Create new class GuiUtils that contains methods, that is frequently used and can be static.

src/main/java/world/bentobox/challenges/panel/CommonGUI.java

@@ -8,7 +8,6 @@ import java.util.Collections;
 import java.util.List;
 
 import world.bentobox.bentobox.api.panels.PanelItem;
-import world.bentobox.bentobox.api.panels.builders.PanelBuilder;
 import world.bentobox.bentobox.api.panels.builders.PanelItemBuilder;
 import world.bentobox.bentobox.api.user.User;
 import world.bentobox.challenges.ChallengesAddon;
@@ -234,65 +233,6 @@ public abstract class CommonGUI
 	}
 
 
-	/**
-	 * This method creates border of black panes around given panel with 5 rows.
-	 * @param panelBuilder PanelBuilder which must be filled with border blocks.
-	 */
-	protected void fillBorder(PanelBuilder panelBuilder)
-	{
-		this.fillBorder(panelBuilder, 5, Material.BLACK_STAINED_GLASS_PANE);
-	}
-
-
-	/**
-	 * This method sets black stained glass pane around Panel with given row count.
-	 * @param panelBuilder object that builds Panel.
-	 * @param rowCount in Panel.
-	 */
-	protected void fillBorder(PanelBuilder panelBuilder, int rowCount)
-	{
-		this.fillBorder(panelBuilder, rowCount, Material.BLACK_STAINED_GLASS_PANE);
-	}
-
-
-	/**
-	 * This method sets blocks with given Material around Panel with 5 rows.
-	 * @param panelBuilder object that builds Panel.
-	 * @param material that will be around Panel.
-	 */
-	protected void fillBorder(PanelBuilder panelBuilder, Material material)
-	{
-		this.fillBorder(panelBuilder, 5, material);
-	}
-
-
-	/**
-	 * This method sets blocks with given Material around Panel with given row count.
-	 * @param panelBuilder object that builds Panel.
-	 * @param rowCount in Panel.
-	 * @param material that will be around Panel.
-	 */
-	protected void fillBorder(PanelBuilder panelBuilder, int rowCount, Material material)
-	{
-		// Only for useful filling.
-		if (rowCount < 3)
-		{
-			return;
-		}
-
-		for (int i = 0; i < 9 * rowCount; i++)
-		{
-			// First (i < 9) and last (i > 35) rows must be filled
-			// First column (i % 9 == 0) and last column (i % 9 == 8) also must be filled.
-
-			if (i < 9 || i > 9 * (rowCount - 1) || i % 9 == 0 || i % 9 == 8)
-			{
-				panelBuilder.item(i, new PanelItemBuilder().name("&2").icon(material).build());
-			}
-		}
-	}
-
-
 	/**
 	 * This method sets new value to ValueObject variable.
 	 * @param value new Value of valueObject.

src/main/java/world/bentobox/challenges/panel/admin/ManageEntitiesGUI.java

@@ -16,7 +16,7 @@ import world.bentobox.challenges.ChallengesAddon;
 import world.bentobox.challenges.panel.CommonGUI;
 import world.bentobox.challenges.panel.util.NumberGUI;
 import world.bentobox.challenges.panel.util.SelectEntityGUI;
-import world.bentobox.challenges.utils.HeadLib;
+import world.bentobox.challenges.utils.GuiUtils;
 
 
 /**
@@ -57,7 +57,7 @@ public class ManageEntitiesGUI extends CommonGUI
 			name(this.user.getTranslation("challenges.gui.admin.edit-entities"));
 
 		// create border
-		this.fillBorder(panelBuilder);
+		GuiUtils.fillBorder(panelBuilder);
 
 		panelBuilder.item(3, this.createButton(Button.ADD));
 		panelBuilder.item(5, this.createButton(Button.REMOVE));
@@ -158,7 +158,9 @@ public class ManageEntitiesGUI extends CommonGUI
 	{
 		return new PanelItemBuilder().
 			name(WordUtils.capitalize(entity.name().toLowerCase().replace("_", " "))).
-			icon(this.asEggs ? this.getEntityEgg(entity) : this.getEntityHead(entity)).
+			icon(this.asEggs ?
+				GuiUtils.getEntityEgg(entity, this.requiredEntities.get(entity)) :
+				GuiUtils.getEntityHead(entity, this.requiredEntities.get(entity))).
 			clickHandler((panel, user1, clickType, slot) -> {
 				// On right click change which entities are selected for deletion.
 				if (clickType.isRightClick())
@@ -190,115 +192,6 @@ public class ManageEntitiesGUI extends CommonGUI
 	}
 
 
-	/**
-	 * This method transforms entity into egg or block that corresponds given entity. If entity egg is not
-	 * found, then it is replaced by block that represents entity or barrier block.
-	 * @param entity Entity which egg must be returned.
-	 * @return ItemStack that may be egg for given entity.
-	 */
-	private ItemStack getEntityEgg(EntityType entity)
-	{
-		ItemStack itemStack;
-
-		switch (entity)
-		{
-			case PIG_ZOMBIE:
-				itemStack = new ItemStack(Material.ZOMBIE_PIGMAN_SPAWN_EGG);
-				break;
-			case ENDER_DRAGON:
-				itemStack = new ItemStack(Material.DRAGON_EGG);
-				break;
-			case WITHER:
-				itemStack = new ItemStack(Material.SOUL_SAND);
-				break;
-			case PLAYER:
-				itemStack = new ItemStack(Material.PLAYER_HEAD);
-				break;
-			case MUSHROOM_COW:
-				itemStack = new ItemStack(Material.MOOSHROOM_SPAWN_EGG);
-				break;
-			case SNOWMAN:
-				itemStack = new ItemStack(Material.CARVED_PUMPKIN);
-				break;
-			case IRON_GOLEM:
-				itemStack = new ItemStack(Material.IRON_BLOCK);
-				break;
-			case ARMOR_STAND:
-				itemStack = new ItemStack(Material.ARMOR_STAND);
-				break;
-			default:
-				Material material = Material.getMaterial(entity.name() + "_SPAWN_EGG");
-
-				if (material == null)
-				{
-					itemStack = new ItemStack(Material.BARRIER);
-				}
-				else
-				{
-					itemStack = new ItemStack(material);
-				}
-
-				break;
-		}
-
-		itemStack.setAmount(this.requiredEntities.get(entity));
-
-		return itemStack;
-	}
-
-
-	/**
-	 * This method transforms entity into player head with skin that corresponds given entity. If entity head
-	 * is not found, then it is replaced by barrier block.
-	 * @param entity Entity which head must be returned.
-	 * @return ItemStack that may be head for given entity.
-	 */
-	private ItemStack getEntityHead(EntityType entity)
-	{
-		ItemStack itemStack;
-
-		switch (entity)
-		{
-			case PLAYER:
-				itemStack = new ItemStack(Material.PLAYER_HEAD);
-				break;
-			case WITHER_SKELETON:
-				itemStack = new ItemStack(Material.WITHER_SKELETON_SKULL);
-				break;
-			case ARMOR_STAND:
-				itemStack = new ItemStack(Material.ARMOR_STAND);
-				break;
-			case SKELETON:
-				itemStack = new ItemStack(Material.SKELETON_SKULL);
-				break;
-			case GIANT:
-			case ZOMBIE:
-				itemStack = new ItemStack(Material.ZOMBIE_HEAD);
-				break;
-			case CREEPER:
-				itemStack = new ItemStack(Material.CREEPER_HEAD);
-				break;
-			case ENDER_DRAGON:
-				itemStack = new ItemStack(Material.DRAGON_HEAD);
-				break;
-			default:
-				HeadLib head = HeadLib.getHead(entity.name());
-
-				if (head == null)
-				{
-					itemStack = new ItemStack(Material.BARRIER);
-				}
-				else
-				{
-					itemStack = head.toItemStack(this.requiredEntities.get(entity));
-				}
-				break;
-		}
-
-		return itemStack;
-	}
-
-
 // ---------------------------------------------------------------------
 // Section: Enums
 // ---------------------------------------------------------------------

src/main/java/world/bentobox/challenges/utils/GuiUtils.java

@@ -0,0 +1,222 @@
+package world.bentobox.challenges.utils;
+
+
+import org.bukkit.Material;
+import org.bukkit.entity.EntityType;
+import org.bukkit.inventory.ItemStack;
+
+import world.bentobox.bentobox.api.panels.builders.PanelBuilder;
+import world.bentobox.bentobox.api.panels.builders.PanelItemBuilder;
+
+
+/**
+ * This class contains static methods that is used through multiple GUIs.
+ */
+public class GuiUtils
+{
+// ---------------------------------------------------------------------
+// Section: Border around GUIs
+// ---------------------------------------------------------------------
+
+
+	/**
+	 * This method creates border of black panes around given panel with 5 rows.
+	 * @param panelBuilder PanelBuilder which must be filled with border blocks.
+	 */
+	public static void fillBorder(PanelBuilder panelBuilder)
+	{
+		GuiUtils.fillBorder(panelBuilder, 5, Material.BLACK_STAINED_GLASS_PANE);
+	}
+
+
+	/**
+	 * This method sets black stained glass pane around Panel with given row count.
+	 * @param panelBuilder object that builds Panel.
+	 * @param rowCount in Panel.
+	 */
+	public static void fillBorder(PanelBuilder panelBuilder, int rowCount)
+	{
+		GuiUtils.fillBorder(panelBuilder, rowCount, Material.BLACK_STAINED_GLASS_PANE);
+	}
+
+
+	/**
+	 * This method sets blocks with given Material around Panel with 5 rows.
+	 * @param panelBuilder object that builds Panel.
+	 * @param material that will be around Panel.
+	 */
+	public static void fillBorder(PanelBuilder panelBuilder, Material material)
+	{
+		GuiUtils.fillBorder(panelBuilder, 5, material);
+	}
+
+
+	/**
+	 * This method sets blocks with given Material around Panel with given row count.
+	 * @param panelBuilder object that builds Panel.
+	 * @param rowCount in Panel.
+	 * @param material that will be around Panel.
+	 */
+	public static void fillBorder(PanelBuilder panelBuilder, int rowCount, Material material)
+	{
+		// Only for useful filling.
+		if (rowCount < 3)
+		{
+			return;
+		}
+
+		for (int i = 0; i < 9 * rowCount; i++)
+		{
+			// First (i < 9) and last (i > 35) rows must be filled
+			// First column (i % 9 == 0) and last column (i % 9 == 8) also must be filled.
+
+			if (i < 9 || i > 9 * (rowCount - 1) || i % 9 == 0 || i % 9 == 8)
+			{
+				panelBuilder.item(i, new PanelItemBuilder().name("&2").icon(material).build());
+			}
+		}
+	}
+
+
+// ---------------------------------------------------------------------
+// Section: Entities Visualization Block
+// ---------------------------------------------------------------------
+
+	/**
+	 * This method transforms entity into egg or block that corresponds given entity.
+	 * If entity egg is not found, then it is replaced by block that represents entity or
+	 * barrier block.
+	 * @param entity Entity which egg must be returned.
+	 * @return ItemStack that may be egg for given entity.
+	 */
+	public static ItemStack getEntityEgg(EntityType entity)
+	{
+		return GuiUtils.getEntityEgg(entity, 1);
+	}
+
+
+	/**
+	 * This method transforms entity into egg or block that corresponds given entity.
+	 * If entity egg is not found, then it is replaced by block that represents entity or
+	 * barrier block.
+	 * @param entity Entity which egg must be returned.
+	 * @param amount Amount of ItemStack elements.
+	 * @return ItemStack that may be egg for given entity.
+	 */
+	public static ItemStack getEntityEgg(EntityType entity, int amount)
+	{
+		ItemStack itemStack;
+
+		switch (entity)
+		{
+			case PIG_ZOMBIE:
+				itemStack = new ItemStack(Material.ZOMBIE_PIGMAN_SPAWN_EGG);
+				break;
+			case ENDER_DRAGON:
+				itemStack = new ItemStack(Material.DRAGON_EGG);
+				break;
+			case WITHER:
+				itemStack = new ItemStack(Material.SOUL_SAND);
+				break;
+			case PLAYER:
+				itemStack = new ItemStack(Material.PLAYER_HEAD);
+				break;
+			case MUSHROOM_COW:
+				itemStack = new ItemStack(Material.MOOSHROOM_SPAWN_EGG);
+				break;
+			case SNOWMAN:
+				itemStack = new ItemStack(Material.CARVED_PUMPKIN);
+				break;
+			case IRON_GOLEM:
+				itemStack = new ItemStack(Material.IRON_BLOCK);
+				break;
+			case ARMOR_STAND:
+				itemStack = new ItemStack(Material.ARMOR_STAND);
+				break;
+			default:
+				Material material = Material.getMaterial(entity.name() + "_SPAWN_EGG");
+
+				if (material == null)
+				{
+					itemStack = new ItemStack(Material.BARRIER);
+				}
+				else
+				{
+					itemStack = new ItemStack(material);
+				}
+
+				break;
+		}
+
+		itemStack.setAmount(amount);
+
+		return itemStack;
+	}
+
+
+	/**
+	 * This method transforms entity into player head with skin that corresponds given
+	 * entity. If entity head is not found, then it is replaced by barrier block.
+	 * @param entity Entity which head must be returned.
+	 * @return ItemStack that may be head for given entity.
+	 */
+	public static ItemStack getEntityHead(EntityType entity)
+	{
+		return GuiUtils.getEntityHead(entity, 1);
+	}
+
+
+	/**
+	 * This method transforms entity into player head with skin that corresponds given
+	 * entity. If entity head is not found, then it is replaced by barrier block.
+	 * @param entity Entity which head must be returned.
+	 * @param amount Amount of ItemStack elements.
+	 * @return ItemStack that may be head for given entity.
+	 */
+	public static ItemStack getEntityHead(EntityType entity, int amount)
+	{
+		ItemStack itemStack;
+
+		switch (entity)
+		{
+			case PLAYER:
+				itemStack = new ItemStack(Material.PLAYER_HEAD);
+				break;
+			case WITHER_SKELETON:
+				itemStack = new ItemStack(Material.WITHER_SKELETON_SKULL);
+				break;
+			case ARMOR_STAND:
+				itemStack = new ItemStack(Material.ARMOR_STAND);
+				break;
+			case SKELETON:
+				itemStack = new ItemStack(Material.SKELETON_SKULL);
+				break;
+			case GIANT:
+			case ZOMBIE:
+				itemStack = new ItemStack(Material.ZOMBIE_HEAD);
+				break;
+			case CREEPER:
+				itemStack = new ItemStack(Material.CREEPER_HEAD);
+				break;
+			case ENDER_DRAGON:
+				itemStack = new ItemStack(Material.DRAGON_HEAD);
+				break;
+			default:
+				HeadLib head = HeadLib.getHead(entity.name());
+
+				if (head == null)
+				{
+					itemStack = new ItemStack(Material.BARRIER);
+				}
+				else
+				{
+					itemStack = head.toItemStack();
+				}
+				break;
+		}
+
+		itemStack.setAmount(amount);
+
+		return itemStack;
+	}
+}