Implement `Container` widget in `iced_pure`

2 files changed, 269 insertions, 0 deletions

diff --git a/pure/src/widget.rs b/pure/src/widget.rs
index 1cbd3b78..3bf6a5aa 100644
--- a/pure/src/widget.rs
+++ b/pure/src/widget.rs
@@ -1,5 +1,6 @@
 mod button;
 mod column;
+mod container;
 mod element;
 mod row;
 mod text;
@@ -7,6 +8,7 @@ mod tree;
 
 pub use button::Button;
 pub use column::Column;
+pub use container::Container;
 pub use element::Element;
 pub use row::Row;
 pub use text::Text;
@@ -74,6 +76,15 @@ pub trait Widget<Message, Renderer> {
     }
 }
 
+pub fn container<'a, Message, Renderer>(
+    content: impl Into<Element<'a, Message, Renderer>>,
+) -> Container<'a, Message, Renderer>
+where
+    Renderer: iced_native::Renderer,
+{
+    Container::new(content)
+}
+
 pub fn column<'a, Message, Renderer>() -> Column<'a, Message, Renderer> {
     Column::new()
 }
diff --git a/pure/src/widget/container.rs b/pure/src/widget/container.rs
new file mode 100644
index 00000000..94a6b07b
--- /dev/null
+++ b/pure/src/widget/container.rs
@@ -0,0 +1,258 @@
+//! Decorate content and apply alignment.
+use crate::{Element, Tree, Widget};
+
+use iced_native::alignment;
+use iced_native::event::{self, Event};
+use iced_native::layout;
+use iced_native::mouse;
+use iced_native::renderer;
+use iced_native::widget::container;
+use iced_native::{
+    Clipboard, Hasher, Layout, Length, Padding, Point, Rectangle, Shell,
+};
+
+use std::any::{self, Any};
+use std::hash::Hash;
+use std::u32;
+
+pub use iced_style::container::{Style, StyleSheet};
+
+/// An element decorating some content.
+///
+/// It is normally used for alignment purposes.
+#[allow(missing_debug_implementations)]
+pub struct Container<'a, Message, Renderer> {
+    padding: Padding,
+    width: Length,
+    height: Length,
+    max_width: u32,
+    max_height: u32,
+    horizontal_alignment: alignment::Horizontal,
+    vertical_alignment: alignment::Vertical,
+    style_sheet: Box<dyn StyleSheet + 'a>,
+    content: Element<'a, Message, Renderer>,
+}
+
+impl<'a, Message, Renderer> Container<'a, Message, Renderer>
+where
+    Renderer: iced_native::Renderer,
+{
+    /// Creates an empty [`Container`].
+    pub fn new<T>(content: T) -> Self
+    where
+        T: Into<Element<'a, Message, Renderer>>,
+    {
+        Container {
+            padding: Padding::ZERO,
+            width: Length::Shrink,
+            height: Length::Shrink,
+            max_width: u32::MAX,
+            max_height: u32::MAX,
+            horizontal_alignment: alignment::Horizontal::Left,
+            vertical_alignment: alignment::Vertical::Top,
+            style_sheet: Default::default(),
+            content: content.into(),
+        }
+    }
+
+    /// Sets the [`Padding`] of the [`Container`].
+    pub fn padding<P: Into<Padding>>(mut self, padding: P) -> Self {
+        self.padding = padding.into();
+        self
+    }
+
+    /// Sets the width of the [`Container`].
+    pub fn width(mut self, width: Length) -> Self {
+        self.width = width;
+        self
+    }
+
+    /// Sets the height of the [`Container`].
+    pub fn height(mut self, height: Length) -> Self {
+        self.height = height;
+        self
+    }
+
+    /// Sets the maximum width of the [`Container`].
+    pub fn max_width(mut self, max_width: u32) -> Self {
+        self.max_width = max_width;
+        self
+    }
+
+    /// Sets the maximum height of the [`Container`] in pixels.
+    pub fn max_height(mut self, max_height: u32) -> Self {
+        self.max_height = max_height;
+        self
+    }
+
+    /// Sets the content alignment for the horizontal axis of the [`Container`].
+    pub fn align_x(mut self, alignment: alignment::Horizontal) -> Self {
+        self.horizontal_alignment = alignment;
+        self
+    }
+
+    /// Sets the content alignment for the vertical axis of the [`Container`].
+    pub fn align_y(mut self, alignment: alignment::Vertical) -> Self {
+        self.vertical_alignment = alignment;
+        self
+    }
+
+    /// Centers the contents in the horizontal axis of the [`Container`].
+    pub fn center_x(mut self) -> Self {
+        self.horizontal_alignment = alignment::Horizontal::Center;
+        self
+    }
+
+    /// Centers the contents in the vertical axis of the [`Container`].
+    pub fn center_y(mut self) -> Self {
+        self.vertical_alignment = alignment::Vertical::Center;
+        self
+    }
+
+    /// Sets the style of the [`Container`].
+    pub fn style(
+        mut self,
+        style_sheet: impl Into<Box<dyn StyleSheet + 'a>>,
+    ) -> Self {
+        self.style_sheet = style_sheet.into();
+        self
+    }
+}
+
+impl<'a, Message, Renderer> Widget<Message, Renderer>
+    for Container<'a, Message, Renderer>
+where
+    Renderer: iced_native::Renderer,
+{
+    fn tag(&self) -> any::TypeId {
+        any::TypeId::of::<()>()
+    }
+
+    fn state(&self) -> Box<dyn Any> {
+        Box::new(())
+    }
+
+    fn children(&self) -> &[Element<Message, Renderer>] {
+        std::slice::from_ref(&self.content)
+    }
+
+    fn width(&self) -> Length {
+        self.width
+    }
+
+    fn height(&self) -> Length {
+        self.height
+    }
+
+    fn layout(
+        &self,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        container::layout(
+            renderer,
+            limits,
+            self.width,
+            self.height,
+            self.padding,
+            self.horizontal_alignment,
+            self.vertical_alignment,
+            |renderer, limits| {
+                self.content.as_widget().layout(renderer, limits)
+            },
+        )
+    }
+
+    fn on_event(
+        &mut self,
+        tree: &mut Tree,
+        event: Event,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+    ) -> event::Status {
+        self.content.as_widget_mut().on_event(
+            &mut tree.children[0],
+            event,
+            layout.children().next().unwrap(),
+            cursor_position,
+            renderer,
+            clipboard,
+            shell,
+        )
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.content.as_widget().mouse_interaction(
+            &tree.children[0],
+            layout.children().next().unwrap(),
+            cursor_position,
+            viewport,
+            renderer,
+        )
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        renderer_style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        viewport: &Rectangle,
+    ) {
+        let style = self.style_sheet.style();
+
+        container::draw_background(renderer, &style, layout.bounds());
+
+        self.content.as_widget().draw(
+            &tree.children[0],
+            renderer,
+            &renderer::Style {
+                text_color: style
+                    .text_color
+                    .unwrap_or(renderer_style.text_color),
+            },
+            layout.children().next().unwrap(),
+            cursor_position,
+            viewport,
+        );
+    }
+
+    fn hash_layout(&self, state: &mut Hasher) {
+        struct Marker;
+        std::any::TypeId::of::<Marker>().hash(state);
+
+        self.padding.hash(state);
+        self.width.hash(state);
+        self.height.hash(state);
+        self.max_width.hash(state);
+        self.max_height.hash(state);
+        self.horizontal_alignment.hash(state);
+        self.vertical_alignment.hash(state);
+
+        self.content.as_widget().hash_layout(state);
+    }
+}
+
+impl<'a, Message, Renderer> From<Container<'a, Message, Renderer>>
+    for Element<'a, Message, Renderer>
+where
+    Renderer: 'a + iced_native::Renderer,
+    Message: 'a,
+{
+    fn from(
+        column: Container<'a, Message, Renderer>,
+    ) -> Element<'a, Message, Renderer> {
+        Element::new(column)
+    }
+}