content: /*
   * Copyright (C) 2010 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.view;
  
  import android.annotation.UnsupportedAppUsage;
  import android.os.IBinder;
  import android.os.Parcel;
  import android.os.Parcelable;
  import android.util.Slog;
  
  /**
   * An input channel specifies the file descriptors used to send input events to
   * a window in another process.  It is Parcelable so that it can be sent
   * to the process that is to receive events.  Only one thread should be reading
   * from an InputChannel at a time.
   * @hide
   */
  public final class InputChannel implements Parcelable {
      private static final String TAG = "InputChannel";
  
      private static final boolean DEBUG = false;
  
      @UnsupportedAppUsage
      public static final @android.annotation.NonNull Parcelable.Creator<InputChannel> CREATOR
              = new Parcelable.Creator<InputChannel>() {
          public InputChannel createFromParcel(Parcel source) {
              InputChannel result = new InputChannel();
              result.readFromParcel(source);
              return result;
          }
  
          public InputChannel[] newArray(int size) {
              return new InputChannel[size];
          }
      };
  
      @SuppressWarnings("unused")
      @UnsupportedAppUsage
      private long mPtr; // used by native code
  
      private static native InputChannel[] nativeOpenInputChannelPair(String name);
  
      private native void nativeDispose(boolean finalized);
      private native void nativeTransferTo(InputChannel other);
      private native void nativeReadFromParcel(Parcel parcel);
      private native void nativeWriteToParcel(Parcel parcel);
      private native void nativeDup(InputChannel target);
      private native IBinder nativeGetToken();
      private native void nativeSetToken(IBinder token);
  
      private native String nativeGetName();
  
      /**
       * Creates an uninitialized input channel.
       * It can be initialized by reading from a Parcel or by transferring the state of
       * another input channel into this one.
       */
      @UnsupportedAppUsage
      public InputChannel() {
      }
  
      @Override
      protected void finalize() throws Throwable {
          try {
              nativeDispose(true);
          } finally {
              super.finalize();
          }
      }
  
      /**
       * Creates a new input channel pair.  One channel should be provided to the input
       * dispatcher and the other to the application's input queue.
       * @param name The descriptive (non-unique) name of the channel pair.
       * @return A pair of input channels.  The first channel is designated as the
       * server channel and should be used to publish input events.  The second channel
       * is designated as the client channel and should be used to consume input events.
       */
      public static InputChannel[] openInputChannelPair(String name) {
          if (name == null) {
              throw new IllegalArgumentException("name must not be null");
          }
  
          if (DEBUG) {
              Slog.d(TAG, "Opening input channel pair '" + name + "'");
          }
          return nativeOpenInputChannelPair(name);
      }
  
      /**
       * Gets the name of the input channel.
       * @return The input channel name.
       */
      public String getName() {
          String name = nativeGetName();
          return name != null ? name : "uninitialized";
      }
  
      /**
       * Disposes the input channel.
       * Explicitly releases the reference this object is holding on the input channel.
       * When all references are released, the input channel will be closed.
       */
      public void dispose() {
          nativeDispose(false);
      }
  
      /**
       * Transfers ownership of the internal state of the input channel to another
       * instance and invalidates this instance.  This is used to pass an input channel
       * as an out parameter in a binder call.
       * @param other The other input channel instance.
       */
      public void transferTo(InputChannel outParameter) {
          if (outParameter == null) {
              throw new IllegalArgumentException("outParameter must not be null");
          }
  
          nativeTransferTo(outParameter);
      }
  
      /**
       * Duplicates the input channel.
       */
      public InputChannel dup() {
          InputChannel target = new InputChannel();
          nativeDup(target);
          return target;
      }
  
      @Override
      public int describeContents() {
          return Parcelable.CONTENTS_FILE_DESCRIPTOR;
      }
  
      public void readFromParcel(Parcel in) {
          if (in == null) {
              throw new IllegalArgumentException("in must not be null");
          }
  
          nativeReadFromParcel(in);
      }
  
      @Override
      public void writeToParcel(Parcel out, int flags) {
          if (out == null) {
              throw new IllegalArgumentException("out must not be null");
          }
  
          nativeWriteToParcel(out);
  
          if ((flags & PARCELABLE_WRITE_RETURN_VALUE) != 0) {
              dispose();
          }
      }
  
      @Override
      public String toString() {
          return getName();
      }
  
      public IBinder getToken() {
          return nativeGetToken();
      }
  
      public void setToken(IBinder token) {
          nativeSetToken(token);
      }
  }
  