samples/training/threadsample/src/com/example/android/threadsample/PhotoThumbnailFragment.java - platform/development.git - Git at Google

 /*
  * Copyright (C) 2012 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.example.android.threadsample;

 import android.content.Context;
 import android.content.Intent;
 import android.database.Cursor;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentTransaction;
 import android.support.v4.app.LoaderManager;
 import android.support.v4.content.CursorLoader;
 import android.support.v4.content.Loader;
 import android.support.v4.content.LocalBroadcastManager;
 import android.support.v4.widget.CursorAdapter;
 import android.util.DisplayMetrics;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
 import android.widget.AbsListView;
 import android.widget.AdapterView;
 import android.widget.GridView;

 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.concurrent.RejectedExecutionException;

 /**
  * PhotoThumbnailFragment displays a GridView of picture thumbnails downloaded from Picasa
  */
 public class PhotoThumbnailFragment extends Fragment implements
         LoaderManager.LoaderCallbacks<Cursor>, AdapterView.OnItemClickListener {

     private static final String STATE_IS_HIDDEN =
             "com.example.android.threadsample.STATE_IS_HIDDEN";

     // The width of each column in the grid
     private int mColumnWidth;

     // A Drawable for a grid cell that's empty
     private Drawable mEmptyDrawable;

     // The GridView for displaying thumbnails
     private GridView mGridView;

     // Denotes if the GridView has been loaded
     private boolean mIsLoaded;

     // Intent for starting the IntentService that downloads the Picasa featured picture RSS feed
     private Intent mServiceIntent;

     // An adapter between a Cursor and the Fragment's GridView
     private GridViewAdapter mAdapter;

     // The URL of the Picasa featured picture RSS feed, in String format
     private static final String PICASA_RSS_URL =
             "http://picasaweb.google.com/data/feed/base/featured?" +
             "alt=rss&kind=photo&access=public&slabel=featured&hl=en_US&imgmax=1600";

     private static final String[] PROJECTION =
     {
         DataProviderContract._ID,
         DataProviderContract.IMAGE_THUMBURL_COLUMN,
         DataProviderContract.IMAGE_URL_COLUMN
     };

     // Constants that define the order of columns in the returned cursor
     private static final int IMAGE_THUMBURL_CURSOR_INDEX = 1;
     private static final int IMAGE_URL_CURSOR_INDEX = 2;

     // Identifies a particular Loader being used in this component
     private static final int URL_LOADER = 0;

     /*
      * This callback is invoked when the framework is starting or re-starting the Loader. It
      * returns a CursorLoader object containing the desired query
      */
     @Override
     public Loader<Cursor> onCreateLoader(int loaderID, Bundle bundle)
     {
         /*
          * Takes action based on the ID of the Loader that's being created
          */
         switch (loaderID) {
             case URL_LOADER:
             // Returns a new CursorLoader
             return new CursorLoader(
                         getActivity(),                                     // Context
                         DataProviderContract.PICTUREURL_TABLE_CONTENTURI,  // Table to query
                         PROJECTION,                                        // Projection to return
                         null,                                              // No selection clause
                         null,                                              // No selection arguments
                         null                                               // Default sort order
             );
             default:
                 // An invalid id was passed in
                 return null;

         }

     }

     /*
      * This callback is invoked when the the Fragment's View is being loaded. It sets up the View.
      */
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup viewGroup, Bundle bundle) {

         // Always call the super method first
         super.onCreateView(inflater, viewGroup, bundle);

         /*
          * Inflates the View from the gridlist layout file, using the layout parameters in
          * "viewGroup"
          */
         View localView = inflater.inflate(R.layout.gridlist, viewGroup, false);

         // Sets the View's data adapter to be a new GridViewAdapter
         mAdapter = new GridViewAdapter(getActivity());

         // Gets a handle to the GridView in the layout
         mGridView = ((GridView) localView.findViewById(android.R.id.list));

         // Instantiates a DisplayMetrics object
         DisplayMetrics localDisplayMetrics = new DisplayMetrics();

         // Gets the current display metrics from the current Window
         getActivity().getWindowManager().getDefaultDisplay().getMetrics(localDisplayMetrics);

         /*
          * Gets the dp value from the thumbSize resource as an integer in dps. The value can
          * be adjusted for specific display sizes, etc. in the dimens.xml file for a particular
          * values-<qualifier> directory
          */
         int pixelSize = getResources().getDimensionPixelSize(R.dimen.thumbSize);

         /*
          * Calculates a width scale factor from the pixel width of the current display and the
          * desired pixel size
          */
         int widthScale = localDisplayMetrics.widthPixels / pixelSize;

         // Calculates the grid column width
         mColumnWidth = (localDisplayMetrics.widthPixels / widthScale);

         // Sets the GridView's column width
         mGridView.setColumnWidth(mColumnWidth);

         // Starts by setting the GridView to have no columns
         mGridView.setNumColumns(-1);

         // Sets the GridView's data adapter
         mGridView.setAdapter(mAdapter);

         /*
          * Sets the GridView's click listener to be this class. As a result, when users click the
          * GridView, PhotoThumbnailFragment.onClick() is invoked.
          */
         mGridView.setOnItemClickListener(this);

         /*
          * Sets the "empty" View for the layout. If there's nothing to show, a ProgressBar
          * is displayed.
          */
         mGridView.setEmptyView(localView.findViewById(R.id.progressRoot));

         // Sets a dark background to show when no image is queued to be downloaded
         mEmptyDrawable = getResources().getDrawable(R.drawable.imagenotqueued);

         // Initializes the CursorLoader
         getLoaderManager().initLoader(URL_LOADER, null, this);

         /*
          * Creates a new Intent to send to the download IntentService. The Intent contains the
          * URL of the Picasa feature picture RSS feed
          */
         mServiceIntent =
                 new Intent(getActivity(), RSSPullService.class)
                         .setData(Uri.parse(PICASA_RSS_URL));

         // If there's no pre-existing state for this Fragment
         if (bundle == null) {
             // If the data wasn't previously loaded
             if (!this.mIsLoaded) {
                 // Starts the IntentService to download the RSS feed data
                 getActivity().startService(mServiceIntent);
             }

         // If this Fragment existed previously, gets its state
         } else if (bundle.getBoolean(STATE_IS_HIDDEN, false)) {

             // Begins a transaction
             FragmentTransaction localFragmentTransaction =
                     getFragmentManager().beginTransaction();

             // Hides the Fragment
             localFragmentTransaction.hide(this);

             // Commits the transaction
             localFragmentTransaction.commit();
         }

         // Returns the View inflated from the layout
         return localView;
     }

     /*
      * This callback is invoked when the Fragment is being destroyed.
      */
     @Override
     public void onDestroyView() {

         // Sets variables to null, to avoid memory leaks
         mGridView = null;

         // If the EmptyDrawable contains something, sets those members to null
         if (mEmptyDrawable != null) {
             this.mEmptyDrawable.setCallback(null);
             this.mEmptyDrawable = null;
         }

         // Always call the super method last
         super.onDestroyView();
     }

     /*
      * This callback is invoked after onDestroyView(). It clears out variables, shuts down the
      * CursorLoader, and so forth
      */
     @Override
     public void onDetach() {

         // Destroys variables and references, and catches Exceptions
         try {
             getLoaderManager().destroyLoader(0);
             if (mAdapter != null) {
                 mAdapter.changeCursor(null);
                 mAdapter = null;
             }
         } catch (Throwable localThrowable) {
         }

         // Always call the super method last
         super.onDetach();
         return;
     }

     /*
      * This is invoked whenever the visibility state of the Fragment changes
      */
     @Override
     public void onHiddenChanged(boolean viewState) {
         super.onHiddenChanged(viewState);
     }

     /*
      * Implements OnItemClickListener.onItemClick() for this View's listener.
      * This implementation detects the View that was clicked and retrieves its picture URL.
      */
     @Override
     public void onItemClick(AdapterView<?> adapterView, View view, int viewId, long rowId) {

         // Returns a one-row cursor for the data that backs the View that was clicked.
         Cursor cursor = (Cursor) mAdapter.getItem(viewId);

         // Retrieves the urlString from the cursor
         String urlString = cursor.getString(IMAGE_URL_CURSOR_INDEX);

         /*
          * Creates a new Intent to get the full picture for the thumbnail that the user clicked.
          * The full photo is loaded into a separate Fragment
          */
         Intent localIntent =
                 new Intent(Constants.ACTION_VIEW_IMAGE)
                 .setData(Uri.parse(urlString));

         // Broadcasts the Intent to receivers in this app. See DisplayActivity.FragmentDisplayer.
         LocalBroadcastManager.getInstance(getActivity()).sendBroadcast(localIntent);
     }

     /*
      * Invoked when the CursorLoader finishes the query. A reference to the Loader and the
      * returned Cursor are passed in as arguments
      */
     @Override
     public void onLoadFinished(Loader<Cursor> loader, Cursor returnCursor) {

         /*
          *  Changes the adapter's Cursor to be the results of the load. This forces the View to
          *  redraw.
          */

         mAdapter.changeCursor(returnCursor);
     }

     /*
      * Invoked when the CursorLoader is being reset. For example, this is called if the
      * data in the provider changes and the Cursor becomes stale.
      */
     @Override
     public void onLoaderReset(Loader<Cursor> loader) {

         // Sets the Adapter's backing data to null. This prevents memory leaks.
         mAdapter.changeCursor(null);
     }

     /*
      * This callback is invoked when the system has to destroy the Fragment for some reason. It
      * allows the Fragment to save its state, so the state can be restored later on.
      */
     @Override
     public void onSaveInstanceState(Bundle bundle) {

         // Saves the show-hide status of the display
         bundle.putBoolean(STATE_IS_HIDDEN, isHidden());

         // Always call the super method last
         super.onSaveInstanceState(bundle);
     }

     // Sets the state of the loaded flag
     public void setLoaded(boolean loadState) {
         mIsLoaded = loadState;
     }

     /**
      * Defines a custom View adapter that extends CursorAdapter. The main reason to do this is to
      * display images based on the backing Cursor, rather than just displaying the URLs that the
      * Cursor contains.
      */
     private class GridViewAdapter extends CursorAdapter {

         /**
          * Simplified constructor that calls the super constructor with the input Context,
          * a null value for Cursor, and no flags
          * @param context A Context for this object
          */
         public GridViewAdapter(Context context) {
             super(context, null, false);
         }

         /**
          *
          * Binds a View and a Cursor
          *
          * @param view An existing View object
          * @param context A Context for the View and Cursor
          * @param cursor The Cursor to bind to the View, representing one row of the returned query.
          */
         @Override
         public void bindView(View view, Context context, Cursor cursor) {

             // Gets a handle to the View
             PhotoView localImageDownloaderView = (PhotoView) view.getTag();

             // Converts the URL string to a URL and tries to retrieve the picture
             try {
                 // Gets the URL
                 URL localURL =
                         new URL(
                             cursor.getString(IMAGE_THUMBURL_CURSOR_INDEX)
                         )
                 ;
                 /*
                  * Invokes setImageURL for the View. If the image isn't already available, this
                  * will download and decode it.
                  */
                 localImageDownloaderView.setImageURL(
                             localURL, true, PhotoThumbnailFragment.this.mEmptyDrawable);

             // Catches an invalid URL
             } catch (MalformedURLException localMalformedURLException) {
                 localMalformedURLException.printStackTrace();

             // Catches errors trying to download and decode the picture in a ThreadPool
             } catch (RejectedExecutionException localRejectedExecutionException) {
             }
         }

         /**
          * Creates a new View that shows the contents of the Cursor
          *
          *
          * @param context A Context for the View and Cursor
          * @param cursor The Cursor to display. This is a single row of the returned query
          * @param viewGroup The viewGroup that's the parent of the new View
          * @return the newly-created View
          */
         @Override
         public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
             // Gets a new layout inflater instance
             LayoutInflater inflater = LayoutInflater.from(context);

             /*
              * Creates a new View by inflating the specified layout file. The root ViewGroup is
              * the root of the layout file. This View is a FrameLayout
              */
             View layoutView = inflater.inflate(R.layout.galleryitem, null);

             /*
              * Creates a second View to hold the thumbnail image.
              */
             View thumbView = layoutView.findViewById(R.id.thumbImage);

             /*
              * Sets layout parameters for the layout based on the layout parameters of a virtual
              * list. In addition, this sets the layoutView's width to be MATCH_PARENT, and its
              * height to be the column width?
              */
             layoutView.setLayoutParams(new AbsListView.LayoutParams(LayoutParams.MATCH_PARENT,
                     PhotoThumbnailFragment.this.mColumnWidth));

             // Sets the layoutView's tag to be the same as the thumbnail image tag.
             layoutView.setTag(thumbView);
             return layoutView;
         }

     }
 }
	/*
	* Copyright (C) 2012 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.example.android.threadsample;

	import android.content.Context;
	import android.content.Intent;
	import android.database.Cursor;
	import android.graphics.drawable.Drawable;
	import android.net.Uri;
	import android.os.Bundle;
	import android.support.v4.app.Fragment;
	import android.support.v4.app.FragmentTransaction;
	import android.support.v4.app.LoaderManager;
	import android.support.v4.content.CursorLoader;
	import android.support.v4.content.Loader;
	import android.support.v4.content.LocalBroadcastManager;
	import android.support.v4.widget.CursorAdapter;
	import android.util.DisplayMetrics;
	import android.view.LayoutInflater;
	import android.view.View;
	import android.view.ViewGroup;
	import android.view.ViewGroup.LayoutParams;
	import android.widget.AbsListView;
	import android.widget.AdapterView;
	import android.widget.GridView;

	import java.net.MalformedURLException;
	import java.net.URL;
	import java.util.concurrent.RejectedExecutionException;

	/**
	* PhotoThumbnailFragment displays a GridView of picture thumbnails downloaded from Picasa
	*/
	public class PhotoThumbnailFragment extends Fragment implements
	LoaderManager.LoaderCallbacks<Cursor>, AdapterView.OnItemClickListener {

	private static final String STATE_IS_HIDDEN =
	"com.example.android.threadsample.STATE_IS_HIDDEN";

	// The width of each column in the grid
	private int mColumnWidth;

	// A Drawable for a grid cell that's empty
	private Drawable mEmptyDrawable;

	// The GridView for displaying thumbnails
	private GridView mGridView;

	// Denotes if the GridView has been loaded
	private boolean mIsLoaded;

	// Intent for starting the IntentService that downloads the Picasa featured picture RSS feed
	private Intent mServiceIntent;

	// An adapter between a Cursor and the Fragment's GridView
	private GridViewAdapter mAdapter;

	// The URL of the Picasa featured picture RSS feed, in String format
	private static final String PICASA_RSS_URL =
	"http://picasaweb.google.com/data/feed/base/featured?" +
	"alt=rss&kind=photo&access=public&slabel=featured&hl=en_US&imgmax=1600";

	private static final String[] PROJECTION =
	{
	DataProviderContract._ID,
	DataProviderContract.IMAGE_THUMBURL_COLUMN,
	DataProviderContract.IMAGE_URL_COLUMN
	};

	// Constants that define the order of columns in the returned cursor
	private static final int IMAGE_THUMBURL_CURSOR_INDEX = 1;
	private static final int IMAGE_URL_CURSOR_INDEX = 2;

	// Identifies a particular Loader being used in this component
	private static final int URL_LOADER = 0;

	/*
	* This callback is invoked when the framework is starting or re-starting the Loader. It
	* returns a CursorLoader object containing the desired query
	*/
	@Override
	public Loader<Cursor> onCreateLoader(int loaderID, Bundle bundle)
	{
	/*
	* Takes action based on the ID of the Loader that's being created
	*/
	switch (loaderID) {
	case URL_LOADER:
	// Returns a new CursorLoader
	return new CursorLoader(
	getActivity(), // Context
	DataProviderContract.PICTUREURL_TABLE_CONTENTURI, // Table to query
	PROJECTION, // Projection to return
	null, // No selection clause
	null, // No selection arguments
	null // Default sort order
	);
	default:
	// An invalid id was passed in
	return null;

	}

	}

	/*
	* This callback is invoked when the the Fragment's View is being loaded. It sets up the View.
	*/
	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup viewGroup, Bundle bundle) {

	// Always call the super method first
	super.onCreateView(inflater, viewGroup, bundle);

	/*
	* Inflates the View from the gridlist layout file, using the layout parameters in
	* "viewGroup"
	*/
	View localView = inflater.inflate(R.layout.gridlist, viewGroup, false);

	// Sets the View's data adapter to be a new GridViewAdapter
	mAdapter = new GridViewAdapter(getActivity());

	// Gets a handle to the GridView in the layout
	mGridView = ((GridView) localView.findViewById(android.R.id.list));

	// Instantiates a DisplayMetrics object
	DisplayMetrics localDisplayMetrics = new DisplayMetrics();

	// Gets the current display metrics from the current Window
	getActivity().getWindowManager().getDefaultDisplay().getMetrics(localDisplayMetrics);

	/*
	* Gets the dp value from the thumbSize resource as an integer in dps. The value can
	* be adjusted for specific display sizes, etc. in the dimens.xml file for a particular
	* values-<qualifier> directory
	*/
	int pixelSize = getResources().getDimensionPixelSize(R.dimen.thumbSize);

	/*
	* Calculates a width scale factor from the pixel width of the current display and the
	* desired pixel size
	*/
	int widthScale = localDisplayMetrics.widthPixels / pixelSize;

	// Calculates the grid column width
	mColumnWidth = (localDisplayMetrics.widthPixels / widthScale);

	// Sets the GridView's column width
	mGridView.setColumnWidth(mColumnWidth);

	// Starts by setting the GridView to have no columns
	mGridView.setNumColumns(-1);

	// Sets the GridView's data adapter
	mGridView.setAdapter(mAdapter);

	/*
	* Sets the GridView's click listener to be this class. As a result, when users click the
	* GridView, PhotoThumbnailFragment.onClick() is invoked.
	*/
	mGridView.setOnItemClickListener(this);

	/*
	* Sets the "empty" View for the layout. If there's nothing to show, a ProgressBar
	* is displayed.
	*/
	mGridView.setEmptyView(localView.findViewById(R.id.progressRoot));

	// Sets a dark background to show when no image is queued to be downloaded
	mEmptyDrawable = getResources().getDrawable(R.drawable.imagenotqueued);

	// Initializes the CursorLoader
	getLoaderManager().initLoader(URL_LOADER, null, this);

	/*
	* Creates a new Intent to send to the download IntentService. The Intent contains the
	* URL of the Picasa feature picture RSS feed
	*/
	mServiceIntent =
	new Intent(getActivity(), RSSPullService.class)
	.setData(Uri.parse(PICASA_RSS_URL));

	// If there's no pre-existing state for this Fragment
	if (bundle == null) {
	// If the data wasn't previously loaded
	if (!this.mIsLoaded) {
	// Starts the IntentService to download the RSS feed data
	getActivity().startService(mServiceIntent);
	}

	// If this Fragment existed previously, gets its state
	} else if (bundle.getBoolean(STATE_IS_HIDDEN, false)) {

	// Begins a transaction
	FragmentTransaction localFragmentTransaction =
	getFragmentManager().beginTransaction();

	// Hides the Fragment
	localFragmentTransaction.hide(this);

	// Commits the transaction
	localFragmentTransaction.commit();
	}

	// Returns the View inflated from the layout
	return localView;
	}

	/*
	* This callback is invoked when the Fragment is being destroyed.
	*/
	@Override
	public void onDestroyView() {

	// Sets variables to null, to avoid memory leaks
	mGridView = null;

	// If the EmptyDrawable contains something, sets those members to null
	if (mEmptyDrawable != null) {
	this.mEmptyDrawable.setCallback(null);
	this.mEmptyDrawable = null;
	}

	// Always call the super method last
	super.onDestroyView();
	}

	/*
	* This callback is invoked after onDestroyView(). It clears out variables, shuts down the
	* CursorLoader, and so forth
	*/
	@Override
	public void onDetach() {

	// Destroys variables and references, and catches Exceptions
	try {
	getLoaderManager().destroyLoader(0);
	if (mAdapter != null) {
	mAdapter.changeCursor(null);
	mAdapter = null;
	}
	} catch (Throwable localThrowable) {
	}

	// Always call the super method last
	super.onDetach();
	return;
	}

	/*
	* This is invoked whenever the visibility state of the Fragment changes
	*/
	@Override
	public void onHiddenChanged(boolean viewState) {
	super.onHiddenChanged(viewState);
	}

	/*
	* Implements OnItemClickListener.onItemClick() for this View's listener.
	* This implementation detects the View that was clicked and retrieves its picture URL.
	*/
	@Override
	public void onItemClick(AdapterView<?> adapterView, View view, int viewId, long rowId) {

	// Returns a one-row cursor for the data that backs the View that was clicked.
	Cursor cursor = (Cursor) mAdapter.getItem(viewId);

	// Retrieves the urlString from the cursor
	String urlString = cursor.getString(IMAGE_URL_CURSOR_INDEX);

	/*
	* Creates a new Intent to get the full picture for the thumbnail that the user clicked.
	* The full photo is loaded into a separate Fragment
	*/
	Intent localIntent =
	new Intent(Constants.ACTION_VIEW_IMAGE)
	.setData(Uri.parse(urlString));

	// Broadcasts the Intent to receivers in this app. See DisplayActivity.FragmentDisplayer.
	LocalBroadcastManager.getInstance(getActivity()).sendBroadcast(localIntent);
	}

	/*
	* Invoked when the CursorLoader finishes the query. A reference to the Loader and the
	* returned Cursor are passed in as arguments
	*/
	@Override
	public void onLoadFinished(Loader<Cursor> loader, Cursor returnCursor) {

	/*
	* Changes the adapter's Cursor to be the results of the load. This forces the View to
	* redraw.
	*/

	mAdapter.changeCursor(returnCursor);
	}

	/*
	* Invoked when the CursorLoader is being reset. For example, this is called if the
	* data in the provider changes and the Cursor becomes stale.
	*/
	@Override
	public void onLoaderReset(Loader<Cursor> loader) {

	// Sets the Adapter's backing data to null. This prevents memory leaks.
	mAdapter.changeCursor(null);
	}

	/*
	* This callback is invoked when the system has to destroy the Fragment for some reason. It
	* allows the Fragment to save its state, so the state can be restored later on.
	*/
	@Override
	public void onSaveInstanceState(Bundle bundle) {

	// Saves the show-hide status of the display
	bundle.putBoolean(STATE_IS_HIDDEN, isHidden());

	// Always call the super method last
	super.onSaveInstanceState(bundle);
	}

	// Sets the state of the loaded flag
	public void setLoaded(boolean loadState) {
	mIsLoaded = loadState;
	}

	/**
	* Defines a custom View adapter that extends CursorAdapter. The main reason to do this is to
	* display images based on the backing Cursor, rather than just displaying the URLs that the
	* Cursor contains.
	*/
	private class GridViewAdapter extends CursorAdapter {

	/**
	* Simplified constructor that calls the super constructor with the input Context,
	* a null value for Cursor, and no flags
	* @param context A Context for this object
	*/
	public GridViewAdapter(Context context) {
	super(context, null, false);
	}

	/**
	*
	* Binds a View and a Cursor
	*
	* @param view An existing View object
	* @param context A Context for the View and Cursor
	* @param cursor The Cursor to bind to the View, representing one row of the returned query.
	*/
	@Override
	public void bindView(View view, Context context, Cursor cursor) {

	// Gets a handle to the View
	PhotoView localImageDownloaderView = (PhotoView) view.getTag();

	// Converts the URL string to a URL and tries to retrieve the picture
	try {
	// Gets the URL
	URL localURL =
	new URL(
	cursor.getString(IMAGE_THUMBURL_CURSOR_INDEX)
	)
	;
	/*
	* Invokes setImageURL for the View. If the image isn't already available, this
	* will download and decode it.
	*/
	localImageDownloaderView.setImageURL(
	localURL, true, PhotoThumbnailFragment.this.mEmptyDrawable);

	// Catches an invalid URL
	} catch (MalformedURLException localMalformedURLException) {
	localMalformedURLException.printStackTrace();

	// Catches errors trying to download and decode the picture in a ThreadPool
	} catch (RejectedExecutionException localRejectedExecutionException) {
	}
	}

	/**
	* Creates a new View that shows the contents of the Cursor
	*
	*
	* @param context A Context for the View and Cursor
	* @param cursor The Cursor to display. This is a single row of the returned query
	* @param viewGroup The viewGroup that's the parent of the new View
	* @return the newly-created View
	*/
	@Override
	public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
	// Gets a new layout inflater instance
	LayoutInflater inflater = LayoutInflater.from(context);

	/*
	* Creates a new View by inflating the specified layout file. The root ViewGroup is
	* the root of the layout file. This View is a FrameLayout
	*/
	View layoutView = inflater.inflate(R.layout.galleryitem, null);

	/*
	* Creates a second View to hold the thumbnail image.
	*/
	View thumbView = layoutView.findViewById(R.id.thumbImage);

	/*
	* Sets layout parameters for the layout based on the layout parameters of a virtual
	* list. In addition, this sets the layoutView's width to be MATCH_PARENT, and its
	* height to be the column width?
	*/
	layoutView.setLayoutParams(new AbsListView.LayoutParams(LayoutParams.MATCH_PARENT,
	PhotoThumbnailFragment.this.mColumnWidth));

	// Sets the layoutView's tag to be the same as the thumbnail image tag.
	layoutView.setTag(thumbView);
	return layoutView;
	}

	}
	}