content: /**
   * Copyright 2010-present Facebook.
   *
   * 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 com.facebook;
  
  import android.os.Handler;
  
  import java.util.*;
  import java.util.concurrent.atomic.AtomicInteger;
  
  /**
   * RequestBatch contains a list of Request objects that can be sent to Facebook in a single round-trip.
   */
  public class RequestBatch extends AbstractList<Request> {
      private static AtomicInteger idGenerator = new AtomicInteger();
  
      private Handler callbackHandler;
      private List<Request> requests = new ArrayList<Request>();
      private int timeoutInMilliseconds = 0;
      private final String id = Integer.valueOf(idGenerator.incrementAndGet()).toString();
      private List<Callback> callbacks = new ArrayList<Callback>();
      private String batchApplicationId;
  
      /**
       * Constructor. Creates an empty batch.
       */
      public RequestBatch() {
          this.requests = new ArrayList<Request>();
      }
  
      /**
       * Constructor.
       * @param requests the requests to add to the batch
       */
      public RequestBatch(Collection<Request> requests) {
          this.requests = new ArrayList<Request>(requests);
      }
  
      /**
       * Constructor.
       * @param requests the requests to add to the batch
       */
      public RequestBatch(Request... requests) {
          this.requests = Arrays.asList(requests);
      }
  
      /**
       * Constructor.
       * @param requests the requests to add to the batch
       */
      public RequestBatch(RequestBatch requests) {
          this.requests = new ArrayList<Request>(requests);
          this.callbackHandler = requests.callbackHandler;
          this.timeoutInMilliseconds = requests.timeoutInMilliseconds;
          this.callbacks = new ArrayList<Callback>(requests.callbacks);
      }
  
      /**
       * Gets the timeout to wait for responses from the server before a timeout error occurs.
       * @return the timeout, in milliseconds; 0 (the default) means do not timeout
       */
      public int getTimeout() {
          return timeoutInMilliseconds;
      }
  
      /**
       * Sets the timeout to wait for responses from the server before a timeout error occurs.
       * @param timeoutInMilliseconds the timeout, in milliseconds; 0 means do not timeout
       */
      public void setTimeout(int timeoutInMilliseconds) {
          if (timeoutInMilliseconds < 0) {
              throw new IllegalArgumentException("Argument timeoutInMilliseconds must be >= 0.");
          }
          this.timeoutInMilliseconds = timeoutInMilliseconds;
      }
  
      /**
       * Adds a batch-level callback which will be called when the entire batch has finished executing.
       *
       * @param callback the callback
       */
      public void addCallback(Callback callback) {
          if (!callbacks.contains(callback)) {
              callbacks.add(callback);
          }
      }
  
      /**
       * Removes a batch-level callback.
       *
       * @param callback the callback
       */
      public void removeCallback(Callback callback) {
          callbacks.remove(callback);
      }
  
      @Override
      public final boolean add(Request request) {
          return requests.add(request);
      }
  
      @Override
      public final void add(int location, Request request) {
          requests.add(location, request);
      }
  
      @Override
      public final void clear() {
          requests.clear();
      }
  
      @Override
      public final Request get(int i) {
          return requests.get(i);
      }
  
      @Override
      public final Request remove(int location) {
          return requests.remove(location);
      }
  
      @Override
      public final Request set(int location, Request request) {
          return requests.set(location, request);
      }
  
      @Override
      public final int size() {
          return requests.size();
      }
  
      final String getId() {
          return id;
      }
  
      final Handler getCallbackHandler() {
          return callbackHandler;
      }
  
      final void setCallbackHandler(Handler callbackHandler) {
          this.callbackHandler = callbackHandler;
      }
  
      final List<Request> getRequests() {
          return requests;
      }
  
      final List<Callback> getCallbacks() {
          return callbacks;
      }
  
      final String getBatchApplicationId() {
          return batchApplicationId;
      }
  
      final void setBatchApplicationId(String batchApplicationId) {
          this.batchApplicationId = batchApplicationId;
      }
  
      /**
       * Executes this batch on the current thread and returns the responses.
       * <p/>
       * This should only be used if you have transitioned off the UI thread.
       *
       * @return a list of Response objects representing the results of the requests; responses are returned in the same
       *         order as the requests were specified.
       *
       * @throws FacebookException
       *            If there was an error in the protocol used to communicate with the service
       * @throws IllegalArgumentException if the passed in RequestBatch is empty
       * @throws NullPointerException if the passed in RequestBatch or any of its contents are null
       */
      public final List<Response> executeAndWait() {
          return executeAndWaitImpl();
      }
  
      /**
       * Executes this batch asynchronously. This function will return immediately, and the batch will
       * be processed on a separate thread. In order to process results of a request, or determine
       * whether a request succeeded or failed, a callback must be specified (see
       * {@link Request#setCallback(com.facebook.Request.Callback)})
       * <p/>
       * This should only be called from the UI thread.
       *
       * @return a RequestAsyncTask that is executing the request
       *
       * @throws IllegalArgumentException if this batch is empty
       * @throws NullPointerException if any of the contents of this batch are null
       */
      public final RequestAsyncTask executeAsync() {
          return executeAsyncImpl();
      }
  
      /**
       * Specifies the interface that consumers of the RequestBatch class can implement in order to be notified when the
       * entire batch completes execution. It will be called after all per-Request callbacks are called.
       */
      public interface Callback {
          /**
           * The method that will be called when a batch completes.
           *
           * @param batch     the RequestBatch containing the Requests which were executed
           */
          void onBatchCompleted(RequestBatch batch);
      }
  
      /**
       * Specifies the interface that consumers of the RequestBatch class can implement in order to be notified when the
       * batch makes progress. The frequency of the callbacks can be controlled using
       * {@link com.facebook.Settings#setOnProgressThreshold(long)}.
       */
      public interface OnProgressCallback extends Callback {
          /**
           * The method that will be called when a batch makes progress.
           *
           * @param batch     the RequestBatch containing the Requests which were executed
           * @param current   the current value of the progress
           * @param max       the max (target) value of the progress
           */
          void onBatchProgress(RequestBatch batch, long current, long max);
      }
  
      List<Response> executeAndWaitImpl() {
          return Request.executeBatchAndWait(this);
      }
  
      RequestAsyncTask executeAsyncImpl() {
          return Request.executeBatchAsync(this);
      }
  }
  