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java.lang.Objectgreenfoot.PlayerData
public class PlayerData
The PlayerData class allows you to store and load data for Greenfoot scenarios, even when the scenario has been uploaded to the Greenfoot website.
You should always check if storage is currently available by PlayerData.isStorageAvailable(). Storage is not always available, and in particular, if the user is not logged in to the Greenfoot website (a very common case), storage will not be available.
When storage is available, you can use PlayerData.getMyData() to get the data for the current user, or PlayerData.getTop(10) or PlayerData.getNearby(10) to get items to show on a scoreboard. These give you back PlayerData items, where you can get the players' image or get/set the current data.
A player's data consists of a score integer, 10 general integers and 5 strings. getTop and getNearby use the score for sorting. You are free to use the general integers and strings as you need for your scenario: things like which level the player reached last time they were playing.
Field Summary | |
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static int |
NUM_INTS
The number of integers that can be stored |
static int |
NUM_STRINGS
The number of Strings that can be stored |
Method Summary | |
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int |
getInt(int index)
Gets the value of the int at the given index (0 to NUM_INTS-1, inclusive) |
static PlayerData |
getMyData()
Gets the data stored for the current user. |
static java.util.List |
getNearby(int maxAmount)
Gets a sorted list of the PlayerData items for this scenario surrounding the current user. |
int |
getRank()
Gets the players overall rank for this scenario. |
int |
getScore()
Gets the player's score |
java.lang.String |
getString(int index)
Gets the value of the String at the given index (0 to NUM_STRINGS-1, inclusive) |
static java.util.List |
getTop(int maxAmount)
Gets a sorted list of the PlayerData items for this scenario, starting at the top. |
GreenfootImage |
getUserImage()
Returns a 50x50 image of the user. |
java.lang.String |
getUserName()
Gets the username of the user that this storage belongs to. |
static boolean |
isStorageAvailable()
A boolean indicating whether storage is available. |
void |
setInt(int index,
int value)
Sets the value of the int at the given index (0 to NUM_INTS-1, inclusive) |
void |
setScore(int score)
Sets the player's score. |
void |
setString(int index,
java.lang.String value)
Gets the value of the String at the given index (0 to NUM_STRINGS-1, inclusive) Passing null is treated as a blank string. |
boolean |
store()
Stores the data. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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public static final int NUM_INTS
public static final int NUM_STRINGS
Method Detail |
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public java.lang.String getUserName()
public int getInt(int index)
Default value is zero.
public java.lang.String getString(int index)
Default value is the empty String.
public void setInt(int index, int value)
public void setString(int index, java.lang.String value)
public int getScore()
public void setScore(int score)
Note that this really does set the player's score. If you want to record only the player's highest score, you must code that yourself, using something like:
if (latestScore > getScore()) { setScore(latestScore); }Without some code like this, you'll always overwrite the player's previous score.
public int getRank()
The player with the highest score will return 1, the player with the second highest score will return 2, and so on. Players with equal scores will get equal ranks, so rank will not necessarily be unique. To find the rank, scores are sorted in descending order (highest score first). If your scores need to be lowest-first, one trick is to store them as negative numbers.
If the rank is unavailable (e.g. because the data hasn't been stored yet), this function will return -1
public static boolean isStorageAvailable()
Storage is unavailable if it is an applet outside the Greenfoot website, or a stand-alone application, or if the user is not logged in to the Greenfoot website. This last case is very common, so you must check this function before attempting to use the other static storage functions. If this function returns false, your scenario must proceed without using storage.
public static PlayerData getMyData()
public boolean store()
If you try to store data for any user other than the current user, it is guaranteed to fail.
public static java.util.List getTop(int maxAmount)
This will return one PlayerData item per user, and it will be sorted in descending order by the score (i.e. the return of getScore()). The parameter allows you to specify a limit on the amount of users' data to retrieve. If there is lots of data stored for users in your app, this may take some time (and bandwidth) to retrieve all users' data, and often you do not need all the users' data.
For example, if you want to show the high-scores, store the score with setScore(score), and then use getTop(10) to get the users with the top ten scores.
Returns null if:
maxAmount
- The maximum number of data items to retrieve.
Passing zero or a negative number will get all the data, but see the note above.
public static java.util.List getNearby(int maxAmount)
This will be one item per user, and it will be sorted in descending order by the score (i.e. the return of getScore()). The parameter allows you to specify a limit on the amount of users' data to retrieve. If there is lots of data stored for users in your app, this may take some time (and bandwidth) to retrieve all users' data, and often you do not need all the users' data.
The items will be those surrounding the current user. So for example, imagine that the player is 50th of 100 total users (when sorted by getScore()). Calling getNearby(5) will get the 48th, 49th, 50th, 51st and 52nd users in that order. Do not rely on the player being at a fixed location in the middle of the list: calling getNearby(5) when the user is 2nd overall will get the 1st, 2nd, 3rd, 4th and 5th users, so the user will be 2nd in the list, and a similar thing will happen if the user is near the end of the list.
For example, if you want to show the high-scores surrounding the player, store the score with setScore(score), and then use getNearby(10) to get the ten users with scores close to the current player.
Returns null if:
maxAmount
- The maximum number of data items to retrieve.
Passing zero or a negative number will get all the data, but see the note above.
public GreenfootImage getUserImage()
On the Greenfoot website, this is their profile picture. If running locally, always returns a dummy image, with their username drawn on the image.
Returns null if:
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