Auto merge of #9529 - paulrouget:focusEvents, r=asajeffrey

Implement focus, blur, focusin and focusout events

Based on https://github.com/servo/servo/pull/7985

Fixes https://github.com/servo/servo/issues/7981

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components/script/dom/document.rs

@@ -38,6 +38,7 @@ use dom::domimplementation::DOMImplementation;
 use dom::element::{Element, ElementCreator};
 use dom::event::{Event, EventBubbles, EventCancelable};
 use dom::eventtarget::EventTarget;
+use dom::focusevent::FocusEvent;
 use dom::htmlanchorelement::HTMLAnchorElement;
 use dom::htmlappletelement::HTMLAppletElement;
 use dom::htmlareaelement::HTMLAreaElement;
@@ -609,17 +610,21 @@ impl Document {
     /// Reassign the focus context to the element that last requested focus during this
     /// transaction, or none if no elements requested it.
     pub fn commit_focus_transaction(&self, focus_type: FocusType) {
-        // TODO: dispatch blur, focus, focusout, and focusin events
 
         if let Some(ref elem) = self.focused.get() {
+            let node = elem.upcast::<Node>();
             elem.set_focus_state(false);
+            // FIXME: pass appropriate relatedTarget
+            self.fire_focus_event(FocusEventType::Blur, node, None);
         }
 
         self.focused.set(self.possibly_focused.get().r());
 
         if let Some(ref elem) = self.focused.get() {
             elem.set_focus_state(true);
-
+            let node = elem.upcast::<Node>();
+            // FIXME: pass appropriate relatedTarget
+            self.fire_focus_event(FocusEventType::Focus, node, None);
             // Update the focus state for all elements in the focus chain.
             // https://html.spec.whatwg.org/multipage/#focus-chain
             if focus_type == FocusType::Element {
@@ -1451,6 +1456,25 @@ impl Document {
     pub fn get_dom_complete(&self) -> u64 {
         self.dom_complete.get()
     }
+
+    // https://html.spec.whatwg.org/multipage/#fire-a-focus-event
+    fn fire_focus_event(&self, focus_event_type: FocusEventType, node: &Node, relatedTarget: Option<&EventTarget>) {
+        let (event_name, does_bubble) = match focus_event_type {
+            FocusEventType::Focus => (DOMString::from("focus"), EventBubbles::DoesNotBubble),
+            FocusEventType::Blur => (DOMString::from("blur"), EventBubbles::DoesNotBubble),
+        };
+        let event = FocusEvent::new(&self.window,
+                                    event_name,
+                                    does_bubble,
+                                    EventCancelable::NotCancelable,
+                                    Some(&self.window),
+                                    0i32,
+                                    relatedTarget);
+        let event = event.upcast::<Event>();
+        event.set_trusted(true);
+        let target = node.upcast();
+        event.fire(target);
+    }
 }
 
 #[derive(PartialEq, HeapSizeOf)]
@@ -2579,3 +2603,9 @@ pub enum FocusType {
     Element,    // The first focus message - focus the element itself
     Parent,     // Focusing a parent element (an iframe)
 }
+
+/// Focus events
+pub enum FocusEventType {
+    Focus,      // Element gained focus. Doesn't bubble.
+    Blur,       // Element lost focus. Doesn't bubble.
+}

components/script/dom/focusevent.rs

@@ -0,0 +1,84 @@
+/* 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::FocusEventBinding;
+use dom::bindings::codegen::Bindings::FocusEventBinding::FocusEventMethods;
+use dom::bindings::codegen::Bindings::UIEventBinding::UIEventMethods;
+use dom::bindings::error::Fallible;
+use dom::bindings::global::GlobalRef;
+use dom::bindings::inheritance::Castable;
+use dom::bindings::js::{JS, MutNullableHeap, Root, RootedReference};
+use dom::bindings::reflector::reflect_dom_object;
+use dom::event::{EventBubbles, EventCancelable};
+use dom::eventtarget::EventTarget;
+use dom::uievent::UIEvent;
+use dom::window::Window;
+use std::default::Default;
+use util::str::DOMString;
+
+#[dom_struct]
+pub struct FocusEvent {
+    uievent: UIEvent,
+    related_target: MutNullableHeap<JS<EventTarget>>,
+}
+
+impl FocusEvent {
+    fn new_inherited() -> FocusEvent {
+        FocusEvent {
+            uievent: UIEvent::new_inherited(),
+            related_target: Default::default(),
+        }
+    }
+
+    pub fn new(window: &Window,
+               type_: DOMString,
+               can_bubble: EventBubbles,
+               cancelable: EventCancelable,
+               view: Option<&Window>,
+               detail: i32,
+               related_target: Option<&EventTarget>) -> Root<FocusEvent> {
+        let event = box FocusEvent::new_inherited();
+        let ev = reflect_dom_object(event, GlobalRef::Window(window), FocusEventBinding::Wrap);
+        ev.upcast::<UIEvent>().InitUIEvent(type_,
+                                           can_bubble == EventBubbles::Bubbles,
+                                           cancelable == EventCancelable::Cancelable,
+                                           view, detail);
+        ev.related_target.set(related_target);
+        ev
+    }
+
+    pub fn Constructor(global: GlobalRef,
+                       type_: DOMString,
+                       init: &FocusEventBinding::FocusEventInit) -> Fallible<Root<FocusEvent>> {
+        let bubbles = if init.parent.parent.bubbles {
+            EventBubbles::Bubbles
+        } else {
+            EventBubbles::DoesNotBubble
+        };
+        let cancelable = if init.parent.parent.cancelable {
+            EventCancelable::Cancelable
+        } else {
+            EventCancelable::NotCancelable
+        };
+        let event = FocusEvent::new(global.as_window(), type_,
+                                    bubbles,
+                                    cancelable,
+                                    init.parent.view.r(),
+                                    init.parent.detail,
+                                    init.relatedTarget.r());
+        Ok(event)
+    }
+}
+
+impl FocusEventMethods for FocusEvent {
+    // https://w3c.github.io/uievents/#widl-FocusEvent-relatedTarget
+    fn GetRelatedTarget(&self) -> Option<Root<EventTarget>> {
+        self.related_target.get()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-event-istrusted
+    fn IsTrusted(&self) -> bool {
+        self.uievent.IsTrusted()
+    }
+}

components/script/dom/mod.rs

@@ -253,6 +253,7 @@ pub mod eventtarget;
 pub mod file;
 pub mod filelist;
 pub mod filereader;
+pub mod focusevent;
 pub mod formdata;
 pub mod htmlanchorelement;
 pub mod htmlappletelement;

components/script/dom/webidls/FocusEvent.webidl

@@ -0,0 +1,14 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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://w3c.github.io/uievents/#interface-FocusEvent
+[Constructor(DOMString typeArg, optional FocusEventInit focusEventInitDict)]
+interface FocusEvent : UIEvent {
+  readonly attribute EventTarget?   relatedTarget;
+};
+
+dictionary FocusEventInit : UIEventInit {
+    EventTarget? relatedTarget = null;
+};