feat: Expose scale factor (#607)

* feat: Reactive scale factor

* feat: Expose scale factor

Author: marc2332

crates/components/src/graph.rs

@@ -43,7 +43,7 @@ pub fn Graph(props: GraphProps) -> Element {
     }));
 
     let canvas = use_canvas(&props, |state| {
-        Box::new(move |canvas, font_collection, region| {
+        Box::new(move |canvas, font_collection, region, _| {
             canvas.translate((region.min_x(), region.min_y()));
 
             let mut paragraph_style = ParagraphStyle::default();

crates/core/src/platform_state.rs

@@ -9,6 +9,7 @@ pub struct NativePlatformState {
     pub preferred_theme: PreferredTheme,
     pub navigation_mode: NavigationMode,
     pub information: PlatformInformation,
+    pub scale_factor: f32,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Default)]

crates/hooks/src/use_canvas.rs

@@ -35,7 +35,7 @@ impl UseCanvas {
 /// # use freya::prelude::*;
 /// fn app() -> Element {
 ///     let canvas = use_canvas((), |_| {
-///         Box::new(|canvas, font_collection, area| {
+///         Box::new(|canvas, font_collection, area, scale_factor| {
 ///             // Draw using the canvas !
 ///         })
 ///     });

crates/renderer/src/app.rs

@@ -81,6 +81,7 @@ impl Application {
             preferred_theme: window.theme().map(|theme| theme.into()).unwrap_or_default(),
             navigation_mode: NavigationMode::default(),
             information: PlatformInformation::from_winit(window),
+            scale_factor: window.scale_factor() as f32,
         });
 
         plugins.send(PluginEvent::WindowCreated(window));

crates/renderer/src/elements/rect.rs

@@ -180,6 +180,6 @@ pub fn render_rect(
     let references = node_ref.get::<References>().unwrap();
 
     if let Some(canvas_ref) = &references.canvas_ref {
-        (canvas_ref.runner)(canvas, font_collection, area);
+        (canvas_ref.runner)(canvas, font_collection, area, scale_factor);
     }
 }

crates/renderer/src/renderer.rs

@@ -397,6 +397,12 @@ impl<'a, State: Clone> ApplicationHandler<EventMessage> for DesktopRenderer<'a,
                 });
             }
             WindowEvent::RedrawRequested => {
+                app.platform_sender.send_if_modified(|state| {
+                    let scale_factor_is_different = state.scale_factor == scale_factor;
+                    state.scale_factor = scale_factor;
+                    scale_factor_is_different
+                });
+
                 if app.measure_layout_on_next_render {
                     app.process_layout(window.inner_size(), scale_factor);
                     app.process_accessibility(window);

crates/state/src/custom_attributes.rs

@@ -47,7 +47,7 @@ impl Display for NodeReference {
     }
 }
 
-pub type CanvasRunner = dyn Fn(&Canvas, &mut FontCollection, Area) + Sync + Send + 'static;
+pub type CanvasRunner = dyn Fn(&Canvas, &mut FontCollection, Area, f32) + Sync + Send + 'static;
 
 /// Canvas Reference
 #[derive(Clone)]

crates/testing/src/launch.rs

@@ -10,9 +10,9 @@ use tokio::sync::mpsc::unbounded_channel;
 use tokio::sync::{broadcast, watch};
 use winit::window::CursorIcon;
 
-use crate::config::TestingConfig;
 use crate::test_handler::TestingHandler;
 use crate::test_utils::TestUtils;
+use crate::{config::TestingConfig, SCALE_FACTOR};
 
 /// Run a Component in a headless testing environment.
 ///
@@ -34,6 +34,7 @@ pub fn launch_test_with_config(root: AppComponent, config: TestingConfig) -> Tes
         preferred_theme: PreferredTheme::default(),
         navigation_mode: NavigationMode::default(),
         information: PlatformInformation::new(config.size, false, false, false),
+        scale_factor: SCALE_FACTOR as f32,
     });
     let mut font_collection = FontCollection::new();
     let font_mgr = FontMgr::default();

examples/render_canvas.rs

@@ -19,7 +19,7 @@ fn app() -> Element {
     });
 
     let canvas = use_canvas(&*state.read(), |state| {
-        Box::new(move |canvas, font_collection, region| {
+        Box::new(move |canvas, font_collection, region, _| {
             canvas.translate((region.min_x(), region.min_y()));
 
             let mut text_paint = Paint::default();

examples/shader.rs

@@ -51,7 +51,7 @@ fn app() -> Element {
         let shader_wrapper = Arc::new(Mutex::new(ShaderWrapper(shader)));
         let instant = Instant::now();
 
-        Box::new(move |canvas, _, region| {
+        Box::new(move |canvas, _, region, _| {
             let shader = shader_wrapper.lock().unwrap();
 
             let mut builder = UniformsBuilder::default();