feat: SVG styling with icon fill color

graphics/src/image/vector.rs

@@ -7,6 +7,8 @@ use iced_native::Size;
 use std::collections::{HashMap, HashSet};
 use std::fs;
 
+type Fill = Option<[u8; 4]>;
+
 /// Entry in cache corresponding to an svg handle
 pub enum Svg {
     /// Parsed svg
@@ -33,9 +35,9 @@ impl Svg {
 #[derive(Debug)]
 pub struct Cache<T: Storage> {
     svgs: HashMap<u64, Svg>,
-    rasterized: HashMap<(u64, u32, u32), T::Entry>,
+    rasterized: HashMap<(u64, u32, u32, Fill), T::Entry>,
     svg_hits: HashSet<u64>,
-    rasterized_hits: HashSet<(u64, u32, u32)>,
+    rasterized_hits: HashSet<(u64, u32, u32, Fill)>,
 }
 
 impl<T: Storage> Cache<T> {
@@ -88,15 +90,18 @@ impl<T: Storage> Cache<T> {
             (scale * height).ceil() as u32,
         );
 
+        let appearance = handle.appearance();
+        let fill = appearance.fill.map(crate::Color::into_rgba8);
+
         // TODO: Optimize!
         // We currently rerasterize the SVG when its size changes. This is slow
         // as heck. A GPU rasterizer like `pathfinder` may perform better.
         // It would be cool to be able to smooth resize the `svg` example.
-        if self.rasterized.contains_key(&(id, width, height)) {
+        if self.rasterized.contains_key(&(id, width, height, fill)) {
             let _ = self.svg_hits.insert(id);
-            let _ = self.rasterized_hits.insert((id, width, height));
+            let _ = self.rasterized_hits.insert((id, width, height, fill));
 
-            return self.rasterized.get(&(id, width, height));
+            return self.rasterized.get(&(id, width, height, fill));
         }
 
         match self.load(handle) {
@@ -121,15 +126,28 @@ impl<T: Storage> Cache<T> {
                     img.as_mut(),
                 )?;
 
-                let allocation =
-                    storage.upload(width, height, img.data(), state)?;
+                let mut rgba = img.take();
+
+                if let Some(color) = fill {
+                    rgba.chunks_exact_mut(4).for_each(|rgba| {
+                        if rgba[3] > 0 {
+                            rgba[0] = color[0];
+                            rgba[1] = color[1];
+                            rgba[2] = color[2];
+                        }
+                    });
+                }
+
+                let allocation = storage.upload(width, height, &rgba, state)?;
                 log::debug!("allocating {} {}x{}", id, width, height);
 
                 let _ = self.svg_hits.insert(id);
-                let _ = self.rasterized_hits.insert((id, width, height));
-                let _ = self.rasterized.insert((id, width, height), allocation);
+                let _ = self.rasterized_hits.insert((id, width, height, fill));
+                let _ = self
+                    .rasterized
+                    .insert((id, width, height, fill), allocation);
 
-                self.rasterized.get(&(id, width, height))
+                self.rasterized.get(&(id, width, height, fill))
             }
             Svg::NotFound => None,
         }

native/src/svg.rs

@@ -6,11 +6,14 @@ use std::hash::{Hash, Hasher as _};
 use std::path::PathBuf;
 use std::sync::Arc;
 
+pub use iced_style::svg::{Appearance, StyleSheet};
+
 /// A handle of Svg data.
 #[derive(Debug, Clone)]
 pub struct Handle {
     id: u64,
     data: Arc<Data>,
+    appearance: Appearance,
 }
 
 impl Handle {
@@ -36,6 +39,7 @@ impl Handle {
         Handle {
             id: hasher.finish(),
             data: Arc::new(data),
+            appearance: Appearance::default(),
         }
     }
 
@@ -48,6 +52,16 @@ impl Handle {
     pub fn data(&self) -> &Data {
         &self.data
     }
+
+    /// Returns the styling [`Appearance`] for the SVG.
+    pub fn appearance(&self) -> Appearance {
+        self.appearance
+    }
+
+    /// Set the [`Appearance`] for the SVG.
+    pub fn set_appearance(&mut self, appearance: Appearance) {
+        self.appearance = appearance;
+    }
 }
 
 impl Hash for Handle {

native/src/widget/helpers.rs

@@ -285,6 +285,12 @@ where
 ///
 /// [`Svg`]: widget::Svg
 /// [`Handle`]: widget::svg::Handle
-pub fn svg(handle: impl Into<widget::svg::Handle>) -> widget::Svg {
+pub fn svg<Renderer>(
+    handle: impl Into<widget::svg::Handle>,
+) -> widget::Svg<Renderer>
+where
+    Renderer: crate::svg::Renderer,
+    Renderer::Theme: crate::svg::StyleSheet,
+{
     widget::Svg::new(handle)
 }

native/src/widget/svg.rs

@@ -9,7 +9,7 @@ use crate::{
 
 use std::path::PathBuf;
 
-pub use svg::Handle;
+pub use svg::{Handle, StyleSheet};
 
 /// A vector graphics image.
 ///
@@ -17,15 +17,25 @@ pub use svg::Handle;
 ///
 /// [`Svg`] images can have a considerable rendering cost when resized,
 /// specially when they are complex.
-#[derive(Debug, Clone)]
-pub struct Svg {
+#[derive(Clone)]
+#[allow(missing_debug_implementations)]
+pub struct Svg<Renderer>
+where
+    Renderer: svg::Renderer,
+    Renderer::Theme: StyleSheet,
+{
     handle: Handle,
     width: Length,
     height: Length,
     content_fit: ContentFit,
+    style: <Renderer::Theme as StyleSheet>::Style,
 }
 
-impl Svg {
+impl<Renderer> Svg<Renderer>
+where
+    Renderer: svg::Renderer,
+    Renderer::Theme: StyleSheet,
+{
     /// Creates a new [`Svg`] from the given [`Handle`].
     pub fn new(handle: impl Into<Handle>) -> Self {
         Svg {
@@ -33,22 +43,26 @@ impl Svg {
             width: Length::Fill,
             height: Length::Shrink,
             content_fit: ContentFit::Contain,
+            style: Default::default(),
         }
     }
 
     /// Creates a new [`Svg`] that will display the contents of the file at the
     /// provided path.
+    #[must_use]
     pub fn from_path(path: impl Into<PathBuf>) -> Self {
         Self::new(Handle::from_path(path))
     }
 
     /// Sets the width of the [`Svg`].
+    #[must_use]
     pub fn width(mut self, width: Length) -> Self {
         self.width = width;
         self
     }
 
     /// Sets the height of the [`Svg`].
+    #[must_use]
     pub fn height(mut self, height: Length) -> Self {
         self.height = height;
         self
@@ -57,17 +71,29 @@ impl Svg {
     /// Sets the [`ContentFit`] of the [`Svg`].
     ///
     /// Defaults to [`ContentFit::Contain`]
+    #[must_use]
     pub fn content_fit(self, content_fit: ContentFit) -> Self {
         Self {
             content_fit,
             ..self
         }
     }
+
+    /// Sets the style variant of this [`Svg`].
+    #[must_use]
+    pub fn style(
+        mut self,
+        style: <Renderer::Theme as StyleSheet>::Style,
+    ) -> Self {
+        self.style = style;
+        self
+    }
 }
 
-impl<Message, Renderer> Widget<Message, Renderer> for Svg
+impl<Message, Renderer> Widget<Message, Renderer> for Svg<Renderer>
 where
     Renderer: svg::Renderer,
+    Renderer::Theme: iced_style::svg::StyleSheet,
 {
     fn width(&self) -> Length {
         self.width
@@ -114,12 +140,15 @@ where
         &self,
         _state: &Tree,
         renderer: &mut Renderer,
-        _theme: &Renderer::Theme,
+        theme: &Renderer::Theme,
         _style: &renderer::Style,
         layout: Layout<'_>,
         _cursor_position: Point,
         _viewport: &Rectangle,
     ) {
+        let mut handle = self.handle.clone();
+        handle.set_appearance(theme.appearance(self.style));
+
         let Size { width, height } = renderer.dimensions(&self.handle);
         let image_size = Size::new(width as f32, height as f32);
 
@@ -138,7 +167,7 @@ where
                 ..bounds
             };
 
-            renderer.draw(self.handle.clone(), drawing_bounds + offset)
+            renderer.draw(handle, drawing_bounds + offset);
         };
 
         if adjusted_fit.width > bounds.width
@@ -146,16 +175,18 @@ where
         {
             renderer.with_layer(bounds, render);
         } else {
-            render(renderer)
+            render(renderer);
         }
     }
 }
 
-impl<'a, Message, Renderer> From<Svg> for Element<'a, Message, Renderer>
+impl<'a, Message, Renderer> From<Svg<Renderer>>
+    for Element<'a, Message, Renderer>
 where
-    Renderer: svg::Renderer,
+    Renderer: svg::Renderer + 'a,
+    Renderer::Theme: iced_style::svg::StyleSheet,
 {
-    fn from(icon: Svg) -> Element<'a, Message, Renderer> {
+    fn from(icon: Svg<Renderer>) -> Element<'a, Message, Renderer> {
         Element::new(icon)
     }
 }

style/src/lib.rs

@@ -32,6 +32,7 @@ pub mod radio;
 pub mod rule;
 pub mod scrollable;
 pub mod slider;
+pub mod svg;
 pub mod text;
 pub mod text_input;
 pub mod theme;

style/src/svg.rs

@@ -0,0 +1,21 @@
+//! Change the appearance of a svg.
+
+use iced_core::Color;
+
+/// The appearance of a svg.
+#[derive(Debug, Default, Clone, Copy)]
+pub struct Appearance {
+    /// Changes the fill color
+    ///
+    /// Useful for coloring a symbolic icon.
+    pub fill: Option<Color>,
+}
+
+/// The stylesheet of a svg.
+pub trait StyleSheet {
+    /// The supported style of the [`StyleSheet`].
+    type Style: Default + Copy;
+
+    /// Produces the [`Appearance`] of the svg.
+    fn appearance(&self, style: Self::Style) -> Appearance;
+}

style/src/theme.rs

@@ -16,6 +16,7 @@ use crate::radio;
 use crate::rule;
 use crate::scrollable;
 use crate::slider;
+use crate::svg;
 use crate::text;
 use crate::text_input;
 use crate::toggler;
@@ -797,6 +798,29 @@ impl From<fn(&Theme) -> rule::Appearance> for Rule {
     }
 }
 
+/**
+ * SVG
+ */
+#[derive(Default, Clone, Copy)]
+pub enum Svg {
+    /// No filtering to the rendered SVG.
+    #[default]
+    Default,
+    /// Apply custom filtering to the SVG.
+    Custom(fn(&Theme) -> svg::Appearance),
+}
+
+impl svg::StyleSheet for Theme {
+    type Style = Svg;
+
+    fn appearance(&self, style: Self::Style) -> svg::Appearance {
+        match style {
+            Svg::Default => Default::default(),
+            Svg::Custom(appearance) => appearance(self),
+        }
+    }
+}
+
 impl rule::StyleSheet for Theme {
     type Style = Rule;