Create iced_widget subcrate and re-organize the whole codebase

widget/src/image.rs

@@ -0,0 +1,205 @@
+//! Display images in your user interface.
+pub mod viewer;
+pub use viewer::Viewer;
+
+use crate::core::image;
+use crate::core::layout;
+use crate::core::renderer;
+use crate::core::widget::Tree;
+use crate::core::{
+    ContentFit, Element, Layout, Length, Point, Rectangle, Size, Vector, Widget,
+};
+
+use std::hash::Hash;
+
+pub use image::Handle;
+
+/// Creates a new [`Viewer`] with the given image `Handle`.
+pub fn viewer<Handle>(handle: Handle) -> Viewer<Handle> {
+    Viewer::new(handle)
+}
+
+/// A frame that displays an image while keeping aspect ratio.
+///
+/// # Example
+///
+/// ```
+/// # use iced_widget::image::{self, Image};
+/// #
+/// let image = Image::<image::Handle>::new("resources/ferris.png");
+/// ```
+///
+/// <img src="https://github.com/iced-rs/iced/blob/9712b319bb7a32848001b96bd84977430f14b623/examples/resources/ferris.png?raw=true" width="300">
+#[derive(Debug)]
+pub struct Image<Handle> {
+    handle: Handle,
+    width: Length,
+    height: Length,
+    content_fit: ContentFit,
+}
+
+impl<Handle> Image<Handle> {
+    /// Creates a new [`Image`] with the given path.
+    pub fn new<T: Into<Handle>>(handle: T) -> Self {
+        Image {
+            handle: handle.into(),
+            width: Length::Shrink,
+            height: Length::Shrink,
+            content_fit: ContentFit::Contain,
+        }
+    }
+
+    /// Sets the width of the [`Image`] boundaries.
+    pub fn width(mut self, width: impl Into<Length>) -> Self {
+        self.width = width.into();
+        self
+    }
+
+    /// Sets the height of the [`Image`] boundaries.
+    pub fn height(mut self, height: impl Into<Length>) -> Self {
+        self.height = height.into();
+        self
+    }
+
+    /// Sets the [`ContentFit`] of the [`Image`].
+    ///
+    /// Defaults to [`ContentFit::Contain`]
+    pub fn content_fit(self, content_fit: ContentFit) -> Self {
+        Self {
+            content_fit,
+            ..self
+        }
+    }
+}
+
+/// Computes the layout of an [`Image`].
+pub fn layout<Renderer, Handle>(
+    renderer: &Renderer,
+    limits: &layout::Limits,
+    handle: &Handle,
+    width: Length,
+    height: Length,
+    content_fit: ContentFit,
+) -> layout::Node
+where
+    Renderer: image::Renderer<Handle = Handle>,
+{
+    // The raw w/h of the underlying image
+    let image_size = {
+        let Size { width, height } = renderer.dimensions(handle);
+
+        Size::new(width as f32, height as f32)
+    };
+
+    // The size to be available to the widget prior to `Shrink`ing
+    let raw_size = limits.width(width).height(height).resolve(image_size);
+
+    // The uncropped size of the image when fit to the bounds above
+    let full_size = content_fit.fit(image_size, raw_size);
+
+    // Shrink the widget to fit the resized image, if requested
+    let final_size = Size {
+        width: match width {
+            Length::Shrink => f32::min(raw_size.width, full_size.width),
+            _ => raw_size.width,
+        },
+        height: match height {
+            Length::Shrink => f32::min(raw_size.height, full_size.height),
+            _ => raw_size.height,
+        },
+    };
+
+    layout::Node::new(final_size)
+}
+
+/// Draws an [`Image`]
+pub fn draw<Renderer, Handle>(
+    renderer: &mut Renderer,
+    layout: Layout<'_>,
+    handle: &Handle,
+    content_fit: ContentFit,
+) where
+    Renderer: image::Renderer<Handle = Handle>,
+    Handle: Clone + Hash,
+{
+    let Size { width, height } = renderer.dimensions(handle);
+    let image_size = Size::new(width as f32, height as f32);
+
+    let bounds = layout.bounds();
+    let adjusted_fit = content_fit.fit(image_size, bounds.size());
+
+    let render = |renderer: &mut Renderer| {
+        let offset = Vector::new(
+            (bounds.width - adjusted_fit.width).max(0.0) / 2.0,
+            (bounds.height - adjusted_fit.height).max(0.0) / 2.0,
+        );
+
+        let drawing_bounds = Rectangle {
+            width: adjusted_fit.width,
+            height: adjusted_fit.height,
+            ..bounds
+        };
+
+        renderer.draw(handle.clone(), drawing_bounds + offset)
+    };
+
+    if adjusted_fit.width > bounds.width || adjusted_fit.height > bounds.height
+    {
+        renderer.with_layer(bounds, render);
+    } else {
+        render(renderer)
+    }
+}
+
+impl<Message, Renderer, Handle> Widget<Message, Renderer> for Image<Handle>
+where
+    Renderer: image::Renderer<Handle = Handle>,
+    Handle: Clone + Hash,
+{
+    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.handle,
+            self.width,
+            self.height,
+            self.content_fit,
+        )
+    }
+
+    fn draw(
+        &self,
+        _state: &Tree,
+        renderer: &mut Renderer,
+        _theme: &Renderer::Theme,
+        _style: &renderer::Style,
+        layout: Layout<'_>,
+        _cursor_position: Point,
+        _viewport: &Rectangle,
+    ) {
+        draw(renderer, layout, &self.handle, self.content_fit)
+    }
+}
+
+impl<'a, Message, Renderer, Handle> From<Image<Handle>>
+    for Element<'a, Message, Renderer>
+where
+    Renderer: image::Renderer<Handle = Handle>,
+    Handle: Clone + Hash + 'a,
+{
+    fn from(image: Image<Handle>) -> Element<'a, Message, Renderer> {
+        Element::new(image)
+    }
+}