Auto merge of #17578 - pyfisch:input-event, r=jdm

Implement the InputEvent

Add WebIDL, from UI Events working draft.
Implement script type for event.

Note that actually firing InputEvents is not part of this commit.

<!-- Please describe your changes on the following line: -->
As part of my effort to improve [keyboard handling](https://groups.google.com/forum/#!topic/mozilla.dev.servo/e6R7eBDjo4M) it is necessary to introduce the InputEvent. While I have a working prototype using the input event this still needs a lot of work  before it can be merged into servo.

cc @jdm

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components/script/dom/inputevent.rs

@@ -0,0 +1,73 @@
+/* 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::InputEventBinding::{self, InputEventMethods};
+use dom::bindings::codegen::Bindings::UIEventBinding::UIEventBinding::UIEventMethods;
+use dom::bindings::error::Fallible;
+use dom::bindings::js::{Root, RootedReference};
+use dom::bindings::reflector::reflect_dom_object;
+use dom::bindings::str::DOMString;
+use dom::uievent::UIEvent;
+use dom::window::Window;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct InputEvent {
+    uievent: UIEvent,
+    data: Option<DOMString>,
+    is_composing: bool,
+}
+
+impl InputEvent {
+    pub fn new(window: &Window,
+               type_: DOMString,
+               can_bubble: bool,
+               cancelable: bool,
+               view: Option<&Window>,
+               detail: i32,
+               data: Option<DOMString>,
+               is_composing: bool) -> Root<InputEvent> {
+        let ev = reflect_dom_object(box InputEvent {
+                                        uievent: UIEvent::new_inherited(),
+                                        data: data,
+                                        is_composing: is_composing,
+                                    },
+                                    window,
+                                    InputEventBinding::Wrap);
+        ev.uievent.InitUIEvent(type_, can_bubble, cancelable, view, detail);
+        ev
+    }
+
+    pub fn Constructor(window: &Window,
+                       type_: DOMString,
+                       init: &InputEventBinding::InputEventInit)
+                       -> Fallible<Root<InputEvent>> {
+        let event = InputEvent::new(window,
+                                    type_,
+                                    init.parent.parent.bubbles,
+                                    init.parent.parent.cancelable,
+                                    init.parent.view.r(),
+                                    init.parent.detail,
+                                    init.data.clone(),
+                                    init.isComposing);
+        Ok(event)
+    }
+}
+
+impl InputEventMethods for InputEvent {
+    // https://w3c.github.io/uievents/#dom-inputevent-data
+    fn GetData(&self) -> Option<DOMString> {
+        self.data.clone()
+    }
+
+    // https://w3c.github.io/uievents/#dom-inputevent-iscomposing
+    fn IsComposing(&self) -> bool {
+        self.is_composing
+    }
+
+    // https://dom.spec.whatwg.org/#dom-event-istrusted
+    fn IsTrusted(&self) -> bool {
+        self.uievent.IsTrusted()
+    }
+}

components/script/dom/mod.rs

@@ -372,6 +372,7 @@ pub mod htmlulistelement;
 pub mod htmlunknownelement;
 pub mod htmlvideoelement;
 pub mod imagedata;
+pub mod inputevent;
 pub mod keyboardevent;
 pub mod location;
 pub mod mediaerror;

components/script/dom/webidls/InputEvent.webidl

@@ -0,0 +1,21 @@
+/* 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/. */
+/*
+ * The origin of this IDL file is
+ * https://w3c.github.io/uievents/#idl-inputevent
+ *
+ */
+
+// https://w3c.github.io/uievents/#idl-inputevent
+[Constructor(DOMString type, optional InputEventInit eventInitDict)]
+interface InputEvent : UIEvent {
+  readonly attribute DOMString? data;
+  readonly attribute boolean isComposing;
+};
+
+// https://w3c.github.io/uievents/#idl-inputeventinit
+dictionary InputEventInit : UIEventInit {
+  DOMString? data = null;
+  boolean isComposing = false;
+};