Add PlayerPickItemEvent

paper-api/src/main/java/io/papermc/paper/event/player/PlayerPickItemEvent.java

@@ -0,0 +1,95 @@
+package io.papermc.paper.event.player;
+
+import com.google.common.base.Preconditions;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.player.PlayerEvent;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Range;
+import org.jspecify.annotations.NullMarked;
+
+/**
+ * Event that is fired when a player uses the pick item functionality (middle-clicking a block or entity to get the
+ * appropriate item). After the handling of this event, the contents of the source and the target slot will be swapped
+ * and the currently selected hotbar slot of the player will be set to the target slot.
+ */
+@NullMarked
+public class PlayerPickItemEvent extends PlayerEvent implements Cancellable {
+
+    private static final HandlerList HANDLER_LIST = new HandlerList();
+
+    private int targetSlot;
+    private int sourceSlot;
+
+    private boolean cancelled;
+
+    @ApiStatus.Internal
+    public PlayerPickItemEvent(final Player player, final int targetSlot, final int sourceSlot) {
+        super(player);
+        this.targetSlot = targetSlot;
+        this.sourceSlot = sourceSlot;
+    }
+
+    /**
+     * Returns the slot the item that is being picked goes into.
+     *
+     * @return hotbar slot (0-8 inclusive)
+     */
+    public @Range(from = 0, to = 8) int getTargetSlot() {
+        return this.targetSlot;
+    }
+
+    /**
+     * Changes the slot the item that is being picked goes into.
+     *
+     * @param targetSlot hotbar slot (0-8 inclusive)
+     */
+    public void setTargetSlot(final @Range(from = 0, to = 8) int targetSlot) {
+        Preconditions.checkArgument(targetSlot >= 0 && targetSlot <= 8, "Target slot must be in range 0 - 8 (inclusive)");
+        this.targetSlot = targetSlot;
+    }
+
+    /**
+     * Returns the slot in which the item that will be put into the players hotbar is located.
+     * <p>
+     * Returns {@code -1} if the item is not in the player's inventory.
+     * If this is the case and the player is in creative mode, the item will be spawned in.
+     *
+     * @return player inventory slot (0-35 inclusive, or {@code -1} if not in the player inventory)
+     */
+    public @Range(from = -1, to = 35) int getSourceSlot() {
+        return this.sourceSlot;
+    }
+
+    /**
+     * Change the source slot from which the item that will be put in the players hotbar will be taken.
+     * <p>
+     * If set to {@code -1} and the player is in creative mode, the item will be spawned in.
+     *
+     * @param sourceSlot player inventory slot (0-35 inclusive, or {@code -1} if not in the player inventory)
+     */
+    public void setSourceSlot(final @Range(from = -1, to = 35) int sourceSlot) {
+        Preconditions.checkArgument(sourceSlot >= -1 && sourceSlot <= 35, "Source slot must be in range of the player's inventory slot, or -1");
+        this.sourceSlot = sourceSlot;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return this.cancelled;
+    }
+
+    @Override
+    public void setCancelled(final boolean cancel) {
+        this.cancelled = cancel;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return HANDLER_LIST;
+    }
+
+    public static HandlerList getHandlerList() {
+        return HANDLER_LIST;
+    }
+}