v17/leanback/src/android/support/v17/leanback/app/RowsFragment.java - platform/frameworks/support - Git at Google

 /*
  * 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.support.v17.leanback.app;

 import java.util.ArrayList;

 import android.animation.TimeAnimator;
 import android.animation.TimeAnimator.TimeListener;
 import android.os.Bundle;
 import android.support.v17.leanback.R;
 import android.support.v17.leanback.widget.ItemBridgeAdapter;
 import android.support.v17.leanback.widget.OnItemViewClickedListener;
 import android.support.v17.leanback.widget.OnItemViewSelectedListener;
 import android.support.v17.leanback.widget.RowPresenter.ViewHolder;
 import android.support.v17.leanback.widget.ScaleFrameLayout;
 import android.support.v17.leanback.widget.VerticalGridView;
 import android.support.v17.leanback.widget.HorizontalGridView;
 import android.support.v17.leanback.widget.RowPresenter;
 import android.support.v17.leanback.widget.ListRowPresenter;
 import android.support.v17.leanback.widget.Presenter;
 import android.support.v7.widget.RecyclerView;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewTreeObserver;
 import android.view.animation.DecelerateInterpolator;
 import android.view.animation.Interpolator;

 /**
  * An ordered set of rows of leanback widgets.
  * <p>
  * A RowsFragment renders the elements of its
  * {@link android.support.v17.leanback.widget.ObjectAdapter} as a set
  * of rows in a vertical list. The elements in this adapter must be subclasses
  * of {@link android.support.v17.leanback.widget.Row}.
  * </p>
  */
 public class RowsFragment extends BaseRowFragment {

     /**
      * Internal helper class that manages row select animation and apply a default
      * dim to each row.
      */
     final class RowViewHolderExtra implements TimeListener {
         final RowPresenter mRowPresenter;
         final Presenter.ViewHolder mRowViewHolder;

         final TimeAnimator mSelectAnimator = new TimeAnimator();

         int mSelectAnimatorDurationInUse;
         Interpolator mSelectAnimatorInterpolatorInUse;
         float mSelectLevelAnimStart;
         float mSelectLevelAnimDelta;

         RowViewHolderExtra(ItemBridgeAdapter.ViewHolder ibvh) {
             mRowPresenter = (RowPresenter) ibvh.getPresenter();
             mRowViewHolder = ibvh.getViewHolder();
             mSelectAnimator.setTimeListener(this);
         }

         @Override
         public void onTimeUpdate(TimeAnimator animation, long totalTime, long deltaTime) {
             if (mSelectAnimator.isRunning()) {
                 updateSelect(totalTime, deltaTime);
             }
         }

         void updateSelect(long totalTime, long deltaTime) {
             float fraction;
             if (totalTime >= mSelectAnimatorDurationInUse) {
                 fraction = 1;
                 mSelectAnimator.end();
             } else {
                 fraction = (float) (totalTime / (double) mSelectAnimatorDurationInUse);
             }
             if (mSelectAnimatorInterpolatorInUse != null) {
                 fraction = mSelectAnimatorInterpolatorInUse.getInterpolation(fraction);
             }
             float level =  mSelectLevelAnimStart + fraction * mSelectLevelAnimDelta;
             mRowPresenter.setSelectLevel(mRowViewHolder, level);
         }

         void animateSelect(boolean select, boolean immediate) {
             mSelectAnimator.end();
             final float end = select ? 1 : 0;
             if (immediate) {
                 mRowPresenter.setSelectLevel(mRowViewHolder, end);
             } else if (mRowPresenter.getSelectLevel(mRowViewHolder) != end) {
                 mSelectAnimatorDurationInUse = mSelectAnimatorDuration;
                 mSelectAnimatorInterpolatorInUse = mSelectAnimatorInterpolator;
                 mSelectLevelAnimStart = mRowPresenter.getSelectLevel(mRowViewHolder);
                 mSelectLevelAnimDelta = end - mSelectLevelAnimStart;
                 mSelectAnimator.start();
             }
         }

     }

     private static final String TAG = "RowsFragment";
     private static final boolean DEBUG = false;

     private ItemBridgeAdapter.ViewHolder mSelectedViewHolder;
     private int mSubPosition;
     private boolean mExpand = true;
     private boolean mViewsCreated;
     private float mRowScaleFactor;
     private int mAlignedTop;
     private boolean mRowScaleEnabled;
     private ScaleFrameLayout mScaleFrameLayout;
     private boolean mAfterEntranceTransition = true;

     private OnItemViewSelectedListener mOnItemViewSelectedListener;
     private OnItemViewClickedListener mOnItemViewClickedListener;

     // Select animation and interpolator are not intended to be
     // exposed at this moment. They might be synced with vertical scroll
     // animation later.
     int mSelectAnimatorDuration;
     Interpolator mSelectAnimatorInterpolator = new DecelerateInterpolator(2);

     private RecyclerView.RecycledViewPool mRecycledViewPool;
     private ArrayList<Presenter> mPresenterMapper;

     private ItemBridgeAdapter.AdapterListener mExternalAdapterListener;

     @Override
     protected VerticalGridView findGridViewFromRoot(View view) {
         return (VerticalGridView) view.findViewById(R.id.container_list);
     }

     /**
      * Sets an item clicked listener on the fragment.
      * OnItemViewClickedListener will override {@link View.OnClickListener} that
      * item presenter sets during {@link Presenter#onCreateViewHolder(ViewGroup)}.
      * So in general,  developer should choose one of the listeners but not both.
      */
     public void setOnItemViewClickedListener(OnItemViewClickedListener listener) {
         mOnItemViewClickedListener = listener;
         if (mViewsCreated) {
             throw new IllegalStateException(
                     "Item clicked listener must be set before views are created");
         }
     }

     /**
      * Returns the item clicked listener.
      */
     public OnItemViewClickedListener getOnItemViewClickedListener() {
         return mOnItemViewClickedListener;
     }

     /**
      * Set the visibility of titles/hovercard of browse rows.
      */
     public void setExpand(boolean expand) {
         mExpand = expand;
         VerticalGridView listView = getVerticalGridView();
         if (listView != null) {
             updateRowScaling();
             final int count = listView.getChildCount();
             if (DEBUG) Log.v(TAG, "setExpand " + expand + " count " + count);
             for (int i = 0; i < count; i++) {
                 View view = listView.getChildAt(i);
                 ItemBridgeAdapter.ViewHolder vh = (ItemBridgeAdapter.ViewHolder) listView.getChildViewHolder(view);
                 setRowViewExpanded(vh, mExpand);
             }
         }
     }

     /**
      * Sets an item selection listener.
      */
     public void setOnItemViewSelectedListener(OnItemViewSelectedListener listener) {
         mOnItemViewSelectedListener = listener;
         VerticalGridView listView = getVerticalGridView();
         if (listView != null) {
             final int count = listView.getChildCount();
             for (int i = 0; i < count; i++) {
                 View view = listView.getChildAt(i);
                 ItemBridgeAdapter.ViewHolder ibvh = (ItemBridgeAdapter.ViewHolder)
                         listView.getChildViewHolder(view);
                 RowPresenter rowPresenter = (RowPresenter) ibvh.getPresenter();
                 RowPresenter.ViewHolder vh = rowPresenter.getRowViewHolder(ibvh.getViewHolder());
                 vh.setOnItemViewSelectedListener(mOnItemViewSelectedListener);
             }
         }
     }

     /**
      * Returns an item selection listener.
      */
     public OnItemViewSelectedListener getOnItemViewSelectedListener() {
         return mOnItemViewSelectedListener;
     }

     /**
      * Enables scaling of rows.
      *
      * @param enable true to enable row scaling
      */
     public void enableRowScaling(boolean enable) {
         mRowScaleEnabled = enable;
     }

     @Override
     void onRowSelected(RecyclerView parent, RecyclerView.ViewHolder viewHolder,
             int position, int subposition) {
         if (mSelectedViewHolder != viewHolder || mSubPosition != subposition) {
             if (DEBUG) Log.v(TAG, "new row selected position " + position + " subposition "
                     + subposition + " view " + viewHolder.itemView);
             mSubPosition = subposition;
             if (mSelectedViewHolder != null) {
                 setRowViewSelected(mSelectedViewHolder, false, false);
             }
             mSelectedViewHolder = (ItemBridgeAdapter.ViewHolder) viewHolder;
             if (mSelectedViewHolder != null) {
                 setRowViewSelected(mSelectedViewHolder, true, false);
             }
         }
     }

     @Override
     int getLayoutResourceId() {
         return R.layout.lb_rows_fragment;
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         mSelectAnimatorDuration = getResources().getInteger(
                 R.integer.lb_browse_rows_anim_duration);
         mRowScaleFactor = getResources().getFraction(
                 R.fraction.lb_browse_rows_scale, 1, 1);
     }

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
         View view = super.onCreateView(inflater, container, savedInstanceState);
         mScaleFrameLayout = (ScaleFrameLayout) view.findViewById(R.id.scale_frame);
         return view;
     }

     @Override
     public void onViewCreated(View view, Bundle savedInstanceState) {
         if (DEBUG) Log.v(TAG, "onViewCreated");
         super.onViewCreated(view, savedInstanceState);
         // Align the top edge of child with id row_content.
         // Need set this for directly using RowsFragment.
         getVerticalGridView().setItemAlignmentViewId(R.id.row_content);
         getVerticalGridView().setSaveChildrenPolicy(VerticalGridView.SAVE_LIMITED_CHILD);

         mRecycledViewPool = null;
         mPresenterMapper = null;
     }

     @Override
     public void onDestroyView() {
         mViewsCreated = false;
         super.onDestroyView();
     }

     @Override
     void setItemAlignment() {
         super.setItemAlignment();
         if (getVerticalGridView() != null) {
             getVerticalGridView().setItemAlignmentOffsetWithPadding(true);
         }
     }

     void setExternalAdapterListener(ItemBridgeAdapter.AdapterListener listener) {
         mExternalAdapterListener = listener;
     }

     /**
      * Returns the view that will change scale.
      */
     View getScaleView() {
         return getVerticalGridView();
     }

     /**
      * Sets the pivots to scale rows fragment.
      */
     void setScalePivots(float pivotX, float pivotY) {
         // set pivot on ScaleFrameLayout, it will be propagated to its child VerticalGridView
         // where we actually change scale.
         mScaleFrameLayout.setPivotX(pivotX);
         mScaleFrameLayout.setPivotY(pivotY);
     }

     private static void setRowViewExpanded(ItemBridgeAdapter.ViewHolder vh, boolean expanded) {
         ((RowPresenter) vh.getPresenter()).setRowViewExpanded(vh.getViewHolder(), expanded);
     }

     private static void setRowViewSelected(ItemBridgeAdapter.ViewHolder vh, boolean selected,
             boolean immediate) {
         RowViewHolderExtra extra = (RowViewHolderExtra) vh.getExtraObject();
         extra.animateSelect(selected, immediate);
         ((RowPresenter) vh.getPresenter()).setRowViewSelected(vh.getViewHolder(), selected);
     }

     private final ItemBridgeAdapter.AdapterListener mBridgeAdapterListener =
             new ItemBridgeAdapter.AdapterListener() {
         @Override
         public void onAddPresenter(Presenter presenter, int type) {
             if (mExternalAdapterListener != null) {
                 mExternalAdapterListener.onAddPresenter(presenter, type);
             }
         }
         @Override
         public void onCreate(ItemBridgeAdapter.ViewHolder vh) {
             VerticalGridView listView = getVerticalGridView();
             if (listView != null) {
                 // set clip children false for slide animation
                 listView.setClipChildren(false);
             }
             setupSharedViewPool(vh);
             mViewsCreated = true;
             vh.setExtraObject(new RowViewHolderExtra(vh));
             // selected state is initialized to false, then driven by grid view onChildSelected
             // events.  When there is rebind, grid view fires onChildSelected event properly.
             // So we don't need do anything special later in onBind or onAttachedToWindow.
             setRowViewSelected(vh, false, true);
             if (mExternalAdapterListener != null) {
                 mExternalAdapterListener.onCreate(vh);
             }
         }
         @Override
         public void onAttachedToWindow(ItemBridgeAdapter.ViewHolder vh) {
             if (DEBUG) Log.v(TAG, "onAttachToWindow");
             // All views share the same mExpand value.  When we attach a view to grid view,
             // we should make sure it pick up the latest mExpand value we set early on other
             // attached views.  For no-structure-change update,  the view is rebound to new data,
             // but again it should use the unchanged mExpand value,  so we don't need do any
             // thing in onBind.
             setRowViewExpanded(vh, mExpand);
             RowPresenter rowPresenter = (RowPresenter) vh.getPresenter();
             RowPresenter.ViewHolder rowVh = rowPresenter.getRowViewHolder(vh.getViewHolder());
             rowVh.setOnItemViewSelectedListener(mOnItemViewSelectedListener);
             rowVh.setOnItemViewClickedListener(mOnItemViewClickedListener);
             rowPresenter.setEntranceTransitionState(rowVh, mAfterEntranceTransition);
             if (mExternalAdapterListener != null) {
                 mExternalAdapterListener.onAttachedToWindow(vh);
             }
         }
         @Override
         public void onDetachedFromWindow(ItemBridgeAdapter.ViewHolder vh) {
             if (mSelectedViewHolder == vh) {
                 setRowViewSelected(mSelectedViewHolder, false, true);
                 mSelectedViewHolder = null;
             }
             if (mExternalAdapterListener != null) {
                 mExternalAdapterListener.onDetachedFromWindow(vh);
             }
         }
         @Override
         public void onBind(ItemBridgeAdapter.ViewHolder vh) {
             if (mExternalAdapterListener != null) {
                 mExternalAdapterListener.onBind(vh);
             }
         }
         @Override
         public void onUnbind(ItemBridgeAdapter.ViewHolder vh) {
             setRowViewSelected(vh, false, true);
             if (mExternalAdapterListener != null) {
                 mExternalAdapterListener.onUnbind(vh);
             }
         }
     };

     private void setupSharedViewPool(ItemBridgeAdapter.ViewHolder bridgeVh) {
         RowPresenter rowPresenter = (RowPresenter) bridgeVh.getPresenter();
         RowPresenter.ViewHolder rowVh = rowPresenter.getRowViewHolder(bridgeVh.getViewHolder());

         if (rowVh instanceof ListRowPresenter.ViewHolder) {
             HorizontalGridView view = ((ListRowPresenter.ViewHolder) rowVh).getGridView();
             // Recycled view pool is shared between all list rows
             if (mRecycledViewPool == null) {
                 mRecycledViewPool = view.getRecycledViewPool();
             } else {
                 view.setRecycledViewPool(mRecycledViewPool);
             }

             ItemBridgeAdapter bridgeAdapter =
                     ((ListRowPresenter.ViewHolder) rowVh).getBridgeAdapter();
             if (mPresenterMapper == null) {
                 mPresenterMapper = bridgeAdapter.getPresenterMapper();
             } else {
                 bridgeAdapter.setPresenterMapper(mPresenterMapper);
             }
         }
     }

     @Override
     void updateAdapter() {
         super.updateAdapter();
         mSelectedViewHolder = null;
         mViewsCreated = false;

         ItemBridgeAdapter adapter = getBridgeAdapter();
         if (adapter != null) {
             adapter.setAdapterListener(mBridgeAdapterListener);
         }
     }

     @Override
     boolean onTransitionPrepare() {
         boolean prepared = super.onTransitionPrepare();
         if (prepared) {
             freezeRows(true);
         }
         return prepared;
     }

     class ExpandPreLayout implements ViewTreeObserver.OnPreDrawListener {

         final View mVerticalView;
         final Runnable mCallback;
         int mState;

         final static int STATE_INIT = 0;
         final static int STATE_FIRST_DRAW = 1;
         final static int STATE_SECOND_DRAW = 2;

         ExpandPreLayout(Runnable callback) {
             mVerticalView = getVerticalGridView();
             mCallback = callback;
         }

         void execute() {
             mVerticalView.getViewTreeObserver().addOnPreDrawListener(this);
             setExpand(false);
             mState = STATE_INIT;
         }

         @Override
         public boolean onPreDraw() {
             if (getView() == null || getActivity() == null) {
                 mVerticalView.getViewTreeObserver().removeOnPreDrawListener(this);
                 return true;
             }
             if (mState == STATE_INIT) {
                 setExpand(true);
                 mState = STATE_FIRST_DRAW;
             } else if (mState == STATE_FIRST_DRAW) {
                 mCallback.run();
                 mVerticalView.getViewTreeObserver().removeOnPreDrawListener(this);
                 mState = STATE_SECOND_DRAW;
             }
             return false;
         }
     }

     void onExpandTransitionStart(boolean expand, final Runnable callback) {
         onTransitionPrepare();
         onTransitionStart();
         if (expand) {
             callback.run();
             return;
         }
         // Run a "pre" layout when we go non-expand, in order to get the initial
         // positions of added rows.
         new ExpandPreLayout(callback).execute();
     }

     private boolean needsScale() {
         return mRowScaleEnabled && !mExpand;
     }

     private void updateRowScaling() {
         final float scaleFactor = needsScale() ? mRowScaleFactor : 1f;
         mScaleFrameLayout.setLayoutScaleY(scaleFactor);
         getScaleView().setScaleY(scaleFactor);
         getScaleView().setScaleX(scaleFactor);
         updateWindowAlignOffset();
     }

     private void updateWindowAlignOffset() {
         int alignOffset = mAlignedTop;
         if (needsScale()) {
             alignOffset = (int) (alignOffset / mRowScaleFactor + 0.5f);
         }
         getVerticalGridView().setWindowAlignmentOffset(alignOffset);
     }

     @Override
     void setWindowAlignmentFromTop(int alignedTop) {
         mAlignedTop = alignedTop;
         final VerticalGridView gridView = getVerticalGridView();
         if (gridView != null) {
             updateWindowAlignOffset();
             // align to a fixed position from top
             gridView.setWindowAlignmentOffsetPercent(
                     VerticalGridView.WINDOW_ALIGN_OFFSET_PERCENT_DISABLED);
             gridView.setWindowAlignment(VerticalGridView.WINDOW_ALIGN_NO_EDGE);
         }
     }

     @Override
     void onTransitionEnd() {
         super.onTransitionEnd();
         freezeRows(false);
     }

     private void freezeRows(boolean freeze) {
         VerticalGridView verticalView = getVerticalGridView();
         if (verticalView != null) {
             final int count = verticalView.getChildCount();
             for (int i = 0; i < count; i++) {
                 ItemBridgeAdapter.ViewHolder ibvh = (ItemBridgeAdapter.ViewHolder)
                     verticalView.getChildViewHolder(verticalView.getChildAt(i));
                 RowPresenter rowPresenter = (RowPresenter) ibvh.getPresenter();
                 RowPresenter.ViewHolder vh = rowPresenter.getRowViewHolder(ibvh.getViewHolder());
                 rowPresenter.freeze(vh, freeze);
             }
         }
     }

     /**
      * For rows that willing to participate entrance transition,  this function
      * hide views if afterTransition is true,  show views if afterTransition is false.
      */
     void setEntranceTransitionState(boolean afterTransition) {
         mAfterEntranceTransition = afterTransition;
         VerticalGridView verticalView = getVerticalGridView();
         if (verticalView != null) {
             final int count = verticalView.getChildCount();
             for (int i = 0; i < count; i++) {
                 ItemBridgeAdapter.ViewHolder ibvh = (ItemBridgeAdapter.ViewHolder)
                     verticalView.getChildViewHolder(verticalView.getChildAt(i));
                 RowPresenter rowPresenter = (RowPresenter) ibvh.getPresenter();
                 RowPresenter.ViewHolder vh = rowPresenter.getRowViewHolder(ibvh.getViewHolder());
                 rowPresenter.setEntranceTransitionState(vh, mAfterEntranceTransition);
             }
         }
     }
 }
	/*
	* 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.support.v17.leanback.app;

	import java.util.ArrayList;

	import android.animation.TimeAnimator;
	import android.animation.TimeAnimator.TimeListener;
	import android.os.Bundle;
	import android.support.v17.leanback.R;
	import android.support.v17.leanback.widget.ItemBridgeAdapter;
	import android.support.v17.leanback.widget.OnItemViewClickedListener;
	import android.support.v17.leanback.widget.OnItemViewSelectedListener;
	import android.support.v17.leanback.widget.RowPresenter.ViewHolder;
	import android.support.v17.leanback.widget.ScaleFrameLayout;
	import android.support.v17.leanback.widget.VerticalGridView;
	import android.support.v17.leanback.widget.HorizontalGridView;
	import android.support.v17.leanback.widget.RowPresenter;
	import android.support.v17.leanback.widget.ListRowPresenter;
	import android.support.v17.leanback.widget.Presenter;
	import android.support.v7.widget.RecyclerView;
	import android.util.Log;
	import android.view.LayoutInflater;
	import android.view.View;
	import android.view.ViewGroup;
	import android.view.ViewTreeObserver;
	import android.view.animation.DecelerateInterpolator;
	import android.view.animation.Interpolator;

	/**
	* An ordered set of rows of leanback widgets.
	* <p>
	* A RowsFragment renders the elements of its
	* {@link android.support.v17.leanback.widget.ObjectAdapter} as a set
	* of rows in a vertical list. The elements in this adapter must be subclasses
	* of {@link android.support.v17.leanback.widget.Row}.
	* </p>
	*/
	public class RowsFragment extends BaseRowFragment {

	/**
	* Internal helper class that manages row select animation and apply a default
	* dim to each row.
	*/
	final class RowViewHolderExtra implements TimeListener {
	final RowPresenter mRowPresenter;
	final Presenter.ViewHolder mRowViewHolder;

	final TimeAnimator mSelectAnimator = new TimeAnimator();

	int mSelectAnimatorDurationInUse;
	Interpolator mSelectAnimatorInterpolatorInUse;
	float mSelectLevelAnimStart;
	float mSelectLevelAnimDelta;

	RowViewHolderExtra(ItemBridgeAdapter.ViewHolder ibvh) {
	mRowPresenter = (RowPresenter) ibvh.getPresenter();
	mRowViewHolder = ibvh.getViewHolder();
	mSelectAnimator.setTimeListener(this);
	}

	@Override
	public void onTimeUpdate(TimeAnimator animation, long totalTime, long deltaTime) {
	if (mSelectAnimator.isRunning()) {
	updateSelect(totalTime, deltaTime);
	}
	}

	void updateSelect(long totalTime, long deltaTime) {
	float fraction;
	if (totalTime >= mSelectAnimatorDurationInUse) {
	fraction = 1;
	mSelectAnimator.end();
	} else {
	fraction = (float) (totalTime / (double) mSelectAnimatorDurationInUse);
	}
	if (mSelectAnimatorInterpolatorInUse != null) {
	fraction = mSelectAnimatorInterpolatorInUse.getInterpolation(fraction);
	}
	float level = mSelectLevelAnimStart + fraction * mSelectLevelAnimDelta;
	mRowPresenter.setSelectLevel(mRowViewHolder, level);
	}

	void animateSelect(boolean select, boolean immediate) {
	mSelectAnimator.end();
	final float end = select ? 1 : 0;
	if (immediate) {
	mRowPresenter.setSelectLevel(mRowViewHolder, end);
	} else if (mRowPresenter.getSelectLevel(mRowViewHolder) != end) {
	mSelectAnimatorDurationInUse = mSelectAnimatorDuration;
	mSelectAnimatorInterpolatorInUse = mSelectAnimatorInterpolator;
	mSelectLevelAnimStart = mRowPresenter.getSelectLevel(mRowViewHolder);
	mSelectLevelAnimDelta = end - mSelectLevelAnimStart;
	mSelectAnimator.start();
	}
	}

	}

	private static final String TAG = "RowsFragment";
	private static final boolean DEBUG = false;

	private ItemBridgeAdapter.ViewHolder mSelectedViewHolder;
	private int mSubPosition;
	private boolean mExpand = true;
	private boolean mViewsCreated;
	private float mRowScaleFactor;
	private int mAlignedTop;
	private boolean mRowScaleEnabled;
	private ScaleFrameLayout mScaleFrameLayout;
	private boolean mAfterEntranceTransition = true;

	private OnItemViewSelectedListener mOnItemViewSelectedListener;
	private OnItemViewClickedListener mOnItemViewClickedListener;

	// Select animation and interpolator are not intended to be
	// exposed at this moment. They might be synced with vertical scroll
	// animation later.
	int mSelectAnimatorDuration;
	Interpolator mSelectAnimatorInterpolator = new DecelerateInterpolator(2);

	private RecyclerView.RecycledViewPool mRecycledViewPool;
	private ArrayList<Presenter> mPresenterMapper;

	private ItemBridgeAdapter.AdapterListener mExternalAdapterListener;

	@Override
	protected VerticalGridView findGridViewFromRoot(View view) {
	return (VerticalGridView) view.findViewById(R.id.container_list);
	}

	/**
	* Sets an item clicked listener on the fragment.
	* OnItemViewClickedListener will override {@link View.OnClickListener} that
	* item presenter sets during {@link Presenter#onCreateViewHolder(ViewGroup)}.
	* So in general, developer should choose one of the listeners but not both.
	*/
	public void setOnItemViewClickedListener(OnItemViewClickedListener listener) {
	mOnItemViewClickedListener = listener;
	if (mViewsCreated) {
	throw new IllegalStateException(
	"Item clicked listener must be set before views are created");
	}
	}

	/**
	* Returns the item clicked listener.
	*/
	public OnItemViewClickedListener getOnItemViewClickedListener() {
	return mOnItemViewClickedListener;
	}

	/**
	* Set the visibility of titles/hovercard of browse rows.
	*/
	public void setExpand(boolean expand) {
	mExpand = expand;
	VerticalGridView listView = getVerticalGridView();
	if (listView != null) {
	updateRowScaling();
	final int count = listView.getChildCount();
	if (DEBUG) Log.v(TAG, "setExpand " + expand + " count " + count);
	for (int i = 0; i < count; i++) {
	View view = listView.getChildAt(i);
	ItemBridgeAdapter.ViewHolder vh = (ItemBridgeAdapter.ViewHolder) listView.getChildViewHolder(view);
	setRowViewExpanded(vh, mExpand);
	}
	}
	}

	/**
	* Sets an item selection listener.
	*/
	public void setOnItemViewSelectedListener(OnItemViewSelectedListener listener) {
	mOnItemViewSelectedListener = listener;
	VerticalGridView listView = getVerticalGridView();
	if (listView != null) {
	final int count = listView.getChildCount();
	for (int i = 0; i < count; i++) {
	View view = listView.getChildAt(i);
	ItemBridgeAdapter.ViewHolder ibvh = (ItemBridgeAdapter.ViewHolder)
	listView.getChildViewHolder(view);
	RowPresenter rowPresenter = (RowPresenter) ibvh.getPresenter();
	RowPresenter.ViewHolder vh = rowPresenter.getRowViewHolder(ibvh.getViewHolder());
	vh.setOnItemViewSelectedListener(mOnItemViewSelectedListener);
	}
	}
	}

	/**
	* Returns an item selection listener.
	*/
	public OnItemViewSelectedListener getOnItemViewSelectedListener() {
	return mOnItemViewSelectedListener;
	}

	/**
	* Enables scaling of rows.
	*
	* @param enable true to enable row scaling
	*/
	public void enableRowScaling(boolean enable) {
	mRowScaleEnabled = enable;
	}

	@Override
	void onRowSelected(RecyclerView parent, RecyclerView.ViewHolder viewHolder,
	int position, int subposition) {
	if (mSelectedViewHolder != viewHolder \|\| mSubPosition != subposition) {
	if (DEBUG) Log.v(TAG, "new row selected position " + position + " subposition "
	+ subposition + " view " + viewHolder.itemView);
	mSubPosition = subposition;
	if (mSelectedViewHolder != null) {
	setRowViewSelected(mSelectedViewHolder, false, false);
	}
	mSelectedViewHolder = (ItemBridgeAdapter.ViewHolder) viewHolder;
	if (mSelectedViewHolder != null) {
	setRowViewSelected(mSelectedViewHolder, true, false);
	}
	}
	}

	@Override
	int getLayoutResourceId() {
	return R.layout.lb_rows_fragment;
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	mSelectAnimatorDuration = getResources().getInteger(
	R.integer.lb_browse_rows_anim_duration);
	mRowScaleFactor = getResources().getFraction(
	R.fraction.lb_browse_rows_scale, 1, 1);
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
	Bundle savedInstanceState) {
	View view = super.onCreateView(inflater, container, savedInstanceState);
	mScaleFrameLayout = (ScaleFrameLayout) view.findViewById(R.id.scale_frame);
	return view;
	}

	@Override
	public void onViewCreated(View view, Bundle savedInstanceState) {
	if (DEBUG) Log.v(TAG, "onViewCreated");
	super.onViewCreated(view, savedInstanceState);
	// Align the top edge of child with id row_content.
	// Need set this for directly using RowsFragment.
	getVerticalGridView().setItemAlignmentViewId(R.id.row_content);
	getVerticalGridView().setSaveChildrenPolicy(VerticalGridView.SAVE_LIMITED_CHILD);

	mRecycledViewPool = null;
	mPresenterMapper = null;
	}

	@Override
	public void onDestroyView() {
	mViewsCreated = false;
	super.onDestroyView();
	}

	@Override
	void setItemAlignment() {
	super.setItemAlignment();
	if (getVerticalGridView() != null) {
	getVerticalGridView().setItemAlignmentOffsetWithPadding(true);
	}
	}

	void setExternalAdapterListener(ItemBridgeAdapter.AdapterListener listener) {
	mExternalAdapterListener = listener;
	}

	/**
	* Returns the view that will change scale.
	*/
	View getScaleView() {
	return getVerticalGridView();
	}

	/**
	* Sets the pivots to scale rows fragment.
	*/
	void setScalePivots(float pivotX, float pivotY) {
	// set pivot on ScaleFrameLayout, it will be propagated to its child VerticalGridView
	// where we actually change scale.
	mScaleFrameLayout.setPivotX(pivotX);
	mScaleFrameLayout.setPivotY(pivotY);
	}

	private static void setRowViewExpanded(ItemBridgeAdapter.ViewHolder vh, boolean expanded) {
	((RowPresenter) vh.getPresenter()).setRowViewExpanded(vh.getViewHolder(), expanded);
	}

	private static void setRowViewSelected(ItemBridgeAdapter.ViewHolder vh, boolean selected,
	boolean immediate) {
	RowViewHolderExtra extra = (RowViewHolderExtra) vh.getExtraObject();
	extra.animateSelect(selected, immediate);
	((RowPresenter) vh.getPresenter()).setRowViewSelected(vh.getViewHolder(), selected);
	}

	private final ItemBridgeAdapter.AdapterListener mBridgeAdapterListener =
	new ItemBridgeAdapter.AdapterListener() {
	@Override
	public void onAddPresenter(Presenter presenter, int type) {
	if (mExternalAdapterListener != null) {
	mExternalAdapterListener.onAddPresenter(presenter, type);
	}
	}
	@Override
	public void onCreate(ItemBridgeAdapter.ViewHolder vh) {
	VerticalGridView listView = getVerticalGridView();
	if (listView != null) {
	// set clip children false for slide animation
	listView.setClipChildren(false);
	}
	setupSharedViewPool(vh);
	mViewsCreated = true;
	vh.setExtraObject(new RowViewHolderExtra(vh));
	// selected state is initialized to false, then driven by grid view onChildSelected
	// events. When there is rebind, grid view fires onChildSelected event properly.
	// So we don't need do anything special later in onBind or onAttachedToWindow.
	setRowViewSelected(vh, false, true);
	if (mExternalAdapterListener != null) {
	mExternalAdapterListener.onCreate(vh);
	}
	}
	@Override
	public void onAttachedToWindow(ItemBridgeAdapter.ViewHolder vh) {
	if (DEBUG) Log.v(TAG, "onAttachToWindow");
	// All views share the same mExpand value. When we attach a view to grid view,
	// we should make sure it pick up the latest mExpand value we set early on other
	// attached views. For no-structure-change update, the view is rebound to new data,
	// but again it should use the unchanged mExpand value, so we don't need do any
	// thing in onBind.
	setRowViewExpanded(vh, mExpand);
	RowPresenter rowPresenter = (RowPresenter) vh.getPresenter();
	RowPresenter.ViewHolder rowVh = rowPresenter.getRowViewHolder(vh.getViewHolder());
	rowVh.setOnItemViewSelectedListener(mOnItemViewSelectedListener);
	rowVh.setOnItemViewClickedListener(mOnItemViewClickedListener);
	rowPresenter.setEntranceTransitionState(rowVh, mAfterEntranceTransition);
	if (mExternalAdapterListener != null) {
	mExternalAdapterListener.onAttachedToWindow(vh);
	}
	}
	@Override
	public void onDetachedFromWindow(ItemBridgeAdapter.ViewHolder vh) {
	if (mSelectedViewHolder == vh) {
	setRowViewSelected(mSelectedViewHolder, false, true);
	mSelectedViewHolder = null;
	}
	if (mExternalAdapterListener != null) {
	mExternalAdapterListener.onDetachedFromWindow(vh);
	}
	}
	@Override
	public void onBind(ItemBridgeAdapter.ViewHolder vh) {
	if (mExternalAdapterListener != null) {
	mExternalAdapterListener.onBind(vh);
	}
	}
	@Override
	public void onUnbind(ItemBridgeAdapter.ViewHolder vh) {
	setRowViewSelected(vh, false, true);
	if (mExternalAdapterListener != null) {
	mExternalAdapterListener.onUnbind(vh);
	}
	}
	};

	private void setupSharedViewPool(ItemBridgeAdapter.ViewHolder bridgeVh) {
	RowPresenter rowPresenter = (RowPresenter) bridgeVh.getPresenter();
	RowPresenter.ViewHolder rowVh = rowPresenter.getRowViewHolder(bridgeVh.getViewHolder());

	if (rowVh instanceof ListRowPresenter.ViewHolder) {
	HorizontalGridView view = ((ListRowPresenter.ViewHolder) rowVh).getGridView();
	// Recycled view pool is shared between all list rows
	if (mRecycledViewPool == null) {
	mRecycledViewPool = view.getRecycledViewPool();
	} else {
	view.setRecycledViewPool(mRecycledViewPool);
	}

	ItemBridgeAdapter bridgeAdapter =
	((ListRowPresenter.ViewHolder) rowVh).getBridgeAdapter();
	if (mPresenterMapper == null) {
	mPresenterMapper = bridgeAdapter.getPresenterMapper();
	} else {
	bridgeAdapter.setPresenterMapper(mPresenterMapper);
	}
	}
	}

	@Override
	void updateAdapter() {
	super.updateAdapter();
	mSelectedViewHolder = null;
	mViewsCreated = false;

	ItemBridgeAdapter adapter = getBridgeAdapter();
	if (adapter != null) {
	adapter.setAdapterListener(mBridgeAdapterListener);
	}
	}

	@Override
	boolean onTransitionPrepare() {
	boolean prepared = super.onTransitionPrepare();
	if (prepared) {
	freezeRows(true);
	}
	return prepared;
	}

	class ExpandPreLayout implements ViewTreeObserver.OnPreDrawListener {

	final View mVerticalView;
	final Runnable mCallback;
	int mState;

	final static int STATE_INIT = 0;
	final static int STATE_FIRST_DRAW = 1;
	final static int STATE_SECOND_DRAW = 2;

	ExpandPreLayout(Runnable callback) {
	mVerticalView = getVerticalGridView();
	mCallback = callback;
	}

	void execute() {
	mVerticalView.getViewTreeObserver().addOnPreDrawListener(this);
	setExpand(false);
	mState = STATE_INIT;
	}

	@Override
	public boolean onPreDraw() {
	if (getView() == null \|\| getActivity() == null) {
	mVerticalView.getViewTreeObserver().removeOnPreDrawListener(this);
	return true;
	}
	if (mState == STATE_INIT) {
	setExpand(true);
	mState = STATE_FIRST_DRAW;
	} else if (mState == STATE_FIRST_DRAW) {
	mCallback.run();
	mVerticalView.getViewTreeObserver().removeOnPreDrawListener(this);
	mState = STATE_SECOND_DRAW;
	}
	return false;
	}
	}

	void onExpandTransitionStart(boolean expand, final Runnable callback) {
	onTransitionPrepare();
	onTransitionStart();
	if (expand) {
	callback.run();
	return;
	}
	// Run a "pre" layout when we go non-expand, in order to get the initial
	// positions of added rows.
	new ExpandPreLayout(callback).execute();
	}

	private boolean needsScale() {
	return mRowScaleEnabled && !mExpand;
	}

	private void updateRowScaling() {
	final float scaleFactor = needsScale() ? mRowScaleFactor : 1f;
	mScaleFrameLayout.setLayoutScaleY(scaleFactor);
	getScaleView().setScaleY(scaleFactor);
	getScaleView().setScaleX(scaleFactor);
	updateWindowAlignOffset();
	}

	private void updateWindowAlignOffset() {
	int alignOffset = mAlignedTop;
	if (needsScale()) {
	alignOffset = (int) (alignOffset / mRowScaleFactor + 0.5f);
	}
	getVerticalGridView().setWindowAlignmentOffset(alignOffset);
	}

	@Override
	void setWindowAlignmentFromTop(int alignedTop) {
	mAlignedTop = alignedTop;
	final VerticalGridView gridView = getVerticalGridView();
	if (gridView != null) {
	updateWindowAlignOffset();
	// align to a fixed position from top
	gridView.setWindowAlignmentOffsetPercent(
	VerticalGridView.WINDOW_ALIGN_OFFSET_PERCENT_DISABLED);
	gridView.setWindowAlignment(VerticalGridView.WINDOW_ALIGN_NO_EDGE);
	}
	}

	@Override
	void onTransitionEnd() {
	super.onTransitionEnd();
	freezeRows(false);
	}

	private void freezeRows(boolean freeze) {
	VerticalGridView verticalView = getVerticalGridView();
	if (verticalView != null) {
	final int count = verticalView.getChildCount();
	for (int i = 0; i < count; i++) {
	ItemBridgeAdapter.ViewHolder ibvh = (ItemBridgeAdapter.ViewHolder)
	verticalView.getChildViewHolder(verticalView.getChildAt(i));
	RowPresenter rowPresenter = (RowPresenter) ibvh.getPresenter();
	RowPresenter.ViewHolder vh = rowPresenter.getRowViewHolder(ibvh.getViewHolder());
	rowPresenter.freeze(vh, freeze);
	}
	}
	}

	/**
	* For rows that willing to participate entrance transition, this function
	* hide views if afterTransition is true, show views if afterTransition is false.
	*/
	void setEntranceTransitionState(boolean afterTransition) {
	mAfterEntranceTransition = afterTransition;
	VerticalGridView verticalView = getVerticalGridView();
	if (verticalView != null) {
	final int count = verticalView.getChildCount();
	for (int i = 0; i < count; i++) {
	ItemBridgeAdapter.ViewHolder ibvh = (ItemBridgeAdapter.ViewHolder)
	verticalView.getChildViewHolder(verticalView.getChildAt(i));
	RowPresenter rowPresenter = (RowPresenter) ibvh.getPresenter();
	RowPresenter.ViewHolder vh = rowPresenter.getRowViewHolder(ibvh.getViewHolder());
	rowPresenter.setEntranceTransitionState(vh, mAfterEntranceTransition);
	}
	}
	}
	}