Auto merge of #13589 - splav:SVGElement#12974, r=pcwalton,Ms2ger

Support SVG element

<!-- Please describe your changes on the following line: -->
minimal SVG element implementation
---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #12974 (github issue number if applicable).

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- [x] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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10 files changed, 338 insertions, 10 deletions

diff --git a/components/script/dom/create.rs b/components/script/dom/create.rs
index 6cdaf2b0e78..98a2e5ad4ed 100644
--- a/components/script/dom/create.rs
+++ b/components/script/dom/create.rs
@@ -76,21 +76,44 @@ use dom::htmltrackelement::HTMLTrackElement;
 use dom::htmlulistelement::HTMLUListElement;
 use dom::htmlunknownelement::HTMLUnknownElement;
 use dom::htmlvideoelement::HTMLVideoElement;
+use dom::svgsvgelement::SVGSVGElement;
 use string_cache::{Atom, QualName};
+use util::prefs::PREFS;
 
-pub fn create_element(name: QualName,
-                      prefix: Option<Atom>,
-                      document: &Document,
-                      creator: ElementCreator)
+fn create_svg_element(name: QualName,
+                      prefix: Option<DOMString>,
+                      document: &Document)
                       -> Root<Element> {
-    // FIXME(ajeffrey): Convert directly from Atom to DOMString.
+    assert!(name.ns == ns!(svg));
 
-    let prefix = prefix.map(|p| DOMString::from(&*p));
+    macro_rules! make(
+        ($ctor:ident) => ({
+            let obj = $ctor::new(name.local, prefix, document);
+            Root::upcast(obj)
+        });
+        ($ctor:ident, $($arg:expr),+) => ({
+            let obj = $ctor::new(name.local, prefix, document, $($arg),+);
+            Root::upcast(obj)
+        })
+    );
 
-    if name.ns != ns!(html) {
+    if !PREFS.get("dom.svg.enabled").as_boolean().unwrap_or(false) {
         return Element::new(name.local, name.ns, prefix, document);
     }
 
+    match name.local {
+        atom!("svg")        => make!(SVGSVGElement),
+        _                   => Element::new(name.local, name.ns, prefix, document),
+    }
+}
+
+fn create_html_element(name: QualName,
+                      prefix: Option<DOMString>,
+                      document: &Document,
+                      creator: ElementCreator)
+                      -> Root<Element> {
+    assert!(name.ns == ns!(html));
+
     macro_rules! make(
         ($ctor:ident) => ({
             let obj = $ctor::new(name.local, prefix, document);
@@ -249,3 +272,19 @@ pub fn create_element(name: QualName,
         _                   => make!(HTMLUnknownElement),
     }
 }
+
+pub fn create_element(name: QualName,
+                      prefix: Option<Atom>,
+                      document: &Document,
+                      creator: ElementCreator)
+                      -> Root<Element> {
+    // FIXME(ajeffrey): Convert directly from Atom to DOMString.
+
+    let prefix = prefix.map(|p| DOMString::from(&*p));
+
+    match name.ns {
+        ns!(html)   => create_html_element(name, prefix, document, creator),
+        ns!(svg)    => create_svg_element(name, prefix, document),
+        _           => Element::new(name.local, name.ns, prefix, document)
+    }
+}
diff --git a/components/script/dom/mod.rs b/components/script/dom/mod.rs
index 2335f8a0a25..ace4f979be6 100644
--- a/components/script/dom/mod.rs
+++ b/components/script/dom/mod.rs
@@ -392,6 +392,9 @@ pub mod storage;
 pub mod storageevent;
 pub mod stylesheet;
 pub mod stylesheetlist;
+pub mod svgelement;
+pub mod svggraphicselement;
+pub mod svgsvgelement;
 pub mod testbinding;
 pub mod testbindingiterable;
 pub mod testbindingpairiterable;
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index c18613ac6a2..b52a8aec965 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -22,6 +22,7 @@ use dom::bindings::conversions::{self, DerivedFrom};
 use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::{Castable, CharacterDataTypeId, ElementTypeId};
 use dom::bindings::inheritance::{EventTargetTypeId, HTMLElementTypeId, NodeTypeId};
+use dom::bindings::inheritance::{SVGElementTypeId, SVGGraphicsElementTypeId};
 use dom::bindings::js::{JS, LayoutJS, MutNullableHeap};
 use dom::bindings::js::Root;
 use dom::bindings::js::RootedReference;
@@ -36,7 +37,7 @@ use dom::element::{Element, ElementCreator};
 use dom::eventtarget::EventTarget;
 use dom::globalscope::GlobalScope;
 use dom::htmlbodyelement::HTMLBodyElement;
-use dom::htmlcanvaselement::LayoutHTMLCanvasElementHelpers;
+use dom::htmlcanvaselement::{HTMLCanvasElement, LayoutHTMLCanvasElementHelpers};
 use dom::htmlcollection::HTMLCollection;
 use dom::htmlelement::HTMLElement;
 use dom::htmliframeelement::{HTMLIFrameElement, HTMLIFrameElementLayoutMethods};
@@ -46,6 +47,7 @@ use dom::htmltextareaelement::{HTMLTextAreaElement, LayoutHTMLTextAreaElementHel
 use dom::nodelist::NodeList;
 use dom::processinginstruction::ProcessingInstruction;
 use dom::range::WeakRangeVec;
+use dom::svgsvgelement::{SVGSVGElement, LayoutSVGSVGElementHelpers};
 use dom::text::Text;
 use dom::virtualmethods::{VirtualMethods, vtable_for};
 use dom::window::Window;
@@ -59,7 +61,7 @@ use libc::{self, c_void, uintptr_t};
 use msg::constellation_msg::PipelineId;
 use parse::html::parse_html_fragment;
 use ref_slice::ref_slice;
-use script_layout_interface::{HTMLCanvasData, OpaqueStyleAndLayoutData};
+use script_layout_interface::{HTMLCanvasData, OpaqueStyleAndLayoutData, SVGSVGData};
 use script_layout_interface::{LayoutElementType, LayoutNodeType, TrustedNodeAddress};
 use script_layout_interface::message::Msg;
 use script_traits::UntrustedNodeAddress;
@@ -955,6 +957,7 @@ pub trait LayoutNodeHelpers {
     fn selection(&self) -> Option<Range<usize>>;
     fn image_url(&self) -> Option<Url>;
     fn canvas_data(&self) -> Option<HTMLCanvasData>;
+    fn svg_data(&self) -> Option<SVGSVGData>;
     fn iframe_pipeline_id(&self) -> PipelineId;
     fn opaque(&self) -> OpaqueNode;
 }
@@ -1088,10 +1091,15 @@ impl LayoutNodeHelpers for LayoutJS<Node> {
     }
 
     fn canvas_data(&self) -> Option<HTMLCanvasData> {
-        self.downcast()
+        self.downcast::<HTMLCanvasElement>()
             .map(|canvas| canvas.data())
     }
 
+    fn svg_data(&self) -> Option<SVGSVGData> {
+        self.downcast::<SVGSVGElement>()
+            .map(|svg| svg.data())
+    }
+
     fn iframe_pipeline_id(&self) -> PipelineId {
         let iframe_element = self.downcast::<HTMLIFrameElement>()
             .expect("not an iframe element!");
@@ -2689,6 +2697,8 @@ impl Into<LayoutElementType> for ElementTypeId {
                 LayoutElementType::HTMLTableSectionElement,
             ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTextAreaElement) =>
                 LayoutElementType::HTMLTextAreaElement,
+            ElementTypeId::SVGElement(SVGElementTypeId::SVGGraphicsElement(SVGGraphicsElementTypeId::SVGSVGElement)) =>
+                LayoutElementType::SVGSVGElement,
             _ => LayoutElementType::Element,
         }
     }
diff --git a/components/script/dom/svgelement.rs b/components/script/dom/svgelement.rs
new file mode 100644
index 00000000000..95fd42c40b6
--- /dev/null
+++ b/components/script/dom/svgelement.rs
@@ -0,0 +1,48 @@
+/* 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 dom::bindings::codegen::Bindings::SVGElementBinding;
+use dom::bindings::inheritance::Castable;
+use dom::bindings::js::Root;
+use dom::bindings::str::DOMString;
+use dom::document::Document;
+use dom::element::Element;
+use dom::node::Node;
+use dom::virtualmethods::VirtualMethods;
+use string_cache::Atom;
+use style::element_state::ElementState;
+
+#[dom_struct]
+pub struct SVGElement {
+    element: Element,
+}
+
+impl SVGElement {
+    pub fn new_inherited(tag_name: Atom, prefix: Option<DOMString>,
+                         document: &Document) -> SVGElement {
+        SVGElement::new_inherited_with_state(ElementState::empty(), tag_name, prefix, document)
+    }
+
+    pub fn new_inherited_with_state(state: ElementState, tag_name: Atom,
+                                    prefix: Option<DOMString>, document: &Document)
+                                    -> SVGElement {
+        SVGElement {
+            element:
+                Element::new_inherited_with_state(state, tag_name, ns!(svg), prefix, document),
+        }
+    }
+
+    #[allow(unrooted_must_root)]
+    pub fn new(local_name: Atom, prefix: Option<DOMString>, document: &Document) -> Root<SVGElement> {
+        Node::reflect_node(box SVGElement::new_inherited(local_name, prefix, document),
+                           document,
+                           SVGElementBinding::Wrap)
+    }
+}
+
+impl VirtualMethods for SVGElement {
+    fn super_type(&self) -> Option<&VirtualMethods> {
+        Some(self.upcast::<Element>() as &VirtualMethods)
+    }
+}
diff --git a/components/script/dom/svggraphicselement.rs b/components/script/dom/svggraphicselement.rs
new file mode 100644
index 00000000000..bd7c8d581f7
--- /dev/null
+++ b/components/script/dom/svggraphicselement.rs
@@ -0,0 +1,48 @@
+/* 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 dom::bindings::codegen::Bindings::SVGGraphicsElementBinding;
+use dom::bindings::inheritance::Castable;
+use dom::bindings::js::Root;
+use dom::bindings::str::DOMString;
+use dom::document::Document;
+use dom::node::Node;
+use dom::svgelement::SVGElement;
+use dom::virtualmethods::VirtualMethods;
+use string_cache::Atom;
+use style::element_state::ElementState;
+
+#[dom_struct]
+pub struct SVGGraphicsElement {
+    svgelement: SVGElement,
+}
+
+impl SVGGraphicsElement {
+    pub fn new_inherited(tag_name: Atom, prefix: Option<DOMString>,
+                         document: &Document) -> SVGGraphicsElement {
+        SVGGraphicsElement::new_inherited_with_state(ElementState::empty(), tag_name, prefix, document)
+    }
+
+    pub fn new_inherited_with_state(state: ElementState, tag_name: Atom,
+                                    prefix: Option<DOMString>, document: &Document)
+                                    -> SVGGraphicsElement {
+        SVGGraphicsElement {
+            svgelement:
+                SVGElement::new_inherited_with_state(state, tag_name, prefix, document),
+        }
+    }
+
+    #[allow(unrooted_must_root)]
+    pub fn new(local_name: Atom, prefix: Option<DOMString>, document: &Document) -> Root<SVGGraphicsElement> {
+        Node::reflect_node(box SVGGraphicsElement::new_inherited(local_name, prefix, document),
+                           document,
+                           SVGGraphicsElementBinding::Wrap)
+    }
+}
+
+impl VirtualMethods for SVGGraphicsElement {
+    fn super_type(&self) -> Option<&VirtualMethods> {
+        Some(self.upcast::<SVGElement>() as &VirtualMethods)
+    }
+}
diff --git a/components/script/dom/svgsvgelement.rs b/components/script/dom/svgsvgelement.rs
new file mode 100644
index 00000000000..11c1e35b9e9
--- /dev/null
+++ b/components/script/dom/svgsvgelement.rs
@@ -0,0 +1,83 @@
+/* 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 dom::attr::Attr;
+use dom::bindings::codegen::Bindings::SVGSVGElementBinding;
+use dom::bindings::inheritance::Castable;
+use dom::bindings::js::{LayoutJS, Root};
+use dom::bindings::str::DOMString;
+use dom::document::Document;
+use dom::element::{AttributeMutation, Element, RawLayoutElementHelpers};
+use dom::node::Node;
+use dom::svggraphicselement::SVGGraphicsElement;
+use dom::virtualmethods::VirtualMethods;
+use script_layout_interface::SVGSVGData;
+use string_cache::Atom;
+use style::attr::AttrValue;
+
+const DEFAULT_WIDTH: u32 = 300;
+const DEFAULT_HEIGHT: u32 = 150;
+
+#[dom_struct]
+pub struct SVGSVGElement {
+    svggraphicselement: SVGGraphicsElement
+}
+
+impl SVGSVGElement {
+    fn new_inherited(local_name: Atom,
+                     prefix: Option<DOMString>,
+                     document: &Document) -> SVGSVGElement {
+        SVGSVGElement {
+            svggraphicselement:
+                SVGGraphicsElement::new_inherited(local_name, prefix, document)
+        }
+    }
+
+    #[allow(unrooted_must_root)]
+    pub fn new(local_name: Atom,
+               prefix: Option<DOMString>,
+               document: &Document) -> Root<SVGSVGElement> {
+        Node::reflect_node(box SVGSVGElement::new_inherited(local_name, prefix, document),
+                           document,
+                           SVGSVGElementBinding::Wrap)
+    }
+}
+
+pub trait LayoutSVGSVGElementHelpers {
+    fn data(&self) -> SVGSVGData;
+}
+
+impl LayoutSVGSVGElementHelpers for LayoutJS<SVGSVGElement> {
+    #[allow(unsafe_code)]
+    fn data(&self) -> SVGSVGData {
+        unsafe {
+            let SVG = &*self.unsafe_get();
+
+            let width_attr = SVG.upcast::<Element>().get_attr_for_layout(&ns!(), &atom!("width"));
+            let height_attr = SVG.upcast::<Element>().get_attr_for_layout(&ns!(), &atom!("height"));
+            SVGSVGData {
+                width: width_attr.map_or(DEFAULT_WIDTH, |val| val.as_uint()),
+                height: height_attr.map_or(DEFAULT_HEIGHT, |val| val.as_uint()),
+            }
+        }
+    }
+}
+
+impl VirtualMethods for SVGSVGElement {
+    fn super_type(&self) -> Option<&VirtualMethods> {
+        Some(self.upcast::<SVGGraphicsElement>() as &VirtualMethods)
+    }
+
+    fn attribute_mutated(&self, attr: &Attr, mutation: AttributeMutation) {
+        self.super_type().unwrap().attribute_mutated(attr, mutation);
+    }
+
+    fn parse_plain_attribute(&self, name: &Atom, value: DOMString) -> AttrValue {
+        match name {
+            &atom!("width") => AttrValue::from_u32(value.into(), DEFAULT_WIDTH),
+            &atom!("height") => AttrValue::from_u32(value.into(), DEFAULT_HEIGHT),
+            _ => self.super_type().unwrap().parse_plain_attribute(name, value),
+        }
+    }
+}
diff --git a/components/script/dom/virtualmethods.rs b/components/script/dom/virtualmethods.rs
index d4cf1609568..c8a8a7436a4 100644
--- a/components/script/dom/virtualmethods.rs
+++ b/components/script/dom/virtualmethods.rs
@@ -7,6 +7,8 @@ use dom::bindings::inheritance::Castable;
 use dom::bindings::inheritance::ElementTypeId;
 use dom::bindings::inheritance::HTMLElementTypeId;
 use dom::bindings::inheritance::NodeTypeId;
+use dom::bindings::inheritance::SVGElementTypeId;
+use dom::bindings::inheritance::SVGGraphicsElementTypeId;
 use dom::bindings::str::DOMString;
 use dom::document::Document;
 use dom::element::{AttributeMutation, Element};
@@ -47,6 +49,7 @@ use dom::htmltemplateelement::HTMLTemplateElement;
 use dom::htmltextareaelement::HTMLTextAreaElement;
 use dom::htmltitleelement::HTMLTitleElement;
 use dom::node::{ChildrenMutation, CloneChildrenFlag, Node, UnbindContext};
+use dom::svgsvgelement::SVGSVGElement;
 use string_cache::Atom;
 use style::attr::AttrValue;
 
@@ -231,6 +234,11 @@ pub fn vtable_for(node: &Node) -> &VirtualMethods {
         NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTitleElement)) => {
             node.downcast::<HTMLTitleElement>().unwrap() as &VirtualMethods
         }
+        NodeTypeId::Element(ElementTypeId::SVGElement(SVGElementTypeId::SVGGraphicsElement(
+                    SVGGraphicsElementTypeId::SVGSVGElement
+                ))) => {
+            node.downcast::<SVGSVGElement>().unwrap() as &VirtualMethods
+        }
         NodeTypeId::Element(ElementTypeId::Element) => {
             node.downcast::<Element>().unwrap() as &VirtualMethods
         }
diff --git a/components/script/dom/webidls/SVGElement.webidl b/components/script/dom/webidls/SVGElement.webidl
new file mode 100644
index 00000000000..02f673a420e
--- /dev/null
+++ b/components/script/dom/webidls/SVGElement.webidl
@@ -0,0 +1,22 @@
+/* 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/. */
+
+// https://svgwg.org/svg2-draft/types.html#InterfaceSVGElement
+[Pref="dom.svg.enabled"]
+interface SVGElement : Element {
+
+  //[SameObject] readonly attribute SVGAnimatedString className;
+
+  //[SameObject] readonly attribute DOMStringMap dataset;
+
+  //readonly attribute SVGSVGElement? ownerSVGElement;
+  //readonly attribute SVGElement? viewportElement;
+
+  //attribute long tabIndex;
+  //void focus();
+  //void blur();
+};
+
+//SVGElement implements GlobalEventHandlers;
+//SVGElement implements SVGElementInstance;
diff --git a/components/script/dom/webidls/SVGGraphicsElement.webidl b/components/script/dom/webidls/SVGGraphicsElement.webidl
new file mode 100644
index 00000000000..d8f90e639ea
--- /dev/null
+++ b/components/script/dom/webidls/SVGGraphicsElement.webidl
@@ -0,0 +1,22 @@
+/* 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/. */
+
+// https://svgwg.org/svg2-draft/types.html#InterfaceSVGGraphicsElement
+[Pref="dom.svg.enabled"]
+//dictionary SVGBoundingBoxOptions {
+//  boolean fill = true;
+//  boolean stroke = false;
+//  boolean markers = false;
+//  boolean clipped = false;
+//};
+
+interface SVGGraphicsElement : SVGElement {
+  //[SameObject] readonly attribute SVGAnimatedTransformList transform;
+
+  //DOMRect getBBox(optional SVGBoundingBoxOptions options);
+  //DOMMatrix? getCTM();
+  //DOMMatrix? getScreenCTM();
+};
+
+//SVGGraphicsElement implements SVGTests;
diff --git a/components/script/dom/webidls/SVGSVGElement.webidl b/components/script/dom/webidls/SVGSVGElement.webidl
new file mode 100644
index 00000000000..bed2c03a74b
--- /dev/null
+++ b/components/script/dom/webidls/SVGSVGElement.webidl
@@ -0,0 +1,45 @@
+/* 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/. */
+
+// https://svgwg.org/svg2-draft/struct.html#InterfaceSVGSVGElement
+[Pref="dom.svg.enabled"]
+interface SVGSVGElement : SVGGraphicsElement {
+
+  //[SameObject] readonly attribute SVGAnimatedLength x;
+  //[SameObject] readonly attribute SVGAnimatedLength y;
+  //[SameObject] readonly attribute SVGAnimatedLength width;
+  //[SameObject] readonly attribute SVGAnimatedLength height;
+
+  //attribute float currentScale;
+  //[SameObject] readonly attribute DOMPointReadOnly currentTranslate;
+
+  //NodeList getIntersectionList(DOMRectReadOnly rect, SVGElement? referenceElement);
+  //NodeList getEnclosureList(DOMRectReadOnly rect, SVGElement? referenceElement);
+  //boolean checkIntersection(SVGElement element, DOMRectReadOnly rect);
+  //boolean checkEnclosure(SVGElement element, DOMRectReadOnly rect);
+
+  //void deselectAll();
+
+  //SVGNumber createSVGNumber();
+  //SVGLength createSVGLength();
+  //SVGAngle createSVGAngle();
+  //DOMPoint createSVGPoint();
+  //DOMMatrix createSVGMatrix();
+  //DOMRect createSVGRect();
+  //SVGTransform createSVGTransform();
+  //SVGTransform createSVGTransformFromMatrix(DOMMatrixReadOnly matrix);
+
+  //Element getElementById(DOMString elementId);
+
+  // Deprecated methods that have no effect when called,
+  // but which are kept for compatibility reasons.
+  //unsigned long suspendRedraw(unsigned long maxWaitMilliseconds);
+  //void unsuspendRedraw(unsigned long suspendHandleID);
+  //void unsuspendRedrawAll();
+  //void forceRedraw();
+};
+
+//SVGSVGElement implements SVGFitToViewBox;
+//SVGSVGElement implements SVGZoomAndPan;
+//SVGSVGElement implements WindowEventHandlers;