content: /*
   * Copyright (C) 2014 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.animation;
  
  import android.content.pm.ActivityInfo.Config;
  import android.content.res.ConstantState;
  import android.util.StateSet;
  import android.view.View;
  
  import java.lang.ref.WeakReference;
  import java.util.ArrayList;
  
  /**
   * Lets you define a number of Animators that will run on the attached View depending on the View's
   * drawable state.
   * <p>
   * It can be defined in an XML file with the <code>&lt;selector></code> element.
   * Each State Animator is defined in a nested <code>&lt;item></code> element.
   *
   * @attr ref android.R.styleable#DrawableStates_state_focused
   * @attr ref android.R.styleable#DrawableStates_state_window_focused
   * @attr ref android.R.styleable#DrawableStates_state_enabled
   * @attr ref android.R.styleable#DrawableStates_state_checkable
   * @attr ref android.R.styleable#DrawableStates_state_checked
   * @attr ref android.R.styleable#DrawableStates_state_selected
   * @attr ref android.R.styleable#DrawableStates_state_activated
   * @attr ref android.R.styleable#DrawableStates_state_active
   * @attr ref android.R.styleable#DrawableStates_state_single
   * @attr ref android.R.styleable#DrawableStates_state_first
   * @attr ref android.R.styleable#DrawableStates_state_middle
   * @attr ref android.R.styleable#DrawableStates_state_last
   * @attr ref android.R.styleable#DrawableStates_state_pressed
   * @attr ref android.R.styleable#StateListAnimatorItem_animation
   */
  public class StateListAnimator implements Cloneable {
  
      private ArrayList<Tuple> mTuples = new ArrayList<Tuple>();
      private Tuple mLastMatch = null;
      private Animator mRunningAnimator = null;
      private WeakReference<View> mViewRef;
      private StateListAnimatorConstantState mConstantState;
      private AnimatorListenerAdapter mAnimatorListener;
      private @Config int mChangingConfigurations;
  
      public StateListAnimator() {
          initAnimatorListener();
      }
  
      private void initAnimatorListener() {
          mAnimatorListener = new AnimatorListenerAdapter() {
              @Override
              public void onAnimationEnd(Animator animation) {
                  animation.setTarget(null);
                  if (mRunningAnimator == animation) {
                      mRunningAnimator = null;
                  }
              }
          };
      }
  
      /**
       * Associates the given animator with the provided drawable state specs so that it will be run
       * when the View's drawable state matches the specs.
       *
       * @param specs The drawable state specs to match against
       * @param animator The animator to run when the specs match
       */
      public void addState(int[] specs, Animator animator) {
          Tuple tuple = new Tuple(specs, animator);
          tuple.mAnimator.addListener(mAnimatorListener);
          mTuples.add(tuple);
          mChangingConfigurations |= animator.getChangingConfigurations();
      }
  
      /**
       * Returns the current {@link android.animation.Animator} which is started because of a state
       * change.
       *
       * @return The currently running Animator or null if no Animator is running
       * @hide
       */
      public Animator getRunningAnimator() {
          return mRunningAnimator;
      }
  
      /**
       * @hide
       */
      public View getTarget() {
          return mViewRef == null ? null : mViewRef.get();
      }
  
      /**
       * Called by View
       * @hide
       */
      public void setTarget(View view) {
          final View current = getTarget();
          if (current == view) {
              return;
          }
          if (current != null) {
              clearTarget();
          }
          if (view != null) {
              mViewRef = new WeakReference<View>(view);
          }
  
      }
  
      private void clearTarget() {
          final int size = mTuples.size();
          for (int i = 0; i < size; i++) {
              mTuples.get(i).mAnimator.setTarget(null);
          }
          mViewRef = null;
          mLastMatch = null;
          mRunningAnimator = null;
      }
  
      @Override
      public StateListAnimator clone() {
          try {
              StateListAnimator clone = (StateListAnimator) super.clone();
              clone.mTuples = new ArrayList<Tuple>(mTuples.size());
              clone.mLastMatch = null;
              clone.mRunningAnimator = null;
              clone.mViewRef = null;
              clone.mAnimatorListener = null;
              clone.initAnimatorListener();
              final int tupleSize = mTuples.size();
              for (int i = 0; i < tupleSize; i++) {
                  final Tuple tuple = mTuples.get(i);
                  final Animator animatorClone = tuple.mAnimator.clone();
                  animatorClone.removeListener(mAnimatorListener);
                  clone.addState(tuple.mSpecs, animatorClone);
              }
              clone.setChangingConfigurations(getChangingConfigurations());
              return clone;
          } catch (CloneNotSupportedException e) {
              throw new AssertionError("cannot clone state list animator", e);
          }
      }
  
      /**
       * Called by View
       * @hide
       */
      public void setState(int[] state) {
          Tuple match = null;
          final int count = mTuples.size();
          for (int i = 0; i < count; i++) {
              final Tuple tuple = mTuples.get(i);
              if (StateSet.stateSetMatches(tuple.mSpecs, state)) {
                  match = tuple;
                  break;
              }
          }
          if (match == mLastMatch) {
              return;
          }
          if (mLastMatch != null) {
              cancel();
          }
          mLastMatch = match;
          if (match != null) {
              start(match);
          }
      }
  
      private void start(Tuple match) {
          match.mAnimator.setTarget(getTarget());
          mRunningAnimator = match.mAnimator;
          mRunningAnimator.start();
      }
  
      private void cancel() {
          if (mRunningAnimator != null) {
              mRunningAnimator.cancel();
              mRunningAnimator = null;
          }
      }
  
      /**
       * @hide
       */
      public ArrayList<Tuple> getTuples() {
          return mTuples;
      }
  
      /**
       * If there is an animation running for a recent state change, ends it.
       * <p>
       * This causes the animation to assign the end value(s) to the View.
       */
      public void jumpToCurrentState() {
          if (mRunningAnimator != null) {
              mRunningAnimator.end();
          }
      }
  
      /**
       * Return a mask of the configuration parameters for which this animator may change, requiring
       * that it be re-created.  The default implementation returns whatever was provided through
       * {@link #setChangingConfigurations(int)} or 0 by default.
       *
       * @return Returns a mask of the changing configuration parameters, as defined by
       * {@link android.content.pm.ActivityInfo}.
       *
       * @see android.content.pm.ActivityInfo
       * @hide
       */
      public @Config int getChangingConfigurations() {
          return mChangingConfigurations;
      }
  
      /**
       * Set a mask of the configuration parameters for which this animator may change, requiring
       * that it should be recreated from resources instead of being cloned.
       *
       * @param configs A mask of the changing configuration parameters, as
       * defined by {@link android.content.pm.ActivityInfo}.
       *
       * @see android.content.pm.ActivityInfo
       * @hide
       */
      public void setChangingConfigurations(@Config int configs) {
          mChangingConfigurations = configs;
      }
  
      /**
       * Sets the changing configurations value to the union of the current changing configurations
       * and the provided configs.
       * This method is called while loading the animator.
       * @hide
       */
      public void appendChangingConfigurations(@Config int configs) {
          mChangingConfigurations |= configs;
      }
  
      /**
       * Return a {@link android.content.res.ConstantState} instance that holds the shared state of
       * this Animator.
       * <p>
       * This constant state is used to create new instances of this animator when needed. Default
       * implementation creates a new {@link StateListAnimatorConstantState}. You can override this
       * method to provide your custom logic or return null if you don't want this animator to be
       * cached.
       *
       * @return The {@link android.content.res.ConstantState} associated to this Animator.
       * @see android.content.res.ConstantState
       * @see #clone()
       * @hide
       */
      public ConstantState<StateListAnimator> createConstantState() {
          return new StateListAnimatorConstantState(this);
      }
  
      /**
       * @hide
       */
      public static class Tuple {
  
          final int[] mSpecs;
  
          final Animator mAnimator;
  
          private Tuple(int[] specs, Animator animator) {
              mSpecs = specs;
              mAnimator = animator;
          }
  
          /**
           * @hide
           */
          public int[] getSpecs() {
              return mSpecs;
          }
  
          /**
           * @hide
           */
          public Animator getAnimator() {
              return mAnimator;
          }
      }
  
      /**
       * Creates a constant state which holds changing configurations information associated with the
       * given Animator.
       * <p>
       * When new instance is called, default implementation clones the Animator.
       */
      private static class StateListAnimatorConstantState
              extends ConstantState<StateListAnimator> {
  
          final StateListAnimator mAnimator;
  
          @Config int mChangingConf;
  
          public StateListAnimatorConstantState(StateListAnimator animator) {
              mAnimator = animator;
              mAnimator.mConstantState = this;
              mChangingConf = mAnimator.getChangingConfigurations();
          }
  
          @Override
          public @Config int getChangingConfigurations() {
              return mChangingConf;
          }
  
          @Override
          public StateListAnimator newInstance() {
              final StateListAnimator clone = mAnimator.clone();
              clone.mConstantState = this;
              return clone;
          }
      }
  }
  