1 files changed, 126 insertions, 0 deletions
diff --git a/components/script/dom/audiotracklist.rs b/components/script/dom/audiotracklist.rs
new file mode 100644
index 00000000000..353c97c2598
--- /dev/null
+++ b/components/script/dom/audiotracklist.rs
@@ -0,0 +1,126 @@
+/* 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::audiotrack::AudioTrack;
+use crate::dom::bindings::cell::DomRefCell;
+use crate::dom::bindings::codegen::Bindings::AudioTrackListBinding::{self, AudioTrackListMethods};
+use crate::dom::bindings::inheritance::Castable;
+use crate::dom::bindings::refcounted::Trusted;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject};
+use crate::dom::bindings::root::{Dom, DomRoot};
+use crate::dom::bindings::str::DOMString;
+use crate::dom::eventtarget::EventTarget;
+use crate::dom::window::Window;
+use crate::task_source::TaskSource;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct AudioTrackList {
+    eventtarget: EventTarget,
+    tracks: DomRefCell<Vec<Dom<AudioTrack>>>,
+}
+
+impl AudioTrackList {
+    pub fn new_inherited(tracks: &[&AudioTrack]) -> AudioTrackList {
+        AudioTrackList {
+            eventtarget: EventTarget::new_inherited(),
+            tracks: DomRefCell::new(tracks.iter().map(|track| Dom::from_ref(&**track)).collect()),
+        }
+    }
+
+    pub fn new(window: &Window, tracks: &[&AudioTrack]) -> DomRoot<AudioTrackList> {
+        reflect_dom_object(
+            Box::new(AudioTrackList::new_inherited(tracks)),
+            window,
+            AudioTrackListBinding::Wrap,
+        )
+    }
+
+    pub fn len(&self) -> usize {
+        self.tracks.borrow().len()
+    }
+
+    pub fn item(&self, idx: usize) -> Option<DomRoot<AudioTrack>> {
+        self.tracks
+            .borrow()
+            .get(idx)
+            .map(|track| DomRoot::from_ref(&**track))
+    }
+
+    pub fn enabled_index(&self) -> Option<usize> {
+        self.tracks
+            .borrow()
+            .iter()
+            .position(|track| track.enabled())
+    }
+
+    // TODO(#22799) Integrate DOM Audio and Video track selection with media player.
+    pub fn set_enabled(&self, idx: usize, value: bool) {
+        let track = match self.item(idx) {
+            Some(t) => t,
+            None => return,
+        };
+
+        // If the chosen tracks enabled status is the same as the new status, return early.
+        if track.enabled() == value {
+            return;
+        }
+        // Set the tracks enabled status.
+        track.set_enabled(value);
+
+        // Queue a task to fire an event named change.
+        let global = &self.global();
+        let this = Trusted::new(self);
+        let (source, canceller) = global
+            .as_window()
+            .task_manager()
+            .media_element_task_source_with_canceller();
+
+        let _ = source.queue_with_canceller(
+            task!(media_track_change: move || {
+                let this = this.root();
+                this.upcast::<EventTarget>().fire_event(atom!("change"));
+            }),
+            &canceller,
+        );
+    }
+
+    pub fn add(&self, track: &AudioTrack) {
+        self.tracks.borrow_mut().push(Dom::from_ref(track));
+    }
+
+    pub fn clear(&self) {
+        self.tracks.borrow_mut().clear();
+    }
+}
+
+impl AudioTrackListMethods for AudioTrackList {
+    // https://html.spec.whatwg.org/multipage/#dom-audiotracklist-length
+    fn Length(&self) -> u32 {
+        self.len() as u32
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-tracklist-item
+    fn IndexedGetter(&self, idx: u32) -> Option<DomRoot<AudioTrack>> {
+        self.item(idx as usize)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-audiotracklist-gettrackbyid
+    fn GetTrackById(&self, id: DOMString) -> Option<DomRoot<AudioTrack>> {
+        self.tracks
+            .borrow()
+            .iter()
+            .find(|track| track.id() == id)
+            .map(|track| DomRoot::from_ref(&**track))
+    }
+
+    // https://html.spec.whatwg.org/multipage/#handler-tracklist-onchange
+    event_handler!(change, GetOnchange, SetOnchange);
+
+    // https://html.spec.whatwg.org/multipage/#handler-tracklist-onaddtrack
+    event_handler!(addtrack, GetOnaddtrack, SetOnaddtrack);
+
+    // https://html.spec.whatwg.org/multipage/#handler-tracklist-onremovetrack
+    event_handler!(removetrack, GetOnremovetrack, SetOnremovetrack);
+}