1 files changed, 80 insertions, 0 deletions
diff --git a/dom/media/VideoTrackList.cpp b/dom/media/VideoTrackList.cpp
new file mode 100644
index 0000000000..79ad1329ff
--- /dev/null
+++ b/dom/media/VideoTrackList.cpp
@@ -0,0 +1,80 @@
+/* -*- Mode: C++; 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/. */
+
+#include "mozilla/dom/VideoTrack.h"
+#include "mozilla/dom/VideoTrackList.h"
+#include "mozilla/dom/VideoTrackListBinding.h"
+
+namespace mozilla::dom {
+
+JSObject* VideoTrackList::WrapObject(JSContext* aCx,
+                                     JS::Handle<JSObject*> aGivenProto) {
+  return VideoTrackList_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+VideoTrack* VideoTrackList::operator[](uint32_t aIndex) {
+  MediaTrack* track = MediaTrackList::operator[](aIndex);
+  return track->AsVideoTrack();
+}
+
+void VideoTrackList::RemoveTrack(const RefPtr<MediaTrack>& aTrack) {
+  // we need to find the video track before |MediaTrackList::RemoveTrack|. Or
+  // mSelectedIndex will not be valid. The check of mSelectedIndex == -1
+  // need to be done after RemoveTrack. Also the call of
+  // |MediaTrackList::RemoveTrack| is necessary even when mSelectedIndex = -1.
+  bool found;
+  VideoTrack* selectedVideoTrack = IndexedGetter(mSelectedIndex, found);
+  MediaTrackList::RemoveTrack(aTrack);
+  if (mSelectedIndex == -1) {
+    // There was no selected track and we don't select another track on removal.
+    return;
+  }
+  MOZ_ASSERT(found, "When mSelectedIndex is set it should point to a track");
+  MOZ_ASSERT(selectedVideoTrack,
+             "The mSelectedIndex should be set to video track only");
+
+  // Let the caller of RemoveTrack deal with choosing the new selected track if
+  // it removes the currently-selected track.
+  if (aTrack == selectedVideoTrack) {
+    mSelectedIndex = -1;
+    return;
+  }
+
+  // The removed track was not the selected track and there is a
+  // currently-selected video track. We need to find the new location of the
+  // selected track.
+  for (size_t ix = 0; ix < mTracks.Length(); ix++) {
+    if (mTracks[ix] == selectedVideoTrack) {
+      mSelectedIndex = ix;
+      return;
+    }
+  }
+}
+
+void VideoTrackList::EmptyTracks() {
+  mSelectedIndex = -1;
+  MediaTrackList::EmptyTracks();
+}
+
+VideoTrack* VideoTrackList::GetSelectedTrack() {
+  if (mSelectedIndex < 0 ||
+      static_cast<size_t>(mSelectedIndex) >= mTracks.Length()) {
+    return nullptr;
+  }
+
+  return operator[](mSelectedIndex);
+}
+
+VideoTrack* VideoTrackList::IndexedGetter(uint32_t aIndex, bool& aFound) {
+  MediaTrack* track = MediaTrackList::IndexedGetter(aIndex, aFound);
+  return track ? track->AsVideoTrack() : nullptr;
+}
+
+VideoTrack* VideoTrackList::GetTrackById(const nsAString& aId) {
+  MediaTrack* track = MediaTrackList::GetTrackById(aId);
+  return track ? track->AsVideoTrack() : nullptr;
+}
+
+}  // namespace mozilla::dom