Add group overlay element

native/src/overlay.rs

@@ -1,9 +1,11 @@
 //! Display interactive elements on top of other widgets.
 mod element;
+mod group;
 
 pub mod menu;
 
 pub use element::Element;
+pub use group::Group;
 pub use menu::Menu;
 
 use crate::event::{self, Event};

native/src/overlay/group.rs

@@ -0,0 +1,165 @@
+use iced_core::{Point, Rectangle, Size};
+
+use crate::event;
+use crate::layout;
+use crate::mouse;
+use crate::overlay;
+use crate::renderer;
+use crate::widget;
+use crate::{Clipboard, Event, Layout, Overlay, Shell};
+
+/// An [`Overlay`] container that displays multiple overlay
+/// [`overlay::Element`] children
+#[allow(missing_debug_implementations)]
+pub struct Group<'a, Message, Renderer> {
+    children: Vec<overlay::Element<'a, Message, Renderer>>,
+}
+
+impl<'a, Message, Renderer> Group<'a, Message, Renderer>
+where
+    Renderer: 'a + crate::Renderer,
+    Message: 'a,
+{
+    /// Creates an empty [`Group`].
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Creates a [`Group`] with the given elements.
+    pub fn with_children(
+        children: Vec<overlay::Element<'a, Message, Renderer>>,
+    ) -> Self {
+        Group { children }
+    }
+
+    /// Adds an [`overlay::Element`] to the [`Group`].
+    pub fn push(
+        mut self,
+        child: impl Into<overlay::Element<'a, Message, Renderer>>,
+    ) -> Self {
+        self.children.push(child.into());
+        self
+    }
+
+    /// Turns the [`Group`] into an overlay [`overlay::Element`]
+    pub fn overlay(self) -> overlay::Element<'a, Message, Renderer> {
+        overlay::Element::new(Point::ORIGIN, Box::new(self))
+    }
+}
+
+impl<'a, Message, Renderer> Default for Group<'a, Message, Renderer>
+where
+    Renderer: 'a + crate::Renderer,
+    Message: 'a,
+{
+    fn default() -> Self {
+        Self::with_children(Vec::new())
+    }
+}
+
+impl<'a, Message, Renderer> Overlay<Message, Renderer>
+    for Group<'a, Message, Renderer>
+where
+    Renderer: crate::Renderer,
+{
+    fn layout(
+        &self,
+        renderer: &Renderer,
+        bounds: Size,
+        _position: Point,
+    ) -> layout::Node {
+        layout::Node::with_children(
+            bounds,
+            self.children
+                .iter()
+                .map(|child| child.layout(renderer, bounds))
+                .collect(),
+        )
+    }
+
+    fn on_event(
+        &mut self,
+        event: Event,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+    ) -> event::Status {
+        self.children
+            .iter_mut()
+            .zip(layout.children())
+            .map(|(child, layout)| {
+                child.on_event(
+                    event.clone(),
+                    layout,
+                    cursor_position,
+                    renderer,
+                    clipboard,
+                    shell,
+                )
+            })
+            .fold(event::Status::Ignored, event::Status::merge)
+    }
+
+    fn draw(
+        &self,
+        renderer: &mut Renderer,
+        theme: &<Renderer as crate::Renderer>::Theme,
+        style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor_position: Point,
+    ) {
+        for (child, layout) in self.children.iter().zip(layout.children()) {
+            child.draw(renderer, theme, style, layout, cursor_position);
+        }
+    }
+
+    fn mouse_interaction(
+        &self,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.children
+            .iter()
+            .zip(layout.children())
+            .map(|(child, layout)| {
+                child.mouse_interaction(
+                    layout,
+                    cursor_position,
+                    viewport,
+                    renderer,
+                )
+            })
+            .max()
+            .unwrap_or_default()
+    }
+
+    fn operate(
+        &mut self,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn widget::Operation<Message>,
+    ) {
+        operation.container(None, &mut |operation| {
+            self.children.iter_mut().zip(layout.children()).for_each(
+                |(child, layout)| {
+                    child.operate(layout, renderer, operation);
+                },
+            )
+        });
+    }
+}
+
+impl<'a, Message, Renderer> From<Group<'a, Message, Renderer>>
+    for overlay::Element<'a, Message, Renderer>
+where
+    Renderer: 'a + crate::Renderer,
+    Message: 'a,
+{
+    fn from(group: Group<'a, Message, Renderer>) -> Self {
+        group.overlay()
+    }
+}