design/src/android/support/design/widget/BottomSheetBehavior.java - platform/frameworks/support - Git at Google

 /*
  * Copyright (C) 2015 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.support.design.widget;

 import android.content.Context;
 import android.content.res.TypedArray;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.support.annotation.IntDef;
 import android.support.design.R;
 import android.support.v4.view.MotionEventCompat;
 import android.support.v4.view.ViewCompat;
 import android.support.v4.widget.ViewDragHelper;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;

 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.ref.WeakReference;


 /**
  * An interaction behavior plugin for a child view of {@link CoordinatorLayout} to make it work as
  * a bottom sheet.
  */
 public class BottomSheetBehavior<V extends View> extends CoordinatorLayout.Behavior<V> {

     /**
      * The bottom sheet is dragging.
      */
     public static final int STATE_DRAGGING = 1;

     /**
      * The bottom sheet is settling.
      */
     public static final int STATE_SETTLING = 2;

     /**
      * The bottom sheet is expanded.
      */
     public static final int STATE_EXPANDED = 3;

     /**
      * The bottom sheet is collapsed.
      */
     public static final int STATE_COLLAPSED = 4;

     /** @hide */
     @IntDef({STATE_EXPANDED, STATE_COLLAPSED, STATE_DRAGGING, STATE_SETTLING})
     @Retention(RetentionPolicy.SOURCE)
     public @interface State {}

     private int mPeekHeight;

     private int mMinOffset;

     private int mMaxOffset;

     @State
     private int mState = STATE_COLLAPSED;

     private ViewDragHelper mViewDragHelper;

     private boolean mIgnoreEvents;

     private int mLastNestedScrollDy;

     private int mParentHeight;

     private WeakReference<V> mViewRef;

     /**
      * Default constructor for instantiating BottomSheetBehaviors.
      */
     public BottomSheetBehavior() {
     }

     /**
      * Default constructor for inflating BottomSheetBehaviors from layout.
      *
      * @param context The {@link Context}.
      * @param attrs   The {@link AttributeSet}.
      */
     public BottomSheetBehavior(Context context, AttributeSet attrs) {
         super(context, attrs);
         TypedArray a = context.obtainStyledAttributes(attrs,
                 R.styleable.BottomSheetBehavior_Params);
         setPeekHeight(a.getDimensionPixelSize(
                 R.styleable.BottomSheetBehavior_Params_behavior_peekHeight, 0));
         a.recycle();
     }

     @Override
     public Parcelable onSaveInstanceState(CoordinatorLayout parent, V child) {
         return new SavedState(super.onSaveInstanceState(parent, child), mState);
     }

     @Override
     public void onRestoreInstanceState(CoordinatorLayout parent, V child, Parcelable state) {
         SavedState ss = (SavedState) state;
         super.onRestoreInstanceState(parent, child, ss.getSuperState());
         mState = ss.state;
         // Intermediate states are restored as collapsed state
         if (mState == STATE_DRAGGING || mState == STATE_SETTLING) {
             mState = STATE_COLLAPSED;
         }
     }

     @Override
     public boolean onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection) {
         // First let the parent lay it out
         parent.onLayoutChild(child, layoutDirection);
         // Offset the bottom sheet
         mParentHeight = parent.getHeight();
         mMinOffset = Math.max(0, mParentHeight - child.getHeight());
         mMaxOffset = mParentHeight - mPeekHeight;
         if (mState == STATE_EXPANDED) {
             ViewCompat.offsetTopAndBottom(child, mMinOffset);
         } else {
             ViewCompat.offsetTopAndBottom(child, mMaxOffset);
             mState = STATE_COLLAPSED;
         }
         if (mViewDragHelper == null) {
             mViewDragHelper = ViewDragHelper.create(parent, mDragCallback);
         }
         mViewRef = new WeakReference<>(child);
         return true;
     }

     @Override
     public boolean onInterceptTouchEvent(CoordinatorLayout parent, V child, MotionEvent event) {
         int action = MotionEventCompat.getActionMasked(event);
         switch (action) {
             case MotionEvent.ACTION_UP:
             case MotionEvent.ACTION_CANCEL:
                 // Reset the ignore flag
                 if (mIgnoreEvents) {
                     mIgnoreEvents = false;
                     return false;
                 }
                 break;
             case MotionEvent.ACTION_DOWN:
                 mIgnoreEvents = !parent.isPointInChildBounds(child,
                         (int) event.getX(), (int) event.getY());
                 break;
         }
         return !mIgnoreEvents && mViewDragHelper.shouldInterceptTouchEvent(event);
     }

     @Override
     public boolean onTouchEvent(CoordinatorLayout parent, V child, MotionEvent event) {
         mViewDragHelper.processTouchEvent(event);
         return true;
     }

     @Override
     public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, V child,
             View directTargetChild, View target, int nestedScrollAxes) {
         mLastNestedScrollDy = 0;
         return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0;
     }

     @Override
     public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, V child, View target, int dx,
             int dy, int[] consumed) {
         int currentTop = child.getTop();
         int newTop = currentTop - dy;
         if (dy > 0) { // Scrolling up
             if (newTop < mMinOffset) {
                 consumed[1] = currentTop - mMinOffset;
                 child.offsetTopAndBottom(-consumed[1]);
                 setStateInternal(STATE_EXPANDED);
             } else {
                 consumed[1] = dy;
                 child.offsetTopAndBottom(-dy);
                 setStateInternal(STATE_DRAGGING);
             }
         } else if (dy < 0) { // Scrolling down
             if (!ViewCompat.canScrollVertically(target, -1)) {
                 if (newTop > mMaxOffset) {
                     consumed[1] = currentTop - mMaxOffset;
                     child.offsetTopAndBottom(-consumed[1]);
                     setStateInternal(STATE_COLLAPSED);
                 } else {
                     consumed[1] = dy;
                     child.offsetTopAndBottom(-dy);
                     setStateInternal(STATE_DRAGGING);
                 }
             }
         }
         mLastNestedScrollDy = dy;
     }

     @Override
     public void onStopNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target) {
         if (mLastNestedScrollDy == 0 || child.getTop() == mMinOffset) {
             return;
         }
         int top;
         int targetState;
         if (mLastNestedScrollDy > 0) {
             top = mMinOffset;
             targetState = STATE_EXPANDED;
         } else {
             top = mMaxOffset;
             targetState = STATE_COLLAPSED;
         }
         setStateInternal(STATE_SETTLING);
         if (mViewDragHelper.smoothSlideViewTo(child, child.getLeft(), top)) {
             ViewCompat.postOnAnimation(child, new SettleRunnable(child, targetState));
         }
     }

     /**
      * Sets the height of the bottom sheet when it is collapsed.
      *
      * @param peekHeight The height of the collapsed bottom sheet in pixels.
      * @attr ref android.support.design.R.styleable#BottomSheetBehavior_Params_behavior_peekHeight
      */
     public final void setPeekHeight(int peekHeight) {
         mPeekHeight = Math.max(0, peekHeight);
         mMaxOffset = mParentHeight - peekHeight;
     }

     /**
      * Gets the height of the bottom sheet when it is collapsed.
      *
      * @return The height of the collapsed bottom sheet.
      * @attr ref android.support.design.R.styleable#BottomSheetBehavior_Params_behavior_peekHeight
      */
     public final int getPeekHeight() {
         return mPeekHeight;
     }

     /**
      * Sets the state of the bottom sheet. The bottom sheet will transition to that state with
      * animation.
      *
      * @param state Either {@link #STATE_COLLAPSED} or {@link #STATE_EXPANDED}.
      */
     public final void setState(@State int state) {
         if (mViewRef == null) {
             return;
         }
         V child = mViewRef.get();
         if (child == null) {
             return;
         }
         int top;
         if (state == STATE_COLLAPSED) {
             top = mMaxOffset;
         } else if (state == STATE_EXPANDED) {
             top = mMinOffset;
         } else {
             throw new IllegalArgumentException("Illegal state argument: " + state);
         }
         setStateInternal(STATE_SETTLING);
         if (mViewDragHelper.smoothSlideViewTo(child, child.getLeft(), top)) {
             ViewCompat.postOnAnimation(child, new SettleRunnable(child, state));
         }
     }

     /**
      * Gets the current state of the bottom sheet.
      *
      * @return One of {@link #STATE_EXPANDED}, {@link #STATE_COLLAPSED}, {@link #STATE_DRAGGING},
      * and {@link #STATE_SETTLING}.
      */
     @State
     public final int getState() {
         return mState;
     }

     private void setStateInternal(@State int state) {
         if (mState == state) {
             return;
         }
         mState = state;
         // TODO: Invoke listeners.
     }

     private final ViewDragHelper.Callback mDragCallback = new ViewDragHelper.Callback() {

         @Override
         public boolean tryCaptureView(View child, int pointerId) {
             return true;
         }

         @Override
         public void onViewDragStateChanged(int state) {
             if (state == ViewDragHelper.STATE_DRAGGING) {
                 setStateInternal(STATE_DRAGGING);
             }
         }

         @Override
         public void onViewReleased(View releasedChild, float xvel, float yvel) {
             int top;
             @State int targetState;
             if (yvel < 0) {
                 top = mMinOffset;
                 targetState = STATE_EXPANDED;
             } else {
                 top = mMaxOffset;
                 targetState = STATE_COLLAPSED;
             }
             setStateInternal(STATE_SETTLING);
             if (mViewDragHelper.settleCapturedViewAt(releasedChild.getLeft(), top)) {
                 ViewCompat.postOnAnimation(releasedChild,
                         new SettleRunnable(releasedChild, targetState));
             }
         }

         @Override
         public int clampViewPositionVertical(View child, int top, int dy) {
             return MathUtils.constrain(top, mMinOffset, mMaxOffset);
         }

         @Override
         public int clampViewPositionHorizontal(View child, int left, int dx) {
             return child.getLeft();
         }
     };

     private class SettleRunnable implements Runnable {

         private final View mView;

         @State
         private final int mTargetState;

         SettleRunnable(View view, @State int targetState) {
             mView = view;
             mTargetState = targetState;
         }

         @Override
         public void run() {
             if (mViewDragHelper != null && mViewDragHelper.continueSettling(true)) {
                 ViewCompat.postOnAnimation(mView, this);
             } else {
                 setStateInternal(mTargetState);
             }
         }
     }

     protected static class SavedState extends View.BaseSavedState {

         @State
         final int state;

         public SavedState(Parcel source) {
             super(source);
             //noinspection ResourceType
             state = source.readInt();
         }

         public SavedState(Parcelable superState, @State int state) {
             super(superState);
             this.state = state;
         }

         @Override
         public void writeToParcel(Parcel out, int flags) {
             super.writeToParcel(out, flags);
             out.writeInt(state);
         }

         public static final Parcelable.Creator<SavedState> CREATOR =
                 new Parcelable.Creator<SavedState>() {
                     @Override
                     public SavedState createFromParcel(Parcel source) {
                         return new SavedState(source);
                     }

                     @Override
                     public SavedState[] newArray(int size) {
                         return new SavedState[size];
                     }
                 };
     }

     /*
      * A utility function to get the {@link BottomSheetBehavior} associated with the {@code view}.
      *
      * @param view The {@link View} with {@link BottomSheetBehavior}.
      * @return The {@link BottomSheetBehavior} associated with the {@code view}.
      */
     @SuppressWarnings("unchecked")
     public static <V extends View> BottomSheetBehavior<V> from(V view) {
         ViewGroup.LayoutParams params = view.getLayoutParams();
         if (!(params instanceof CoordinatorLayout.LayoutParams)) {
             throw new IllegalArgumentException("The view is not a child of CoordinatorLayout");
         }
         CoordinatorLayout.Behavior behavior = ((CoordinatorLayout.LayoutParams) params)
                 .getBehavior();
         if (!(behavior instanceof BottomSheetBehavior)) {
             throw new IllegalArgumentException(
                     "The view is not associated with BottomSheetBehavior");
         }
         return (BottomSheetBehavior<V>) behavior;
     }

 }
	/*
	* Copyright (C) 2015 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.support.design.widget;

	import android.content.Context;
	import android.content.res.TypedArray;
	import android.os.Parcel;
	import android.os.Parcelable;
	import android.support.annotation.IntDef;
	import android.support.design.R;
	import android.support.v4.view.MotionEventCompat;
	import android.support.v4.view.ViewCompat;
	import android.support.v4.widget.ViewDragHelper;
	import android.util.AttributeSet;
	import android.view.MotionEvent;
	import android.view.View;
	import android.view.ViewGroup;

	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;
	import java.lang.ref.WeakReference;


	/**
	* An interaction behavior plugin for a child view of {@link CoordinatorLayout} to make it work as
	* a bottom sheet.
	*/
	public class BottomSheetBehavior<V extends View> extends CoordinatorLayout.Behavior<V> {

	/**
	* The bottom sheet is dragging.
	*/
	public static final int STATE_DRAGGING = 1;

	/**
	* The bottom sheet is settling.
	*/
	public static final int STATE_SETTLING = 2;

	/**
	* The bottom sheet is expanded.
	*/
	public static final int STATE_EXPANDED = 3;

	/**
	* The bottom sheet is collapsed.
	*/
	public static final int STATE_COLLAPSED = 4;

	/** @hide */
	@IntDef({STATE_EXPANDED, STATE_COLLAPSED, STATE_DRAGGING, STATE_SETTLING})
	@Retention(RetentionPolicy.SOURCE)
	public @interface State {}

	private int mPeekHeight;

	private int mMinOffset;

	private int mMaxOffset;

	@State
	private int mState = STATE_COLLAPSED;

	private ViewDragHelper mViewDragHelper;

	private boolean mIgnoreEvents;

	private int mLastNestedScrollDy;

	private int mParentHeight;

	private WeakReference<V> mViewRef;

	/**
	* Default constructor for instantiating BottomSheetBehaviors.
	*/
	public BottomSheetBehavior() {
	}

	/**
	* Default constructor for inflating BottomSheetBehaviors from layout.
	*
	* @param context The {@link Context}.
	* @param attrs The {@link AttributeSet}.
	*/
	public BottomSheetBehavior(Context context, AttributeSet attrs) {
	super(context, attrs);
	TypedArray a = context.obtainStyledAttributes(attrs,
	R.styleable.BottomSheetBehavior_Params);
	setPeekHeight(a.getDimensionPixelSize(
	R.styleable.BottomSheetBehavior_Params_behavior_peekHeight, 0));
	a.recycle();
	}

	@Override
	public Parcelable onSaveInstanceState(CoordinatorLayout parent, V child) {
	return new SavedState(super.onSaveInstanceState(parent, child), mState);
	}

	@Override
	public void onRestoreInstanceState(CoordinatorLayout parent, V child, Parcelable state) {
	SavedState ss = (SavedState) state;
	super.onRestoreInstanceState(parent, child, ss.getSuperState());
	mState = ss.state;
	// Intermediate states are restored as collapsed state
	if (mState == STATE_DRAGGING \|\| mState == STATE_SETTLING) {
	mState = STATE_COLLAPSED;
	}
	}

	@Override
	public boolean onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection) {
	// First let the parent lay it out
	parent.onLayoutChild(child, layoutDirection);
	// Offset the bottom sheet
	mParentHeight = parent.getHeight();
	mMinOffset = Math.max(0, mParentHeight - child.getHeight());
	mMaxOffset = mParentHeight - mPeekHeight;
	if (mState == STATE_EXPANDED) {
	ViewCompat.offsetTopAndBottom(child, mMinOffset);
	} else {
	ViewCompat.offsetTopAndBottom(child, mMaxOffset);
	mState = STATE_COLLAPSED;
	}
	if (mViewDragHelper == null) {
	mViewDragHelper = ViewDragHelper.create(parent, mDragCallback);
	}
	mViewRef = new WeakReference<>(child);
	return true;
	}

	@Override
	public boolean onInterceptTouchEvent(CoordinatorLayout parent, V child, MotionEvent event) {
	int action = MotionEventCompat.getActionMasked(event);
	switch (action) {
	case MotionEvent.ACTION_UP:
	case MotionEvent.ACTION_CANCEL:
	// Reset the ignore flag
	if (mIgnoreEvents) {
	mIgnoreEvents = false;
	return false;
	}
	break;
	case MotionEvent.ACTION_DOWN:
	mIgnoreEvents = !parent.isPointInChildBounds(child,
	(int) event.getX(), (int) event.getY());
	break;
	}
	return !mIgnoreEvents && mViewDragHelper.shouldInterceptTouchEvent(event);
	}

	@Override
	public boolean onTouchEvent(CoordinatorLayout parent, V child, MotionEvent event) {
	mViewDragHelper.processTouchEvent(event);
	return true;
	}

	@Override
	public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, V child,
	View directTargetChild, View target, int nestedScrollAxes) {
	mLastNestedScrollDy = 0;
	return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0;
	}

	@Override
	public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, V child, View target, int dx,
	int dy, int[] consumed) {
	int currentTop = child.getTop();
	int newTop = currentTop - dy;
	if (dy > 0) { // Scrolling up
	if (newTop < mMinOffset) {
	consumed[1] = currentTop - mMinOffset;
	child.offsetTopAndBottom(-consumed[1]);
	setStateInternal(STATE_EXPANDED);
	} else {
	consumed[1] = dy;
	child.offsetTopAndBottom(-dy);
	setStateInternal(STATE_DRAGGING);
	}
	} else if (dy < 0) { // Scrolling down
	if (!ViewCompat.canScrollVertically(target, -1)) {
	if (newTop > mMaxOffset) {
	consumed[1] = currentTop - mMaxOffset;
	child.offsetTopAndBottom(-consumed[1]);
	setStateInternal(STATE_COLLAPSED);
	} else {
	consumed[1] = dy;
	child.offsetTopAndBottom(-dy);
	setStateInternal(STATE_DRAGGING);
	}
	}
	}
	mLastNestedScrollDy = dy;
	}

	@Override
	public void onStopNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target) {
	if (mLastNestedScrollDy == 0 \|\| child.getTop() == mMinOffset) {
	return;
	}
	int top;
	int targetState;
	if (mLastNestedScrollDy > 0) {
	top = mMinOffset;
	targetState = STATE_EXPANDED;
	} else {
	top = mMaxOffset;
	targetState = STATE_COLLAPSED;
	}
	setStateInternal(STATE_SETTLING);
	if (mViewDragHelper.smoothSlideViewTo(child, child.getLeft(), top)) {
	ViewCompat.postOnAnimation(child, new SettleRunnable(child, targetState));
	}
	}

	/**
	* Sets the height of the bottom sheet when it is collapsed.
	*
	* @param peekHeight The height of the collapsed bottom sheet in pixels.
	* @attr ref android.support.design.R.styleable#BottomSheetBehavior_Params_behavior_peekHeight
	*/
	public final void setPeekHeight(int peekHeight) {
	mPeekHeight = Math.max(0, peekHeight);
	mMaxOffset = mParentHeight - peekHeight;
	}

	/**
	* Gets the height of the bottom sheet when it is collapsed.
	*
	* @return The height of the collapsed bottom sheet.
	* @attr ref android.support.design.R.styleable#BottomSheetBehavior_Params_behavior_peekHeight
	*/
	public final int getPeekHeight() {
	return mPeekHeight;
	}

	/**
	* Sets the state of the bottom sheet. The bottom sheet will transition to that state with
	* animation.
	*
	* @param state Either {@link #STATE_COLLAPSED} or {@link #STATE_EXPANDED}.
	*/
	public final void setState(@State int state) {
	if (mViewRef == null) {
	return;
	}
	V child = mViewRef.get();
	if (child == null) {
	return;
	}
	int top;
	if (state == STATE_COLLAPSED) {
	top = mMaxOffset;
	} else if (state == STATE_EXPANDED) {
	top = mMinOffset;
	} else {
	throw new IllegalArgumentException("Illegal state argument: " + state);
	}
	setStateInternal(STATE_SETTLING);
	if (mViewDragHelper.smoothSlideViewTo(child, child.getLeft(), top)) {
	ViewCompat.postOnAnimation(child, new SettleRunnable(child, state));
	}
	}

	/**
	* Gets the current state of the bottom sheet.
	*
	* @return One of {@link #STATE_EXPANDED}, {@link #STATE_COLLAPSED}, {@link #STATE_DRAGGING},
	* and {@link #STATE_SETTLING}.
	*/
	@State
	public final int getState() {
	return mState;
	}

	private void setStateInternal(@State int state) {
	if (mState == state) {
	return;
	}
	mState = state;
	// TODO: Invoke listeners.
	}

	private final ViewDragHelper.Callback mDragCallback = new ViewDragHelper.Callback() {

	@Override
	public boolean tryCaptureView(View child, int pointerId) {
	return true;
	}

	@Override
	public void onViewDragStateChanged(int state) {
	if (state == ViewDragHelper.STATE_DRAGGING) {
	setStateInternal(STATE_DRAGGING);
	}
	}

	@Override
	public void onViewReleased(View releasedChild, float xvel, float yvel) {
	int top;
	@State int targetState;
	if (yvel < 0) {
	top = mMinOffset;
	targetState = STATE_EXPANDED;
	} else {
	top = mMaxOffset;
	targetState = STATE_COLLAPSED;
	}
	setStateInternal(STATE_SETTLING);
	if (mViewDragHelper.settleCapturedViewAt(releasedChild.getLeft(), top)) {
	ViewCompat.postOnAnimation(releasedChild,
	new SettleRunnable(releasedChild, targetState));
	}
	}

	@Override
	public int clampViewPositionVertical(View child, int top, int dy) {
	return MathUtils.constrain(top, mMinOffset, mMaxOffset);
	}

	@Override
	public int clampViewPositionHorizontal(View child, int left, int dx) {
	return child.getLeft();
	}
	};

	private class SettleRunnable implements Runnable {

	private final View mView;

	@State
	private final int mTargetState;

	SettleRunnable(View view, @State int targetState) {
	mView = view;
	mTargetState = targetState;
	}

	@Override
	public void run() {
	if (mViewDragHelper != null && mViewDragHelper.continueSettling(true)) {
	ViewCompat.postOnAnimation(mView, this);
	} else {
	setStateInternal(mTargetState);
	}
	}
	}

	protected static class SavedState extends View.BaseSavedState {

	@State
	final int state;

	public SavedState(Parcel source) {
	super(source);
	//noinspection ResourceType
	state = source.readInt();
	}

	public SavedState(Parcelable superState, @State int state) {
	super(superState);
	this.state = state;
	}

	@Override
	public void writeToParcel(Parcel out, int flags) {
	super.writeToParcel(out, flags);
	out.writeInt(state);
	}

	public static final Parcelable.Creator<SavedState> CREATOR =
	new Parcelable.Creator<SavedState>() {
	@Override
	public SavedState createFromParcel(Parcel source) {
	return new SavedState(source);
	}

	@Override
	public SavedState[] newArray(int size) {
	return new SavedState[size];
	}
	};
	}

	/*
	* A utility function to get the {@link BottomSheetBehavior} associated with the {@code view}.
	*
	* @param view The {@link View} with {@link BottomSheetBehavior}.
	* @return The {@link BottomSheetBehavior} associated with the {@code view}.
	*/
	@SuppressWarnings("unchecked")
	public static <V extends View> BottomSheetBehavior<V> from(V view) {
	ViewGroup.LayoutParams params = view.getLayoutParams();
	if (!(params instanceof CoordinatorLayout.LayoutParams)) {
	throw new IllegalArgumentException("The view is not a child of CoordinatorLayout");
	}
	CoordinatorLayout.Behavior behavior = ((CoordinatorLayout.LayoutParams) params)
	.getBehavior();
	if (!(behavior instanceof BottomSheetBehavior)) {
	throw new IllegalArgumentException(
	"The view is not associated with BottomSheetBehavior");
	}
	return (BottomSheetBehavior<V>) behavior;
	}

	}