Ungate responsive from the lazy feature flag

widget/src/responsive.rs

@@ -0,0 +1,192 @@
+use crate::core::layout::{self, Layout};
+use crate::core::mouse;
+use crate::core::overlay;
+use crate::core::renderer;
+use crate::core::widget;
+use crate::core::widget::tree::{self, Tree};
+use crate::core::{
+    self, Clipboard, Element, Event, Length, Rectangle, Shell, Size, Vector,
+    Widget,
+};
+use crate::horizontal_space;
+
+/// A widget that is aware of its dimensions.
+///
+/// A [`Responsive`] widget will always try to fill all the available space of
+/// its parent.
+#[allow(missing_debug_implementations)]
+pub struct Responsive<
+    'a,
+    Message,
+    Theme = crate::Theme,
+    Renderer = crate::Renderer,
+> {
+    view: Box<dyn Fn(Size) -> Element<'a, Message, Theme, Renderer> + 'a>,
+    content: Element<'a, Message, Theme, Renderer>,
+}
+
+impl<'a, Message, Theme, Renderer> Responsive<'a, Message, Theme, Renderer>
+where
+    Renderer: core::Renderer,
+{
+    /// Creates a new [`Responsive`] widget with a closure that produces its
+    /// contents.
+    ///
+    /// The `view` closure will be provided with the current [`Size`] of
+    /// the [`Responsive`] widget and, therefore, can be used to build the
+    /// contents of the widget in a responsive way.
+    pub fn new(
+        view: impl Fn(Size) -> Element<'a, Message, Theme, Renderer> + 'a,
+    ) -> Self {
+        Self {
+            view: Box::new(view),
+            content: Element::new(horizontal_space().width(0)),
+        }
+    }
+}
+
+impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer>
+    for Responsive<'_, Message, Theme, Renderer>
+where
+    Renderer: core::Renderer,
+{
+    fn tag(&self) -> tree::Tag {
+        struct Marker;
+        tree::Tag::of::<Marker>()
+    }
+
+    fn diff(&mut self, _tree: &mut Tree) {
+        // Diff is deferred to layout
+    }
+
+    fn size(&self) -> Size<Length> {
+        Size {
+            width: Length::Fill,
+            height: Length::Fill,
+        }
+    }
+
+    fn layout(
+        &mut self,
+        tree: &mut Tree,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        let size = limits.max();
+
+        self.content = (self.view)(size);
+        tree.diff_children(std::slice::from_mut(&mut self.content));
+
+        self.content.as_widget_mut().layout(
+            &mut tree.children[0],
+            renderer,
+            &limits.loose(),
+        )
+    }
+
+    fn update(
+        &mut self,
+        tree: &mut Tree,
+        event: &Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+        viewport: &Rectangle,
+    ) {
+        self.content.as_widget_mut().update(
+            &mut tree.children[0],
+            event,
+            layout,
+            cursor,
+            renderer,
+            clipboard,
+            shell,
+            viewport,
+        );
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+    ) {
+        self.content.as_widget().draw(
+            &tree.children[0],
+            renderer,
+            theme,
+            style,
+            layout,
+            cursor,
+            viewport,
+        );
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.content.as_widget().mouse_interaction(
+            &tree.children[0],
+            layout,
+            cursor,
+            viewport,
+            renderer,
+        )
+    }
+
+    fn operate(
+        &mut self,
+        tree: &mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn widget::Operation,
+    ) {
+        self.content.as_widget_mut().operate(
+            &mut tree.children[0],
+            layout,
+            renderer,
+            operation,
+        );
+    }
+
+    fn overlay<'a>(
+        &'a mut self,
+        tree: &'a mut Tree,
+        layout: Layout<'a>,
+        renderer: &Renderer,
+        viewport: &Rectangle,
+        translation: Vector,
+    ) -> Option<overlay::Element<'a, Message, Theme, Renderer>> {
+        self.content.as_widget_mut().overlay(
+            &mut tree.children[0],
+            layout,
+            renderer,
+            viewport,
+            translation,
+        )
+    }
+}
+
+impl<'a, Message, Theme, Renderer>
+    From<Responsive<'a, Message, Theme, Renderer>>
+    for Element<'a, Message, Theme, Renderer>
+where
+    Message: 'a,
+    Theme: 'a,
+    Renderer: core::Renderer + 'a,
+{
+    fn from(responsive: Responsive<'a, Message, Theme, Renderer>) -> Self {
+        Self::new(responsive)
+    }
+}