Auto merge of #13972 - shravan-achar:master, r=Manishearth,emilio,jdm

ImageMaps: Implemented support for parsing coord attribute to a shape…

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Image Maps: (Part 1) Implemented support for parsing coord attribute to a shape object.
                       Implemented a hit_test method to see if a point is within the area. Tests for constructors                      and hit_test included

---

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- [ ] `./mach build -d` does not report any errors
- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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

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… object in HTMLAreaElement

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This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/13972)

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4 files changed, 339 insertions, 2 deletions

diff --git a/components/script/dom/htmlanchorelement.rs b/components/script/dom/htmlanchorelement.rs
index 52c355f2bab..3731b9d46de 100644
--- a/components/script/dom/htmlanchorelement.rs
+++ b/components/script/dom/htmlanchorelement.rs
@@ -576,7 +576,7 @@ fn is_current_browsing_context(target: DOMString) -> bool {
 }
 
 /// https://html.spec.whatwg.org/multipage/#following-hyperlinks-2
-fn follow_hyperlink(subject: &Element, hyperlink_suffix: Option<String>, referrer_policy: Option<ReferrerPolicy>) {
+pub fn follow_hyperlink(subject: &Element, hyperlink_suffix: Option<String>, referrer_policy: Option<ReferrerPolicy>) {
     // Step 1: replace.
     // Step 2: source browsing context.
     // Step 3: target browsing context.
diff --git a/components/script/dom/htmlareaelement.rs b/components/script/dom/htmlareaelement.rs
index 79240885167..7b86a61a773 100644
--- a/components/script/dom/htmlareaelement.rs
+++ b/components/script/dom/htmlareaelement.rs
@@ -2,6 +2,8 @@
  * 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::activation::Activatable;
+use dom::bindings::codegen::Bindings::DOMTokenListBinding::DOMTokenListMethods;
 use dom::bindings::codegen::Bindings::HTMLAreaElementBinding;
 use dom::bindings::codegen::Bindings::HTMLAreaElementBinding::HTMLAreaElementMethods;
 use dom::bindings::inheritance::Castable;
@@ -9,13 +11,208 @@ use dom::bindings::js::{MutNullableJS, Root};
 use dom::bindings::str::DOMString;
 use dom::document::Document;
 use dom::domtokenlist::DOMTokenList;
+use dom::element::Element;
+use dom::event::Event;
+use dom::eventtarget::EventTarget;
+use dom::htmlanchorelement::follow_hyperlink;
 use dom::htmlelement::HTMLElement;
-use dom::node::Node;
+use dom::node::{Node, document_from_node};
 use dom::virtualmethods::VirtualMethods;
+use euclid::point::Point2D;
 use html5ever_atoms::LocalName;
+use net_traits::ReferrerPolicy;
 use std::default::Default;
+use std::f32;
 use style::attr::AttrValue;
 
+#[derive(PartialEq)]
+#[derive(Debug)]
+pub enum Area {
+    Circle { left: f32, top: f32, radius: f32 },
+    Rectangle { top_left: (f32, f32), bottom_right: (f32, f32) },
+    Polygon { points: Vec<f32> },
+}
+
+pub enum Shape {
+    Circle,
+    Rectangle,
+    Polygon,
+}
+
+// https://html.spec.whatwg.org/multipage/#rules-for-parsing-a-list-of-floating-point-numbers
+// https://html.spec.whatwg.org/multipage/#image-map-processing-model
+impl Area {
+    pub fn parse(coord: &str, target: Shape) -> Option<Area> {
+        let points_count =  match target {
+            Shape::Circle => 3,
+            Shape::Rectangle => 4,
+            Shape::Polygon => 0,
+        };
+
+        let size = coord.len();
+        let num = coord.as_bytes();
+        let mut index = 0;
+
+        // Step 4: Walk till char is not a delimiter
+        while index < size {
+            let val = num[index];
+            match val {
+                b',' | b';' | b' ' | b'\t' | b'\n' | 0x0C | b'\r'  => {},
+                _ => break,
+            }
+
+            index += 1;
+        }
+
+        //This vector will hold all parsed coordinates
+        let mut number_list = Vec::new();
+        let mut array = Vec::new();
+        let ar_ref = &mut array;
+
+        // Step 5: walk till end of string
+        while index < size {
+            // Step 5.1: walk till we hit a valid char i.e., 0 to 9, dot or dash, e, E
+            while index < size {
+                let val = num[index];
+                match val {
+                    b'0'...b'9' | b'.' | b'-' | b'E' | b'e' => break,
+                    _ => {},
+                }
+
+                index += 1;
+            }
+
+            // Step 5.2: collect valid symbols till we hit another delimiter
+            while index < size {
+                let val = num[index];
+
+                match val {
+                    b',' | b';' | b' ' | b'\t' | b'\n' | 0x0C | b'\r' => break,
+                    _ => (*ar_ref).push(val),
+                }
+
+                index += 1;
+            }
+
+            // The input does not consist any valid charecters
+            if (*ar_ref).is_empty() {
+                break;
+            }
+
+            // Convert String to float
+            match String::from_utf8((*ar_ref).clone()).unwrap().parse::<f32>() {
+                Ok(v) => number_list.push(v),
+                Err(_) => number_list.push(0.0),
+            };
+
+            (*ar_ref).clear();
+
+            // For rectangle and circle, stop parsing once we have three
+            // and four coordinates respectively
+            if points_count > 0 && number_list.len() == points_count {
+                break;
+            }
+        }
+
+        let final_size = number_list.len();
+
+        match target {
+            Shape::Circle => {
+                if final_size == 3 {
+                    if number_list[2] <= 0.0 {
+                        None
+                    } else {
+                        Some(Area::Circle {
+                                 left: number_list[0],
+                                 top: number_list[1],
+                                 radius: number_list[2]
+                             })
+                    }
+                } else {
+                    None
+                }
+            },
+
+            Shape::Rectangle => {
+                if final_size == 4 {
+                    if number_list[0] > number_list[2] {
+                        number_list.swap(0, 2);
+                    }
+
+                    if number_list[1] > number_list[3] {
+                        number_list.swap(1, 3);
+                    }
+
+                    Some(Area::Rectangle {
+                             top_left: (number_list[0], number_list[1]),
+                             bottom_right: (number_list[2], number_list[3])
+                         })
+                } else {
+                    None
+                }
+            },
+
+            Shape::Polygon => {
+                if final_size >= 6 {
+                    if final_size % 2 != 0 {
+                        // Drop last element if there are odd number of coordinates
+                        number_list.remove(final_size - 1);
+                    }
+                    Some(Area::Polygon { points: number_list })
+                } else {
+                    None
+                }
+            },
+        }
+    }
+
+    pub fn hit_test(&self, p: Point2D<f32>) -> bool {
+        match *self {
+            Area::Circle { left, top, radius } => {
+                (p.x - left) * (p.x - left) +
+                (p.y - top) * (p.y - top) -
+                radius * radius <= 0.0
+            },
+
+            Area::Rectangle { top_left, bottom_right } => {
+                p.x <= bottom_right.0 && p.x >= top_left.0 &&
+                p.y <= bottom_right.1 && p.y >= top_left.1
+            },
+
+            //TODO polygon hit_test
+            _ => false,
+        }
+    }
+
+    pub fn absolute_coords(&self, p: Point2D<f32>) -> Area {
+        match *self {
+            Area::Rectangle { top_left, bottom_right } => {
+                Area::Rectangle {
+                    top_left: (top_left.0 + p.x, top_left.1 + p.y),
+                    bottom_right: (bottom_right.0 + p.x, bottom_right.1 + p.y)
+                }
+            },
+            Area::Circle { left, top, radius } => {
+                Area::Circle {
+                    left: (left + p.x),
+                    top: (top + p.y),
+                    radius: radius
+                }
+            },
+            Area::Polygon { ref points } => {
+//                let new_points = Vec::new();
+                let iter = points.iter().enumerate().map(|(index, point)| {
+                    match index % 2 {
+                        0 => point + p.x as f32,
+                        _ => point + p.y as f32,
+                    }
+                });
+                Area::Polygon { points: iter.collect::<Vec<_>>() }
+            },
+        }
+    }
+}
+
 #[dom_struct]
 pub struct HTMLAreaElement {
     htmlelement: HTMLElement,
@@ -38,6 +235,26 @@ impl HTMLAreaElement {
                            document,
                            HTMLAreaElementBinding::Wrap)
     }
+
+    pub fn get_shape_from_coords(&self) -> Option<Area> {
+       let elem = self.upcast::<Element>();
+       let shape = elem.get_string_attribute(&"shape".into());
+       let shp: Shape = match shape.to_lowercase().as_ref() {
+           "circle" => Shape::Circle,
+           "circ" => Shape::Circle,
+           "rectangle" => Shape::Rectangle,
+           "rect" => Shape::Rectangle,
+           "polygon" => Shape::Rectangle,
+           "poly" => Shape::Polygon,
+           _ => return None,
+        };
+        if elem.has_attribute(&"coords".into()) {
+            let attribute = elem.get_string_attribute(&"coords".into());
+            Area::parse(&attribute, shp)
+        } else {
+            None
+        }
+    }
 }
 
 impl VirtualMethods for HTMLAreaElement {
@@ -61,3 +278,40 @@ impl HTMLAreaElementMethods for HTMLAreaElement {
         })
     }
 }
+
+impl Activatable for HTMLAreaElement {
+    // https://html.spec.whatwg.org/multipage/#the-area-element:activation-behaviour
+    fn as_element(&self) -> &Element {
+        self.upcast::<Element>()
+    }
+
+    fn is_instance_activatable(&self) -> bool {
+        self.as_element().has_attribute(&local_name!("href"))
+    }
+
+    fn pre_click_activation(&self) {
+    }
+
+    fn canceled_activation(&self) {
+    }
+
+    fn implicit_submission(&self, _ctrl_key: bool, _shift_key: bool,
+                           _alt_key: bool, _meta_key: bool) {
+    }
+
+    fn activation_behavior(&self, _event: &Event, _target: &EventTarget) {
+        // Step 1
+        let doc = document_from_node(self);
+        if !doc.is_fully_active() {
+            return;
+        }
+        // Step 2
+        // TODO : We should be choosing a browsing context and navigating to it.
+        // Step 3
+        let referrer_policy = match self.RelList().Contains("noreferrer".into()) {
+            true => Some(ReferrerPolicy::NoReferrer),
+            false => None,
+        };
+        follow_hyperlink(self.upcast::<Element>(), None, referrer_policy);
+    }
+}
diff --git a/components/script/dom/htmlimageelement.rs b/components/script/dom/htmlimageelement.rs
index a86f0258918..29ddcd0a7c4 100644
--- a/components/script/dom/htmlimageelement.rs
+++ b/components/script/dom/htmlimageelement.rs
@@ -3,10 +3,14 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use app_units::{Au, AU_PER_PX};
+use dom::activation::Activatable;
 use dom::attr::Attr;
 use dom::bindings::cell::DOMRefCell;
+use dom::bindings::codegen::Bindings::DOMRectBinding::DOMRectBinding::DOMRectMethods;
+use dom::bindings::codegen::Bindings::ElementBinding::ElementBinding::ElementMethods;
 use dom::bindings::codegen::Bindings::HTMLImageElementBinding;
 use dom::bindings::codegen::Bindings::HTMLImageElementBinding::HTMLImageElementMethods;
+use dom::bindings::codegen::Bindings::MouseEventBinding::MouseEventMethods;
 use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
 use dom::bindings::error::Fallible;
 use dom::bindings::inheritance::Castable;
@@ -15,17 +19,23 @@ use dom::bindings::refcounted::Trusted;
 use dom::bindings::str::DOMString;
 use dom::document::Document;
 use dom::element::{AttributeMutation, Element, RawLayoutElementHelpers};
+use dom::event::Event;
 use dom::eventtarget::EventTarget;
+use dom::htmlareaelement::HTMLAreaElement;
 use dom::htmlelement::HTMLElement;
+use dom::htmlmapelement::HTMLMapElement;
+use dom::mouseevent::MouseEvent;
 use dom::node::{Node, NodeDamage, document_from_node, window_from_node};
 use dom::values::UNSIGNED_LONG_MAX;
 use dom::virtualmethods::VirtualMethods;
 use dom::window::Window;
+use euclid::point::Point2D;
 use html5ever_atoms::LocalName;
 use ipc_channel::ipc;
 use ipc_channel::router::ROUTER;
 use net_traits::image::base::{Image, ImageMetadata};
 use net_traits::image_cache_thread::{ImageResponder, ImageResponse};
+use num_traits::ToPrimitive;
 use script_thread::Runnable;
 use servo_url::ServoUrl;
 use std::i32;
@@ -234,6 +244,38 @@ impl HTMLImageElement {
 
         Ok(image)
     }
+    pub fn areas(&self) -> Option<Vec<Root<HTMLAreaElement>>> {
+        let elem = self.upcast::<Element>();
+        let usemap_attr;
+        if elem.has_attribute(&LocalName::from("usemap")) {
+            usemap_attr = elem.get_string_attribute(&local_name!("usemap"));
+        } else {
+            return None;
+        }
+
+        let (first, last) = usemap_attr.split_at(1);
+
+        match first {
+            "#" => {},
+            _ => return None,
+        };
+
+        match last.len() {
+            0 => return None,
+            _ => {},
+        };
+
+        let map = self.upcast::<Node>()
+                      .following_siblings()
+                      .filter_map(Root::downcast::<HTMLMapElement>)
+                      .find(|n| n.upcast::<Element>().get_string_attribute(&LocalName::from("name")) == last);
+
+        let elements: Vec<Root<HTMLAreaElement>> = map.unwrap().upcast::<Node>()
+                      .children()
+                      .filter_map(Root::downcast::<HTMLAreaElement>)
+                      .collect();
+        Some(elements)
+    }
 }
 
 pub trait LayoutHTMLImageElementHelpers {
@@ -429,6 +471,43 @@ impl VirtualMethods for HTMLImageElement {
             _ => self.super_type().unwrap().parse_plain_attribute(name, value),
         }
     }
+
+    fn handle_event(&self, event: &Event) {
+       if (event.type_() == atom!("click")) {
+           let area_elements = self.areas();
+           let elements = if let Some(x) = area_elements {
+               x
+           } else {
+               return
+           };
+
+           // Fetch click coordinates
+           let mouse_event = if let Some(x) = event.downcast::<MouseEvent>() {
+               x
+           } else {
+               return;
+           };
+
+           let point = Point2D::new(mouse_event.ClientX().to_f32().unwrap(), mouse_event.ClientY().to_f32().unwrap());
+           // Walk HTMLAreaElements
+           let mut index = 0;
+           while index < elements.len() {
+               let shape = elements[index].get_shape_from_coords();
+               let p = Point2D::new(self.upcast::<Element>().GetBoundingClientRect().X() as f32,
+               self.upcast::<Element>().GetBoundingClientRect().Y() as f32);
+               let shp = if let Some(x) = shape {
+                   x.absolute_coords(p)
+               } else {
+                   return
+               };
+               if shp.hit_test(point) {
+                   elements[index].activation_behavior(event, self.upcast());
+                   return
+               }
+               index += 1;
+           }
+       }
+    }
 }
 
 fn image_dimension_setter(element: &Element, attr: LocalName, value: u32) {
diff --git a/components/script/test.rs b/components/script/test.rs
index 31353b5ffa3..83523c47817 100644
--- a/components/script/test.rs
+++ b/components/script/test.rs
@@ -10,6 +10,10 @@ pub use dom::bindings::cell::DOMRefCell;
 pub use dom::bindings::js::JS;
 pub use dom::node::Node;
 
+pub mod area {
+    pub use dom::htmlareaelement::{Area, Shape};
+}
+
 pub mod size_of {
     use dom::characterdata::CharacterData;
     use dom::element::Element;