Add a canvas create, break script’s dependency on gfx.

The build time on my laptop after touching gfx goes from 1m37s ot 46s.

1 files changed, 78 insertions, 0 deletions

diff --git a/src/components/canvas/canvas_render_task.rs b/src/components/canvas/canvas_render_task.rs
new file mode 100644
index 00000000000..7eafd1aef09
--- /dev/null
+++ b/src/components/canvas/canvas_render_task.rs
@@ -0,0 +1,78 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use azure::azure_hl::{DrawTarget, Color, B8G8R8A8, SkiaBackend, StrokeOptions, DrawOptions};
+use azure::azure_hl::ColorPattern;
+use geom::rect::Rect;
+use geom::size::Size2D;
+
+use std::comm;
+use std::task::TaskBuilder;
+
+pub enum CanvasMsg {
+    FillRect(Rect<f32>),
+    ClearRect(Rect<f32>),
+    StrokeRect(Rect<f32>),
+    Recreate(Size2D<i32>),
+    Close,
+}
+
+pub struct CanvasRenderTask {
+    drawtarget: DrawTarget,
+    fill_color: ColorPattern,
+    stroke_color: ColorPattern,
+    stroke_opts: StrokeOptions,
+}
+
+impl CanvasRenderTask {
+    fn new(size: Size2D<i32>) -> CanvasRenderTask {
+        CanvasRenderTask {
+            drawtarget: CanvasRenderTask::create(size),
+            fill_color: ColorPattern::new(Color::new(0., 0., 0., 1.)),
+            stroke_color: ColorPattern::new(Color::new(0., 0., 0., 1.)),
+            stroke_opts: StrokeOptions::new(1.0, 1.0),
+        }
+    }
+
+    pub fn start(size: Size2D<i32>) -> Sender<CanvasMsg> {
+        let (chan, port) = comm::channel::<CanvasMsg>();
+        let builder = TaskBuilder::new().named("CanvasTask");
+        builder.spawn(proc() {
+            let mut renderer = CanvasRenderTask::new(size);
+
+            loop {
+                match port.recv() {
+                    FillRect(ref rect) => renderer.fill_rect(rect),
+                    StrokeRect(ref rect) => renderer.stroke_rect(rect),
+                    ClearRect(ref rect) => renderer.clear_rect(rect),
+                    Recreate(size) => renderer.recreate(size),
+                    Close => break,
+                }
+            }
+        });
+        chan
+    }
+
+    fn fill_rect(&self, rect: &Rect<f32>) {
+        let drawopts = DrawOptions::new(1.0, 0);
+        self.drawtarget.fill_rect(rect, &self.fill_color, Some(&drawopts));
+    }
+
+    fn clear_rect(&self, rect: &Rect<f32>) {
+        self.drawtarget.clear_rect(rect);
+    }
+
+    fn stroke_rect(&self, rect: &Rect<f32>) {
+        let drawopts = DrawOptions::new(1.0, 0);
+        self.drawtarget.stroke_rect(rect, &self.stroke_color, &self.stroke_opts, &drawopts);
+    }
+
+    fn create(size: Size2D<i32>) -> DrawTarget {
+        DrawTarget::new(SkiaBackend, size, B8G8R8A8)
+    }
+
+    fn recreate(&mut self, size: Size2D<i32>) {
+        self.drawtarget = CanvasRenderTask::create(size);
+    }
+}