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Achievements

Add achievement to challenge players with custom goals.

Adding achievements​

To add a new achievement create a new class implementing the AchievementDefinition interface.

CustomAchievement.java
public class CustomAchievement implements AchievementDefinition {
    @Override
    public AchievementDetails details() {
        return AchievementDetails.title("Title of the achievement")
                .description("For learning purpose")
                .goal(4);
    }
}
// add the achievement
achievements.add(new CustomAchievement());

// progress fom 0 of 4 to 2 of 4
achievements.progess(CustomAchievement.class);
achievements.progess(CustomAchievement.class);

// unlock achievement by reaching goal
achievements.progess(CustomAchievement.class, 2);

Manual progression​

In the example above we used manual progression for the achievement. Manual progression should only be used when necessary.

Automatic progression​

Automatic progression can be added by overwriting the progress method. ScrewBox will automatically update the progress of such achievements. An example for an automatic progression:

ClickTenTimesAchievement.java
public class ClickTenTimesAchievement implements AchievementDefinition {
    @Override
    public AchievementDetails details() {
        return AchievementDetails.title("Click {goal} times.")
                .description("Achieved when clicked {goal} times.")
                .goal(10);
    }

    @Override
    public int progress(Engine engine) {
        return engine.mouse().isPressedLeft() ? 1 : 0;
    }
}

Absolute progression​

Progression can be additive (default) and also absolute. Achievements with absolute progression will check the progress value against the goal instead of adding it to the current progress. Example for using absolute progression:

PlayForTwoMinutesAchievement.java
public class PlayForTwoMinutesAchievement implements AchievementDefinition {

    @Override
    public AchievementDetails details() {
        return AchievementDetails.title("Play for 2 minutes")
                .goal(120)
                .useAbsoluteProgression();
    }

    @Override
    public int progress(Engine engine) {
        return (int) engine.loop().runningTime().seconds();
    }
}

Completing an achievement​

When a Achievement is completed the default reaction is a UI notification. Off cause this behaviour can be customized:

// custom completion reaction: logging the achievement title
achievements.setCompletionReaction(achievement ->
    engine.log().info(achievement.title()));