Add RegisterTagEvent

Author: aromaa

build.gradle.kts

@@ -146,6 +146,7 @@ tasks {
         exclude("org/spongepowered/api/event/lifecycle/RegisterBuilderEvent.java")
         exclude("org/spongepowered/api/event/lifecycle/RegisterRegistryEvent.java")
         exclude("org/spongepowered/api/event/lifecycle/RegisterRegistryValueEvent.java")
+        exclude("org/spongepowered/api/event/lifecycle/RegisterTagEvent.java")
         exclude("org/spongepowered/api/event/lifecycle/RegisterCommandEvent.java")
         exclude("org/spongepowered/api/event/lifecycle/RegisterFactoryEvent.java")
         exclude("org/spongepowered/api/event/lifecycle/RegisterWorldEvent.java")

src/main/java/org/spongepowered/api/event/lifecycle/RegisterTagEvent.java

@@ -0,0 +1,79 @@
+/*
+ * This file is part of SpongeAPI, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.api.event.lifecycle;
+
+import org.spongepowered.api.registry.DefaultedRegistryReference;
+import org.spongepowered.api.registry.RegistryKey;
+import org.spongepowered.api.tag.Tag;
+
+import java.util.function.BiPredicate;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+
+/**
+ * Lifecycle event for applying modifications to {@link Tag tags}.
+ *
+ * <p>This event provides mechanism for plugins to <strong>propose</strong>
+ * changes to the tags that are processed during tag construction.</p>
+ *
+ * <p>The following chain of events take place during tag construction:</p>
+ * <ul>
+ *     <li>Tags are merged from data packs</li>
+ *     <li>Append proposed tags</li>
+ *     <li>Apply filter to ALL present tags</li>
+ *     <li>Remaining items makes up the final tag</li>
+ * </ul>
+ */
+public interface RegisterTagEvent extends LifecycleEvent {
+
+    <T> TagStep<T> tag(Tag<T> tag);
+
+    interface TagStep<T> {
+
+        default TagStep<T> delete() {
+            return this.filter($ -> false);
+        }
+
+        TagStep<T> filter(Predicate<DefaultedRegistryReference<T>> predicate);
+
+        default TagStep<T> filterTags(Predicate<Tag<T>> predicate) {
+            return this.filterTags((t, k) -> predicate.test(t));
+        }
+
+        TagStep<T> filterTags(BiPredicate<Tag<T>, DefaultedRegistryReference<T>> predicate);
+
+        TagStep<T> append(RegistryKey<T> key);
+
+        TagStep<T> append(Tag<T> tag);
+
+        TagStep<T> test(Predicate<DefaultedRegistryReference<T>> predicate, Consumer<TagStep<T>> consumer);
+
+        default TagStep<T> testTags(Predicate<Tag<T>> predicate, Consumer<TagStep<T>> consumer) {
+            return this.testTags((t, k) -> predicate.test(t), consumer);
+        }
+
+        TagStep<T> testTags(BiPredicate<Tag<T>, DefaultedRegistryReference<T>> predicate, Consumer<TagStep<T>> consumer);
+    }
+}