Merge pull request #36 from Etrayed/fix/redundant-interfaces

Interface Changes

core/src/main/java/de/pxav/kelp/core/inventory/listener/ClickListener.java

@@ -7,6 +7,7 @@
  *
  * @author pxav
  */
+@FunctionalInterface
 public interface ClickListener {
 
   /**

core/src/main/java/de/pxav/kelp/core/inventory/widget/ToggleableWidget.java

@@ -4,6 +4,8 @@
 import de.pxav.kelp.core.inventory.item.KelpItem;
 import de.pxav.kelp.core.player.KelpPlayer;
 
+import java.util.function.Supplier;
+
 /**
  * This widget is used to handle button interactions
  * toggling a certain setting.
@@ -29,7 +31,7 @@ public class ToggleableWidget implements SimpleWidget {
   private KelpPlayer player;
 
   // the condition to be checked every time the widget updates
-  private Condition condition;
+  private Supplier<Boolean> condition;
 
   // The slot of the inventory, where the widget should finally be located.
   private int slot;
@@ -64,7 +66,7 @@ public ToggleableWidget slot(int slot) {
    * @param condition The condition to be fulfilled.
    * @return Current instance of the widget.
    */
-  public ToggleableWidget condition(Condition condition) {
+  public ToggleableWidget condition(Supplier<Boolean> condition) {
     this.condition = condition;
     return this;
   }
@@ -178,7 +180,7 @@ public KelpPlayer getPlayer() {
    */
   @Override
   public KelpItem render() {
-    if (condition.getCondition()) {
+    if (condition.get()) {
       return this.whenTrue.slot(slot);
     } else {
       return this.whenFalse.slot(slot);

core/src/main/java/de/pxav/kelp/core/reflect/MethodCriterion.java

@@ -2,6 +2,7 @@
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
+import java.util.function.Predicate;
 
 /**
  * This class contains all criteria you can use for searching/filtering
@@ -10,9 +11,8 @@
  * @see MethodFinder
  * @author pxav
  */
-public interface MethodCriterion {
-
-  boolean matches(Method method);
+@FunctionalInterface
+public interface MethodCriterion extends Predicate<Method> {
 
   static MethodCriterion annotatedWith(Class<? extends Annotation> annotation) {
     return method -> method.isAnnotationPresent(annotation);
@@ -36,4 +36,7 @@ static MethodCriterion locatedIn(String packageName) {
             .equals(packageName);
   }
 
+  static MethodCriterion fromPredicate(Predicate<Method> predicate) {
+    return predicate::test;
+  }
 }

core/src/main/java/de/pxav/kelp/core/reflect/MethodFinder.java

@@ -57,7 +57,7 @@ public Stream<Method> filter(String[] packageNames, MethodCriterion... methodCri
 
           boolean allMatch = true;
           for (MethodCriterion methodCriterion : methodCriteria) {
-            if (!methodCriterion.matches(method)) {
+            if (!methodCriterion.test(method)) {
               allMatch = false;
               break;
             }

core/src/main/java/de/pxav/kelp/core/reflect/TypeCriterion.java

@@ -1,6 +1,7 @@
 package de.pxav.kelp.core.reflect;
 
 import java.lang.annotation.Annotation;
+import java.util.function.Predicate;
 
 /**
  * This class contains all criteria you can use for searching/filtering
@@ -9,16 +10,8 @@
  * @see TypeFinder
  * @author pxav
  */
-public interface TypeCriterion {
-
-  /**
-   * Returns {@code true} if the given criteria are fulfilled
-   * by the given class.
-   *
-   * @param c The class you want to check
-   * @return  {@code true} if the criteria matches the class
-   */
-  boolean matches(Class<?> c);
+@FunctionalInterface
+public interface TypeCriterion extends Predicate<Class<?>> {
 
   /**
    * Checks if the class is annotated with a certain
@@ -56,4 +49,7 @@ static TypeCriterion locatedIn(String packageName) {
     return c -> c.getPackage().getName().equals(packageName);
   }
 
+  static TypeCriterion fromPredicate(Predicate<Class<?>> predicate) {
+    return predicate::test;
+  }
 }

core/src/main/java/de/pxav/kelp/core/reflect/TypeFinder.java

@@ -48,7 +48,7 @@ public Stream<Class<?>> filter(String[] packageNames, TypeCriterion... typeCrite
         Class<?> c = current.loadClass();
         boolean allMatch = true;
         for (TypeCriterion typeCriterion : typeCriteria) {
-          if (!typeCriterion.matches(c)) {
+          if (!typeCriterion.test(c)) {
             allMatch = false;
             break;
           }

core/src/main/java/de/pxav/kelp/core/scheduler/KelpSchedulerRunnable.java

@@ -14,6 +14,7 @@
  *
  * @author pxav
  */
+@FunctionalInterface
 public interface KelpSchedulerRunnable {
 
   /**

core/src/main/java/de/pxav/kelp/core/scheduler/synchronize/Retrievable.java

@@ -11,6 +11,7 @@
  *
  * @author pxav
  */
+@FunctionalInterface
 public interface Retrievable {
 
   /**