/*
 * Copyright (C) 2006 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 it.sephiroth.android.library.widget;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Gravity;
import android.view.SoundEffectConstants;
import android.view.View;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.ExpandableListAdapter;
import android.widget.ListAdapter;

import java.util.ArrayList;

import it.sephiroth.android.library.R;

/**
 * A view that shows items in a vertically scrolling two-level list. This
 * differs from the {@link it.sephiroth.android.library.widget.HListView} by allowing two levels: groups which can
 * individually be expanded to show its children. The items come from the
 * {@link android.widget.ExpandableListAdapter} associated with this view.
 * <p/>
 * Expandable lists are able to show an indicator beside each item to display
 * the item's current state (the states are usually one of expanded group,
 * collapsed group, child, or last child). Use
 * {@link #setChildIndicator(Drawable)} or {@link #setGroupIndicator(Drawable)}
 * (or the corresponding XML attributes) to set these indicators (see the docs
 * for each method to see additional state that each Drawable can have). The
 * default style for an {@link ExpandableHListView} provides indicators which
 * will be shown next to Views given to the {@link ExpandableHListView}. The
 * layouts android.R.layout.simple_expandable_list_item_1 and
 * android.R.layout.simple_expandable_list_item_2 (which should be used with
 * {@link android.widget.SimpleCursorTreeAdapter}) contain the preferred position information
 * for indicators.
 * <p/>
 * The context menu information set by an {@link ExpandableHListView} will be a
 * {@link ExpandableListContextMenuInfo} object with
 * {@link ExpandableListContextMenuInfo#packedPosition} being a packed position
 * that can be used with {@link #getPackedPositionType(long)} and the other
 * similar methods.
 * <p/>
 * <em><b>Note:</b></em> You cannot use the value <code>wrap_content</code>
 * for the <code>android:layout_height</code> attribute of a
 * ExpandableListView in XML if the parent's size is also not strictly specified
 * (for example, if the parent were ScrollView you could not specify
 * wrap_content since it also can be any length. However, you can use
 * wrap_content if the ExpandableListView parent has a specific size, such as
 * 100 pixels.
 *
 * @attr ref android.R.styleable#ExpandableListView_groupIndicator
 * @attr ref android.R.styleable#ExpandableListView_indicatorLeft
 * @attr ref android.R.styleable#ExpandableListView_indicatorRight
 * @attr ref android.R.styleable#ExpandableListView_childIndicator
 * @attr ref android.R.styleable#ExpandableListView_childIndicatorLeft
 * @attr ref android.R.styleable#ExpandableListView_childIndicatorRight
 * @attr ref android.R.styleable#ExpandableListView_childDivider
 * @attr ref android.R.styleable#ExpandableListView_indicatorStart
 * @attr ref android.R.styleable#ExpandableListView_indicatorEnd
 * @attr ref android.R.styleable#ExpandableListView_childIndicatorStart
 * @attr ref android.R.styleable#ExpandableListView_childIndicatorEnd
 */
public class ExpandableHListView extends HListView {

	/**
	 * The packed position represents a group.
	 */
	public static final int PACKED_POSITION_TYPE_GROUP = 0;

	/**
	 * The packed position represents a child.
	 */
	public static final int PACKED_POSITION_TYPE_CHILD = 1;

	/**
	 * The packed position represents a neither/null/no preference.
	 */
	public static final int PACKED_POSITION_TYPE_NULL = 2;

	/**
	 * The value for a packed position that represents neither/null/no
	 * preference. This value is not otherwise possible since a group type
	 * (first bit 0) should not have a child position filled.
	 */
	public static final long PACKED_POSITION_VALUE_NULL = 0x00000000FFFFFFFFL;

	/** The mask (in packed position representation) for the child */
	private static final long PACKED_POSITION_MASK_CHILD = 0x00000000FFFFFFFFL;

	/** The mask (in packed position representation) for the group */
	private static final long PACKED_POSITION_MASK_GROUP = 0x7FFFFFFF00000000L;

	/** The mask (in packed position representation) for the type */
	private static final long PACKED_POSITION_MASK_TYPE = 0x8000000000000000L;

	/** The shift amount (in packed position representation) for the group */
	private static final long PACKED_POSITION_SHIFT_GROUP = 32;

	/** The shift amount (in packed position representation) for the type */
	private static final long PACKED_POSITION_SHIFT_TYPE = 63;

	/** The mask (in integer child position representation) for the child */
	private static final long PACKED_POSITION_INT_MASK_CHILD = 0xFFFFFFFF;

	/** The mask (in integer group position representation) for the group */
	private static final long PACKED_POSITION_INT_MASK_GROUP = 0x7FFFFFFF;

	/** Serves as the glue/translator between a ListView and an ExpandableListView */
	private ExpandableHListConnector mConnector;

	/** Gives us Views through group+child positions */
	private ExpandableListAdapter mAdapter;

	/** Left bound for drawing the indicator. */
	private int mIndicatorTop;

	/** Right bound for drawing the indicator. */
	private int mIndicatorLeft;

	/** Group indicator gravity */
	private int mIndicatorGravity;

	/** Child indicator gravity */
	private int mChildIndicatorGravity;

	private int mChildIndicatorTop;

	private int mChildIndicatorLeft;

	/**
	 * Denotes when a child indicator should inherit this bound from the generic
	 * indicator bounds
	 */
	public static final int CHILD_INDICATOR_INHERIT = - 1;

	/**
	 * Denotes an undefined value for an indicator
	 */
	private static final int INDICATOR_UNDEFINED = - 2;

	/** The indicator drawn next to a group. */
	private Drawable mGroupIndicator;

	/** The indicator drawn next to a child. */
	private Drawable mChildIndicator;

	private static final int[] EMPTY_STATE_SET = { };

	/** State indicating the group is expanded. */
	private static final int[] GROUP_EXPANDED_STATE_SET = { android.R.attr.state_expanded };

	/** State indicating the group is empty (has no children). */
	private static final int[] GROUP_EMPTY_STATE_SET = { android.R.attr.state_empty };

	/** State indicating the group is expanded and empty (has no children). */
	private static final int[] GROUP_EXPANDED_EMPTY_STATE_SET = { android.R.attr.state_expanded, android.R.attr.state_empty };

	/** States for the group where the 0th bit is expanded and 1st bit is empty. */
	private static final int[][] GROUP_STATE_SETS = { EMPTY_STATE_SET, // 00
			GROUP_EXPANDED_STATE_SET, // 01
			GROUP_EMPTY_STATE_SET, // 10
			GROUP_EXPANDED_EMPTY_STATE_SET // 11
	};

	/** State indicating the child is the last within its group. */
	private static final int[] CHILD_LAST_STATE_SET = { android.R.attr.state_last };

	/** Drawable to be used as a divider when it is adjacent to any children */
	private Drawable mChildDivider;

	// Bounds of the indicator to be drawn
	private final Rect mIndicatorRect = new Rect();

	private final Rect mTempRect = new Rect();

	private int mGroupIndicatorWidth;
	private int mGroupIndicatorHeight;
	private int mChildIndicatorWidth;
	private int mChildIndicatorHeight;

	public ExpandableHListView( Context context ) {
		this( context, null );
	}

	public ExpandableHListView( Context context, AttributeSet attrs ) {
		this( context, attrs, R.attr.hlv_expandableListViewStyle );
	}

	public ExpandableHListView( Context context, AttributeSet attrs, int defStyle ) {
		super( context, attrs, defStyle );

		TypedArray a = context.obtainStyledAttributes( attrs, R.styleable.ExpandableHListView, defStyle, 0 );

		setGroupIndicator( a.getDrawable( R.styleable.ExpandableHListView_hlv_groupIndicator ) );
		setChildIndicator( a.getDrawable( R.styleable.ExpandableHListView_hlv_childIndicator ) );

		mIndicatorLeft = a.getDimensionPixelSize( R.styleable.ExpandableHListView_hlv_indicatorPaddingLeft, 0 );
		mIndicatorTop = a.getDimensionPixelSize( R.styleable.ExpandableHListView_hlv_indicatorPaddingTop, 0 );

		mIndicatorGravity = a.getInt( R.styleable.ExpandableHListView_hlv_indicatorGravity, Gravity.NO_GRAVITY );
		mChildIndicatorGravity = a.getInt( R.styleable.ExpandableHListView_hlv_childIndicatorGravity, Gravity.NO_GRAVITY );

		mChildIndicatorLeft = a.getDimensionPixelSize( R.styleable.ExpandableHListView_hlv_childIndicatorPaddingLeft, 0 );
		mChildIndicatorTop = a.getDimensionPixelSize( R.styleable.ExpandableHListView_hlv_childIndicatorPaddingTop, 0 );

		mChildDivider = a.getDrawable( R.styleable.ExpandableHListView_hlv_childDivider );
		a.recycle();
	}

	public void onRtlPropertiesChanged( int layoutDirection ) {
		resolveIndicator();
		resolveChildIndicator();
	}

	/**
	 * Resolve start/end indicator. start/end indicator always takes precedence over left/right
	 * indicator when defined.
	 */
	private void resolveIndicator() {
		if( null != mGroupIndicator ) {
			mGroupIndicatorWidth = mGroupIndicator.getIntrinsicWidth();
			mGroupIndicatorHeight = mGroupIndicator.getIntrinsicHeight();
		}
		else {
			mGroupIndicatorWidth = 0;
			mGroupIndicatorHeight = 0;
		}
	}

	/**
	 * Resolve start/end child indicator. start/end child indicator always takes precedence over
	 * left/right child indicator when defined.
	 */
	private void resolveChildIndicator() {
		if( null != mChildIndicator ) {
			mChildIndicatorWidth = mChildIndicator.getIntrinsicWidth();
			mChildIndicatorHeight = mChildIndicator.getIntrinsicHeight();
		}
		else {
			mChildIndicatorWidth = 0;
			mChildIndicatorHeight = 0;
		}
	}


	@Override
	protected void dispatchDraw( Canvas canvas ) {
		// Draw children, etc.
		super.dispatchDraw( canvas );

		// If we have any indicators to draw, we do it here
		if( ( mChildIndicator == null ) && ( mGroupIndicator == null ) ) {
			return;
		}

		int saveCount = 0;

		final int headerViewsCount = getHeaderViewsCount();

		final int lastChildFlPos = mItemCount - getFooterViewsCount() - headerViewsCount - 1;

		final int myRight = getRight();

		ExpandableHListConnector.PositionMetadata pos;
		View item;
		Drawable indicator;
		int left, right;

		// Start at a value that is neither child nor group
		int lastItemType = ~ ( ExpandableHListPosition.CHILD | ExpandableHListPosition.GROUP );

		final Rect indicatorRect = mIndicatorRect;

		// The "child" mentioned in the following two lines is this
		// View's child, not referring to an expandable list's
		// notion of a child (as opposed to a group)
		final int childCount = getChildCount();
		for( int i = 0, childFlPos = mFirstPosition - headerViewsCount; i < childCount; i++, childFlPos++ ) {

			if( childFlPos < 0 ) {
				// This child is header
				continue;
			}
			else if( childFlPos > lastChildFlPos ) {
				// This child is footer, so are all subsequent children
				break;
			}

			item = getChildAt( i );
			left = item.getLeft();
			right = item.getRight();

			// This item isn't on the screen
			if( ( right < 0 ) || ( left > myRight ) ) continue;

			// Get more expandable list-related info for this item
			pos = mConnector.getUnflattenedPos( childFlPos );

			// If this item type and the previous item type are different, then we need to change
			// the left & right bounds
			if( pos.position.type != lastItemType ) {
				if( pos.position.type == ExpandableHListPosition.CHILD ) {
					indicatorRect.top = item.getTop() + mChildIndicatorTop;
					indicatorRect.bottom = item.getBottom() + mChildIndicatorTop;
				}
				else {
					indicatorRect.top = item.getTop() + mIndicatorTop;
					indicatorRect.bottom = item.getBottom() + mIndicatorTop;
				}

				lastItemType = pos.position.type;
			}

			if( indicatorRect.top != indicatorRect.bottom ) {
				if( pos.position.type == ExpandableHListPosition.CHILD ) {
					indicatorRect.left = left + mChildIndicatorLeft;
					indicatorRect.right = right + mChildIndicatorLeft;
				}
				else {
					indicatorRect.left = left + mIndicatorLeft;
					indicatorRect.right = right + mIndicatorLeft;
				}


				// Get the indicator (with its state set to the item's state)
				indicator = getIndicator( pos );
				if( indicator != null ) {

					if( pos.position.type == ExpandableHListPosition.CHILD ) {
						Gravity.apply( mChildIndicatorGravity, mChildIndicatorWidth, mChildIndicatorHeight, indicatorRect, mTempRect );
					}
					else {
						Gravity.apply( mIndicatorGravity, mGroupIndicatorWidth, mGroupIndicatorHeight, indicatorRect, mTempRect );
					}

					// Draw the indicator
					indicator.setBounds( mTempRect );
					indicator.draw( canvas );
				}
			}
			pos.recycle();
		}
	}

	/**
	 * Gets the indicator for the item at the given position. If the indicator
	 * is stateful, the state will be given to the indicator.
	 *
	 * @param pos The flat list position of the item whose indicator
	 *            should be returned.
	 * @return The indicator in the proper state.
	 */
	private Drawable getIndicator( ExpandableHListConnector.PositionMetadata pos ) {
		Drawable indicator;

		if( pos.position.type == ExpandableHListPosition.GROUP ) {
			indicator = mGroupIndicator;

			if( indicator != null && indicator.isStateful() ) {
				// Empty check based on availability of data.  If the groupMetadata isn't null,
				// we do a check on it. Otherwise, the group is collapsed so we consider it
				// empty for performance reasons.
				boolean isEmpty = ( pos.groupMetadata == null ) || ( pos.groupMetadata.lastChildFlPos == pos.groupMetadata.flPos );

				final int stateSetIndex = ( pos.isExpanded() ? 1 : 0 ) | // Expanded?
				                          ( isEmpty ? 2 : 0 ); // Empty?
				indicator.setState( GROUP_STATE_SETS[stateSetIndex] );
			}
		}
		else {
			indicator = mChildIndicator;

			if( indicator != null && indicator.isStateful() ) {
				// No need for a state sets array for the child since it only has two states
				final int stateSet[] = pos.position.flatListPos == pos.groupMetadata.lastChildFlPos ? CHILD_LAST_STATE_SET : EMPTY_STATE_SET;
				indicator.setState( stateSet );
			}
		}

		return indicator;
	}

	/**
	 * Sets the drawable that will be drawn adjacent to every child in the list. This will
	 * be drawn using the same height as the normal divider ({@link #setDivider(Drawable)}) or
	 * if it does not have an intrinsic height, the height set by {@link #setDividerWidth(int)}.
	 *
	 * @param childDivider The drawable to use.
	 */
	public void setChildDivider( Drawable childDivider ) {
		mChildDivider = childDivider;
	}

	@Override
	void drawDivider( Canvas canvas, Rect bounds, int childIndex ) {
		int flatListPosition = childIndex + mFirstPosition;

		// Only proceed as possible child if the divider isn't above all items (if it is above
		// all items, then the item below it has to be a group)
		if( flatListPosition >= 0 ) {
			final int adjustedPosition = getFlatPositionForConnector( flatListPosition );
			ExpandableHListConnector.PositionMetadata pos = mConnector.getUnflattenedPos( adjustedPosition );
			// If this item is a child, or it is a non-empty group that is expanded
			if( ( pos.position.type == ExpandableHListPosition.CHILD ) || ( pos.isExpanded() && pos.groupMetadata.lastChildFlPos != pos.groupMetadata.flPos ) ) {
				// These are the cases where we draw the child divider
				final Drawable divider = mChildDivider;
				divider.setBounds( bounds );
				divider.draw( canvas );
				pos.recycle();
				return;
			}
			pos.recycle();
		}

		// Otherwise draw the default divider
		super.drawDivider( canvas, bounds, flatListPosition );
	}

	/**
	 * This overloaded method should not be used, instead use
	 * {@link #setAdapter(ExpandableListAdapter)}.
	 * <p/>
	 * {@inheritDoc}
	 */
	@Override
	public void setAdapter( ListAdapter adapter ) {
		throw new RuntimeException( "For ExpandableListView, use setAdapter(ExpandableListAdapter) instead of " + "setAdapter(ListAdapter)" );
	}

	/**
	 * This method should not be used, use {@link #getExpandableListAdapter()}.
	 */
	@Override
	public ListAdapter getAdapter() {
	    /*
	     * The developer should never really call this method on an
         * ExpandableListView, so it would be nice to throw a RuntimeException,
         * but AdapterView calls this
         */
		return super.getAdapter();
	}

	/**
	 * Register a callback to be invoked when an item has been clicked and the
	 * caller prefers to receive a ListView-style position instead of a group
	 * and/or child position. In most cases, the caller should use
	 * {@link #setOnGroupClickListener} and/or {@link #setOnChildClickListener}.
	 * <p/>
	 * {@inheritDoc}
	 */
	@Override
	public void setOnItemClickListener( OnItemClickListener l ) {
		super.setOnItemClickListener( l );
	}

	/**
	 * Sets the adapter that provides data to this view.
	 *
	 * @param adapter The adapter that provides data to this view.
	 */
	public void setAdapter( ExpandableListAdapter adapter ) {
		// Set member variable
		mAdapter = adapter;

		if( adapter != null ) {
			// Create the connector
			mConnector = new ExpandableHListConnector( adapter );
		}
		else {
			mConnector = null;
		}

		// Link the ListView (superclass) to the expandable list data through the connector
		super.setAdapter( mConnector );
	}

	/**
	 * Gets the adapter that provides data to this view.
	 *
	 * @return The adapter that provides data to this view.
	 */
	public ExpandableListAdapter getExpandableListAdapter() {
		return mAdapter;
	}

	/**
	 * @param position An absolute (including header and footer) flat list position.
	 * @return true if the position corresponds to a header or a footer item.
	 */
	private boolean isHeaderOrFooterPosition( int position ) {
		final int footerViewsStart = mItemCount - getFooterViewsCount();
		return ( position < getHeaderViewsCount() || position >= footerViewsStart );
	}

	/**
	 * Converts an absolute item flat position into a group/child flat position, shifting according
	 * to the number of header items.
	 *
	 * @param flatListPosition The absolute flat position
	 * @return A group/child flat position as expected by the connector.
	 */
	private int getFlatPositionForConnector( int flatListPosition ) {
		return flatListPosition - getHeaderViewsCount();
	}

	/**
	 * Converts a group/child flat position into an absolute flat position, that takes into account
	 * the possible headers.
	 *
	 * @param flatListPosition The child/group flat position
	 * @return An absolute flat position.
	 */
	private int getAbsoluteFlatPosition( int flatListPosition ) {
		return flatListPosition + getHeaderViewsCount();
	}

	@Override
	public boolean performItemClick( View v, int position, long id ) {
		// Ignore clicks in header/footers
		if( isHeaderOrFooterPosition( position ) ) {
			// Clicked on a header/footer, so ignore pass it on to super
			return super.performItemClick( v, position, id );
		}

		// Internally handle the item click
		final int adjustedPosition = getFlatPositionForConnector( position );
		return handleItemClick( v, adjustedPosition, id );
	}

	/**
	 * This will either expand/collapse groups (if a group was clicked) or pass
	 * on the click to the proper child (if a child was clicked)
	 *
	 * @param position The flat list position. This has already been factored to
	 *                 remove the header/footer.
	 * @param id       The ListAdapter ID, not the group or child ID.
	 */
	boolean handleItemClick( View v, int position, long id ) {
		final ExpandableHListConnector.PositionMetadata posMetadata = mConnector.getUnflattenedPos( position );

		id = getChildOrGroupId( posMetadata.position );

		boolean returnValue;
		if( posMetadata.position.type == ExpandableHListPosition.GROUP ) {
		    /* It's a group, so handle collapsing/expanding */

            /* It's a group click, so pass on event */
			if( mOnGroupClickListener != null ) {
				if( mOnGroupClickListener.onGroupClick( this, v, posMetadata.position.groupPos, id ) ) {
					posMetadata.recycle();
					return true;
				}
			}

			if( posMetadata.isExpanded() ) {
			    /* Collapse it */
				mConnector.collapseGroup( posMetadata );

				playSoundEffect( SoundEffectConstants.CLICK );

				if( mOnGroupCollapseListener != null ) {
					mOnGroupCollapseListener.onGroupCollapse( posMetadata.position.groupPos );
				}
			}
			else {
			    /* Expand it */
				mConnector.expandGroup( posMetadata );

				playSoundEffect( SoundEffectConstants.CLICK );

				if( mOnGroupExpandListener != null ) {
					mOnGroupExpandListener.onGroupExpand( posMetadata.position.groupPos );
				}

				final int groupPos = posMetadata.position.groupPos;
				final int groupFlatPos = posMetadata.position.flatListPos;

				final int shiftedGroupPosition = groupFlatPos + getHeaderViewsCount();
				smoothScrollToPosition( shiftedGroupPosition + mAdapter.getChildrenCount( groupPos ), shiftedGroupPosition );
			}

			returnValue = true;
		}
		else {
		    /* It's a child, so pass on event */
			if( mOnChildClickListener != null ) {
				playSoundEffect( SoundEffectConstants.CLICK );
				return mOnChildClickListener.onChildClick( this, v, posMetadata.position.groupPos, posMetadata.position.childPos, id );
			}

			returnValue = false;
		}

		posMetadata.recycle();

		return returnValue;
	}

	/**
	 * Expand a group in the grouped list view
	 *
	 * @param groupPos the group to be expanded
	 * @return True if the group was expanded, false otherwise (if the group
	 * was already expanded, this will return false)
	 */
	public boolean expandGroup( int groupPos ) {
		return expandGroup( groupPos, false );
	}

	/**
	 * Expand a group in the grouped list view
	 *
	 * @param groupPos the group to be expanded
	 * @param animate  true if the expanding group should be animated in
	 * @return True if the group was expanded, false otherwise (if the group
	 * was already expanded, this will return false)
	 */
	public boolean expandGroup( int groupPos, boolean animate ) {
		ExpandableHListPosition elGroupPos = ExpandableHListPosition.obtain( ExpandableHListPosition.GROUP, groupPos, - 1, - 1 );
		ExpandableHListConnector.PositionMetadata pm = mConnector.getFlattenedPos( elGroupPos );
		elGroupPos.recycle();
		boolean retValue = mConnector.expandGroup( pm );

		if( mOnGroupExpandListener != null ) {
			mOnGroupExpandListener.onGroupExpand( groupPos );
		}

		if( animate ) {
			final int groupFlatPos = pm.position.flatListPos;

			final int shiftedGroupPosition = groupFlatPos + getHeaderViewsCount();
			smoothScrollToPosition( shiftedGroupPosition + mAdapter.getChildrenCount( groupPos ), shiftedGroupPosition );
		}
		pm.recycle();

		return retValue;
	}

	/**
	 * Collapse a group in the grouped list view
	 *
	 * @param groupPos position of the group to collapse
	 * @return True if the group was collapsed, false otherwise (if the group
	 * was already collapsed, this will return false)
	 */
	public boolean collapseGroup( int groupPos ) {
		boolean retValue = mConnector.collapseGroup( groupPos );

		if( mOnGroupCollapseListener != null ) {
			mOnGroupCollapseListener.onGroupCollapse( groupPos );
		}

		return retValue;
	}

	/** Used for being notified when a group is collapsed */
	public interface OnGroupCollapseListener {
		/**
		 * Callback method to be invoked when a group in this expandable list has
		 * been collapsed.
		 *
		 * @param groupPosition The group position that was collapsed
		 */
		void onGroupCollapse( int groupPosition );
	}

	private OnGroupCollapseListener mOnGroupCollapseListener;

	public void setOnGroupCollapseListener(
			OnGroupCollapseListener onGroupCollapseListener ) {
		mOnGroupCollapseListener = onGroupCollapseListener;
	}

	/** Used for being notified when a group is expanded */
	public interface OnGroupExpandListener {
		/**
		 * Callback method to be invoked when a group in this expandable list has
		 * been expanded.
		 *
		 * @param groupPosition The group position that was expanded
		 */
		void onGroupExpand( int groupPosition );
	}

	private OnGroupExpandListener mOnGroupExpandListener;

	public void setOnGroupExpandListener(
			OnGroupExpandListener onGroupExpandListener ) {
		mOnGroupExpandListener = onGroupExpandListener;
	}

	/**
	 * Interface definition for a callback to be invoked when a group in this
	 * expandable list has been clicked.
	 */
	public interface OnGroupClickListener {
		/**
		 * Callback method to be invoked when a group in this expandable list has
		 * been clicked.
		 *
		 * @param parent        The ExpandableHListConnector where the click happened
		 * @param v             The view within the expandable list/ListView that was clicked
		 * @param groupPosition The group position that was clicked
		 * @param id            The row id of the group that was clicked
		 * @return True if the click was handled
		 */
		boolean onGroupClick(
				ExpandableHListView parent, View v, int groupPosition, long id );
	}

	private OnGroupClickListener mOnGroupClickListener;

	public void setOnGroupClickListener( OnGroupClickListener onGroupClickListener ) {
		mOnGroupClickListener = onGroupClickListener;
	}

	/**
	 * Interface definition for a callback to be invoked when a child in this
	 * expandable list has been clicked.
	 */
	public interface OnChildClickListener {
		/**
		 * Callback method to be invoked when a child in this expandable list has
		 * been clicked.
		 *
		 * @param parent        The ExpandableListView where the click happened
		 * @param v             The view within the expandable list/ListView that was clicked
		 * @param groupPosition The group position that contains the child that
		 *                      was clicked
		 * @param childPosition The child position within the group
		 * @param id            The row id of the child that was clicked
		 * @return True if the click was handled
		 */
		boolean onChildClick(
				ExpandableHListView parent, View v, int groupPosition, int childPosition, long id );
	}

	private OnChildClickListener mOnChildClickListener;

	public void setOnChildClickListener( OnChildClickListener onChildClickListener ) {
		mOnChildClickListener = onChildClickListener;
	}

	/**
	 * Converts a flat list position (the raw position of an item (child or group)
	 * in the list) to a group and/or child position (represented in a
	 * packed position). This is useful in situations where the caller needs to
	 * use the underlying {@link android.widget.ListView}'s methods. Use
	 * {@link ExpandableHListView#getPackedPositionType} ,
	 * {@link ExpandableHListView#getPackedPositionChild},
	 * {@link ExpandableHListView#getPackedPositionGroup} to unpack.
	 *
	 * @param flatListPosition The flat list position to be converted.
	 * @return The group and/or child position for the given flat list position
	 * in packed position representation. #PACKED_POSITION_VALUE_NULL if
	 * the position corresponds to a header or a footer item.
	 */
	public long getExpandableListPosition( int flatListPosition ) {
		if( isHeaderOrFooterPosition( flatListPosition ) ) {
			return PACKED_POSITION_VALUE_NULL;
		}

		final int adjustedPosition = getFlatPositionForConnector( flatListPosition );
		ExpandableHListConnector.PositionMetadata pm = mConnector.getUnflattenedPos( adjustedPosition );
		long packedPos = pm.position.getPackedPosition();
		pm.recycle();
		return packedPos;
	}

	/**
	 * Converts a group and/or child position to a flat list position. This is
	 * useful in situations where the caller needs to use the underlying
	 * {@link android.widget.ListView}'s methods.
	 *
	 * @param packedPosition The group and/or child positions to be converted in
	 *                       packed position representation. Use
	 *                       {@link #getPackedPositionForChild(int, int)} or
	 *                       {@link #getPackedPositionForGroup(int)}.
	 * @return The flat list position for the given child or group.
	 */
	public int getFlatListPosition( long packedPosition ) {
		ExpandableHListPosition elPackedPos = ExpandableHListPosition.obtainPosition( packedPosition );
		ExpandableHListConnector.PositionMetadata pm = mConnector.getFlattenedPos( elPackedPos );
		elPackedPos.recycle();
		final int flatListPosition = pm.position.flatListPos;
		pm.recycle();
		return getAbsoluteFlatPosition( flatListPosition );
	}

	/**
	 * Gets the position of the currently selected group or child (along with
	 * its type). Can return {@link #PACKED_POSITION_VALUE_NULL} if no selection.
	 *
	 * @return A packed position containing the currently selected group or
	 * child's position and type. #PACKED_POSITION_VALUE_NULL if no selection
	 * or if selection is on a header or a footer item.
	 */
	public long getSelectedPosition() {
		final int selectedPos = getSelectedItemPosition();

		// The case where there is no selection (selectedPos == -1) is also handled here.
		return getExpandableListPosition( selectedPos );
	}

	/**
	 * Gets the ID of the currently selected group or child. Can return -1 if no
	 * selection.
	 *
	 * @return The ID of the currently selected group or child. -1 if no
	 * selection.
	 */
	public long getSelectedId() {
		long packedPos = getSelectedPosition();
		if( packedPos == PACKED_POSITION_VALUE_NULL ) return - 1;

		int groupPos = getPackedPositionGroup( packedPos );

		if( getPackedPositionType( packedPos ) == PACKED_POSITION_TYPE_GROUP ) {
			// It's a group
			return mAdapter.getGroupId( groupPos );
		}
		else {
			// It's a child
			return mAdapter.getChildId( groupPos, getPackedPositionChild( packedPos ) );
		}
	}

	/**
	 * Sets the selection to the specified group.
	 *
	 * @param groupPosition The position of the group that should be selected.
	 */
	public void setSelectedGroup( int groupPosition ) {
		ExpandableHListPosition elGroupPos = ExpandableHListPosition.obtainGroupPosition( groupPosition );
		ExpandableHListConnector.PositionMetadata pm = mConnector.getFlattenedPos( elGroupPos );
		elGroupPos.recycle();
		final int absoluteFlatPosition = getAbsoluteFlatPosition( pm.position.flatListPos );
		super.setSelection( absoluteFlatPosition );
		pm.recycle();
	}

	/**
	 * Sets the selection to the specified child. If the child is in a collapsed
	 * group, the group will only be expanded and child subsequently selected if
	 * shouldExpandGroup is set to true, otherwise the method will return false.
	 *
	 * @param groupPosition     The position of the group that contains the child.
	 * @param childPosition     The position of the child within the group.
	 * @param shouldExpandGroup Whether the child's group should be expanded if
	 *                          it is collapsed.
	 * @return Whether the selection was successfully set on the child.
	 */
	public boolean setSelectedChild( int groupPosition, int childPosition, boolean shouldExpandGroup ) {
		ExpandableHListPosition elChildPos = ExpandableHListPosition.obtainChildPosition( groupPosition, childPosition );
		ExpandableHListConnector.PositionMetadata flatChildPos = mConnector.getFlattenedPos( elChildPos );

		if( flatChildPos == null ) {
			// The child's group isn't expanded

			// Shouldn't expand the group, so return false for we didn't set the selection
			if( ! shouldExpandGroup ) return false;

			expandGroup( groupPosition );

			flatChildPos = mConnector.getFlattenedPos( elChildPos );

			// Sanity check
			if( flatChildPos == null ) {
				throw new IllegalStateException( "Could not find child" );
			}
		}

		int absoluteFlatPosition = getAbsoluteFlatPosition( flatChildPos.position.flatListPos );
		super.setSelection( absoluteFlatPosition );

		elChildPos.recycle();
		flatChildPos.recycle();

		return true;
	}

	/**
	 * Whether the given group is currently expanded.
	 *
	 * @param groupPosition The group to check.
	 * @return Whether the group is currently expanded.
	 */
	public boolean isGroupExpanded( int groupPosition ) {
		return mConnector.isGroupExpanded( groupPosition );
	}

	/**
	 * Gets the type of a packed position. See
	 * {@link #getPackedPositionForChild(int, int)}.
	 *
	 * @param packedPosition The packed position for which to return the type.
	 * @return The type of the position contained within the packed position,
	 * either {@link #PACKED_POSITION_TYPE_CHILD}, {@link #PACKED_POSITION_TYPE_GROUP}, or
	 * {@link #PACKED_POSITION_TYPE_NULL}.
	 */
	public static int getPackedPositionType( long packedPosition ) {
		if( packedPosition == PACKED_POSITION_VALUE_NULL ) {
			return PACKED_POSITION_TYPE_NULL;
		}

		return ( packedPosition & PACKED_POSITION_MASK_TYPE ) == PACKED_POSITION_MASK_TYPE ? PACKED_POSITION_TYPE_CHILD : PACKED_POSITION_TYPE_GROUP;
	}

	/**
	 * Gets the group position from a packed position. See
	 * {@link #getPackedPositionForChild(int, int)}.
	 *
	 * @param packedPosition The packed position from which the group position
	 *                       will be returned.
	 * @return The group position portion of the packed position. If this does
	 * not contain a group, returns -1.
	 */
	public static int getPackedPositionGroup( long packedPosition ) {
		// Null
		if( packedPosition == PACKED_POSITION_VALUE_NULL ) return - 1;

		return (int) ( ( packedPosition & PACKED_POSITION_MASK_GROUP ) >> PACKED_POSITION_SHIFT_GROUP );
	}

	/**
	 * Gets the child position from a packed position that is of
	 * {@link #PACKED_POSITION_TYPE_CHILD} type (use {@link #getPackedPositionType(long)}).
	 * To get the group that this child belongs to, use
	 * {@link #getPackedPositionGroup(long)}. See
	 * {@link #getPackedPositionForChild(int, int)}.
	 *
	 * @param packedPosition The packed position from which the child position
	 *                       will be returned.
	 * @return The child position portion of the packed position. If this does
	 * not contain a child, returns -1.
	 */
	public static int getPackedPositionChild( long packedPosition ) {
		// Null
		if( packedPosition == PACKED_POSITION_VALUE_NULL ) return - 1;

		// Group since a group type clears this bit
		if( ( packedPosition & PACKED_POSITION_MASK_TYPE ) != PACKED_POSITION_MASK_TYPE ) return - 1;

		return (int) ( packedPosition & PACKED_POSITION_MASK_CHILD );
	}

	/**
	 * Returns the packed position representation of a child's position.
	 * <p/>
	 * In general, a packed position should be used in
	 * situations where the position given to/returned from an
	 * {@link ExpandableListAdapter} or {@link ExpandableHListView} method can
	 * either be a child or group. The two positions are packed into a single
	 * long which can be unpacked using
	 * {@link #getPackedPositionChild(long)},
	 * {@link #getPackedPositionGroup(long)}, and
	 * {@link #getPackedPositionType(long)}.
	 *
	 * @param groupPosition The child's parent group's position.
	 * @param childPosition The child position within the group.
	 * @return The packed position representation of the child (and parent group).
	 */
	public static long getPackedPositionForChild( int groupPosition, int childPosition ) {
		return ( ( (long) PACKED_POSITION_TYPE_CHILD ) << PACKED_POSITION_SHIFT_TYPE ) |
		       ( ( ( (long) groupPosition ) & PACKED_POSITION_INT_MASK_GROUP ) << PACKED_POSITION_SHIFT_GROUP ) | ( childPosition & PACKED_POSITION_INT_MASK_CHILD );
	}

	/**
	 * Returns the packed position representation of a group's position. See
	 * {@link #getPackedPositionForChild(int, int)}.
	 *
	 * @param groupPosition The child's parent group's position.
	 * @return The packed position representation of the group.
	 */
	public static long getPackedPositionForGroup( int groupPosition ) {
		// No need to OR a type in because PACKED_POSITION_GROUP == 0
		return ( ( ( (long) groupPosition ) & PACKED_POSITION_INT_MASK_GROUP ) << PACKED_POSITION_SHIFT_GROUP );
	}

	@Override
	ContextMenuInfo createContextMenuInfo( View view, int flatListPosition, long id ) {
		if( isHeaderOrFooterPosition( flatListPosition ) ) {
			// Return normal info for header/footer view context menus
			return new AdapterContextMenuInfo( view, flatListPosition, id );
		}

		final int adjustedPosition = getFlatPositionForConnector( flatListPosition );
		ExpandableHListConnector.PositionMetadata pm = mConnector.getUnflattenedPos( adjustedPosition );
		ExpandableHListPosition pos = pm.position;

		id = getChildOrGroupId( pos );
		long packedPosition = pos.getPackedPosition();

		pm.recycle();

		return new ExpandableListContextMenuInfo( view, packedPosition, id );
	}

	/**
	 * Gets the ID of the group or child at the given <code>position</code>.
	 * This is useful since there is no ListAdapter ID -> ExpandableListAdapter
	 * ID conversion mechanism (in some cases, it isn't possible).
	 *
	 * @param position The position of the child or group whose ID should be
	 *                 returned.
	 */
	private long getChildOrGroupId( ExpandableHListPosition position ) {
		if( position.type == ExpandableHListPosition.CHILD ) {
			return mAdapter.getChildId( position.groupPos, position.childPos );
		}
		else {
			return mAdapter.getGroupId( position.groupPos );
		}
	}

	/**
	 * Sets the indicator to be drawn next to a child.
	 *
	 * @param childIndicator The drawable to be used as an indicator. If the
	 *                       child is the last child for a group, the state
	 *                       {@link android.R.attr#state_last} will be set.
	 */
	public void setChildIndicator( Drawable childIndicator ) {
		mChildIndicator = childIndicator;
		resolveChildIndicator();
	}

	/**
	 * Sets the indicator to be drawn next to a group.
	 *
	 * @param groupIndicator The drawable to be used as an indicator. If the
	 *                       group is empty, the state {@link android.R.attr#state_empty} will be
	 *                       set. If the group is expanded, the state
	 *                       {@link android.R.attr#state_expanded} will be set.
	 */
	public void setGroupIndicator( Drawable groupIndicator ) {
		mGroupIndicator = groupIndicator;
		resolveIndicator();
	}

	/**
	 * Extra menu information specific to an {@link ExpandableHListView} provided
	 * to the
	 * {@link android.view.View.OnCreateContextMenuListener#onCreateContextMenu(ContextMenu, View, ContextMenuInfo) }
	 * callback when a context menu is brought up for this AdapterView.
	 */
	public static class ExpandableListContextMenuInfo implements ContextMenu.ContextMenuInfo {

		public ExpandableListContextMenuInfo( View targetView, long packedPosition, long id ) {
			this.targetView = targetView;
			this.packedPosition = packedPosition;
			this.id = id;
		}

		/**
		 * The view for which the context menu is being displayed. This
		 * will be one of the children Views of this {@link ExpandableHListView}.
		 */
		public View targetView;

		/**
		 * The packed position in the list represented by the adapter for which
		 * the context menu is being displayed. Use the methods
		 * {@link ExpandableHListView#getPackedPositionType},
		 * {@link ExpandableHListView#getPackedPositionChild}, and
		 * {@link ExpandableHListView#getPackedPositionGroup} to unpack this.
		 */
		public long packedPosition;

		/**
		 * The ID of the item (group or child) for which the context menu is
		 * being displayed.
		 */
		public long id;
	}

	static class SavedState extends BaseSavedState {
		ArrayList<ExpandableHListConnector.GroupMetadata> expandedGroupMetadataList;

		/**
		 * Constructor called from {@link ExpandableHListView#onSaveInstanceState()}
		 */
		SavedState(
				Parcelable superState, ArrayList<ExpandableHListConnector.GroupMetadata> expandedGroupMetadataList ) {
			super( superState );
			this.expandedGroupMetadataList = expandedGroupMetadataList;
		}

		/**
		 * Constructor called from {@link #CREATOR}
		 */
		private SavedState( Parcel in ) {
			super( in );
			expandedGroupMetadataList = new ArrayList<ExpandableHListConnector.GroupMetadata>();
			in.readList( expandedGroupMetadataList, ExpandableHListConnector.class.getClassLoader() );
		}

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

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

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

	@Override
	public Parcelable onSaveInstanceState() {
		Parcelable superState = super.onSaveInstanceState();
		return new SavedState( superState, mConnector != null ? mConnector.getExpandedGroupMetadataList() : null );
	}

	@Override
	public void onRestoreInstanceState( Parcelable state ) {
		if( ! ( state instanceof SavedState ) ) {
			super.onRestoreInstanceState( state );
			return;
		}

		SavedState ss = (SavedState) state;
		super.onRestoreInstanceState( ss.getSuperState() );

		if( mConnector != null && ss.expandedGroupMetadataList != null ) {
			mConnector.setExpandedGroupMetadataList( ss.expandedGroupMetadataList );
		}
	}

	@Override
	public void onInitializeAccessibilityEvent( AccessibilityEvent event ) {
		super.onInitializeAccessibilityEvent( event );
		event.setClassName( ExpandableHListView.class.getName() );
	}

	@TargetApi( Build.VERSION_CODES.ICE_CREAM_SANDWICH )
	@Override
	public void onInitializeAccessibilityNodeInfo( AccessibilityNodeInfo info ) {
		super.onInitializeAccessibilityNodeInfo( info );
		info.setClassName( ExpandableHListView.class.getName() );
	}
}

