WIP: Add example app to test text rendering

gpui/examples/text.rs

@@ -0,0 +1,113 @@
+use gpui::{
+    fonts::{Properties, Weight},
+    platform::{current as platform, Runner},
+    scene::Glyph,
+    Element as _,
+};
+use log::LevelFilter;
+use pathfinder_color::ColorU;
+use simplelog::SimpleLogger;
+
+fn main() {
+    SimpleLogger::init(LevelFilter::Info, Default::default()).expect("could not initialize logger");
+
+    let mut app = gpui::App::new(()).unwrap();
+    platform::runner()
+        .on_finish_launching(move || {
+            app.platform().activate(true);
+            app.add_window(|_| View);
+        })
+        .run();
+}
+
+struct View;
+struct Element;
+
+impl gpui::Entity for View {
+    type Event = ();
+}
+
+impl gpui::View for View {
+    fn ui_name() -> &'static str {
+        "view"
+    }
+
+    fn render<'a>(&self, app: &gpui::AppContext) -> gpui::ElementBox {
+        Element.boxed()
+    }
+}
+
+impl gpui::Element for Element {
+    type LayoutState = ();
+
+    type PaintState = ();
+
+    fn layout(
+        &mut self,
+        constraint: gpui::SizeConstraint,
+        ctx: &mut gpui::LayoutContext,
+    ) -> (pathfinder_geometry::vector::Vector2F, Self::LayoutState) {
+        (constraint.max, ())
+    }
+
+    fn after_layout(
+        &mut self,
+        size: pathfinder_geometry::vector::Vector2F,
+        layout: &mut Self::LayoutState,
+        ctx: &mut gpui::AfterLayoutContext,
+    ) {
+    }
+
+    fn paint(
+        &mut self,
+        bounds: pathfinder_geometry::rect::RectF,
+        layout: &mut Self::LayoutState,
+        ctx: &mut gpui::PaintContext,
+    ) -> Self::PaintState {
+        let font_size = 18.;
+        let family = ctx.font_cache.load_family(&["Fira Code"]).unwrap();
+        let normal = ctx
+            .font_cache
+            .select_font(family, &Default::default())
+            .unwrap();
+        let bold = ctx
+            .font_cache
+            .select_font(
+                family,
+                &Properties {
+                    weight: Weight::BOLD,
+                    ..Default::default()
+                },
+            )
+            .unwrap();
+
+        let line = ctx.text_layout_cache.layout_str(
+            "xxXX",
+            font_size,
+            &[(0..1, normal), (1..2, bold), (2..3, normal), (3..4, bold)],
+        );
+
+        for run in line.runs {
+            for glyph in run.glyphs {
+                ctx.scene.push_glyph(Glyph {
+                    font_id: run.font_id,
+                    font_size,
+                    id: glyph.id,
+                    origin: glyph.position,
+                    color: ColorU::black(),
+                });
+            }
+        }
+    }
+
+    fn dispatch_event(
+        &mut self,
+        event: &gpui::Event,
+        bounds: pathfinder_geometry::rect::RectF,
+        layout: &mut Self::LayoutState,
+        paint: &mut Self::PaintState,
+        ctx: &mut gpui::EventContext,
+    ) -> bool {
+        false
+    }
+}