Added Retriever injection

cardshifter-core/src/main/java/net/zomis/cardshifter/ecs/base/Retriever.java

@@ -0,0 +1,11 @@
+package net.zomis.cardshifter.ecs.base;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(value = RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface Retriever {
+}

cardshifter-core/src/main/java/net/zomis/cardshifter/ecs/base/RetrieverSingleton.java

@@ -0,0 +1,11 @@
+package net.zomis.cardshifter.ecs.base;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(value = RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface RetrieverSingleton {
+}

cardshifter-core/src/main/java/net/zomis/cardshifter/ecs/base/Retrievers.java

@@ -0,0 +1,75 @@
+package net.zomis.cardshifter.ecs.base;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.Arrays;
+import java.util.Set;
+
+public class Retrievers {
+
+	public static <T extends Component> ComponentRetriever<T> component(Class<T> clazz) {
+		return new ComponentRetriever<>(clazz);
+	}
+
+	public static <T extends Component> ComponentRetriever<T> singleton(Class<T> class1) {
+		return new ComponentRetriever<T>(null) {
+
+			@Override
+			public boolean has(Entity entity) {
+				return get(entity) != null;
+			}
+
+			@Override
+			public T get(Entity entity) {
+				return singleton(entity.getGame(), class1);
+			}
+
+		};
+	}
+
+	public static <T extends Component> T singleton(ECSGame game, Class<T> class1) {
+		Set<Entity> all = game.getEntitiesWithComponent(class1);
+		if (all.size() != 1) {
+			throw new IllegalStateException("Expected to find exactly one " + class1.getSimpleName() + ", found " + all.size());
+		}
+		return all.iterator().next().getComponent(class1);
+	}
+
+	public static void inject(Object object, ECSGame game) {
+		Field[] fields = object.getClass().getDeclaredFields();
+		Arrays.stream(fields).filter(field -> field.getAnnotation(Retriever.class) != null).forEach(field -> injectField(object, field, game));
+		Arrays.stream(fields).filter(field -> field.getAnnotation(RetrieverSingleton.class) != null).forEach(field -> injectSingleton(object, field, game));
+	}
+
+	private static void injectSingleton(Object obj, Field field, ECSGame game) {
+		Class<? extends Component> clazz = field.getType().asSubclass(Component.class);
+		field.setAccessible(true);
+		try {
+			field.set(obj, Retrievers.singleton(game, clazz));
+		} catch (IllegalArgumentException | IllegalAccessException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	private static void injectField(Object obj, Field field, ECSGame game) {
+		if (field.getType() != ComponentRetriever.class) {
+			throw new RuntimeException(field.getType() + " is not a ComponentRetriever");
+		}
+
+		Type genericFieldType = field.getGenericType();
+
+		if(genericFieldType instanceof ParameterizedType){
+			ParameterizedType aType = (ParameterizedType) genericFieldType;
+			Type[] fieldArgTypes = aType.getActualTypeArguments();
+			Class<?> fieldArgClass = (Class<?>) fieldArgTypes[0];
+			try {
+				field.setAccessible(true);
+				field.set(obj, Retrievers.component(fieldArgClass.asSubclass(Component.class)));
+			} catch (IllegalAccessException e) {
+				throw new RuntimeException(e);
+			}
+		}
+	}
+
+}

cardshifter-core/src/test/java/net/zomis/cardshifter/ecs/InjectionTest.java

@@ -0,0 +1,39 @@
+package net.zomis.cardshifter.ecs;
+
+import static org.junit.Assert.*;
+import net.zomis.cardshifter.ecs.base.ComponentRetriever;
+import net.zomis.cardshifter.ecs.base.ECSGame;
+import net.zomis.cardshifter.ecs.base.Entity;
+import net.zomis.cardshifter.ecs.base.Retriever;
+import net.zomis.cardshifter.ecs.base.RetrieverSingleton;
+import net.zomis.cardshifter.ecs.base.Retrievers;
+import net.zomis.cardshifter.ecs.components.PlayerComponent;
+import net.zomis.cardshifter.ecs.phase.Phase;
+import net.zomis.cardshifter.ecs.phase.PhaseController;
+
+import org.junit.Test;
+
+public class InjectionTest {
+
+	@RetrieverSingleton
+	private PhaseController phases;
+
+	@Retriever
+	private ComponentRetriever<PlayerComponent> playerData;
+
+	@Test
+	public void inject() {
+		ECSGame game = new ECSGame();
+		PhaseController phase = new PhaseController();
+		phase.addPhase(new Phase(null, "Main"));
+		game.newEntity().addComponent(phase);
+		Entity player = game.newEntity().addComponent(new PlayerComponent(42, "Tester"));
+
+		Retrievers.inject(this, game);
+
+		assertEquals(42, playerData.get(player).getIndex());
+		assertEquals(phase, phases);
+		assertEquals("Main", phases.getCurrentPhase().getName());
+	}
+
+}