1 files changed, 160 insertions, 0 deletions
diff --git a/components/script/dom/wheelevent.rs b/components/script/dom/wheelevent.rs
new file mode 100644
index 00000000000..d7e33b84633
--- /dev/null
+++ b/components/script/dom/wheelevent.rs
@@ -0,0 +1,160 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+use crate::dom::bindings::codegen::Bindings::MouseEventBinding::MouseEventMethods;
+use crate::dom::bindings::codegen::Bindings::WheelEventBinding;
+use crate::dom::bindings::codegen::Bindings::WheelEventBinding::WheelEventMethods;
+use crate::dom::bindings::error::Fallible;
+use crate::dom::bindings::inheritance::Castable;
+use crate::dom::bindings::num::Finite;
+use crate::dom::bindings::reflector::reflect_dom_object;
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::str::DOMString;
+use crate::dom::event::{Event, EventBubbles, EventCancelable};
+use crate::dom::mouseevent::MouseEvent;
+use crate::dom::window::Window;
+use dom_struct::dom_struct;
+use std::cell::Cell;
+
+#[dom_struct]
+pub struct WheelEvent {
+    mouseevent: MouseEvent,
+    delta_x: Cell<Finite<f64>>,
+    delta_y: Cell<Finite<f64>>,
+    delta_z: Cell<Finite<f64>>,
+    delta_mode: Cell<u32>,
+}
+
+impl WheelEvent {
+    fn new_inherited() -> WheelEvent {
+        WheelEvent {
+            mouseevent: MouseEvent::new_inherited(),
+            delta_x: Cell::new(Finite::wrap(0.0)),
+            delta_y: Cell::new(Finite::wrap(0.0)),
+            delta_z: Cell::new(Finite::wrap(0.0)),
+            delta_mode: Cell::new(0),
+        }
+    }
+
+    pub fn new_unintialized(window: &Window) -> DomRoot<WheelEvent> {
+        reflect_dom_object(Box::new(WheelEvent::new_inherited()), window)
+    }
+
+    pub fn new(
+        window: &Window,
+        type_: DOMString,
+        can_bubble: EventBubbles,
+        cancelable: EventCancelable,
+        view: Option<&Window>,
+        detail: i32,
+        delta_x: Finite<f64>,
+        delta_y: Finite<f64>,
+        delta_z: Finite<f64>,
+        delta_mode: u32,
+    ) -> DomRoot<WheelEvent> {
+        let ev = WheelEvent::new_unintialized(window);
+        ev.InitWheelEvent(
+            type_,
+            bool::from(can_bubble),
+            bool::from(cancelable),
+            view,
+            detail,
+            delta_x,
+            delta_y,
+            delta_z,
+            delta_mode,
+        );
+
+        ev
+    }
+
+    #[allow(non_snake_case)]
+    pub fn Constructor(
+        window: &Window,
+        type_: DOMString,
+        init: &WheelEventBinding::WheelEventInit,
+    ) -> Fallible<DomRoot<WheelEvent>> {
+        let event = WheelEvent::new(
+            window,
+            type_,
+            EventBubbles::from(init.parent.parent.parent.parent.bubbles),
+            EventCancelable::from(init.parent.parent.parent.parent.cancelable),
+            init.parent.parent.parent.view.as_deref(),
+            init.parent.parent.parent.detail,
+            init.deltaX,
+            init.deltaY,
+            init.deltaZ,
+            init.deltaMode,
+        );
+
+        Ok(event)
+    }
+}
+
+impl WheelEventMethods for WheelEvent {
+    // https://w3c.github.io/uievents/#widl-WheelEvent-deltaX
+    fn DeltaX(&self) -> Finite<f64> {
+        self.delta_x.get()
+    }
+
+    // https://w3c.github.io/uievents/#widl-WheelEvent-deltaY
+    fn DeltaY(&self) -> Finite<f64> {
+        self.delta_y.get()
+    }
+
+    // https://w3c.github.io/uievents/#widl-WheelEvent-deltaZ
+    fn DeltaZ(&self) -> Finite<f64> {
+        self.delta_z.get()
+    }
+
+    // https://w3c.github.io/uievents/#widl-WheelEvent-deltaMode
+    fn DeltaMode(&self) -> u32 {
+        self.delta_mode.get()
+    }
+
+    // https://w3c.github.io/uievents/#widl-WheelEvent-initWheelEvent
+    fn InitWheelEvent(
+        &self,
+        type_arg: DOMString,
+        can_bubble_arg: bool,
+        cancelable_arg: bool,
+        view_arg: Option<&Window>,
+        detail_arg: i32,
+        delta_x_arg: Finite<f64>,
+        delta_y_arg: Finite<f64>,
+        delta_z_arg: Finite<f64>,
+        delta_mode_arg: u32,
+    ) {
+        if self.upcast::<Event>().dispatching() {
+            return;
+        }
+
+        self.upcast::<MouseEvent>().InitMouseEvent(
+            type_arg,
+            can_bubble_arg,
+            cancelable_arg,
+            view_arg,
+            detail_arg,
+            self.mouseevent.ScreenX(),
+            self.mouseevent.ScreenY(),
+            self.mouseevent.ClientX(),
+            self.mouseevent.ClientY(),
+            self.mouseevent.CtrlKey(),
+            self.mouseevent.AltKey(),
+            self.mouseevent.ShiftKey(),
+            self.mouseevent.MetaKey(),
+            self.mouseevent.Button(),
+            self.mouseevent.GetRelatedTarget().as_deref(),
+        );
+        self.delta_x.set(delta_x_arg);
+        self.delta_y.set(delta_y_arg);
+        self.delta_z.set(delta_z_arg);
+        self.delta_mode.set(delta_mode_arg);
+    }
+
+    // https://dom.spec.whatwg.org/#dom-event-istrusted
+    fn IsTrusted(&self) -> bool {
+        self.mouseevent.IsTrusted()
+    }
+}