomData,
+        }
+    }
+}
+
+impl<V: View, C: Component<V> + 'static> Element<V> for ComponentAdapter<V, C> {
+    type LayoutState = AnyElement<V>;
+
+    type PaintState = ();
+
+    fn layout(
+        &mut self,
+        constraint: SizeConstraint,
+        view: &mut V,
+        cx: &mut LayoutContext<V>,
+    ) -> (Vector2F, Self::LayoutState) {
+        let component = self.component.take().unwrap();
+        let mut element = component.render(view, cx.view_context());
+        let constraint = element.layout(constraint, view, cx);
+        (constraint, element)
+    }
+
+    fn paint(
+        &mut self,
+        scene: &mut SceneBuilder,
+        bounds: RectF,
+        visible_bounds: RectF,
+        layout: &mut Self::LayoutState,
+        view: &mut V,
+        cx: &mut PaintContext<V>,
+    ) -> Self::PaintState {
+        layout.paint(scene, bounds.origin(), visible_bounds, view, cx)
+    }
+
+    fn rect_for_text_range(
+        &self,
+        range_utf16: std::ops::Range<usize>,
+        _: RectF,
+        _: RectF,
+        element: &Self::LayoutState,
+        _: &Self::PaintState,
+        view: &V,
+        cx: &ViewContext<V>,
+    ) -> Option<RectF> {
+        element.rect_for_text_range(range_utf16, view, cx)
+    }
+
+    fn debug(
+        &self,
+        _: RectF,
+        element: &Self::LayoutState,
+        _: &Self::PaintState,
+        view: &V,
+        cx: &ViewContext<V>,
+    ) -> serde_json::Value {
+        element.debug(view, cx)
+    }
+}