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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.view;
     18 
     19 import android.annotation.NonNull;
     20 import android.annotation.UnsupportedAppUsage;
     21 import android.os.Looper;
     22 import android.os.MessageQueue;
     23 
     24 import com.android.internal.util.VirtualRefBasePtr;
     25 
     26 import java.lang.ref.WeakReference;
     27 
     28 /**
     29  * Provides streaming access to frame stats information from the rendering
     30  * subsystem to apps.
     31  *
     32  * @hide
     33  */
     34 public class FrameMetricsObserver {
     35     @UnsupportedAppUsage
     36     private MessageQueue mMessageQueue;
     37 
     38     private WeakReference<Window> mWindow;
     39 
     40     @UnsupportedAppUsage
     41     private FrameMetrics mFrameMetrics;
     42 
     43     /* pacage */ Window.OnFrameMetricsAvailableListener mListener;
     44     /** @hide */
     45     public VirtualRefBasePtr mNative;
     46 
     47     /**
     48      * Creates a FrameMetricsObserver
     49      *
     50      * @param looper the looper to use when invoking callbacks
     51      */
     52     FrameMetricsObserver(@NonNull Window window, @NonNull Looper looper,
     53             @NonNull Window.OnFrameMetricsAvailableListener listener) {
     54         if (looper == null) {
     55             throw new NullPointerException("looper cannot be null");
     56         }
     57 
     58         mMessageQueue = looper.getQueue();
     59         if (mMessageQueue == null) {
     60             throw new IllegalStateException("invalid looper, null message queue\n");
     61         }
     62 
     63         mFrameMetrics = new FrameMetrics();
     64         mWindow = new WeakReference<>(window);
     65         mListener = listener;
     66     }
     67 
     68     // Called by native on the provided Handler
     69     @SuppressWarnings("unused")
     70     @UnsupportedAppUsage
     71     private void notifyDataAvailable(int dropCount) {
     72         final Window window = mWindow.get();
     73         if (window != null) {
     74             mListener.onFrameMetricsAvailable(window, mFrameMetrics, dropCount);
     75         }
     76     }
     77 }
     78