FacebookUtilities.java

package com.charlesmadere.android.classygames.utilities;


import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;


/**
 * Class for constants and methods relating to Facebook. Further documentation
 * on what this class is doing can be found on the Facebook website:
 * https://developers.facebook.com/docs/reference/api/using-pictures/
 */
public final class FacebookUtilities
{


	private final static String GRAPH_API_URL = "https://graph.facebook.com/";
	private final static String PICTURE = "/picture";
	private final static String TYPE = "?type=";
	private final static String ACCESS_TOKEN = "&access_token=";
	private final static String RETURN_SSL_RESOURCES_1 = "&return_ssl_resources=1";

	private final static String PICTURE_LARGE = PICTURE + TYPE + "large" + RETURN_SSL_RESOURCES_1;
	private final static String PICTURE_NORMAL = PICTURE + TYPE + "normal" + RETURN_SSL_RESOURCES_1;
	private final static String PICTURE_SMALL = PICTURE + TYPE + "small" + RETURN_SSL_RESOURCES_1;
	private final static String PICTURE_SQUARE = PICTURE + TYPE + "square" + RETURN_SSL_RESOURCES_1;


	/**
	 * The user's Facebook Access Token. Note that it's possible for this
	 * String to be null. More about access tokens here:
	 * https://developers.facebook.com/docs/getting-started/graphapi/#login
	 */
	private static String accessToken;
	private static final String KEY_ACCESS_TOKEN = "KEY_ACCESS_TOKEN";
	private static final String PREFERENCES_NAME = "FacebookUtilities_Preferences";




	/**
	 * Returns the complete Facebook API access token query string. So that
	 * would be "&access_token=FC030F". Please only use this method if the
	 * user's Facebook access token is not null or empty!
	 *
	 * @param activity
	 * The Activity that is calling this method.
	 *
	 * @return
	 * Returns the complete Facebook API access token query string, ready to be
	 * used in a Facebook Graph API request.
	 */
	private static String getAccessToken(final Activity activity)
	{
		if (Utilities.validString(accessToken))
		{
			return ACCESS_TOKEN + accessToken;
		}
		else
		{
			accessToken = getPreferences(activity).getString(KEY_ACCESS_TOKEN, null);

			if (Utilities.validString(accessToken))
			{
				return ACCESS_TOKEN + accessToken;
			}
			else
			{
				return null;
			}
		}
	}


	/**
	 * Sets the user's Facebook access token. This is needed as some Facebook
	 * API requests require the user's access token in order to run without
	 * worriment of hitting an API rate limit. More on the subject here:
	 * https://developers.facebook.com/docs/reference/api/using-pictures/#ratelimits
	 *
	 * @param activity
	 * The Activity that is calling this method.
	 *
	 * @param accessToken
	 * The user's Facebook Access Token.
	 */
	public static void setAccessToken(final Activity activity, final String accessToken)
	{
		getPreferences(activity).edit()
			.putString(KEY_ACCESS_TOKEN, accessToken)
			.commit();

		FacebookUtilities.accessToken = accessToken;
	}


	private static String getFriendsPicture(final Activity activity, final long id, final String picture)
	{
		if (Utilities.validString(getAccessToken(activity)))
		{
			return GRAPH_API_URL + id + picture + ACCESS_TOKEN + accessToken;
		}
		else
		{
			return GRAPH_API_URL + id + picture;
		}
	}


	/**
	 * Returns the large profile picture URL for the given user ID.
	 *
	 * @param activity
	 * The Activity that is calling this method.
	 *
	 * @param id
	 * The Facebook user ID of the person that you want a profile picture for.
	 *
	 * @return
	 * Returns the URL as a String. This URL could be typed directly into a
	 * browser if you wanted to test to make sure that it works.
	 */
	public static String getFriendsPictureLarge(final Activity activity, final long id)
	{
		return getFriendsPicture(activity, id, PICTURE_LARGE);
	}


	/**
	 * Returns the normal profile picture URL for the given user ID.
	 *
	 * @param activity
	 * The Activity that is calling this method.
	 *
	 * @param id
	 * The Facebook user ID of the person that you want a profile picture for.
	 *
	 * @return
	 * Returns the URL as a String. This URL could be typed directly into a
	 * browser if you wanted to test to make sure that it works.
	 */
	public static String getFriendsPictureNormal(final Activity activity, final long id)
	{
		return getFriendsPicture(activity, id, PICTURE_NORMAL);
	}


	/**
	 * Returns the small profile picture URL for the given user ID.
	 *
	 * @param activity
	 * The Activity that is calling this method.
	 *
	 * @param id
	 * The Facebook user ID of the person that you want a profile picture for.
	 *
	 * @return
	 * Returns the URL as a String. This URL could be typed directly into a
	 * browser if you wanted to test to make sure that it works.
	 */
	public static String getFriendsPictureSmall(final Activity activity, final long id)
	{
		return getFriendsPicture(activity, id, PICTURE_SMALL);
	}


	/**
	 * Returns the square profile picture URL for the given user ID.
	 *
	 * @param activity
	 * The Activity that is calling this method.
	 *
	 * @param id
	 * The Facebook user ID of the person that you want a profile picture for.
	 *
	 * @return
	 * Returns the URL as a String. This URL could be typed directly into a
	 * browser if you wanted to test to make sure that it works.
	 */
	public static String getFriendsPictureSquare(final Activity activity, final long id)
	{
		return getFriendsPicture(activity, id, PICTURE_SQUARE);
	}


	/**
	 * @return
	 * Returns the SharedPreferences handle that should be used for data needed
	 * within this class.
	 */
	private static SharedPreferences getPreferences(final Activity activity)
	{
		return activity.getSharedPreferences(PREFERENCES_NAME, Context.MODE_PRIVATE);
	}


}