Support custom renderers in iced_test through renderer::Headless trait

core/src/lib.rs

@@ -40,6 +40,7 @@ mod pixels;
 mod point;
 mod rectangle;
 mod rotation;
+mod settings;
 mod shadow;
 mod shell;
 mod size;
@@ -67,6 +68,7 @@ pub use point::Point;
 pub use rectangle::Rectangle;
 pub use renderer::Renderer;
 pub use rotation::Rotation;
+pub use settings::Settings;
 pub use shadow::Shadow;
 pub use shell::Shell;
 pub use size::Size;

core/src/renderer.rs

@@ -3,7 +3,8 @@
 mod null;
 
 use crate::{
-    Background, Border, Color, Rectangle, Shadow, Size, Transformation, Vector,
+    Background, Border, Color, Font, Pixels, Rectangle, Shadow, Size,
+    Transformation, Vector,
 };
 
 /// A component that can be used by widgets to draw themselves on a screen.
@@ -100,3 +101,19 @@ impl Default for Style {
         }
     }
 }
+
+/// A headless renderer is a renderer that can render offscreen without
+/// a window nor a compositor.
+pub trait Headless {
+    /// Creates a new [`Headless`] renderer;
+    fn new(default_font: Font, default_text_size: Pixels) -> Self;
+
+    /// Draws offscreen into a screenshot, returning a collection of
+    /// bytes representing the rendered pixels in RGBA order.
+    fn screenshot(
+        &mut self,
+        size: Size<u32>,
+        scale_factor: f32,
+        background_color: Color,
+    ) -> Vec<u8>;
+}

core/src/settings.rs

@@ -0,0 +1,50 @@
+//! Configure your application.
+use crate::{Font, Pixels};
+
+use std::borrow::Cow;
+
+/// The settings of an iced program.
+#[derive(Debug, Clone)]
+pub struct Settings {
+    /// The identifier of the application.
+    ///
+    /// If provided, this identifier may be used to identify the application or
+    /// communicate with it through the windowing system.
+    pub id: Option<String>,
+
+    /// The fonts to load on boot.
+    pub fonts: Vec<Cow<'static, [u8]>>,
+
+    /// The default [`Font`] to be used.
+    ///
+    /// By default, it uses [`Family::SansSerif`](crate::font::Family::SansSerif).
+    pub default_font: Font,
+
+    /// The text size that will be used by default.
+    ///
+    /// The default value is `16.0`.
+    pub default_text_size: Pixels,
+
+    /// If set to true, the renderer will try to perform antialiasing for some
+    /// primitives.
+    ///
+    /// Enabling it can produce a smoother result in some widgets, like the
+    /// [`Canvas`], at a performance cost.
+    ///
+    /// By default, it is disabled.
+    ///
+    /// [`Canvas`]: crate::widget::Canvas
+    pub antialiasing: bool,
+}
+
+impl Default for Settings {
+    fn default() -> Self {
+        Self {
+            id: None,
+            fonts: Vec::new(),
+            default_font: Font::default(),
+            default_text_size: Pixels(16.0),
+            antialiasing: false,
+        }
+    }
+}