| package aurelienribon.tweenengine; |
| |
| /** |
| * The TweenAccessor interface lets you interpolate any attribute from any |
| * object. Just implement it as you want and register it to the engine by |
| * calling {@link Tween#registerAccessor}. |
| * <p/> |
| * |
| * <h2>Example</h2> |
| * |
| * The following code snippet presents an example of implementation for tweening |
| * a Particle class. This Particle class is supposed to only define a position |
| * with an "x" and an "y" fields, and their associated getters and setters. |
| * <p/> |
| * |
| * <pre> {@code |
| * public class ParticleAccessor implements TweenAccessor<Particle> { |
| * public static final int X = 1; |
| * public static final int Y = 2; |
| * public static final int XY = 3; |
| * |
| * public int getValues(Particle target, int tweenType, float[] returnValues) { |
| * switch (tweenType) { |
| * case X: returnValues[0] = target.getX(); return 1; |
| * case Y: returnValues[0] = target.getY(); return 1; |
| * case XY: |
| * returnValues[0] = target.getX(); |
| * returnValues[1] = target.getY(); |
| * return 2; |
| * default: assert false; return 0; |
| * } |
| * } |
| * |
| * public void setValues(Particle target, int tweenType, float[] newValues) { |
| * switch (tweenType) { |
| * case X: target.setX(newValues[0]); break; |
| * case Y: target.setY(newValues[1]); break; |
| * case XY: |
| * target.setX(newValues[0]); |
| * target.setY(newValues[1]); |
| * break; |
| * default: assert false; break; |
| * } |
| * } |
| * } |
| * }</pre> |
| * |
| * Once done, you only need to register this TweenAccessor once to be able to |
| * use it for every Particle objects in your application: |
| * <p/> |
| * |
| * <pre> {@code |
| * Tween.registerAccessor(Particle.class, new ParticleAccessor()); |
| * }</pre> |
| * |
| * And that's all, the Tween Engine can no work with all your particles! |
| * |
| * @author Aurelien Ribon | http://www.aurelienribon.com/ |
| */ |
| public interface TweenAccessor<T> { |
| /** |
| * Gets one or many values from the target object associated to the |
| * given tween type. It is used by the Tween Engine to determine starting |
| * values. |
| * |
| * @param target The target object of the tween. |
| * @param tweenType An integer representing the tween type. |
| * @param returnValues An array which should be modified by this method. |
| * @return The count of modified slots from the returnValues array. |
| */ |
| public int getValues(T target, int tweenType, float[] returnValues); |
| |
| /** |
| * This method is called by the Tween Engine each time a running tween |
| * associated with the current target object has been updated. |
| * |
| * @param target The target object of the tween. |
| * @param tweenType An integer representing the tween type. |
| * @param newValues The new values determined by the Tween Engine. |
| */ |
| public void setValues(T target, int tweenType, float[] newValues); |
| } |