1 files changed, 69 insertions, 0 deletions
diff --git a/dom/media/webvtt/WebVTTListener.h b/dom/media/webvtt/WebVTTListener.h
new file mode 100644
index 0000000000..45f6bc90d6
--- /dev/null
+++ b/dom/media/webvtt/WebVTTListener.h
@@ -0,0 +1,69 @@
+/* -*- 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/. */
+
+#ifndef mozilla_dom_WebVTTLoadListener_h
+#define mozilla_dom_WebVTTLoadListener_h
+
+#include "nsIWebVTTListener.h"
+#include "nsIStreamListener.h"
+#include "nsIChannelEventSink.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+
+class nsIWebVTTParserWrapper;
+
+namespace mozilla::dom {
+
+class HTMLTrackElement;
+
+class WebVTTListener final : public nsIWebVTTListener,
+                             public nsIStreamListener,
+                             public nsIChannelEventSink,
+                             public nsIInterfaceRequestor {
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_NSIWEBVTTLISTENER
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSICHANNELEVENTSINK
+  NS_DECL_NSIINTERFACEREQUESTOR
+
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(WebVTTListener, nsIStreamListener)
+
+ public:
+  explicit WebVTTListener(HTMLTrackElement* aElement);
+
+  /**
+   * Loads the WebVTTListener. Must call this in order for the listener to be
+   * ready to parse data that is passed to it.
+   */
+  nsresult LoadResource();
+
+  /**
+   * When this listener is not going to be used anymore, its owner should take
+   * a responsibility to call `Cancel()` to prevent this listener making any
+   * changes for the track element.
+   */
+  bool IsCanceled() const;
+  void Cancel();
+
+ private:
+  ~WebVTTListener();
+
+  // List of error codes returned from the WebVTT parser that we care about.
+  enum ErrorCodes { BadSignature = 0 };
+  static nsresult ParseChunk(nsIInputStream* aInStream, void* aClosure,
+                             const char* aFromSegment, uint32_t aToOffset,
+                             uint32_t aCount, uint32_t* aWriteCount);
+
+  RefPtr<HTMLTrackElement> mElement;
+  nsCOMPtr<nsIWebVTTParserWrapper> mParserWrapper;
+  nsresult mParserWrapperError;
+  bool mCancel = false;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_WebVTTListener_h