src/com/android/photos/views/HeaderGridView.java - LeafOS-Project/android_packages_apps_Gallery2 - Gitiles

 /*
  * Copyright (C) 2013 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 com.android.photos.views;

 import android.content.Context;
 import android.database.DataSetObservable;
 import android.database.DataSetObserver;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
 import android.widget.Filter;
 import android.widget.Filterable;
 import android.widget.FrameLayout;
 import android.widget.GridView;
 import android.widget.ListAdapter;
 import android.widget.WrapperListAdapter;

 import java.util.ArrayList;

 /**
  * A {@link GridView} that supports adding header rows in a
  * very similar way to {@link ListView}.
  * See {@link HeaderGridView#addHeaderView(View, Object, boolean)}
  */
 public class HeaderGridView extends GridView {
     private static final String TAG = "HeaderGridView";

     /**
      * A class that represents a fixed view in a list, for example a header at the top
      * or a footer at the bottom.
      */
     private static class FixedViewInfo {
         /** The view to add to the grid */
         public View view;
         public ViewGroup viewContainer;
         /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */
         public Object data;
         /** <code>true</code> if the fixed view should be selectable in the grid */
         public boolean isSelectable;
     }

     private ArrayList<FixedViewInfo> mHeaderViewInfos = new ArrayList<FixedViewInfo>();

     private void initHeaderGridView() {
         super.setClipChildren(false);
     }

     public HeaderGridView(Context context) {
         super(context);
         initHeaderGridView();
     }

     public HeaderGridView(Context context, AttributeSet attrs) {
         super(context, attrs);
         initHeaderGridView();
     }

     public HeaderGridView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         initHeaderGridView();
     }

     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
         ListAdapter adapter = getAdapter();
         if (adapter != null && adapter instanceof HeaderViewGridAdapter) {
             ((HeaderViewGridAdapter) adapter).setNumColumns(getNumColumns());
         }
     }

     @Override
     public void setClipChildren(boolean clipChildren) {
        // Ignore, since the header rows depend on not being clipped
     }

     /**
      * Add a fixed view to appear at the top of the grid. If addHeaderView is
      * called more than once, the views will appear in the order they were
      * added. Views added using this call can take focus if they want.
      * <p>
      * NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
      * the supplied cursor with one that will also account for header views.
      *
      * @param v The view to add.
      * @param data Data to associate with this view
      * @param isSelectable whether the item is selectable
      */
     public void addHeaderView(View v, Object data, boolean isSelectable) {
         ListAdapter adapter = getAdapter();

         if (adapter != null && ! (adapter instanceof HeaderViewGridAdapter)) {
             throw new IllegalStateException(
                     "Cannot add header view to grid -- setAdapter has already been called.");
         }

         FixedViewInfo info = new FixedViewInfo();
         FrameLayout fl = new FullWidthFixedViewLayout(getContext());
         fl.addView(v);
         info.view = v;
         info.viewContainer = fl;
         info.data = data;
         info.isSelectable = isSelectable;
         mHeaderViewInfos.add(info);

         // in the case of re-adding a header view, or adding one later on,
         // we need to notify the observer
         if (adapter != null) {
             ((HeaderViewGridAdapter) adapter).notifyDataSetChanged();
         }
     }

     /**
      * Add a fixed view to appear at the top of the grid. If addHeaderView is
      * called more than once, the views will appear in the order they were
      * added. Views added using this call can take focus if they want.
      * <p>
      * NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
      * the supplied cursor with one that will also account for header views.
      *
      * @param v The view to add.
      */
     public void addHeaderView(View v) {
         addHeaderView(v, null, true);
     }

     public int getHeaderViewCount() {
         return mHeaderViewInfos.size();
     }

     /**
      * Removes a previously-added header view.
      *
      * @param v The view to remove
      * @return true if the view was removed, false if the view was not a header
      *         view
      */
     public boolean removeHeaderView(View v) {
         if (mHeaderViewInfos.size() > 0) {
             boolean result = false;
             ListAdapter adapter = getAdapter();
             if (adapter != null && ((HeaderViewGridAdapter) adapter).removeHeader(v)) {
                 result = true;
             }
             removeFixedViewInfo(v, mHeaderViewInfos);
             return result;
         }
         return false;
     }

     private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) {
         int len = where.size();
         for (int i = 0; i < len; ++i) {
             FixedViewInfo info = where.get(i);
             if (info.view == v) {
                 where.remove(i);
                 break;
             }
         }
     }

     @Override
     public void setAdapter(ListAdapter adapter) {
         if (mHeaderViewInfos.size() > 0) {
             HeaderViewGridAdapter hadapter = new HeaderViewGridAdapter(mHeaderViewInfos, adapter);
             int numColumns = getNumColumns();
             if (numColumns > 1) {
                 hadapter.setNumColumns(numColumns);
             }
             super.setAdapter(hadapter);
         } else {
             super.setAdapter(adapter);
         }
     }

     private class FullWidthFixedViewLayout extends FrameLayout {
         public FullWidthFixedViewLayout(Context context) {
             super(context);
         }

         @Override
         protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
             int targetWidth = HeaderGridView.this.getMeasuredWidth()
                     - HeaderGridView.this.getPaddingLeft()
                     - HeaderGridView.this.getPaddingRight();
             widthMeasureSpec = MeasureSpec.makeMeasureSpec(targetWidth,
                     MeasureSpec.getMode(widthMeasureSpec));
             super.onMeasure(widthMeasureSpec, heightMeasureSpec);
         }
     }

     /**
      * ListAdapter used when a HeaderGridView has header views. This ListAdapter
      * wraps another one and also keeps track of the header views and their
      * associated data objects.
      *<p>This is intended as a base class; you will probably not need to
      * use this class directly in your own code.
      */
     private static class HeaderViewGridAdapter implements WrapperListAdapter, Filterable {

         // This is used to notify the container of updates relating to number of columns
         // or headers changing, which changes the number of placeholders needed
         private final DataSetObservable mDataSetObservable = new DataSetObservable();

         private final ListAdapter mAdapter;
         private int mNumColumns = 1;

         // This ArrayList is assumed to NOT be null.
         ArrayList<FixedViewInfo> mHeaderViewInfos;

         boolean mAreAllFixedViewsSelectable;

         private final boolean mIsFilterable;

         public HeaderViewGridAdapter(ArrayList<FixedViewInfo> headerViewInfos, ListAdapter adapter) {
             mAdapter = adapter;
             mIsFilterable = adapter instanceof Filterable;

             if (headerViewInfos == null) {
                 throw new IllegalArgumentException("headerViewInfos cannot be null");
             }
             mHeaderViewInfos = headerViewInfos;

             mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);
         }

         public int getHeadersCount() {
             return mHeaderViewInfos.size();
         }

         @Override
         public boolean isEmpty() {
             return (mAdapter == null || mAdapter.isEmpty()) && getHeadersCount() == 0;
         }

         public void setNumColumns(int numColumns) {
             if (numColumns < 1) {
                 throw new IllegalArgumentException("Number of columns must be 1 or more");
             }
             if (mNumColumns != numColumns) {
                 mNumColumns = numColumns;
                 notifyDataSetChanged();
             }
         }

         private boolean areAllListInfosSelectable(ArrayList<FixedViewInfo> infos) {
             if (infos != null) {
                 for (FixedViewInfo info : infos) {
                     if (!info.isSelectable) {
                         return false;
                     }
                 }
             }
             return true;
         }

         public boolean removeHeader(View v) {
             for (int i = 0; i < mHeaderViewInfos.size(); i++) {
                 FixedViewInfo info = mHeaderViewInfos.get(i);
                 if (info.view == v) {
                     mHeaderViewInfos.remove(i);

                     mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);

                     mDataSetObservable.notifyChanged();
                     return true;
                 }
             }

             return false;
         }

         @Override
         public int getCount() {
             if (mAdapter != null) {
                 return getHeadersCount() * mNumColumns + mAdapter.getCount();
             } else {
                 return getHeadersCount() * mNumColumns;
             }
         }

         @Override
         public boolean areAllItemsEnabled() {
             if (mAdapter != null) {
                 return mAreAllFixedViewsSelectable && mAdapter.areAllItemsEnabled();
             } else {
                 return true;
             }
         }

         @Override
         public boolean isEnabled(int position) {
             // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
             int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
             if (position < numHeadersAndPlaceholders) {
                 return (position % mNumColumns == 0)
                         && mHeaderViewInfos.get(position / mNumColumns).isSelectable;
             }

             // Adapter
             final int adjPosition = position - numHeadersAndPlaceholders;
             int adapterCount = 0;
             if (mAdapter != null) {
                 adapterCount = mAdapter.getCount();
                 if (adjPosition < adapterCount) {
                     return mAdapter.isEnabled(adjPosition);
                 }
             }

             throw new ArrayIndexOutOfBoundsException(position);
         }

         @Override
         public Object getItem(int position) {
             // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
             int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
             if (position < numHeadersAndPlaceholders) {
                 if (position % mNumColumns == 0) {
                     return mHeaderViewInfos.get(position / mNumColumns).data;
                 }
                 return null;
             }

             // Adapter
             final int adjPosition = position - numHeadersAndPlaceholders;
             int adapterCount = 0;
             if (mAdapter != null) {
                 adapterCount = mAdapter.getCount();
                 if (adjPosition < adapterCount) {
                     return mAdapter.getItem(adjPosition);
                 }
             }

             throw new ArrayIndexOutOfBoundsException(position);
         }

         @Override
         public long getItemId(int position) {
             int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
             if (mAdapter != null && position >= numHeadersAndPlaceholders) {
                 int adjPosition = position - numHeadersAndPlaceholders;
                 int adapterCount = mAdapter.getCount();
                 if (adjPosition < adapterCount) {
                     return mAdapter.getItemId(adjPosition);
                 }
             }
             return -1;
         }

         @Override
         public boolean hasStableIds() {
             if (mAdapter != null) {
                 return mAdapter.hasStableIds();
             }
             return false;
         }

         @Override
         public View getView(int position, View convertView, ViewGroup parent) {
             // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
             int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns ;
             if (position < numHeadersAndPlaceholders) {
                 View headerViewContainer = mHeaderViewInfos
                         .get(position / mNumColumns).viewContainer;
                 if (position % mNumColumns == 0) {
                     return headerViewContainer;
                 } else {
                     if (convertView == null) {
                         convertView = new View(parent.getContext());
                     }
                     // We need to do this because GridView uses the height of the last item
                     // in a row to determine the height for the entire row.
                     convertView.setVisibility(View.INVISIBLE);
                     convertView.setMinimumHeight(headerViewContainer.getHeight());
                     return convertView;
                 }
             }

             // Adapter
             final int adjPosition = position - numHeadersAndPlaceholders;
             int adapterCount = 0;
             if (mAdapter != null) {
                 adapterCount = mAdapter.getCount();
                 if (adjPosition < adapterCount) {
                     return mAdapter.getView(adjPosition, convertView, parent);
                 }
             }

             throw new ArrayIndexOutOfBoundsException(position);
         }

         @Override
         public int getItemViewType(int position) {
             int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
             if (position < numHeadersAndPlaceholders && (position % mNumColumns != 0)) {
                 // Placeholders get the last view type number
                 return mAdapter != null ? mAdapter.getViewTypeCount() : 1;
             }
             if (mAdapter != null && position >= numHeadersAndPlaceholders) {
                 int adjPosition = position - numHeadersAndPlaceholders;
                 int adapterCount = mAdapter.getCount();
                 if (adjPosition < adapterCount) {
                     return mAdapter.getItemViewType(adjPosition);
                 }
             }

             return AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER;
         }

         @Override
         public int getViewTypeCount() {
             if (mAdapter != null) {
                 return mAdapter.getViewTypeCount() + 1;
             }
             return 2;
         }

         @Override
         public void registerDataSetObserver(DataSetObserver observer) {
             mDataSetObservable.registerObserver(observer);
             if (mAdapter != null) {
                 mAdapter.registerDataSetObserver(observer);
             }
         }

         @Override
         public void unregisterDataSetObserver(DataSetObserver observer) {
             mDataSetObservable.unregisterObserver(observer);
             if (mAdapter != null) {
                 mAdapter.unregisterDataSetObserver(observer);
             }
         }

         @Override
         public Filter getFilter() {
             if (mIsFilterable) {
                 return ((Filterable) mAdapter).getFilter();
             }
             return null;
         }

         @Override
         public ListAdapter getWrappedAdapter() {
             return mAdapter;
         }

         public void notifyDataSetChanged() {
             mDataSetObservable.notifyChanged();
         }
     }
 }
	/*
	* Copyright (C) 2013 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 com.android.photos.views;

	import android.content.Context;
	import android.database.DataSetObservable;
	import android.database.DataSetObserver;
	import android.util.AttributeSet;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.AdapterView;
	import android.widget.Filter;
	import android.widget.Filterable;
	import android.widget.FrameLayout;
	import android.widget.GridView;
	import android.widget.ListAdapter;
	import android.widget.WrapperListAdapter;

	import java.util.ArrayList;

	/**
	* A {@link GridView} that supports adding header rows in a
	* very similar way to {@link ListView}.
	* See {@link HeaderGridView#addHeaderView(View, Object, boolean)}
	*/
	public class HeaderGridView extends GridView {
	private static final String TAG = "HeaderGridView";

	/**
	* A class that represents a fixed view in a list, for example a header at the top
	* or a footer at the bottom.
	*/
	private static class FixedViewInfo {
	/** The view to add to the grid */
	public View view;
	public ViewGroup viewContainer;
	/** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */
	public Object data;
	/** <code>true</code> if the fixed view should be selectable in the grid */
	public boolean isSelectable;
	}

	private ArrayList<FixedViewInfo> mHeaderViewInfos = new ArrayList<FixedViewInfo>();

	private void initHeaderGridView() {
	super.setClipChildren(false);
	}

	public HeaderGridView(Context context) {
	super(context);
	initHeaderGridView();
	}

	public HeaderGridView(Context context, AttributeSet attrs) {
	super(context, attrs);
	initHeaderGridView();
	}

	public HeaderGridView(Context context, AttributeSet attrs, int defStyle) {
	super(context, attrs, defStyle);
	initHeaderGridView();
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	ListAdapter adapter = getAdapter();
	if (adapter != null && adapter instanceof HeaderViewGridAdapter) {
	((HeaderViewGridAdapter) adapter).setNumColumns(getNumColumns());
	}
	}

	@Override
	public void setClipChildren(boolean clipChildren) {
	// Ignore, since the header rows depend on not being clipped
	}

	/**
	* Add a fixed view to appear at the top of the grid. If addHeaderView is
	* called more than once, the views will appear in the order they were
	* added. Views added using this call can take focus if they want.
	* <p>
	* NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
	* the supplied cursor with one that will also account for header views.
	*
	* @param v The view to add.
	* @param data Data to associate with this view
	* @param isSelectable whether the item is selectable
	*/
	public void addHeaderView(View v, Object data, boolean isSelectable) {
	ListAdapter adapter = getAdapter();

	if (adapter != null && ! (adapter instanceof HeaderViewGridAdapter)) {
	throw new IllegalStateException(
	"Cannot add header view to grid -- setAdapter has already been called.");
	}

	FixedViewInfo info = new FixedViewInfo();
	FrameLayout fl = new FullWidthFixedViewLayout(getContext());
	fl.addView(v);
	info.view = v;
	info.viewContainer = fl;
	info.data = data;
	info.isSelectable = isSelectable;
	mHeaderViewInfos.add(info);

	// in the case of re-adding a header view, or adding one later on,
	// we need to notify the observer
	if (adapter != null) {
	((HeaderViewGridAdapter) adapter).notifyDataSetChanged();
	}
	}

	/**
	* Add a fixed view to appear at the top of the grid. If addHeaderView is
	* called more than once, the views will appear in the order they were
	* added. Views added using this call can take focus if they want.
	* <p>
	* NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
	* the supplied cursor with one that will also account for header views.
	*
	* @param v The view to add.
	*/
	public void addHeaderView(View v) {
	addHeaderView(v, null, true);
	}

	public int getHeaderViewCount() {
	return mHeaderViewInfos.size();
	}

	/**
	* Removes a previously-added header view.
	*
	* @param v The view to remove
	* @return true if the view was removed, false if the view was not a header
	* view
	*/
	public boolean removeHeaderView(View v) {
	if (mHeaderViewInfos.size() > 0) {
	boolean result = false;
	ListAdapter adapter = getAdapter();
	if (adapter != null && ((HeaderViewGridAdapter) adapter).removeHeader(v)) {
	result = true;
	}
	removeFixedViewInfo(v, mHeaderViewInfos);
	return result;
	}
	return false;
	}

	private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) {
	int len = where.size();
	for (int i = 0; i < len; ++i) {
	FixedViewInfo info = where.get(i);
	if (info.view == v) {
	where.remove(i);
	break;
	}
	}
	}

	@Override
	public void setAdapter(ListAdapter adapter) {
	if (mHeaderViewInfos.size() > 0) {
	HeaderViewGridAdapter hadapter = new HeaderViewGridAdapter(mHeaderViewInfos, adapter);
	int numColumns = getNumColumns();
	if (numColumns > 1) {
	hadapter.setNumColumns(numColumns);
	}
	super.setAdapter(hadapter);
	} else {
	super.setAdapter(adapter);
	}
	}

	private class FullWidthFixedViewLayout extends FrameLayout {
	public FullWidthFixedViewLayout(Context context) {
	super(context);
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	int targetWidth = HeaderGridView.this.getMeasuredWidth()
	- HeaderGridView.this.getPaddingLeft()
	- HeaderGridView.this.getPaddingRight();
	widthMeasureSpec = MeasureSpec.makeMeasureSpec(targetWidth,
	MeasureSpec.getMode(widthMeasureSpec));
	super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	}
	}

	/**
	* ListAdapter used when a HeaderGridView has header views. This ListAdapter
	* wraps another one and also keeps track of the header views and their
	* associated data objects.
	*<p>This is intended as a base class; you will probably not need to
	* use this class directly in your own code.
	*/
	private static class HeaderViewGridAdapter implements WrapperListAdapter, Filterable {

	// This is used to notify the container of updates relating to number of columns
	// or headers changing, which changes the number of placeholders needed
	private final DataSetObservable mDataSetObservable = new DataSetObservable();

	private final ListAdapter mAdapter;
	private int mNumColumns = 1;

	// This ArrayList is assumed to NOT be null.
	ArrayList<FixedViewInfo> mHeaderViewInfos;

	boolean mAreAllFixedViewsSelectable;

	private final boolean mIsFilterable;

	public HeaderViewGridAdapter(ArrayList<FixedViewInfo> headerViewInfos, ListAdapter adapter) {
	mAdapter = adapter;
	mIsFilterable = adapter instanceof Filterable;

	if (headerViewInfos == null) {
	throw new IllegalArgumentException("headerViewInfos cannot be null");
	}
	mHeaderViewInfos = headerViewInfos;

	mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);
	}

	public int getHeadersCount() {
	return mHeaderViewInfos.size();
	}

	@Override
	public boolean isEmpty() {
	return (mAdapter == null \|\| mAdapter.isEmpty()) && getHeadersCount() == 0;
	}

	public void setNumColumns(int numColumns) {
	if (numColumns < 1) {
	throw new IllegalArgumentException("Number of columns must be 1 or more");
	}
	if (mNumColumns != numColumns) {
	mNumColumns = numColumns;
	notifyDataSetChanged();
	}
	}

	private boolean areAllListInfosSelectable(ArrayList<FixedViewInfo> infos) {
	if (infos != null) {
	for (FixedViewInfo info : infos) {
	if (!info.isSelectable) {
	return false;
	}
	}
	}
	return true;
	}

	public boolean removeHeader(View v) {
	for (int i = 0; i < mHeaderViewInfos.size(); i++) {
	FixedViewInfo info = mHeaderViewInfos.get(i);
	if (info.view == v) {
	mHeaderViewInfos.remove(i);

	mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);

	mDataSetObservable.notifyChanged();
	return true;
	}
	}

	return false;
	}

	@Override
	public int getCount() {
	if (mAdapter != null) {
	return getHeadersCount() * mNumColumns + mAdapter.getCount();
	} else {
	return getHeadersCount() * mNumColumns;
	}
	}

	@Override
	public boolean areAllItemsEnabled() {
	if (mAdapter != null) {
	return mAreAllFixedViewsSelectable && mAdapter.areAllItemsEnabled();
	} else {
	return true;
	}
	}

	@Override
	public boolean isEnabled(int position) {
	// Header (negative positions will throw an ArrayIndexOutOfBoundsException)
	int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
	if (position < numHeadersAndPlaceholders) {
	return (position % mNumColumns == 0)
	&& mHeaderViewInfos.get(position / mNumColumns).isSelectable;
	}

	// Adapter
	final int adjPosition = position - numHeadersAndPlaceholders;
	int adapterCount = 0;
	if (mAdapter != null) {
	adapterCount = mAdapter.getCount();
	if (adjPosition < adapterCount) {
	return mAdapter.isEnabled(adjPosition);
	}
	}

	throw new ArrayIndexOutOfBoundsException(position);
	}

	@Override
	public Object getItem(int position) {
	// Header (negative positions will throw an ArrayIndexOutOfBoundsException)
	int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
	if (position < numHeadersAndPlaceholders) {
	if (position % mNumColumns == 0) {
	return mHeaderViewInfos.get(position / mNumColumns).data;
	}
	return null;
	}

	// Adapter
	final int adjPosition = position - numHeadersAndPlaceholders;
	int adapterCount = 0;
	if (mAdapter != null) {
	adapterCount = mAdapter.getCount();
	if (adjPosition < adapterCount) {
	return mAdapter.getItem(adjPosition);
	}
	}

	throw new ArrayIndexOutOfBoundsException(position);
	}

	@Override
	public long getItemId(int position) {
	int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
	if (mAdapter != null && position >= numHeadersAndPlaceholders) {
	int adjPosition = position - numHeadersAndPlaceholders;
	int adapterCount = mAdapter.getCount();
	if (adjPosition < adapterCount) {
	return mAdapter.getItemId(adjPosition);
	}
	}
	return -1;
	}

	@Override
	public boolean hasStableIds() {
	if (mAdapter != null) {
	return mAdapter.hasStableIds();
	}
	return false;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
	// Header (negative positions will throw an ArrayIndexOutOfBoundsException)
	int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns ;
	if (position < numHeadersAndPlaceholders) {
	View headerViewContainer = mHeaderViewInfos
	.get(position / mNumColumns).viewContainer;
	if (position % mNumColumns == 0) {
	return headerViewContainer;
	} else {
	if (convertView == null) {
	convertView = new View(parent.getContext());
	}
	// We need to do this because GridView uses the height of the last item
	// in a row to determine the height for the entire row.
	convertView.setVisibility(View.INVISIBLE);
	convertView.setMinimumHeight(headerViewContainer.getHeight());
	return convertView;
	}
	}

	// Adapter
	final int adjPosition = position - numHeadersAndPlaceholders;
	int adapterCount = 0;
	if (mAdapter != null) {
	adapterCount = mAdapter.getCount();
	if (adjPosition < adapterCount) {
	return mAdapter.getView(adjPosition, convertView, parent);
	}
	}

	throw new ArrayIndexOutOfBoundsException(position);
	}

	@Override
	public int getItemViewType(int position) {
	int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
	if (position < numHeadersAndPlaceholders && (position % mNumColumns != 0)) {
	// Placeholders get the last view type number
	return mAdapter != null ? mAdapter.getViewTypeCount() : 1;
	}
	if (mAdapter != null && position >= numHeadersAndPlaceholders) {
	int adjPosition = position - numHeadersAndPlaceholders;
	int adapterCount = mAdapter.getCount();
	if (adjPosition < adapterCount) {
	return mAdapter.getItemViewType(adjPosition);
	}
	}

	return AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER;
	}

	@Override
	public int getViewTypeCount() {
	if (mAdapter != null) {
	return mAdapter.getViewTypeCount() + 1;
	}
	return 2;
	}

	@Override
	public void registerDataSetObserver(DataSetObserver observer) {
	mDataSetObservable.registerObserver(observer);
	if (mAdapter != null) {
	mAdapter.registerDataSetObserver(observer);
	}
	}

	@Override
	public void unregisterDataSetObserver(DataSetObserver observer) {
	mDataSetObservable.unregisterObserver(observer);
	if (mAdapter != null) {
	mAdapter.unregisterDataSetObserver(observer);
	}
	}

	@Override
	public Filter getFilter() {
	if (mIsFilterable) {
	return ((Filterable) mAdapter).getFilter();
	}
	return null;
	}

	@Override
	public ListAdapter getWrappedAdapter() {
	return mAdapter;
	}

	public void notifyDataSetChanged() {
	mDataSetObservable.notifyChanged();
	}
	}
	}