Implement `iced_glutin` :tada:

4 files changed, 59 insertions, 345 deletions

diff --git a/glow/src/backend.rs b/glow/src/backend.rs
index 5e2aa837..8c578d5e 100644
--- a/glow/src/backend.rs
+++ b/glow/src/backend.rs
@@ -36,12 +36,6 @@ impl Backend {
         }
     }
 
-    /// Draws the provided primitives in the given [`Target`].
-    ///
-    /// The text provided as overlay will be renderer on top of the primitives.
-    /// This is useful for rendering debug information.
-    ///
-    /// [`Target`]: struct.Target.html
     pub fn draw<T: AsRef<str>>(
         &mut self,
         gl: &glow::Context,
@@ -50,6 +44,7 @@ impl Backend {
         overlay_text: &[T],
     ) -> mouse::Interaction {
         let viewport_size = viewport.physical_size();
+        let scale_factor = viewport.scale_factor() as f32;
         let projection = viewport.projection();
 
         let mut layers = Layer::generate(primitive, viewport);
@@ -58,7 +53,7 @@ impl Backend {
         for layer in layers {
             self.flush(
                 gl,
-                viewport.scale_factor() as f32,
+                scale_factor,
                 projection,
                 &layer,
                 viewport_size.width,
@@ -78,7 +73,8 @@ impl Backend {
         target_width: u32,
         target_height: u32,
     ) {
-        let bounds = (layer.bounds * scale_factor).round();
+        let mut bounds = (layer.bounds * scale_factor).round();
+        bounds.height = bounds.height.min(target_height);
 
         if !layer.quads.is_empty() {
             self.quad_pipeline.draw(
@@ -204,3 +200,20 @@ impl backend::Text for Backend {
         self.text_pipeline.space_width(size)
     }
 }
+
+#[cfg(feature = "image")]
+impl backend::Image for Backend {
+    fn dimensions(&self, _handle: &iced_native::image::Handle) -> (u32, u32) {
+        (50, 50)
+    }
+}
+
+#[cfg(feature = "svg")]
+impl backend::Svg for Backend {
+    fn viewport_dimensions(
+        &self,
+        _handle: &iced_native::svg::Handle,
+    ) -> (u32, u32) {
+        (50, 50)
+    }
+}
diff --git a/glow/src/widget.rs b/glow/src/widget.rs
index 16e7ca88..362465f4 100644
--- a/glow/src/widget.rs
+++ b/glow/src/widget.rs
@@ -38,7 +38,16 @@ pub use slider::Slider;
 #[doc(no_inline)]
 pub use text_input::TextInput;
 
-pub use iced_native::{Image, Space, Text};
+#[cfg(feature = "canvas")]
+#[cfg_attr(docsrs, doc(cfg(feature = "canvas")))]
+pub mod canvas;
+
+#[cfg(feature = "canvas")]
+#[doc(no_inline)]
+pub use canvas::Canvas;
+
+pub use iced_native::{Image, Space};
 
 pub type Column<'a, Message> = iced_native::Column<'a, Message, Renderer>;
 pub type Row<'a, Message> = iced_native::Row<'a, Message, Renderer>;
+pub type Text = iced_native::Text<Renderer>;
diff --git a/glow/src/widget/canvas.rs b/glow/src/widget/canvas.rs
index 325f90ce..bef34857 100644
--- a/glow/src/widget/canvas.rs
+++ b/glow/src/widget/canvas.rs
@@ -6,196 +6,4 @@
 //!
 //! [`Canvas`]: struct.Canvas.html
 //! [`Frame`]: struct.Frame.html
-use crate::{Defaults, Primitive, Renderer};
-
-use iced_native::{
-    layout, Element, Hasher, Layout, Length, MouseCursor, Point, Size, Widget,
-};
-use std::hash::Hash;
-
-pub mod layer;
-pub mod path;
-
-mod drawable;
-mod fill;
-mod frame;
-mod stroke;
-mod text;
-
-pub use drawable::Drawable;
-pub use fill::Fill;
-pub use frame::Frame;
-pub use layer::Layer;
-pub use path::Path;
-pub use stroke::{LineCap, LineJoin, Stroke};
-pub use text::Text;
-
-/// A widget capable of drawing 2D graphics.
-///
-/// A [`Canvas`] may contain multiple layers. A [`Layer`] is drawn using the
-/// painter's algorithm. In other words, layers will be drawn on top of each
-/// other in the same order they are pushed into the [`Canvas`].
-///
-/// [`Canvas`]: struct.Canvas.html
-/// [`Layer`]: layer/trait.Layer.html
-///
-/// # Examples
-/// The repository has a couple of [examples] showcasing how to use a
-/// [`Canvas`]:
-///
-/// - [`clock`], an application that uses the [`Canvas`] widget to draw a clock
-/// and its hands to display the current time.
-/// - [`solar_system`], an animated solar system drawn using the [`Canvas`] widget
-/// and showcasing how to compose different transforms.
-///
-/// [examples]: https://github.com/hecrj/iced/tree/0.1/examples
-/// [`clock`]: https://github.com/hecrj/iced/tree/0.1/examples/clock
-/// [`solar_system`]: https://github.com/hecrj/iced/tree/0.1/examples/solar_system
-///
-/// ## Drawing a simple circle
-/// If you want to get a quick overview, here's how we can draw a simple circle:
-///
-/// ```no_run
-/// # mod iced {
-/// #     pub use iced_wgpu::canvas;
-/// #     pub use iced_native::Color;
-/// # }
-/// use iced::canvas::{self, layer, Canvas, Drawable, Fill, Frame, Path};
-/// use iced::Color;
-///
-/// // First, we define the data we need for drawing
-/// #[derive(Debug)]
-/// struct Circle {
-///     radius: f32,
-/// }
-///
-/// // Then, we implement the `Drawable` trait
-/// impl Drawable for Circle {
-///     fn draw(&self, frame: &mut Frame) {
-///         // We create a `Path` representing a simple circle
-///         let circle = Path::new(|p| p.circle(frame.center(), self.radius));
-///
-///         // And fill it with some color
-///         frame.fill(&circle, Fill::Color(Color::BLACK));
-///     }
-/// }
-///
-/// // We can use a `Cache` to avoid unnecessary re-tessellation
-/// let cache: layer::Cache<Circle> = layer::Cache::new();
-///
-/// // Finally, we simply provide the data to our `Cache` and push the resulting
-/// // layer into a `Canvas`
-/// let canvas = Canvas::new()
-///     .push(cache.with(&Circle { radius: 50.0 }));
-/// ```
-#[derive(Debug)]
-pub struct Canvas<'a> {
-    width: Length,
-    height: Length,
-    layers: Vec<Box<dyn Layer + 'a>>,
-}
-
-impl<'a> Canvas<'a> {
-    const DEFAULT_SIZE: u16 = 100;
-
-    /// Creates a new [`Canvas`] with no layers.
-    ///
-    /// [`Canvas`]: struct.Canvas.html
-    pub fn new() -> Self {
-        Canvas {
-            width: Length::Units(Self::DEFAULT_SIZE),
-            height: Length::Units(Self::DEFAULT_SIZE),
-            layers: Vec::new(),
-        }
-    }
-
-    /// Sets the width of the [`Canvas`].
-    ///
-    /// [`Canvas`]: struct.Canvas.html
-    pub fn width(mut self, width: Length) -> Self {
-        self.width = width;
-        self
-    }
-
-    /// Sets the height of the [`Canvas`].
-    ///
-    /// [`Canvas`]: struct.Canvas.html
-    pub fn height(mut self, height: Length) -> Self {
-        self.height = height;
-        self
-    }
-
-    /// Adds a [`Layer`] to the [`Canvas`].
-    ///
-    /// It will be drawn on top of previous layers.
-    ///
-    /// [`Layer`]: layer/trait.Layer.html
-    /// [`Canvas`]: struct.Canvas.html
-    pub fn push(mut self, layer: impl Layer + 'a) -> Self {
-        self.layers.push(Box::new(layer));
-        self
-    }
-}
-
-impl<'a, Message> Widget<Message, Renderer> for Canvas<'a> {
-    fn width(&self) -> Length {
-        self.width
-    }
-
-    fn height(&self) -> Length {
-        self.height
-    }
-
-    fn layout(
-        &self,
-        _renderer: &Renderer,
-        limits: &layout::Limits,
-    ) -> layout::Node {
-        let limits = limits.width(self.width).height(self.height);
-        let size = limits.resolve(Size::ZERO);
-
-        layout::Node::new(size)
-    }
-
-    fn draw(
-        &self,
-        _renderer: &mut Renderer,
-        _defaults: &Defaults,
-        layout: Layout<'_>,
-        _cursor_position: Point,
-    ) -> (Primitive, MouseCursor) {
-        let bounds = layout.bounds();
-        let origin = Point::new(bounds.x, bounds.y);
-        let size = Size::new(bounds.width, bounds.height);
-
-        (
-            Primitive::Group {
-                primitives: self
-                    .layers
-                    .iter()
-                    .map(|layer| Primitive::Cached {
-                        origin,
-                        cache: layer.draw(size),
-                    })
-                    .collect(),
-            },
-            MouseCursor::Idle,
-        )
-    }
-
-    fn hash_layout(&self, state: &mut Hasher) {
-        std::any::TypeId::of::<Canvas<'static>>().hash(state);
-
-        self.width.hash(state);
-        self.height.hash(state);
-    }
-}
-
-impl<'a, Message> From<Canvas<'a>> for Element<'a, Message, Renderer>
-where
-    Message: 'static,
-{
-    fn from(canvas: Canvas<'a>) -> Element<'a, Message, Renderer> {
-        Element::new(canvas)
-    }
-}
+pub use iced_graphics::canvas::*;
diff --git a/glow/src/window/compositor.rs b/glow/src/window/compositor.rs
index 514904a8..1117166f 100644
--- a/glow/src/window/compositor.rs
+++ b/glow/src/window/compositor.rs
@@ -1,180 +1,64 @@
-use crate::{Renderer, Settings, Viewport};
+use crate::{Backend, Renderer, Settings, Viewport};
 
+use core::ffi::c_void;
 use glow::HasContext;
+use iced_graphics::Size;
 use iced_native::mouse;
-use raw_window_handle::HasRawWindowHandle;
 
 /// A window graphics backend for iced powered by `glow`.
 #[allow(missing_debug_implementations)]
 pub struct Compositor {
-    connection: surfman::Connection,
-    device: surfman::Device,
-    gl_context: surfman::Context,
-    gl: Option<glow::Context>,
+    gl: glow::Context,
 }
 
-impl iced_graphics::window::Compositor for Compositor {
+impl iced_graphics::window::GLCompositor for Compositor {
     type Settings = Settings;
     type Renderer = Renderer;
-    type Surface = ();
-    type SwapChain = ();
 
-    fn new(_settings: Self::Settings) -> Self {
-        let connection = surfman::Connection::new().expect("Create connection");
+    unsafe fn new(
+        settings: Self::Settings,
+        loader_function: impl FnMut(&str) -> *const c_void,
+    ) -> (Self, Self::Renderer) {
+        let gl = glow::Context::from_loader_function(loader_function);
 
-        let adapter = connection
-            .create_hardware_adapter()
-            .expect("Create adapter");
+        gl.clear_color(1.0, 1.0, 1.0, 1.0);
 
-        let mut device =
-            connection.create_device(&adapter).expect("Create device");
+        // Enable auto-conversion from/to sRGB
+        gl.enable(glow::FRAMEBUFFER_SRGB);
 
-        let context_descriptor = device
-            .create_context_descriptor(&surfman::ContextAttributes {
-                version: surfman::GLVersion::new(3, 0),
-                flags: surfman::ContextAttributeFlags::empty(),
-            })
-            .expect("Create context descriptor");
+        // Enable alpha blending
+        gl.enable(glow::BLEND);
+        gl.blend_func(glow::SRC_ALPHA, glow::ONE_MINUS_SRC_ALPHA);
 
-        let gl_context = device
-            .create_context(&context_descriptor)
-            .expect("Create context");
+        let renderer = Renderer::new(Backend::new(&gl, settings));
 
-        Self {
-            connection,
-            device,
-            gl_context,
-            gl: None,
-        }
-    }
-
-    fn create_renderer(&mut self, settings: Settings) -> Renderer {
-        self.device
-            .make_context_current(&self.gl_context)
-            .expect("Make context current");
-
-        Renderer::new(crate::Backend::new(self.gl.as_ref().unwrap(), settings))
-    }
-
-    fn create_surface<W: HasRawWindowHandle>(
-        &mut self,
-        window: &W,
-    ) -> Self::Surface {
-        let native_widget = self
-            .connection
-            .create_native_widget_from_rwh(window.raw_window_handle())
-            .expect("Create widget");
-
-        let surface = self
-            .device
-            .create_surface(
-                &self.gl_context,
-                surfman::SurfaceAccess::GPUOnly,
-                surfman::SurfaceType::Widget { native_widget },
-            )
-            .expect("Create surface");
-
-        let surfman::SurfaceInfo { .. } = self.device.surface_info(&surface);
-
-        self.device
-            .bind_surface_to_context(&mut self.gl_context, surface)
-            .expect("Bind surface to context");
-
-        self.device
-            .make_context_current(&self.gl_context)
-            .expect("Make context current");
-
-        self.gl = Some(glow::Context::from_loader_function(|s| {
-            self.device.get_proc_address(&self.gl_context, s)
-        }));
-
-        //let mut framebuffer =
-        //    skia_safe::gpu::gl::FramebufferInfo::from_fboid(framebuffer_object);
-
-        //framebuffer.format = gl::RGBA8;
-
-        //framebuffer
+        (Self { gl }, renderer)
     }
 
-    fn create_swap_chain(
-        &mut self,
-        _surface: &Self::Surface,
-        width: u32,
-        height: u32,
-    ) -> Self::SwapChain {
-        let mut surface = self
-            .device
-            .unbind_surface_from_context(&mut self.gl_context)
-            .expect("Unbind surface")
-            .expect("Active surface");
-
-        self.device
-            .resize_surface(
-                &self.gl_context,
-                &mut surface,
-                euclid::Size2D::new(width as i32, height as i32),
-            )
-            .expect("Resize surface");
-
-        self.device
-            .bind_surface_to_context(&mut self.gl_context, surface)
-            .expect("Bind surface to context");
-
-        let gl = self.gl.as_ref().unwrap();
-
+    fn resize_viewport(&mut self, physical_size: Size<u32>) {
         unsafe {
-            gl.viewport(0, 0, width as i32, height as i32);
-            gl.clear_color(1.0, 1.0, 1.0, 1.0);
-
-            // Enable auto-conversion from/to sRGB
-            gl.enable(glow::FRAMEBUFFER_SRGB);
-
-            // Enable alpha blending
-            gl.enable(glow::BLEND);
-            gl.blend_func(glow::SRC_ALPHA, glow::ONE_MINUS_SRC_ALPHA);
+            self.gl.viewport(
+                0,
+                0,
+                physical_size.width as i32,
+                physical_size.height as i32,
+            );
         }
     }
 
     fn draw<T: AsRef<str>>(
         &mut self,
         renderer: &mut Self::Renderer,
-        swap_chain: &mut Self::SwapChain,
         viewport: &Viewport,
         output: &<Self::Renderer as iced_native::Renderer>::Output,
         overlay: &[T],
     ) -> mouse::Interaction {
-        let gl = self.gl.as_ref().unwrap();
+        let gl = &self.gl;
 
         unsafe {
             gl.clear(glow::COLOR_BUFFER_BIT);
         }
 
-        let mouse = renderer.backend_mut().draw(gl, viewport, output, overlay);
-
-        {
-            let mut surface = self
-                .device
-                .unbind_surface_from_context(&mut self.gl_context)
-                .expect("Unbind surface")
-                .expect("Active surface");
-
-            self.device
-                .present_surface(&self.gl_context, &mut surface)
-                .expect("Present surface");
-
-            self.device
-                .bind_surface_to_context(&mut self.gl_context, surface)
-                .expect("Bind surface to context");
-        }
-
-        mouse
-    }
-}
-
-impl Drop for Compositor {
-    fn drop(&mut self) {
-        self.device
-            .destroy_context(&mut self.gl_context)
-            .expect("Destroy context");
+        renderer.backend_mut().draw(gl, viewport, output, overlay)
     }
 }