api: Audience.filter

KyoriPowered · May 13, 2021 · 20e1612 · 20e1612
1 parent 9ba3b62
commit 20e1612
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Showing 4 changed files with 87 additions and 6 deletions.
diff --git a/api/src/main/java/net/kyori/adventure/audience/Audience.java b/api/src/main/java/net/kyori/adventure/audience/Audience.java
@@ -25,16 +25,17 @@
 
 import java.util.Arrays;
 import java.util.function.Consumer;
+import java.util.function.Predicate;
 import java.util.stream.Collector;
 import net.kyori.adventure.bossbar.BossBar;
-import net.kyori.adventure.identity.Identified;
 import net.kyori.adventure.identity.Identity;
 import net.kyori.adventure.inventory.Book;
 import net.kyori.adventure.sound.Sound;
 import net.kyori.adventure.sound.SoundStop;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.ComponentLike;
 import net.kyori.adventure.title.Title;
+import net.kyori.adventure.identity.Identified;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
@@ -134,6 +135,21 @@ public interface Audience {
     return Audiences.COLLECTOR;
   }
 
+  /**
+   * Filters this audience.
+   *
+   * <p>The returned {@code Audience} may be the same, or a completely different one.</p>
+   *
+   * @param filter the filter
+   * @since 4.8.0
+   */
+  default @NonNull Audience filterAudience(final @NonNull Predicate<? super Audience> filter) {
+    if(filter.test(this)) {
+      return this;
+    }
+    return empty();
+  }
+
   /**
    * Executes an action against all audiences.
    *
@@ -143,7 +159,7 @@ public interface Audience {
    * @param action the action
    * @since 4.8.0
    */
-  default void foreach(final @NonNull Consumer<? super Audience> action) {
+  default void forEachAudience(final @NonNull Consumer<? super Audience> action) {
     action.accept(this);
   }
 

diff --git a/api/src/main/java/net/kyori/adventure/audience/EmptyAudience.java b/api/src/main/java/net/kyori/adventure/audience/EmptyAudience.java
@@ -23,6 +23,7 @@
  */
 package net.kyori.adventure.audience;
 
+import java.util.function.Consumer;
 import net.kyori.adventure.identity.Identity;
 import net.kyori.adventure.inventory.Book;
 import net.kyori.adventure.text.ComponentLike;
@@ -32,6 +33,10 @@
 final class EmptyAudience implements Audience {
   static final EmptyAudience INSTANCE = new EmptyAudience();
 
+  @Override
+  public void forEachAudience(final @NonNull Consumer<? super Audience> action) {
+  }
+
   @Override
   public void sendMessage(final @NonNull ComponentLike message) {
   }

diff --git a/api/src/main/java/net/kyori/adventure/audience/ForwardingAudience.java b/api/src/main/java/net/kyori/adventure/audience/ForwardingAudience.java
@@ -23,8 +23,11 @@
  */
 package net.kyori.adventure.audience;
 
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 import java.util.function.Consumer;
+import java.util.function.Predicate;
 import net.kyori.adventure.bossbar.BossBar;
 import net.kyori.adventure.identity.Identified;
 import net.kyori.adventure.identity.Identity;
@@ -34,6 +37,7 @@
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.title.Title;
 import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.jetbrains.annotations.ApiStatus;
 
 /**
@@ -57,8 +61,27 @@ public interface ForwardingAudience extends Audience {
   @NonNull Iterable<? extends Audience> audiences();
 
   @Override
-  default void foreach(final @NonNull Consumer<? super Audience> action) {
-    for(final Audience audience : this.audiences()) audience.foreach(action);
+  default @NonNull Audience filterAudience(final @NonNull Predicate<? super Audience> filter) {
+    @Nullable List<Audience> audiences = null;
+    for(final Audience audience : this.audiences()) {
+      if(filter.test(audience)) { // todo(kashike): should we test before filtering children?
+        final Audience filtered = audience.filterAudience(filter);
+        if(filtered != Audience.empty()) {
+          if(audiences == null) {
+            audiences = new ArrayList<>();
+          }
+          audiences.add(filtered);
+        }
+      }
+    }
+    return audiences != null
+      ? Audience.audience(audiences)
+      : Audience.empty();
+  }
+
+  @Override
+  default void forEachAudience(final @NonNull Consumer<? super Audience> action) {
+    for(final Audience audience : this.audiences()) audience.forEachAudience(action);
   }
 
   @Override
@@ -164,8 +187,16 @@ interface Single extends ForwardingAudience {
     }
 
     @Override
-    default void foreach(final @NonNull Consumer<? super Audience> action) {
-      this.audience().foreach(action);
+    default @NonNull Audience filterAudience(final @NonNull Predicate<? super Audience> filter) {
+      final Audience audience = this.audience();
+      return filter.test(audience) // todo(kashike): should we be testing "audience" or "this"
+        ? this
+        : Audience.empty();
+    }
+
+    @Override
+    default void forEachAudience(final @NonNull Consumer<? super Audience> action) {
+      this.audience().forEachAudience(action);
     }
 
     @Override

diff --git a/api/src/test/java/net/kyori/adventure/audience/AudienceTest.java b/api/src/test/java/net/kyori/adventure/audience/AudienceTest.java
@@ -24,10 +24,12 @@
 package net.kyori.adventure.audience;
 
 import com.google.common.testing.EqualsTester;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
 
 import static com.google.common.truth.Truth.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -52,6 +54,33 @@ void testOf_many() {
     assertThat(((ForwardingAudience) ma).audiences()).containsExactly(a0, a1).inOrder();
   }
 
+  @Test
+  void testForEachAudienceEmpty() {
+    final AtomicInteger touched = new AtomicInteger(0);
+    Audience.empty().forEachAudience(audience -> touched.incrementAndGet());
+    assertEquals(0, touched.get());
+  }
+
+  @Test
+  void testForEachAudienceForwarded() {
+    final AtomicInteger touched = new AtomicInteger(0);
+    Audience.audience(
+      new Audience() {
+      }
+    ).forEachAudience(audience -> touched.incrementAndGet());
+    assertEquals(1, touched.get());
+  }
+
+  @Test
+  void testForEachAudienceForwardedOfEmpty() {
+    final AtomicInteger touched = new AtomicInteger(0);
+    Audience.audience(
+      Audience.empty(),
+      Audience.empty()
+    ).forEachAudience(audience -> touched.incrementAndGet());
+    assertEquals(0, touched.get());
+  }
+
   @Test
   void testEquality() {
     new EqualsTester()