SPIGOT-1532: Add PlayerSwapHandItemsEvent

By: MinusKube <MinusKube@bitbucket.org>

paper-api/src/main/java/org/bukkit/event/player/PlayerSwapHandItemsEvent.java

@@ -0,0 +1,81 @@
+package org.bukkit.event.player;
+
+import org.bukkit.entity.Player;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
+import org.bukkit.inventory.ItemStack;
+
+/**
+ * Called when a player swap items between main hand and off hand using the
+ * hotkey.
+ */
+public class PlayerSwapHandItemsEvent extends PlayerEvent implements Cancellable {
+
+    private static final HandlerList handlers = new HandlerList();
+    //
+    private ItemStack mainHandItem;
+    private ItemStack offHandItem;
+    private boolean cancelled;
+
+    public PlayerSwapHandItemsEvent(Player player, ItemStack mainHandItem, ItemStack offHandItem) {
+        super(player);
+
+        this.mainHandItem = mainHandItem;
+        this.offHandItem = offHandItem;
+    }
+
+    /**
+     * Gets the item switched to the main hand.
+     *
+     * @return item in the main hand
+     */
+    public ItemStack getMainHandItem() {
+        return mainHandItem;
+    }
+
+    /**
+     * Sets the item in the main hand.
+     *
+     * @param mainHandItem new item in the main hand
+     */
+    public void setMainHandItem(ItemStack mainHandItem) {
+        this.mainHandItem = mainHandItem;
+    }
+
+    /**
+     * Gets the item switched to the off hand.
+     *
+     * @return item in the off hand
+     */
+    public ItemStack getOffHandItem() {
+        return offHandItem;
+    }
+
+    /**
+     * Sets the item in the off hand.
+     *
+     * @param offHandItem new item in the off hand
+     */
+    public void setOffHandItem(ItemStack offHandItem) {
+        this.offHandItem = offHandItem;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.cancelled = cancel;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+}