Revert "Remove entity work from main extension branch for now"

This reverts commit fbaa6c1f5f.

api/geyser/src/main/java/org/geysermc/geyser/api/entity/EntityIdentifier.java

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2019-2022 GeyserMC. http://geysermc.org
+ *
+ * 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.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.api.entity;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.geysermc.geyser.api.GeyserApi;
+
+/**
+ * Represents the data sent over to a client regarding
+ * an entity's identifier.
+ */
+public interface EntityIdentifier {
+
+    /**
+     * Gets whether this entity has a spawn egg or not.
+     *
+     * @return whether this entity has a spawn egg or not
+     */
+    boolean hasSpawnEgg();
+
+    /**
+     * Gets the entity's identifier that is sent to the client.
+     *
+     * @return the entity's identifier that is sent to the client.
+     */
+    @NonNull
+    String identifier();
+
+    /**
+     * Gets whether the entity is summonable or not.
+     *
+     * @return whether the entity is summonable or not
+     */
+    boolean isSummonable();
+
+    @NonNull
+    static Builder builder() {
+        return GeyserApi.api().providerManager().builderProvider().provideBuilder(Builder.class);
+    }
+
+    interface Builder {
+
+        /**
+         * Sets whether the entity has a spawn egg or not.
+         *
+         * @param spawnEgg whether the entity has a spawn egg or not
+         * @return the builder
+         */
+        Builder spawnEgg(boolean spawnEgg);
+
+        /**
+         * Sets the entity's identifier that is sent to the client.
+         *
+         * @param identifier the entity's identifier that is sent to the client
+         * @return the builder
+         */
+        Builder identifier(String identifier);
+
+        /**
+         * Sets whether the entity is summonable or not.
+         *
+         * @param summonable whether the entity is summonable or not
+         * @return the builder
+         */
+        Builder summonable(boolean summonable);
+
+        /**
+         * Builds the entity identifier.
+         *
+         * @return the entity identifier
+         */
+        EntityIdentifier build();
+    }
+}

api/geyser/src/main/java/org/geysermc/geyser/api/event/entity/DefineEntitiesEvent.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2019-2022 GeyserMC. http://geysermc.org
+ *
+ * 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.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.api.event.entity;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.geysermc.geyser.api.connection.GeyserConnection;
+import org.geysermc.geyser.api.entity.EntityIdentifier;
+import org.geysermc.geyser.api.event.Event;
+
+import java.util.List;
+
+/**
+ * Called when Geyser sends a list of available entities to the
+ * Bedrock client. This will typically contain all the available
+ * entities within vanilla, but can be modified to include any custom
+ * entity defined through a resource pack.
+ *
+ * @param connection the {@link GeyserConnection} that is receiving the entities
+ * @param identifiers a mutable list of all the {@link EntityIdentifier}s
+ *                    sent to the client
+ */
+public record DefineEntitiesEvent(@NonNull GeyserConnection connection, @NonNull List<EntityIdentifier> identifiers) implements Event {
+}