Update API for better item selection handling

api/src/main/java/de/epiceric/shopchest/api/event/ShopPreCreateEvent.java

@@ -1,11 +1,10 @@
 package de.epiceric.shopchest.api.event;
 
-import de.epiceric.shopchest.api.shop.ShopProduct;
-
 import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
+import org.bukkit.inventory.ItemStack;
 
 /**
  * Called when a player enters the command to create a shop
@@ -20,15 +19,17 @@ public class ShopPreCreateEvent extends Event implements Cancellable {
     private static final HandlerList handlers = new HandlerList();
 
     private Player player;
-    private ShopProduct product;
+    private ItemStack itemStack;
+    private int amount;
     private double buyPrice;
     private double sellPrice;
     private boolean admin;
     private boolean cancelled;
 
-    public ShopPreCreateEvent(Player player, ShopProduct product, double buyPrice, double sellPrice, boolean admin) {
+    public ShopPreCreateEvent(Player player, ItemStack itemStack, int amount, double buyPrice, double sellPrice, boolean admin) {
         this.player = player;
-        this.product = product;
+        this.itemStack = itemStack;
+        this.amount = amount;
         this.buyPrice = buyPrice;
         this.sellPrice = sellPrice;
         this.admin = admin;
@@ -45,13 +46,23 @@ public class ShopPreCreateEvent extends Event implements Cancellable {
     }
 
     /**
-     * Gets the product the shop will sell or buy
+     * Gets the item stack the shop will sell or buy
      * 
-     * @return the product
+     * @return the product or {@code null} if it has not been selected
      * @since 1.13
      */
-    public ShopProduct getProduct() {
+    public ItemStack getItemStack() {
-        return product;
+        return itemStack == null ? null : itemStack.clone();
+    }
+
+    /**
+     * Gets the amount of items the shop will sell or buy
+     * 
+     * @return the amount
+     * @since 1.13
+     */
+    public int getAmount() {
+        return amount;
     }
 
     /**
@@ -60,8 +71,8 @@ public class ShopPreCreateEvent extends Event implements Cancellable {
      * @return whether the item has been selected
      * @since 1.13
      */
-    public boolean hasProduct() {
+    public boolean isItemSelected() {
-        return getProduct() != null;
+        return getItemStack() != null;
     }
 
     /**

api/src/main/java/de/epiceric/shopchest/api/event/ShopSelectItemEvent.java

@@ -4,8 +4,7 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
-
+import org.bukkit.inventory.ItemStack;
-import de.epiceric.shopchest.api.shop.ShopProduct;
 
 /**
  * Called when a player has selected an item
@@ -16,14 +15,20 @@ public class ShopSelectItemEvent extends Event implements Cancellable {
     private static final HandlerList handlers = new HandlerList();
 
     private Player player;
-    private ShopProduct product;
+    private ItemStack item;
+    private int amount;
     private double buyPrice;
     private double sellPrice;
     private boolean admin;
     private boolean cancelled;
 
-    public ShopSelectItemEvent(Player player) {
+    public ShopSelectItemEvent(Player player, ItemStack item, int amount, double buyPrice, double sellPrice, boolean admin) {
         this.player = player;
+        this.item = item == null ? null : item.clone();
+        this.amount = amount;
+        this.buyPrice = buyPrice;
+        this.sellPrice = sellPrice;
+        this.admin = admin;
     }
 
     /**
@@ -42,18 +47,35 @@ public class ShopSelectItemEvent extends Event implements Cancellable {
      * @return the item
      * @since 1.13
      */
-    public ShopProduct getProduct() {
+    public ItemStack getItem() {
-        return product;
+        return item;
     }
 
     /**
      * Sets the item
+     * <p>
+     * If {@code item} is {@code null}, the event will be cancelled.
      * 
-     * @param product the item
+     * @param item the item
      * @since 1.13
      */
-    public void setProduct(ShopProduct product) {
+    public void setItem(ItemStack item) {
-        this.product = product;
+        if (item == null) {
+            setCancelled(true);
+            this.item = null;
+        } else {
+            this.item = item.clone();
+        }
+    }
+
+    /**
+     * Gets the amount of items the player wants to sell or buy at the shop
+     * 
+     * @return the amount
+     * @since 1.13
+     */
+    public int getAmount() {
+        return amount;
     }
 
     /**

api/src/main/java/de/epiceric/shopchest/api/flag/SelectFlag.java

@@ -8,12 +8,56 @@ import de.epiceric.shopchest.api.player.ShopPlayer;
  * Represents the flag a player has after entering the create command
  */
 public class SelectFlag implements Flag {
+    private int amount;
+    private double buyPrice;
+    private double sellPrice;
+    private boolean admin;
     private GameMode gameMode;
 
-    public SelectFlag(GameMode gameMode) {
+    public SelectFlag(int amount, double buyPrice, double sellPrice, boolean admin, GameMode gameMode) {
+        this.amount = amount;
+        this.buyPrice = buyPrice;
+        this.sellPrice = sellPrice;
+        this.admin = admin;
         this.gameMode = gameMode;
     }
 
+    /**
+     * Gets the amount of items the player wants their shop to sell or buy
+     * 
+     * @return the amount
+     */
+    public int getAmount() {
+        return amount;
+    }
+
+    /**
+     * Gets the price the player wants others to buy the product for
+     * 
+     * @return the buy price
+     */
+    public double getBuyPrice() {
+        return buyPrice;
+    }
+
+    /**
+     * Gets whether the player wants to create an admin shop
+     * 
+     * @return whether the players wants to create an admin shop
+     */
+    public boolean isAdminShop() {
+        return admin;
+    }
+
+    /**
+     * Gets the price the player wants others to sell the product for
+     * 
+     * @return the sell price
+     */
+    public double getSellPrice() {
+        return sellPrice;
+    }
+
     /**
      * Gets the game mode the player had before entering the command
      * <p>