1 files changed, 140 insertions, 0 deletions
diff --git a/components/script/dom/texttracklist.rs b/components/script/dom/texttracklist.rs
new file mode 100644
index 00000000000..faeb9f0cd6d
--- /dev/null
+++ b/components/script/dom/texttracklist.rs
@@ -0,0 +1,140 @@
+/* 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::cell::DomRefCell;
+use crate::dom::bindings::codegen::Bindings::TextTrackListBinding::TextTrackListMethods;
+use crate::dom::bindings::codegen::UnionTypes::VideoTrackOrAudioTrackOrTextTrack;
+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::event::Event;
+use crate::dom::eventtarget::EventTarget;
+use crate::dom::texttrack::TextTrack;
+use crate::dom::trackevent::TrackEvent;
+use crate::dom::window::Window;
+use crate::task_source::TaskSource;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct TextTrackList {
+    eventtarget: EventTarget,
+    dom_tracks: DomRefCell<Vec<Dom<TextTrack>>>,
+}
+
+impl TextTrackList {
+    pub fn new_inherited(tracks: &[&TextTrack]) -> TextTrackList {
+        TextTrackList {
+            eventtarget: EventTarget::new_inherited(),
+            dom_tracks: DomRefCell::new(tracks.iter().map(|g| Dom::from_ref(&**g)).collect()),
+        }
+    }
+
+    pub fn new(window: &Window, tracks: &[&TextTrack]) -> DomRoot<TextTrackList> {
+        reflect_dom_object(Box::new(TextTrackList::new_inherited(tracks)), window)
+    }
+
+    pub fn item(&self, idx: usize) -> Option<DomRoot<TextTrack>> {
+        self.dom_tracks
+            .borrow()
+            .get(idx as usize)
+            .map(|t| DomRoot::from_ref(&**t))
+    }
+
+    pub fn find(&self, track: &TextTrack) -> Option<usize> {
+        self.dom_tracks
+            .borrow()
+            .iter()
+            .enumerate()
+            .filter(|(_, t)| **t == track)
+            .next()
+            .map(|(i, _)| i)
+    }
+
+    pub fn add(&self, track: &TextTrack) {
+        // Only add a track if it does not exist in the list
+        if self.find(track).is_none() {
+            self.dom_tracks.borrow_mut().push(Dom::from_ref(track));
+
+            let this = Trusted::new(self);
+            let (source, canceller) = &self
+                .global()
+                .as_window()
+                .task_manager()
+                .media_element_task_source_with_canceller();
+
+            let idx = match self.find(&track) {
+                Some(t) => t,
+                None => return,
+            };
+
+            let _ = source.queue_with_canceller(
+                task!(track_event_queue: move || {
+                    let this = this.root();
+
+                    if let Some(track) = this.item(idx) {
+                        let event = TrackEvent::new(
+                            &this.global(),
+                            atom!("addtrack"),
+                            false,
+                            false,
+                            &Some(VideoTrackOrAudioTrackOrTextTrack::TextTrack(
+                                DomRoot::from_ref(&track)
+                            )),
+                        );
+
+                        event.upcast::<Event>().fire(this.upcast::<EventTarget>());
+                    }
+                }),
+                &canceller,
+            );
+            track.add_track_list(self);
+        }
+    }
+
+    // FIXME(#22314, dlrobertson) allow TextTracks to be
+    // removed from the TextTrackList.
+    #[allow(dead_code)]
+    pub fn remove(&self, idx: usize) {
+        if let Some(track) = self.dom_tracks.borrow().get(idx) {
+            track.remove_track_list();
+        }
+        self.dom_tracks.borrow_mut().remove(idx);
+        self.upcast::<EventTarget>()
+            .fire_event(atom!("removetrack"));
+    }
+}
+
+impl TextTrackListMethods for TextTrackList {
+    // https://html.spec.whatwg.org/multipage/#dom-texttracklist-length
+    fn Length(&self) -> u32 {
+        self.dom_tracks.borrow().len() as u32
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-texttracklist-item
+    fn IndexedGetter(&self, idx: u32) -> Option<DomRoot<TextTrack>> {
+        self.item(idx as usize)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-texttracklist-gettrackbyid
+    fn GetTrackById(&self, id: DOMString) -> Option<DomRoot<TextTrack>> {
+        let id_str = String::from(id.clone());
+        self.dom_tracks
+            .borrow()
+            .iter()
+            .filter(|track| track.id() == &id_str)
+            .next()
+            .map(|t| DomRoot::from_ref(&**t))
+    }
+
+    // https://html.spec.whatwg.org/multipage/#handler-texttracklist-onchange
+    event_handler!(change, GetOnchange, SetOnchange);
+
+    // https://html.spec.whatwg.org/multipage/#handler-texttracklist-onaddtrack
+    event_handler!(addtrack, GetOnaddtrack, SetOnaddtrack);
+
+    // https://html.spec.whatwg.org/multipage/#handler-texttracklist-onremovetrack
+    event_handler!(removetrack, GetOnremovetrack, SetOnremovetrack);
+}