Make the SkiaRenderer public in the Rust API

It's also public in the C++ API and this is the equivalent change on the Rust API side.

api/rs/slint/Cargo.toml

@@ -134,13 +134,13 @@ renderer-winit-software = ["renderer-software"]
 renderer-femtovg = ["i-slint-backend-selector/renderer-femtovg", "std"]
 
 ## Render using [Skia](https://skia.org/).
-renderer-skia = ["i-slint-backend-selector/renderer-skia", "std"]
+renderer-skia = ["i-slint-backend-selector/renderer-skia", "dep:i-slint-renderer-skia", "std"]
 
 ## Same as `renderer-skia`, but Skia will always use OpenGL.
-renderer-skia-opengl = ["i-slint-backend-selector/renderer-skia-opengl", "std"]
+renderer-skia-opengl = ["i-slint-backend-selector/renderer-skia-opengl", "dep:i-slint-renderer-skia", "std"]
 
 ## Same as `renderer-skia`, but Skia will always use Vulkan.
-renderer-skia-vulkan = ["i-slint-backend-selector/renderer-skia-vulkan", "std"]
+renderer-skia-vulkan = ["i-slint-backend-selector/renderer-skia-vulkan", "dep:i-slint-renderer-skia", "std"]
 
 ## Render using the software renderer.
 renderer-software = ["i-slint-backend-selector/renderer-software", "i-slint-core/software-renderer"]
@@ -153,6 +153,7 @@ backend-linuxkms = ["i-slint-backend-selector/backend-linuxkms", "std"]
 i-slint-core = { version = "=1.2.0", path = "../../../internal/core", default-features = false }
 slint-macros = { version = "=1.2.0", path = "../macros" }
 i-slint-backend-selector = { version = "=1.2.0", path = "../../../internal/backends/selector" }
+i-slint-renderer-skia = { version = "=1.2.0", path = "../../../internal/renderers/skia", optional = true, default-features = false }
 
 const-field-offset = { version = "0.1.2", path = "../../../helper_crates/const-field-offset" }
 document-features = { version = "0.2.0", optional = true }
@@ -177,4 +178,4 @@ rustdoc-args = [
   "--html-in-header",
   "docs/resources/slint-docs-highlight.html",
 ]
-features = ["document-features", "log", "gettext", "renderer-software", "renderer-femtovg"]
+features = ["document-features", "log", "gettext", "renderer-software", "renderer-femtovg", "renderer-skia"]

api/rs/slint/lib.rs

@@ -349,6 +349,14 @@ macro_rules! init_translations {
 /// The [Slint on Microcontrollers](crate::docs::mcu) documentation has additional examples.
 pub mod platform {
     pub use i_slint_core::platform::*;
+
+    /// This module contains the [`skia_renderer::SkiaRenderer`] and related types.
+    ///
+    /// It is only enabled when the `renderer-skia` Slint feature is enabled.
+    #[cfg(any(feature = "renderer-skia", feature = "renderer-skia-opengl", feature = "renderer-skia-vulkan"))]
+    pub mod skia_renderer {
+        pub use i_slint_renderer_skia::SkiaRenderer;
+    }
 }
 
 /// Helper type that helps checking that the generated code is generated for the right version

internal/renderers/skia/lib.rs

@@ -68,7 +68,13 @@ pub struct SkiaRenderer {
 }
 
 impl SkiaRenderer {
-    /// Creates a new renderer is associated with the provided window adapter.
+    /// Creates a new renderer for the given window/display handle. The provided size
+    /// must match the size of the underlying native window.
+    /// 
+    /// Subsequent calls to [`Self::render()`] will render into the window.
+    /// 
+    /// Safety: It is the caller's responsibility to ensure that the underlying native
+    /// window exists and remains valid for the life-time of the SkiaRenderer.
     pub fn new(
         window_handle: raw_window_handle::WindowHandle<'_>,
         display_handle: raw_window_handle::DisplayHandle<'_>,
@@ -79,20 +85,7 @@ impl SkiaRenderer {
         Ok(Self::new_with_surface(surface))
     }
 
-    /// Creates a new renderer with the given surface trait implementation.
-    pub fn new_with_surface(surface: impl Surface + 'static) -> Self {
-        Self {
-            maybe_window_adapter: Default::default(),
-            rendering_notifier: Default::default(),
-            image_cache: Default::default(),
-            path_cache: Default::default(),
-            rendering_metrics_collector: Default::default(),
-            rendering_first_time: Cell::new(true),
-            surface: Box::new(surface),
-        }
-    }
-
-    /// Render the scene in the previously associated window.
+    /// Render the scene to the window.
     pub fn render(&self) -> Result<(), i_slint_core::platform::PlatformError> {
         self.internal_render_with_post_callback(None)
     }
@@ -436,6 +429,8 @@ pub trait Surface {
 }
 
 pub trait SkiaRendererExt {
+    fn new_with_surface(surface: impl Surface + 'static) -> Self;
+
     fn render_with_post_callback(
         &self,
         post_render_cb: Option<&dyn Fn(&mut dyn ItemRenderer)>,
@@ -443,6 +438,19 @@ pub trait SkiaRendererExt {
 }
 
 impl SkiaRendererExt for SkiaRenderer {
+    /// Creates a new renderer with the given surface trait implementation.
+    fn new_with_surface(surface: impl Surface + 'static) -> Self {
+        Self {
+            maybe_window_adapter: Default::default(),
+            rendering_notifier: Default::default(),
+            image_cache: Default::default(),
+            path_cache: Default::default(),
+            rendering_metrics_collector: Default::default(),
+            rendering_first_time: Cell::new(true),
+            surface: Box::new(surface),
+        }
+    }
+
     fn render_with_post_callback(
         &self,
         post_render_cb: Option<&dyn Fn(&mut dyn ItemRenderer)>,