Make use of FromStr and Default traits in lib canvas

fixup! Make use of FromStr and Default traits in lib canvas

2 files changed, 109 insertions, 82 deletions

diff --git a/components/canvas_traits/lib.rs b/components/canvas_traits/lib.rs
index 6f2924d2171..00cde267e83 100644
--- a/components/canvas_traits/lib.rs
+++ b/components/canvas_traits/lib.rs
@@ -37,6 +37,8 @@ use ipc_channel::ipc::{IpcSender, IpcSharedMemory};
 use layers::platform::surface::NativeSurface;
 use offscreen_gl_context::GLContextAttributes;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use std::default::Default;
+use std::str::FromStr;
 use std::sync::mpsc::Sender;
 use util::mem::HeapSizeOf;
 
@@ -345,6 +347,19 @@ pub enum LineCapStyle {
     Square = 2,
 }
 
+impl FromStr for LineCapStyle {
+    type Err = ();
+
+    fn from_str(string: &str) -> Result<LineCapStyle, ()> {
+        match string {
+            "butt" => Ok(LineCapStyle::Butt),
+            "round" => Ok(LineCapStyle::Round),
+            "square" => Ok(LineCapStyle::Square),
+            _ => Err(()),
+        }
+    }
+}
+
 impl LineCapStyle {
     pub fn to_azure_style(&self) -> CapStyle {
         match *self {
@@ -353,15 +368,6 @@ impl LineCapStyle {
             LineCapStyle::Square => CapStyle::Square,
         }
     }
-
-    pub fn from_str(string: &str) -> Option<LineCapStyle> {
-        match string {
-            "butt" => Some(LineCapStyle::Butt),
-            "round" => Some(LineCapStyle::Round),
-            "square" => Some(LineCapStyle::Square),
-            _ => None
-        }
-    }
 }
 
 #[derive(Copy, Clone, PartialEq, Deserialize, Serialize, HeapSizeOf)]
@@ -371,6 +377,19 @@ pub enum LineJoinStyle {
     Miter = 2,
 }
 
+impl FromStr for LineJoinStyle {
+    type Err = ();
+
+    fn from_str(string: &str) -> Result<LineJoinStyle, ()> {
+        match string {
+            "round" => Ok(LineJoinStyle::Round),
+            "bevel" => Ok(LineJoinStyle::Bevel),
+            "miter" => Ok(LineJoinStyle::Miter),
+            _ => Err(()),
+        }
+    }
+}
+
 impl LineJoinStyle {
     pub fn to_azure_style(&self) -> JoinStyle {
         match *self {
@@ -379,15 +398,6 @@ impl LineJoinStyle {
             LineJoinStyle::Miter => JoinStyle::Miter,
         }
     }
-
-    pub fn from_str(string: &str) -> Option<LineJoinStyle> {
-        match string {
-            "round" => Some(LineJoinStyle::Round),
-            "bevel" => Some(LineJoinStyle::Bevel),
-            "miter" => Some(LineJoinStyle::Miter),
-            _ => None
-        }
-    }
 }
 
 #[derive(Copy, Clone, PartialEq, Deserialize, Serialize)]
@@ -398,14 +408,16 @@ pub enum RepetitionStyle {
     NoRepeat,
 }
 
-impl RepetitionStyle {
-    pub fn from_str(string: &str) -> Option<RepetitionStyle> {
+impl FromStr for RepetitionStyle {
+    type Err = ();
+
+    fn from_str(string: &str) -> Result<RepetitionStyle, ()> {
         match string {
-            "repeat" => Some(RepetitionStyle::Repeat),
-            "repeat-x" => Some(RepetitionStyle::RepeatX),
-            "repeat-y" => Some(RepetitionStyle::RepeatY),
-            "no-repeat" => Some(RepetitionStyle::NoRepeat),
-            _ => None
+            "repeat" => Ok(RepetitionStyle::Repeat),
+            "repeat-x" => Ok(RepetitionStyle::RepeatX),
+            "repeat-y" => Ok(RepetitionStyle::RepeatY),
+            "no-repeat" => Ok(RepetitionStyle::NoRepeat),
+            _ => Err(()),
         }
     }
 }
@@ -425,6 +437,27 @@ pub enum CompositionStyle {
     Xor,
 }
 
+impl FromStr for CompositionStyle {
+    type Err = ();
+
+    fn from_str(string: &str) -> Result<CompositionStyle, ()> {
+        match string {
+            "source-in"        => Ok(CompositionStyle::SrcIn),
+            "source-out"       => Ok(CompositionStyle::SrcOut),
+            "source-over"      => Ok(CompositionStyle::SrcOver),
+            "source-atop"      => Ok(CompositionStyle::SrcAtop),
+            "destination-in"   => Ok(CompositionStyle::DestIn),
+            "destination-out"  => Ok(CompositionStyle::DestOut),
+            "destination-over" => Ok(CompositionStyle::DestOver),
+            "destination-atop" => Ok(CompositionStyle::DestAtop),
+            "copy"             => Ok(CompositionStyle::Copy),
+            "lighter"          => Ok(CompositionStyle::Lighter),
+            "xor"              => Ok(CompositionStyle::Xor),
+            _ => Err(())
+        }
+    }
+}
+
 impl CompositionStyle {
     pub fn to_azure_style(&self) -> CompositionOp {
         match *self {
@@ -442,23 +475,6 @@ impl CompositionStyle {
         }
     }
 
-    pub fn from_str(string: &str) -> Option<CompositionStyle> {
-        match string {
-            "source-in"        => Some(CompositionStyle::SrcIn),
-            "source-out"       => Some(CompositionStyle::SrcOut),
-            "source-over"      => Some(CompositionStyle::SrcOver),
-            "source-atop"      => Some(CompositionStyle::SrcAtop),
-            "destination-in"   => Some(CompositionStyle::DestIn),
-            "destination-out"  => Some(CompositionStyle::DestOut),
-            "destination-over" => Some(CompositionStyle::DestOver),
-            "destination-atop" => Some(CompositionStyle::DestAtop),
-            "copy"             => Some(CompositionStyle::Copy),
-            "lighter"          => Some(CompositionStyle::Lighter),
-            "xor"              => Some(CompositionStyle::Xor),
-            _ => None
-        }
-    }
-
     pub fn to_str(&self) -> &str {
         match *self {
             CompositionStyle::SrcIn    => "source-in",
@@ -495,6 +511,31 @@ pub enum BlendingStyle {
     Luminosity,
 }
 
+impl FromStr for BlendingStyle {
+    type Err = ();
+
+    fn from_str(string: &str) -> Result<BlendingStyle, ()> {
+        match string {
+            "multiply"    => Ok(BlendingStyle::Multiply),
+            "screen"      => Ok(BlendingStyle::Screen),
+            "overlay"     => Ok(BlendingStyle::Overlay),
+            "darken"      => Ok(BlendingStyle::Darken),
+            "lighten"     => Ok(BlendingStyle::Lighten),
+            "color-dodge" => Ok(BlendingStyle::ColorDodge),
+            "color-burn"  => Ok(BlendingStyle::ColorBurn),
+            "hard-light"  => Ok(BlendingStyle::HardLight),
+            "soft-light"  => Ok(BlendingStyle::SoftLight),
+            "difference"  => Ok(BlendingStyle::Difference),
+            "exclusion"   => Ok(BlendingStyle::Exclusion),
+            "hue"         => Ok(BlendingStyle::Hue),
+            "saturation"  => Ok(BlendingStyle::Saturation),
+            "color"       => Ok(BlendingStyle::Color),
+            "luminosity"  => Ok(BlendingStyle::Luminosity),
+            _ => Err(())
+        }
+    }
+}
+
 impl BlendingStyle {
     pub fn to_azure_style(&self) -> CompositionOp {
         match *self {
@@ -516,27 +557,6 @@ impl BlendingStyle {
         }
     }
 
-    pub fn from_str(string: &str) -> Option<BlendingStyle> {
-        match string {
-            "multiply"    => Some(BlendingStyle::Multiply),
-            "screen"      => Some(BlendingStyle::Screen),
-            "overlay"     => Some(BlendingStyle::Overlay),
-            "darken"      => Some(BlendingStyle::Darken),
-            "lighten"     => Some(BlendingStyle::Lighten),
-            "color-dodge" => Some(BlendingStyle::ColorDodge),
-            "color-burn"  => Some(BlendingStyle::ColorBurn),
-            "hard-light"  => Some(BlendingStyle::HardLight),
-            "soft-light"  => Some(BlendingStyle::SoftLight),
-            "difference"  => Some(BlendingStyle::Difference),
-            "exclusion"   => Some(BlendingStyle::Exclusion),
-            "hue"         => Some(BlendingStyle::Hue),
-            "saturation"  => Some(BlendingStyle::Saturation),
-            "color"       => Some(BlendingStyle::Color),
-            "luminosity"  => Some(BlendingStyle::Luminosity),
-            _ => None
-        }
-    }
-
     pub fn to_str(&self) -> &str {
         match *self {
             BlendingStyle::Multiply   => "multiply",
@@ -564,28 +584,34 @@ pub enum CompositionOrBlending {
     Blending(BlendingStyle),
 }
 
-impl CompositionOrBlending {
-    pub fn to_azure_style(&self) -> CompositionOp {
-        match *self {
-            CompositionOrBlending::Composition(op) => op.to_azure_style(),
-            CompositionOrBlending::Blending(op) => op.to_azure_style(),
-        }
-    }
-
-    pub fn default() -> CompositionOrBlending {
+impl Default for CompositionOrBlending {
+    fn default() -> CompositionOrBlending {
         CompositionOrBlending::Composition(CompositionStyle::SrcOver)
     }
+}
+
+impl FromStr for CompositionOrBlending {
+    type Err = ();
 
-    pub fn from_str(string: &str) -> Option<CompositionOrBlending> {
-        if let Some(op) = CompositionStyle::from_str(string) {
-            return Some(CompositionOrBlending::Composition(op));
+    fn from_str(string: &str) -> Result<CompositionOrBlending, ()> {
+        if let Ok(op) = CompositionStyle::from_str(string) {
+            return Ok(CompositionOrBlending::Composition(op));
         }
 
-        if let Some(op) = BlendingStyle::from_str(string) {
-            return Some(CompositionOrBlending::Blending(op));
+        if let Ok(op) = BlendingStyle::from_str(string) {
+            return Ok(CompositionOrBlending::Blending(op));
         }
 
-        None
+        Err(())
+    }
+}
+
+impl CompositionOrBlending {
+    pub fn to_azure_style(&self) -> CompositionOp {
+        match *self {
+            CompositionOrBlending::Composition(op) => op.to_azure_style(),
+            CompositionOrBlending::Blending(op) => op.to_azure_style(),
+        }
     }
 }
 
diff --git a/components/script/dom/canvasrenderingcontext2d.rs b/components/script/dom/canvasrenderingcontext2d.rs
index 893ad97b526..57feaf5e9d7 100644
--- a/components/script/dom/canvasrenderingcontext2d.rs
+++ b/components/script/dom/canvasrenderingcontext2d.rs
@@ -45,6 +45,7 @@ use std::borrow::ToOwned;
 use std::cell::RefCell;
 use std::cmp;
 use std::fmt;
+use std::str::FromStr;
 use std::sync::mpsc::channel;
 
 use url::Url;
@@ -568,7 +569,7 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D {
 
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-globalcompositeoperation
     fn SetGlobalCompositeOperation(&self, op_str: DOMString) {
-        if let Some(op) = CompositionOrBlending::from_str(&op_str) {
+        if let Ok(op) = CompositionOrBlending::from_str(&op_str) {
             self.state.borrow_mut().global_composition = op;
             self.ipc_renderer
                 .send(CanvasMsg::Canvas2d(Canvas2dMsg::SetGlobalComposition(op)))
@@ -1006,7 +1007,7 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D {
             },
         };
 
-        if let Some(rep) = RepetitionStyle::from_str(&repetition) {
+        if let Ok(rep) = RepetitionStyle::from_str(&repetition) {
             return Ok(CanvasPattern::new(self.global.root().r(),
                                          image_data,
                                          Size2D::new(image_size.width as i32, image_size.height as i32),
@@ -1045,7 +1046,7 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D {
 
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-linecap
     fn SetLineCap(&self, cap_str: DOMString) {
-        if let Some(cap) = LineCapStyle::from_str(&cap_str) {
+        if let Ok(cap) = LineCapStyle::from_str(&cap_str) {
             self.state.borrow_mut().line_cap = cap;
             self.ipc_renderer.send(CanvasMsg::Canvas2d(Canvas2dMsg::SetLineCap(cap))).unwrap()
         }
@@ -1063,7 +1064,7 @@ impl CanvasRenderingContext2DMethods for CanvasRenderingContext2D {
 
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-linejoin
     fn SetLineJoin(&self, join_str: DOMString) {
-        if let Some(join) = LineJoinStyle::from_str(&join_str) {
+        if let Ok(join) = LineJoinStyle::from_str(&join_str) {
             self.state.borrow_mut().line_join = join;
             self.ipc_renderer.send(CanvasMsg::Canvas2d(Canvas2dMsg::SetLineJoin(join))).unwrap()
         }