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.widget;
  
  import android.content.BroadcastReceiver;
  import android.content.Context;
  import android.content.Intent;
  import android.content.IntentFilter;
  import android.content.res.TypedArray;
  import android.os.Message;
  import android.util.AttributeSet;
  import android.util.Log;
  import android.view.RemotableViewMethod;
  import android.widget.RemoteViews.RemoteView;
  
  /**
   * Simple {@link ViewAnimator} that will animate between two or more views
   * that have been added to it.  Only one child is shown at a time.  If
   * requested, can automatically flip between each child at a regular interval.
   *
   * @attr ref android.R.styleable#AdapterViewFlipper_flipInterval
   * @attr ref android.R.styleable#AdapterViewFlipper_autoStart
   */
  @RemoteView
  public class AdapterViewFlipper extends AdapterViewAnimator {
      private static final String TAG = "ViewFlipper";
      private static final boolean LOGD = false;
  
      private static final int DEFAULT_INTERVAL = 10000;
  
      private int mFlipInterval = DEFAULT_INTERVAL;
      private boolean mAutoStart = false;
  
      private boolean mRunning = false;
      private boolean mStarted = false;
      private boolean mVisible = false;
      private boolean mUserPresent = true;
      private boolean mAdvancedByHost = false;
  
      public AdapterViewFlipper(Context context) {
          super(context);
      }
  
      public AdapterViewFlipper(Context context, AttributeSet attrs) {
          this(context, attrs, 0);
      }
  
      public AdapterViewFlipper(Context context, AttributeSet attrs, int defStyleAttr) {
          this(context, attrs, defStyleAttr, 0);
      }
  
      public AdapterViewFlipper(
              Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
          super(context, attrs, defStyleAttr, defStyleRes);
  
          final TypedArray a = context.obtainStyledAttributes(attrs,
                  com.android.internal.R.styleable.AdapterViewFlipper, defStyleAttr, defStyleRes);
          saveAttributeDataForStyleable(context, com.android.internal.R.styleable.AdapterViewFlipper,
                  attrs, a, defStyleAttr, defStyleRes);
          mFlipInterval = a.getInt(
                  com.android.internal.R.styleable.AdapterViewFlipper_flipInterval, DEFAULT_INTERVAL);
          mAutoStart = a.getBoolean(
                  com.android.internal.R.styleable.AdapterViewFlipper_autoStart, false);
  
          // A view flipper should cycle through the views
          mLoopViews = true;
  
          a.recycle();
      }
  
      private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
          @Override
          public void onReceive(Context context, Intent intent) {
              final String action = intent.getAction();
              if (Intent.ACTION_SCREEN_OFF.equals(action)) {
                  mUserPresent = false;
                  updateRunning();
              } else if (Intent.ACTION_USER_PRESENT.equals(action)) {
                  mUserPresent = true;
                  updateRunning(false);
              }
          }
      };
  
      @Override
      protected void onAttachedToWindow() {
          super.onAttachedToWindow();
  
          // Listen for broadcasts related to user-presence
          final IntentFilter filter = new IntentFilter();
          filter.addAction(Intent.ACTION_SCREEN_OFF);
          filter.addAction(Intent.ACTION_USER_PRESENT);
  
          // OK, this is gross but needed. This class is supported by the
          // remote views machanism and as a part of that the remote views
          // can be inflated by a context for another user without the app
          // having interact users permission - just for loading resources.
          // For exmaple, when adding widgets from a user profile to the
          // home screen. Therefore, we register the receiver as the current
          // user not the one the context is for.
          getContext().registerReceiverAsUser(mReceiver, android.os.Process.myUserHandle(),
                  filter, null, getHandler());
  
  
          if (mAutoStart) {
              // Automatically start when requested
              startFlipping();
          }
      }
  
      @Override
      protected void onDetachedFromWindow() {
          super.onDetachedFromWindow();
          mVisible = false;
  
          getContext().unregisterReceiver(mReceiver);
          updateRunning();
      }
  
      @Override
      protected void onWindowVisibilityChanged(int visibility) {
          super.onWindowVisibilityChanged(visibility);
          mVisible = (visibility == VISIBLE);
          updateRunning(false);
      }
  
      @Override
      public void setAdapter(Adapter adapter) {
          super.setAdapter(adapter);
          updateRunning();
      }
  
      /**
       * Returns the flip interval, in milliseconds.
       *
       * @return the flip interval in milliseconds
       *
       * @see #setFlipInterval(int)
       *
       * @attr ref android.R.styleable#AdapterViewFlipper_flipInterval
       */
      public int getFlipInterval() {
          return mFlipInterval;
      }
  
      /**
       * How long to wait before flipping to the next view.
       *
       * @param flipInterval flip interval in milliseconds
       *
       * @see #getFlipInterval()
       *
       * @attr ref android.R.styleable#AdapterViewFlipper_flipInterval
       */
      public void setFlipInterval(int flipInterval) {
          mFlipInterval = flipInterval;
      }
  
      /**
       * Start a timer to cycle through child views
       */
      public void startFlipping() {
          mStarted = true;
          updateRunning();
      }
  
      /**
       * No more flips
       */
      public void stopFlipping() {
          mStarted = false;
          updateRunning();
      }
  
      /**
      * {@inheritDoc}
      */
     @Override
     @RemotableViewMethod
     public void showNext() {
         // if the flipper is currently flipping automatically, and showNext() is called
         // we should we should make sure to reset the timer
         if (mRunning) {
             removeCallbacks(mFlipRunnable);
             postDelayed(mFlipRunnable, mFlipInterval);
         }
         super.showNext();
     }
  
     /**
      * {@inheritDoc}
      */
     @Override
     @RemotableViewMethod
     public void showPrevious() {
         // if the flipper is currently flipping automatically, and showPrevious() is called
         // we should we should make sure to reset the timer
         if (mRunning) {
             removeCallbacks(mFlipRunnable);
             postDelayed(mFlipRunnable, mFlipInterval);
         }
         super.showPrevious();
     }
  
      /**
       * Internal method to start or stop dispatching flip {@link Message} based
       * on {@link #mRunning} and {@link #mVisible} state.
       */
      private void updateRunning() {
          // by default when we update running, we want the
          // current view to animate in
          updateRunning(true);
      }
  
      /**
       * Internal method to start or stop dispatching flip {@link Message} based
       * on {@link #mRunning} and {@link #mVisible} state.
       *
       * @param flipNow Determines whether or not to execute the animation now, in
       *            addition to queuing future flips. If omitted, defaults to
       *            true.
       */
      private void updateRunning(boolean flipNow) {
          boolean running = !mAdvancedByHost && mVisible && mStarted && mUserPresent
                  && mAdapter != null;
          if (running != mRunning) {
              if (running) {
                  showOnly(mWhichChild, flipNow);
                  postDelayed(mFlipRunnable, mFlipInterval);
              } else {
                  removeCallbacks(mFlipRunnable);
              }
              mRunning = running;
          }
          if (LOGD) {
              Log.d(TAG, "updateRunning() mVisible=" + mVisible + ", mStarted=" + mStarted
                      + ", mUserPresent=" + mUserPresent + ", mRunning=" + mRunning);
          }
      }
  
      /**
       * Returns true if the child views are flipping.
       */
      public boolean isFlipping() {
          return mStarted;
      }
  
      /**
       * Set if this view automatically calls {@link #startFlipping()} when it
       * becomes attached to a window.
       */
      public void setAutoStart(boolean autoStart) {
          mAutoStart = autoStart;
      }
  
      /**
       * Returns true if this view automatically calls {@link #startFlipping()}
       * when it becomes attached to a window.
       */
      public boolean isAutoStart() {
          return mAutoStart;
      }
  
      private final Runnable mFlipRunnable = new Runnable() {
          @Override
          public void run() {
              if (mRunning) {
                  showNext();
              }
          }
      };
  
      /**
       * Called by an {@link android.appwidget.AppWidgetHost} to indicate that it will be
       * automatically advancing the views of this {@link AdapterViewFlipper} by calling
       * {@link AdapterViewFlipper#advance()} at some point in the future. This allows
       * {@link AdapterViewFlipper} to prepare by no longer Advancing its children.
       */
      @Override
      public void fyiWillBeAdvancedByHostKThx() {
          mAdvancedByHost = true;
          updateRunning(false);
      }
  
      @Override
      public CharSequence getAccessibilityClassName() {
          return AdapterViewFlipper.class.getName();
      }
  }
  