content: /*
   * Copyright (C) 2018 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 com.android.quickstep;
  
  import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
  
  import android.annotation.TargetApi;
  import android.content.Context;
  import android.content.Intent;
  import android.os.Build;
  import android.os.Bundle;
  import android.os.Handler;
  
  import com.android.quickstep.ActivityControlHelper.ActivityInitListener;
  import com.android.quickstep.util.RemoteAnimationProvider;
  
  import java.lang.ref.WeakReference;
  import java.util.function.BiPredicate;
  
  /**
   * Utility class to track create/destroy for some {@link BaseRecentsActivity}.
   */
  @TargetApi(Build.VERSION_CODES.P)
  public class RecentsActivityTracker<T extends BaseRecentsActivity> implements ActivityInitListener {
  
      private static WeakReference<BaseRecentsActivity> sCurrentActivity =
              new WeakReference<>(null);
      private static final Scheduler sScheduler = new Scheduler();
  
      private final BiPredicate<T, Boolean> mOnInitListener;
  
      public RecentsActivityTracker(BiPredicate<T, Boolean> onInitListener) {
          mOnInitListener = onInitListener;
      }
  
      @Override
      public void register() {
          sScheduler.schedule(this);
      }
  
      @Override
      public void unregister() {
          sScheduler.clearReference(this);
      }
  
      private boolean init(T activity, boolean visible) {
          return mOnInitListener.test(activity, visible);
      }
  
      public static <T extends BaseRecentsActivity> T getCurrentActivity() {
          return (T) sCurrentActivity.get();
      }
  
      @Override
      public void registerAndStartActivity(Intent intent, RemoteAnimationProvider animProvider,
              Context context, Handler handler, long duration) {
          register();
  
          Bundle options = animProvider.toActivityOptions(handler, duration, context).toBundle();
          context.startActivity(intent, options);
      }
  
      public static void onRecentsActivityCreate(BaseRecentsActivity activity) {
          sCurrentActivity = new WeakReference<>(activity);
          sScheduler.initIfPending(activity, false);
      }
  
  
      public static void onRecentsActivityNewIntent(BaseRecentsActivity activity) {
          sScheduler.initIfPending(activity, activity.isStarted());
      }
  
      public static void onRecentsActivityDestroy(BaseRecentsActivity activity) {
          if (sCurrentActivity.get() == activity) {
              sCurrentActivity.clear();
          }
      }
  
  
      private static class Scheduler implements Runnable {
  
          private WeakReference<RecentsActivityTracker> mPendingTracker = new WeakReference<>(null);
  
          public synchronized void schedule(RecentsActivityTracker tracker) {
              mPendingTracker = new WeakReference<>(tracker);
              MAIN_EXECUTOR.execute(this);
          }
  
          @Override
          public void run() {
              BaseRecentsActivity activity = sCurrentActivity.get();
              if (activity != null) {
                  initIfPending(activity, activity.isStarted());
              }
          }
  
          public synchronized boolean initIfPending(BaseRecentsActivity activity,
                  boolean alreadyOnHome) {
              RecentsActivityTracker tracker = mPendingTracker.get();
              if (tracker != null) {
                  if (!tracker.init(activity, alreadyOnHome)) {
                      mPendingTracker.clear();
                  }
                  return true;
              }
              return false;
          }
  
          public synchronized boolean clearReference(RecentsActivityTracker tracker) {
              if (mPendingTracker.get() == tracker) {
                  mPendingTracker.clear();
                  return true;
              }
              return false;
          }
      }
  }
  