Animationen als eigener Prozess

Die Animations API verwendet Funktionale Aspekte der Java 8 API und erlaubt die Animation beliebiger Objekte, aber ist vor allem auf die `shape.*` Klassen ausgelegt.

src/schule/ngb/zm/anim/Animations.java

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+package schule.ngb.zm.anim;
+
+import schule.ngb.zm.Color;
+import schule.ngb.zm.Constants;
+import schule.ngb.zm.Vector;
+import schule.ngb.zm.tasks.TaskRunner;
+import schule.ngb.zm.util.Log;
+import schule.ngb.zm.util.Validator;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.concurrent.Future;
+import java.util.function.*;
+
+public class Animations {
+
+	public static final <T> Future<T> animateProperty( String propName, T target, double to, int runtime, DoubleUnaryOperator easing ) {
+		double from;
+		try {
+			from = callGetter(target, propName, double.class);
+		} catch( InvocationTargetException | NoSuchMethodException |
+				 IllegalAccessException ex ) {
+			throw new RuntimeException("Can't access property getter for animation.", ex);
+		}
+
+		Method propSetter;
+		try {
+			propSetter = findSetter(target, propName, double.class);
+		} catch( NoSuchMethodException ex ) {
+			throw new RuntimeException("Can't find property setter for animation.", ex);
+		}
+
+		return animateProperty(target, from, to, runtime, easing, ( d ) -> {
+			try {
+				propSetter.invoke(target, d);
+			} catch( IllegalAccessException | InvocationTargetException e ) {
+				throw new RuntimeException("Can't access property setter for animation.", e);
+			}
+		});
+	}
+
+	public static final <T> Future<T> animateProperty( String propName, T target, Color to, int runtime, DoubleUnaryOperator easing ) {
+		Color from;
+		try {
+			from = callGetter(target, propName, Color.class);
+		} catch( InvocationTargetException | NoSuchMethodException |
+				 IllegalAccessException ex ) {
+			throw new RuntimeException("Can't access property getter for animation.", ex);
+		}
+
+		Method propSetter;
+		try {
+			propSetter = findSetter(target, propName, Color.class);
+		} catch( NoSuchMethodException ex ) {
+			throw new RuntimeException("Can't find property setter for animation.", ex);
+		}
+
+		return animateProperty(target, from, to, runtime, easing, ( d ) -> {
+			try {
+				propSetter.invoke(target, d);
+			} catch( IllegalAccessException | InvocationTargetException e ) {
+				throw new RuntimeException("Can't access property setter for animation.", e);
+			}
+		});
+	}
+
+	public static final <T> Future<T> animateProperty( String propName, T target, Vector to, int runtime, DoubleUnaryOperator easing ) {
+		Vector from;
+		try {
+			from = callGetter(target, propName, Vector.class);
+		} catch( InvocationTargetException | NoSuchMethodException |
+				 IllegalAccessException ex ) {
+			throw new RuntimeException("Can't access property getter for animation.", ex);
+		}
+
+		Method propSetter;
+		try {
+			propSetter = findSetter(target, propName, Vector.class);
+		} catch( NoSuchMethodException ex ) {
+			throw new RuntimeException("Can't find property setter for animation.", ex);
+		}
+
+		return animateProperty(target, from, to, runtime, easing, ( d ) -> {
+			try {
+				propSetter.invoke(target, d);
+			} catch( IllegalAccessException | InvocationTargetException e ) {
+				throw new RuntimeException("Can't access property setter for animation.", e);
+			}
+		});
+	}
+
+	private static final <T, R> R callGetter( T target, String propName, Class<R> propType ) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+		String getterName = makeMethodName("get", propName);
+		Method getter = target.getClass().getMethod(getterName);
+		if( getter != null && getter.getReturnType().equals(propType) ) {
+			return (R) getter.invoke(target);
+		} else {
+			throw new NoSuchMethodException(String.format("No getter for property <%s> found.", propName));
+		}
+	}
+
+	private static final <T, R> Method findSetter( T target, String propName, Class<R> propType ) throws NoSuchMethodException {
+		String setterName = makeMethodName("set", propName);
+		Method setter = target.getClass().getMethod(setterName, propType);
+		if( setter != null && setter.getReturnType().equals(void.class) && setter.getParameterCount() == 1 ) {
+			return setter;
+		} else {
+			throw new NoSuchMethodException(String.format("No setter for property <%s> found.", propName));
+		}
+	}
+
+	private static final String makeMethodName( String prefix, String propName ) {
+		String firstChar = propName.substring(0, 1).toUpperCase();
+		String tail = "";
+		if( propName.length() > 1 ) {
+			tail = propName.substring(1);
+		}
+		return prefix + firstChar + tail;
+	}
+
+	public static final <T> Future<T> animateProperty( T target, final double from, final double to, int runtime, DoubleUnaryOperator easing, DoubleConsumer propSetter ) {
+		Validator.requireNotNull(target);
+		Validator.requireNotNull(propSetter);
+		return animate(target, runtime, easing, ( e ) -> propSetter.accept(Constants.interpolate(from, to, e)));
+	}
+
+	public static final <T> Future<T> animateProperty( T target, final Color from, final Color to, int runtime, DoubleUnaryOperator easing, Consumer<Color> propSetter ) {
+		return animate(target, runtime, easing, ( e ) -> propSetter.accept(Color.interpolate(from, to, e)));
+	}
+
+
+	public static final <T> Future<T> animateProperty( T target, final Vector from, final Vector to, int runtime, DoubleUnaryOperator easing, Consumer<Vector> propSetter ) {
+		return animate(target, runtime, easing, ( e ) -> propSetter.accept(Vector.interpolate(from, to, e)));
+	}
+
+	public static final <T, R> Future<T> animateProperty( T target, R from, R to, int runtime, DoubleUnaryOperator easing, DoubleFunction<R> interpolator, Consumer<R> propSetter ) {
+		return animate(target, runtime, easing, interpolator, ( t, r ) -> propSetter.accept(r));
+	}
+
+
+	public static final <T, R> Future<T> animate( T target, int runtime, DoubleUnaryOperator easing, DoubleFunction<R> interpolator, BiConsumer<T, R> applicator ) {
+		return animate(target, runtime, easing, ( e ) -> applicator.accept(target, interpolator.apply(e)));
+	}
+
+	public static final <T> Future<T> animate( T target, int runtime, DoubleUnaryOperator easing, DoubleConsumer stepper ) {
+		final long starttime = System.currentTimeMillis();
+		return TaskRunner.run(() -> {
+			double t = 0.0;
+			do {
+				// One animation step for t in [0,1]
+				stepper.accept(easing.applyAsDouble(t));
+				try {
+					Thread.sleep(1000 / Constants.framesPerSecond);
+				} catch( InterruptedException ex ) {
+				}
+				t = (double) (System.currentTimeMillis() - starttime) / (double) runtime;
+			} while( t < 1.0 );
+			stepper.accept(easing.applyAsDouble(1.0));
+		}, target);
+	}
+
+	public static final <T, R> Future<T> animate( T target, int runtime, Animator<T, R> animator ) {
+		return animate(
+			target, runtime,
+			animator::easing,
+			animator::interpolator,
+			animator::applicator
+		);
+	}
+
+	public static <T> Future<?> animate( Animation<T> animation ) {
+		animation.start();
+		return null;
+	}
+
+	public static <T> Future<?> animate( Animation<T> animation, DoubleUnaryOperator easing ) {
+		animation.start(easing);
+		return null;
+	}
+
+	public static final Log LOG = Log.getLogger(Animations.class);
+
+}

src/schule/ngb/zm/anim/Animator.java

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+package schule.ngb.zm.anim;
+
+public interface Animator<T, R> {
+
+	double easing(double t);
+
+	R interpolator(double e);
+
+	void applicator(T target, R value);
+
+}