Merge pull request #1346 from PaperMC/feature/book-like

feature(api): Add BookLike interface

Author: kezz

api/src/main/java/net/kyori/adventure/audience/Audience.java

@@ -38,6 +38,7 @@
 import net.kyori.adventure.chat.SignedMessage;
 import net.kyori.adventure.dialog.DialogLike;
 import net.kyori.adventure.inventory.Book;
+import net.kyori.adventure.inventory.BookLike;
 import net.kyori.adventure.pointer.Pointered;
 import net.kyori.adventure.resource.ResourcePackInfo;
 import net.kyori.adventure.resource.ResourcePackInfoLike;
@@ -514,7 +515,21 @@ default void stopSound(final SoundStop stop) {
    */
   @ForwardingAudienceOverrideNotRequired
   default void openBook(final Book.Builder book) {
-    this.openBook(book.build());
+    this.openBook(Objects.requireNonNull(book, "book").build());
+  }
+
+  /**
+   * Opens a book.
+   *
+   * <p>When possible, no item should persist after closing the book.</p>
+   *
+   * @param book a book
+   * @see Book
+   * @since 5.0.0
+   */
+  @ForwardingAudienceOverrideNotRequired
+  default void openBook(final BookLike book) {
+    this.openBook(Objects.requireNonNull(book, "book").asBook());
   }
 
   /**

api/src/main/java/net/kyori/adventure/inventory/Book.java

@@ -43,7 +43,7 @@
  * @see Audience#openBook(Book)
  * @since 4.0.0
  */
-public sealed interface Book extends Buildable<Book.Builder> permits BookImpl {
+public sealed interface Book extends Buildable<Book.Builder>, BookLike permits BookImpl {
   /**
    * Creates a book.
    *

api/src/main/java/net/kyori/adventure/inventory/BookImpl.java

@@ -76,6 +76,11 @@ public Builder toBuilder() {
       .pages(this.pages);
   }
 
+  @Override
+  public Book asBook() {
+    return this;
+  }
+
   static final class BuilderImpl implements Builder {
     private Component title = Component.empty();
     private Component author = Component.empty();

api/src/main/java/net/kyori/adventure/inventory/BookLike.java

@@ -0,0 +1,43 @@
+/*
+ * This file is part of adventure, licensed under the MIT License.
+ *
+ * Copyright (c) 2017-2025 KyoriPowered
+ *
+ * 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 net.kyori.adventure.inventory;
+
+import org.jetbrains.annotations.Contract;
+
+/**
+ * Something that can be represented as a {@link Book}.
+ *
+ * @since 5.0.0
+ */
+@FunctionalInterface
+public interface BookLike {
+  /**
+   * Gets a {@link Book} representation of this object.
+   *
+   * @return a book
+   * @since 5.0.0
+   */
+  @Contract(pure = true)
+  Book asBook();
+}