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      1 /*
      2  * Copyright (C) 2010 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.os.Looper;
     20 import android.os.MessageQueue;
     21 import android.util.LongSparseArray;
     22 import android.util.Pools.Pool;
     23 import android.util.Pools.SimplePool;
     24 
     25 import dalvik.system.CloseGuard;
     26 
     27 import java.lang.ref.WeakReference;
     28 
     29 /**
     30  * An input queue provides a mechanism for an application to receive incoming
     31  * input events.  Currently only usable from native code.
     32  */
     33 public final class InputQueue {
     34     private final LongSparseArray<ActiveInputEvent> mActiveEventArray =
     35             new LongSparseArray<ActiveInputEvent>(20);
     36     private final Pool<ActiveInputEvent> mActiveInputEventPool =
     37             new SimplePool<ActiveInputEvent>(20);
     38 
     39     private final CloseGuard mCloseGuard = CloseGuard.get();
     40 
     41     private long mPtr;
     42 
     43     private static native long nativeInit(WeakReference<InputQueue> weakQueue,
     44             MessageQueue messageQueue);
     45     private static native long nativeSendKeyEvent(long ptr, KeyEvent e, boolean preDispatch);
     46     private static native long nativeSendMotionEvent(long ptr, MotionEvent e);
     47     private static native void nativeDispose(long ptr);
     48 
     49     /** @hide */
     50     public InputQueue() {
     51         mPtr = nativeInit(new WeakReference<InputQueue>(this), Looper.myQueue());
     52 
     53         mCloseGuard.open("dispose");
     54     }
     55 
     56     @Override
     57     protected void finalize() throws Throwable {
     58         try {
     59             dispose(true);
     60         } finally {
     61             super.finalize();
     62         }
     63     }
     64 
     65     /** @hide */
     66     public void dispose() {
     67         dispose(false);
     68     }
     69 
     70     /** @hide */
     71     public void dispose(boolean finalized) {
     72         if (mCloseGuard != null) {
     73             if (finalized) {
     74                 mCloseGuard.warnIfOpen();
     75             }
     76             mCloseGuard.close();
     77         }
     78 
     79         if (mPtr != 0) {
     80             nativeDispose(mPtr);
     81             mPtr = 0;
     82         }
     83     }
     84 
     85     /** @hide */
     86     public long getNativePtr() {
     87         return mPtr;
     88     }
     89 
     90     /** @hide */
     91     public void sendInputEvent(InputEvent e, Object token, boolean predispatch,
     92             FinishedInputEventCallback callback) {
     93         ActiveInputEvent event = obtainActiveInputEvent(token, callback);
     94         long id;
     95         if (e instanceof KeyEvent) {
     96             id = nativeSendKeyEvent(mPtr, (KeyEvent) e, predispatch);
     97         } else {
     98             id = nativeSendMotionEvent(mPtr, (MotionEvent) e);
     99         }
    100         mActiveEventArray.put(id, event);
    101     }
    102 
    103     private void finishInputEvent(long id, boolean handled) {
    104         int index = mActiveEventArray.indexOfKey(id);
    105         if (index >= 0) {
    106             ActiveInputEvent e = mActiveEventArray.valueAt(index);
    107             mActiveEventArray.removeAt(index);
    108             e.mCallback.onFinishedInputEvent(e.mToken, handled);
    109             recycleActiveInputEvent(e);
    110         }
    111     }
    112 
    113     private ActiveInputEvent obtainActiveInputEvent(Object token,
    114             FinishedInputEventCallback callback) {
    115         ActiveInputEvent e = mActiveInputEventPool.acquire();
    116         if (e == null) {
    117             e = new ActiveInputEvent();
    118         }
    119         e.mToken = token;
    120         e.mCallback = callback;
    121         return e;
    122     }
    123 
    124     private void recycleActiveInputEvent(ActiveInputEvent e) {
    125         e.recycle();
    126         mActiveInputEventPool.release(e);
    127     }
    128 
    129     private final class ActiveInputEvent {
    130         public Object mToken;
    131         public FinishedInputEventCallback mCallback;
    132 
    133         public void recycle() {
    134             mToken = null;
    135             mCallback = null;
    136         }
    137     }
    138 
    139     /**
    140      * Interface to receive notification of when an InputQueue is associated
    141      * and dissociated with a thread.
    142      */
    143     public static interface Callback {
    144         /**
    145          * Called when the given InputQueue is now associated with the
    146          * thread making this call, so it can start receiving events from it.
    147          */
    148         void onInputQueueCreated(InputQueue queue);
    149 
    150         /**
    151          * Called when the given InputQueue is no longer associated with
    152          * the thread and thus not dispatching events.
    153          */
    154         void onInputQueueDestroyed(InputQueue queue);
    155     }
    156 
    157     /** @hide */
    158     public static interface FinishedInputEventCallback {
    159         void onFinishedInputEvent(Object token, boolean handled);
    160     }
    161 
    162 }
    163