Adds linear gradient support to 2D meshes in the canvas widget.

graphics/src/widget/canvas/stroke.rs

@@ -1,10 +1,14 @@
 use iced_native::Color;
 
+use crate::widget::canvas::Gradient;
+
 /// The style of a stroke.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone)]
 pub struct Stroke<'a> {
-    /// The color of the stroke.
-    pub color: Color,
+    /// The color or gradient of the stroke.
+    ///
+    /// By default, it is set to [`StrokeStyle::Solid`] `BLACK`.
+    pub style: StrokeStyle<'a>,
     /// The distance between the two edges of the stroke.
     pub width: f32,
     /// The shape to be used at the end of open subpaths when they are stroked.
@@ -19,7 +23,10 @@ pub struct Stroke<'a> {
 impl<'a> Stroke<'a> {
     /// Sets the color of the [`Stroke`].
     pub fn with_color(self, color: Color) -> Self {
-        Stroke { color, ..self }
+        Stroke {
+            style: StrokeStyle::Solid(color),
+            ..self
+        }
     }
 
     /// Sets the width of the [`Stroke`].
@@ -41,7 +48,7 @@ impl<'a> Stroke<'a> {
 impl<'a> Default for Stroke<'a> {
     fn default() -> Self {
         Stroke {
-            color: Color::BLACK,
+            style: StrokeStyle::Solid(Color::BLACK),
             width: 1.0,
             line_cap: LineCap::default(),
             line_join: LineJoin::default(),
@@ -50,6 +57,15 @@ impl<'a> Default for Stroke<'a> {
     }
 }
 
+/// The color or gradient of a [`Stroke`].
+#[derive(Debug, Clone, Copy)]
+pub enum StrokeStyle<'a> {
+    /// A solid color
+    Solid(Color),
+    /// A color gradient
+    Gradient(&'a Gradient),
+}
+
 /// The shape used at the end of open subpaths when they are stroked.
 #[derive(Debug, Clone, Copy)]
 pub enum LineCap {