1 files changed, 79 insertions, 0 deletions
diff --git a/widget/android/AndroidVsync.h b/widget/android/AndroidVsync.h
new file mode 100644
index 0000000000..d50e1ec71f
--- /dev/null
+++ b/widget/android/AndroidVsync.h
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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_widget_AndroidVsync_h
+#define mozilla_widget_AndroidVsync_h
+
+#include "mozilla/DataMutex.h"
+#include "mozilla/java/AndroidVsyncNatives.h"
+#include "mozilla/ThreadSafeWeakPtr.h"
+#include "mozilla/TimeStamp.h"
+
+namespace mozilla {
+namespace widget {
+
+class AndroidVsyncSupport;
+
+/**
+ * A thread-safe way to listen to vsync notifications on Android. All methods
+ * can be called on any thread.
+ * Observers must keep a strong reference to the AndroidVsync instance until
+ * they unregister themselves.
+ */
+class AndroidVsync final : public SupportsThreadSafeWeakPtr<AndroidVsync> {
+ public:
+  MOZ_DECLARE_REFCOUNTED_TYPENAME(AndroidVsync)
+
+  static RefPtr<AndroidVsync> GetInstance();
+
+  ~AndroidVsync();
+
+  class Observer {
+   public:
+    // Will be called on the Java UI thread.
+    virtual void OnVsync(const TimeStamp& aTimeStamp) = 0;
+    // Will be called on the Java UI thread.
+    virtual void OnMaybeUpdateRefreshRate() {}
+    // Called when the observer is unregistered, in case it wants to
+    // manage its own lifetime.
+    virtual void Dispose() {}
+    virtual ~Observer() = default;
+  };
+
+  // INPUT observers are called before RENDER observers.
+  enum ObserverType { INPUT, RENDER };
+  void RegisterObserver(Observer* aObserver, ObserverType aType);
+  void UnregisterObserver(Observer* aObserver, ObserverType aType);
+
+  void OnMaybeUpdateRefreshRate();
+
+ private:
+  friend class AndroidVsyncSupport;
+
+  AndroidVsync();
+
+  // Called by Java, via AndroidVsyncSupport
+  void NotifyVsync(int64_t aFrameTimeNanos);
+
+  struct Impl {
+    void UpdateObservingVsync();
+
+    nsTArray<Observer*> mInputObservers;
+    nsTArray<Observer*> mRenderObservers;
+    RefPtr<AndroidVsyncSupport> mSupport;
+    java::AndroidVsync::GlobalRef mSupportJava;
+    bool mObservingVsync = false;
+  };
+
+  DataMutex<Impl> mImpl;
+
+  static StaticDataMutex<ThreadSafeWeakPtr<AndroidVsync>> sInstance;
+};
+
+}  // namespace widget
+}  // namespace mozilla
+
+#endif  // mozilla_widget_AndroidVsync_h