Create `iced_widget` subcrate and re-organize the whole codebase

1 files changed, 368 insertions, 0 deletions

diff --git a/widget/src/container.rs b/widget/src/container.rs
new file mode 100644
index 00000000..9d932772
--- /dev/null
+++ b/widget/src/container.rs
@@ -0,0 +1,368 @@
+//! Decorate content and apply alignment.
+use crate::core::alignment::{self, Alignment};
+use crate::core::event::{self, Event};
+use crate::core::layout;
+use crate::core::mouse;
+use crate::core::overlay;
+use crate::core::renderer;
+use crate::core::widget::{self, Operation, Tree};
+use crate::core::{
+    Background, Clipboard, Color, Element, Layout, Length, Padding, Pixels,
+    Point, Rectangle, Shell, Widget,
+};
+
+pub use iced_style::container::{Appearance, StyleSheet};
+
+/// An element decorating some content.
+///
+/// It is normally used for alignment purposes.
+#[allow(missing_debug_implementations)]
+pub struct Container<'a, Message, Renderer = crate::Renderer>
+where
+    Renderer: crate::core::Renderer,
+    Renderer::Theme: StyleSheet,
+{
+    id: Option<Id>,
+    padding: Padding,
+    width: Length,
+    height: Length,
+    max_width: f32,
+    max_height: f32,
+    horizontal_alignment: alignment::Horizontal,
+    vertical_alignment: alignment::Vertical,
+    style: <Renderer::Theme as StyleSheet>::Style,
+    content: Element<'a, Message, Renderer>,
+}
+
+impl<'a, Message, Renderer> Container<'a, Message, Renderer>
+where
+    Renderer: crate::core::Renderer,
+    Renderer::Theme: StyleSheet,
+{
+    /// Creates an empty [`Container`].
+    pub fn new<T>(content: T) -> Self
+    where
+        T: Into<Element<'a, Message, Renderer>>,
+    {
+        Container {
+            id: None,
+            padding: Padding::ZERO,
+            width: Length::Shrink,
+            height: Length::Shrink,
+            max_width: f32::INFINITY,
+            max_height: f32::INFINITY,
+            horizontal_alignment: alignment::Horizontal::Left,
+            vertical_alignment: alignment::Vertical::Top,
+            style: Default::default(),
+            content: content.into(),
+        }
+    }
+
+    /// Sets the [`Id`] of the [`Container`].
+    pub fn id(mut self, id: Id) -> Self {
+        self.id = Some(id);
+        self
+    }
+
+    /// 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: impl Into<Length>) -> Self {
+        self.width = width.into();
+        self
+    }
+
+    /// Sets the height of the [`Container`].
+    pub fn height(mut self, height: impl Into<Length>) -> Self {
+        self.height = height.into();
+        self
+    }
+
+    /// Sets the maximum width of the [`Container`].
+    pub fn max_width(mut self, max_width: impl Into<Pixels>) -> Self {
+        self.max_width = max_width.into().0;
+        self
+    }
+
+    /// Sets the maximum height of the [`Container`].
+    pub fn max_height(mut self, max_height: impl Into<Pixels>) -> Self {
+        self.max_height = max_height.into().0;
+        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: impl Into<<Renderer::Theme as StyleSheet>::Style>,
+    ) -> Self {
+        self.style = style.into();
+        self
+    }
+}
+
+impl<'a, Message, Renderer> Widget<Message, Renderer>
+    for Container<'a, Message, Renderer>
+where
+    Renderer: crate::core::Renderer,
+    Renderer::Theme: StyleSheet,
+{
+    fn children(&self) -> Vec<Tree> {
+        vec![Tree::new(&self.content)]
+    }
+
+    fn diff(&self, tree: &mut Tree) {
+        tree.diff_children(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 {
+        layout(
+            renderer,
+            limits,
+            self.width,
+            self.height,
+            self.max_width,
+            self.max_height,
+            self.padding,
+            self.horizontal_alignment,
+            self.vertical_alignment,
+            |renderer, limits| {
+                self.content.as_widget().layout(renderer, limits)
+            },
+        )
+    }
+
+    fn operate(
+        &self,
+        tree: &mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn Operation<Message>,
+    ) {
+        operation.container(
+            self.id.as_ref().map(|id| &id.0),
+            &mut |operation| {
+                self.content.as_widget().operate(
+                    &mut tree.children[0],
+                    layout.children().next().unwrap(),
+                    renderer,
+                    operation,
+                );
+            },
+        );
+    }
+
+    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,
+        theme: &Renderer::Theme,
+        renderer_style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        viewport: &Rectangle,
+    ) {
+        let style = theme.appearance(&self.style);
+
+        draw_background(renderer, &style, layout.bounds());
+
+        self.content.as_widget().draw(
+            &tree.children[0],
+            renderer,
+            theme,
+            &renderer::Style {
+                text_color: style
+                    .text_color
+                    .unwrap_or(renderer_style.text_color),
+            },
+            layout.children().next().unwrap(),
+            cursor_position,
+            viewport,
+        );
+    }
+
+    fn overlay<'b>(
+        &'b mut self,
+        tree: &'b mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+    ) -> Option<overlay::Element<'b, Message, Renderer>> {
+        self.content.as_widget_mut().overlay(
+            &mut tree.children[0],
+            layout.children().next().unwrap(),
+            renderer,
+        )
+    }
+}
+
+impl<'a, Message, Renderer> From<Container<'a, Message, Renderer>>
+    for Element<'a, Message, Renderer>
+where
+    Message: 'a,
+    Renderer: 'a + crate::core::Renderer,
+    Renderer::Theme: StyleSheet,
+{
+    fn from(
+        column: Container<'a, Message, Renderer>,
+    ) -> Element<'a, Message, Renderer> {
+        Element::new(column)
+    }
+}
+
+/// Computes the layout of a [`Container`].
+pub fn layout<Renderer>(
+    renderer: &Renderer,
+    limits: &layout::Limits,
+    width: Length,
+    height: Length,
+    max_width: f32,
+    max_height: f32,
+    padding: Padding,
+    horizontal_alignment: alignment::Horizontal,
+    vertical_alignment: alignment::Vertical,
+    layout_content: impl FnOnce(&Renderer, &layout::Limits) -> layout::Node,
+) -> layout::Node {
+    let limits = limits
+        .loose()
+        .max_width(max_width)
+        .max_height(max_height)
+        .width(width)
+        .height(height);
+
+    let mut content = layout_content(renderer, &limits.pad(padding).loose());
+    let padding = padding.fit(content.size(), limits.max());
+    let size = limits.pad(padding).resolve(content.size());
+
+    content.move_to(Point::new(padding.left, padding.top));
+    content.align(
+        Alignment::from(horizontal_alignment),
+        Alignment::from(vertical_alignment),
+        size,
+    );
+
+    layout::Node::with_children(size.pad(padding), vec![content])
+}
+
+/// Draws the background of a [`Container`] given its [`Appearance`] and its `bounds`.
+pub fn draw_background<Renderer>(
+    renderer: &mut Renderer,
+    appearance: &Appearance,
+    bounds: Rectangle,
+) where
+    Renderer: crate::core::Renderer,
+{
+    if appearance.background.is_some() || appearance.border_width > 0.0 {
+        renderer.fill_quad(
+            renderer::Quad {
+                bounds,
+                border_radius: appearance.border_radius.into(),
+                border_width: appearance.border_width,
+                border_color: appearance.border_color,
+            },
+            appearance
+                .background
+                .unwrap_or(Background::Color(Color::TRANSPARENT)),
+        );
+    }
+}
+
+/// The identifier of a [`Container`].
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Id(widget::Id);
+
+impl Id {
+    /// Creates a custom [`Id`].
+    pub fn new(id: impl Into<std::borrow::Cow<'static, str>>) -> Self {
+        Self(widget::Id::new(id))
+    }
+
+    /// Creates a unique [`Id`].
+    ///
+    /// This function produces a different [`Id`] every time it is called.
+    pub fn unique() -> Self {
+        Self(widget::Id::unique())
+    }
+}
+
+impl From<Id> for widget::Id {
+    fn from(id: Id) -> Self {
+        id.0
+    }
+}