Auto merge of #26697 - utsavoza:ugo/issue-11681/22-05-2020, r=jdm

Implement CanvasRenderingContext2d.fillText

The PR consists of broadly two main changes:
- Implementation of Canvas2dRenderingContext.font
- Basic implementation of Canvas2dRenderingContext.fillText

Although I am not fully sure about the long term goals for the canvas backend in Servo, I assumed limited scope for font and text handling (should support simple text drawing with font selection) in the current implementation as I believe a more complete implementation would eventually be brought in as a part of #22957.

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #11681
- [x] There are tests for these changes

1 files changed, 51 insertions, 6 deletions

diff --git a/components/script/dom/offscreencanvasrenderingcontext2d.rs b/components/script/dom/offscreencanvasrenderingcontext2d.rs
index a3a873250f1..8c3deb001f4 100644
--- a/components/script/dom/offscreencanvasrenderingcontext2d.rs
+++ b/components/script/dom/offscreencanvasrenderingcontext2d.rs
@@ -3,10 +3,13 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use crate::canvas_state::CanvasState;
+use crate::dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasDirection;
 use crate::dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasFillRule;
 use crate::dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasImageSource;
 use crate::dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasLineCap;
 use crate::dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasLineJoin;
+use crate::dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasTextAlign;
+use crate::dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasTextBaseline;
 use crate::dom::bindings::codegen::Bindings::OffscreenCanvasRenderingContext2DBinding::OffscreenCanvasRenderingContext2DMethods;
 use crate::dom::bindings::codegen::UnionTypes::StringOrCanvasGradientOrCanvasPattern;
 use crate::dom::bindings::error::ErrorResult;
@@ -60,11 +63,6 @@ impl OffscreenCanvasRenderingContext2D {
         ));
         reflect_dom_object(boxed, global)
     }
-    /*
-    pub fn get_canvas_state(&self) -> Ref<CanvasState> {
-        self.canvas_state.borrow()
-    }
-    */
 
     pub fn set_canvas_bitmap_dimensions(&self, size: Size2D<u64>) {
         self.canvas_state.set_bitmap_dimensions(size);
@@ -249,7 +247,13 @@ impl OffscreenCanvasRenderingContext2DMethods for OffscreenCanvasRenderingContex
 
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-filltext
     fn FillText(&self, text: DOMString, x: f64, y: f64, max_width: Option<f64>) {
-        self.canvas_state.fill_text(text, x, y, max_width)
+        self.canvas_state.fill_text(
+            self.htmlcanvas.as_ref().map(|c| &**c),
+            text,
+            x,
+            y,
+            max_width,
+        )
     }
 
     // https://html.spec.whatwg.org/multipage/#textmetrics
@@ -257,6 +261,47 @@ impl OffscreenCanvasRenderingContext2DMethods for OffscreenCanvasRenderingContex
         self.canvas_state.measure_text(&self.global(), text)
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-font
+    fn Font(&self) -> DOMString {
+        self.canvas_state.font()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-font
+    fn SetFont(&self, value: DOMString) {
+        self.canvas_state
+            .set_font(self.htmlcanvas.as_ref().map(|c| &**c), value)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-textalign
+    fn TextAlign(&self) -> CanvasTextAlign {
+        self.canvas_state.text_align()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-textalign
+    fn SetTextAlign(&self, value: CanvasTextAlign) {
+        self.canvas_state.set_text_align(value)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-textbaseline
+    fn TextBaseline(&self) -> CanvasTextBaseline {
+        self.canvas_state.text_baseline()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-textbaseline
+    fn SetTextBaseline(&self, value: CanvasTextBaseline) {
+        self.canvas_state.set_text_baseline(value)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-direction
+    fn Direction(&self) -> CanvasDirection {
+        self.canvas_state.direction()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-context-2d-direction
+    fn SetDirection(&self, value: CanvasDirection) {
+        self.canvas_state.set_direction(value)
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-linewidth
     fn LineWidth(&self) -> f64 {
         self.canvas_state.line_width()