Added some methods inside BlockHandler

src/main/java/net/minestom/server/instance/block/BlockHandler.java

@@ -1,4 +1,64 @@
 package net.minestom.server.instance.block;
 
+import net.minestom.server.entity.Player;
+import net.minestom.server.instance.Instance;
+import net.minestom.server.utils.BlockPosition;
+import net.minestom.server.utils.NamespaceID;
+import org.jetbrains.annotations.NotNull;
+
 public interface BlockHandler {
+
+    /**
+     * Called when a block has been placed.
+     *
+     * @param instance      the instance of the block
+     * @param block         the block
+     * @param blockPosition the position of the block
+     */
+    void onPlace(@NotNull Instance instance, @NotNull Block block, @NotNull BlockPosition blockPosition);
+
+    /**
+     * Called when a block has been destroyed or replaced.
+     *
+     * @param instance      the instance of the block
+     * @param block         the block
+     * @param blockPosition the position of the block
+     */
+    void onDestroy(@NotNull Instance instance, @NotNull Block block, @NotNull BlockPosition blockPosition);
+
+    /**
+     * Handles interactions with this block. Can also block normal item use (containers should block when opening the
+     * menu, this prevents the player from placing a block when opening it for instance).
+     *
+     * @param player        the player interacting
+     * @param hand          the hand used to interact
+     * @param block         the block
+     * @param blockPosition the position of this block
+     * @return true if this block blocks normal item use, false otherwise
+     */
+    boolean onInteract(@NotNull Player player, @NotNull Player.Hand hand,
+                       @NotNull Block block, @NotNull BlockPosition blockPosition);
+
+    /**
+     * Gets the drag of this block.
+     * <p>
+     * Has to be between 0 and 1.
+     *
+     * @param instance      the instance of the block
+     * @param block         the block
+     * @param blockPosition the block position
+     * @return the drag to apply
+     */
+    default float getDrag(@NotNull Instance instance, @NotNull Block block, @NotNull BlockPosition blockPosition) {
+        return 0.5f;
+    }
+
+    /**
+     * Gets the id of this handler.
+     * <p>
+     * Used to write the block entity in the anvil world format.
+     *
+     * @return the namespace id of this handler
+     */
+    @NotNull NamespaceID getNamespaceId();
 }