1 files changed, 72 insertions, 0 deletions
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/AndroidVsync.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/AndroidVsync.java
new file mode 100644
index 0000000000..c87bf466d0
--- /dev/null
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/gfx/AndroidVsync.java
@@ -0,0 +1,72 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * 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/. */
+
+package org.mozilla.gecko.gfx;
+
+import android.os.Handler;
+import android.os.Looper;
+import android.view.Choreographer;
+import org.mozilla.gecko.annotation.WrapForJNI;
+import org.mozilla.gecko.mozglue.JNIObject;
+
+/** This class receives HW vsync events through a {@link Choreographer}. */
+@WrapForJNI
+/* package */ final class AndroidVsync extends JNIObject implements Choreographer.FrameCallback {
+  @WrapForJNI
+  @Override // JNIObject
+  protected native void disposeNative();
+
+  private static final String LOGTAG = "AndroidVsync";
+
+  /* package */ Choreographer mChoreographer;
+  private volatile boolean mObservingVsync;
+
+  public AndroidVsync() {
+    final Handler mainHandler = new Handler(Looper.getMainLooper());
+    mainHandler.post(
+        new Runnable() {
+          @Override
+          public void run() {
+            mChoreographer = Choreographer.getInstance();
+            if (mObservingVsync) {
+              mChoreographer.postFrameCallback(AndroidVsync.this);
+            }
+          }
+        });
+  }
+
+  @WrapForJNI(stubName = "NotifyVsync")
+  private native void nativeNotifyVsync(final long frameTimeNanos);
+
+  // Choreographer callback implementation.
+  public void doFrame(final long frameTimeNanos) {
+    if (mObservingVsync) {
+      mChoreographer.postFrameCallback(this);
+      nativeNotifyVsync(frameTimeNanos);
+    }
+  }
+
+  /**
+   * Start/stop observing Vsync event.
+   *
+   * @param enable true to start observing; false to stop.
+   * @return true if observing and false if not.
+   */
+  @WrapForJNI
+  public synchronized boolean observeVsync(final boolean enable) {
+    if (mObservingVsync != enable) {
+      mObservingVsync = enable;
+
+      if (mChoreographer != null) {
+        if (enable) {
+          mChoreographer.postFrameCallback(this);
+        } else {
+          mChoreographer.removeFrameCallback(this);
+        }
+      }
+    }
+    return mObservingVsync;
+  }
+}