1 files changed, 80 insertions, 0 deletions
diff --git a/gfx/layers/apz/src/AsyncPanZoomAnimation.h b/gfx/layers/apz/src/AsyncPanZoomAnimation.h
new file mode 100644
index 000000000..039c0684e
--- /dev/null
+++ b/gfx/layers/apz/src/AsyncPanZoomAnimation.h
@@ -0,0 +1,80 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et 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_layers_AsyncPanZoomAnimation_h_
+#define mozilla_layers_AsyncPanZoomAnimation_h_
+
+#include "base/message_loop.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/TimeStamp.h"
+#include "FrameMetrics.h"
+#include "nsISupportsImpl.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace layers {
+
+class WheelScrollAnimation;
+class SmoothScrollAnimation;
+
+class AsyncPanZoomAnimation {
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AsyncPanZoomAnimation)
+
+public:
+  explicit AsyncPanZoomAnimation()
+  { }
+
+  virtual bool DoSample(FrameMetrics& aFrameMetrics,
+                        const TimeDuration& aDelta) = 0;
+
+  bool Sample(FrameMetrics& aFrameMetrics,
+              const TimeDuration& aDelta) {
+    // In some situations, particularly when handoff is involved, it's possible
+    // for |aDelta| to be negative on the first call to sample. Ignore such a
+    // sample here, to avoid each derived class having to deal with this case.
+    if (aDelta.ToMilliseconds() <= 0) {
+      return true;
+    }
+
+    return DoSample(aFrameMetrics, aDelta);
+  }
+
+  /**
+   * Get the deferred tasks in |mDeferredTasks| and place them in |aTasks|. See
+   * |mDeferredTasks| for more information.  Clears |mDeferredTasks|.
+   */
+  nsTArray<RefPtr<Runnable>> TakeDeferredTasks() {
+    return Move(mDeferredTasks);
+  }
+
+  virtual WheelScrollAnimation* AsWheelScrollAnimation() {
+    return nullptr;
+  }
+  virtual SmoothScrollAnimation* AsSmoothScrollAnimation() {
+    return nullptr;
+  }
+
+  virtual bool WantsRepaints() {
+    return true;
+  }
+
+protected:
+  // Protected destructor, to discourage deletion outside of Release():
+  virtual ~AsyncPanZoomAnimation()
+  { }
+
+  /**
+   * Tasks scheduled for execution after the APZC's mMonitor is released.
+   * Derived classes can add tasks here in Sample(), and the APZC can call
+   * ExecuteDeferredTasks() to execute them.
+   */
+  nsTArray<RefPtr<Runnable>> mDeferredTasks;
+};
+
+} // namespace layers
+} // namespace mozilla
+
+#endif // mozilla_layers_AsyncPanZoomAnimation_h_