Make iced_tiny_skia optional with a tiny-skia feature

graphics/src/backend.rs

@@ -10,6 +10,9 @@ use std::borrow::Cow;
 ///
 /// [`Renderer`]: crate::Renderer
 pub trait Backend {
+    /// The compositor of this [`Backend`].
+    type Compositor;
+
     /// The custom kind of primitives this [`Backend`] supports.
     type Primitive: TryFrom<Mesh, Error = &'static str>;
 }

graphics/src/compositor.rs

@@ -15,7 +15,7 @@ pub trait Compositor: Sized {
     type Settings: Default;
 
     /// The iced renderer of the backend.
-    type Renderer: iced_core::Renderer;
+    type Renderer;
 
     /// The surface of the backend.
     type Surface;
@@ -122,3 +122,63 @@ pub struct Information {
     /// Contains the graphics backend.
     pub backend: String,
 }
+
+impl Compositor for () {
+    type Settings = ();
+    type Renderer = ();
+    type Surface = ();
+
+    async fn new<W: Window + Clone>(
+        _settings: Self::Settings,
+        _compatible_window: W,
+    ) -> Result<Self, Error> {
+        Ok(())
+    }
+
+    fn create_renderer(&self) -> Self::Renderer {}
+
+    fn create_surface<W: Window + Clone>(
+        &mut self,
+        _window: W,
+        _width: u32,
+        _height: u32,
+    ) -> Self::Surface {
+    }
+
+    fn configure_surface(
+        &mut self,
+        _surface: &mut Self::Surface,
+        _width: u32,
+        _height: u32,
+    ) {
+    }
+
+    fn fetch_information(&self) -> Information {
+        Information {
+            adapter: String::from("Null Renderer"),
+            backend: String::from("Null"),
+        }
+    }
+
+    fn present<T: AsRef<str>>(
+        &mut self,
+        _renderer: &mut Self::Renderer,
+        _surface: &mut Self::Surface,
+        _viewport: &Viewport,
+        _background_color: Color,
+        _overlay: &[T],
+    ) -> Result<(), SurfaceError> {
+        Ok(())
+    }
+
+    fn screenshot<T: AsRef<str>>(
+        &mut self,
+        _renderer: &mut Self::Renderer,
+        _surface: &mut Self::Surface,
+        _viewport: &Viewport,
+        _background_color: Color,
+        _overlay: &[T],
+    ) -> Vec<u8> {
+        vec![]
+    }
+}

graphics/src/geometry.rs

@@ -18,11 +18,11 @@ pub use text::Text;
 
 pub use crate::gradient::{self, Gradient};
 
-use crate::core::Size;
+use crate::core::{self, Size};
 use crate::Cached;
 
 /// A renderer capable of drawing some [`Self::Geometry`].
-pub trait Renderer: crate::core::Renderer {
+pub trait Renderer: core::Renderer {
     /// The kind of geometry this renderer can draw.
     type Geometry: Cached;
 

graphics/src/geometry/frame.rs

@@ -1,7 +1,6 @@
 //! Draw and generate geometry.
 use crate::core::{Point, Radians, Rectangle, Size, Vector};
 use crate::geometry::{self, Fill, Path, Stroke, Text};
-use crate::Cached;
 
 /// The region of a surface that can be used to draw geometry.
 #[allow(missing_debug_implementations)]
@@ -173,7 +172,7 @@ where
 /// of each method.
 #[allow(missing_docs)]
 pub trait Backend: Sized {
-    type Geometry: Cached;
+    type Geometry;
 
     fn width(&self) -> f32;
     fn height(&self) -> f32;

graphics/src/mesh.rs

@@ -1,6 +1,6 @@
 //! Draw triangles!
 use crate::color;
-use crate::core::{self, Rectangle, Size};
+use crate::core::{Rectangle, Size};
 use crate::gradient;
 use crate::Damage;
 
@@ -76,7 +76,7 @@ pub struct GradientVertex2D {
 }
 
 /// A renderer capable of drawing a [`Mesh`].
-pub trait Renderer: core::Renderer {
+pub trait Renderer {
     /// Draws the given [`Mesh`].
     fn draw_mesh(&mut self, mesh: Mesh);
 }