Adds a partially usable arena menu openable through a command

src/main/java/net/knarcraft/minigames/gui/ArenaGUI.java

@@ -0,0 +1,96 @@
+package net.knarcraft.minigames.gui;
+
+import net.knarcraft.knargui.AbstractGUI;
+import net.knarcraft.knargui.GUIAction;
+import net.knarcraft.knargui.item.GUIItemFactory;
+import net.knarcraft.minigames.MiniGames;
+import net.knarcraft.minigames.arena.ArenaSession;
+import net.md_5.bungee.api.ChatColor;
+import org.bukkit.Material;
+import org.bukkit.event.inventory.ClickType;
+import org.bukkit.inventory.ItemStack;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A generic GUI for all arenas
+ */
+public abstract class ArenaGUI extends AbstractGUI {
+
+    /**
+     * Instantiates a new arena gui
+     *
+     * @param inventorySize <p>The size of the GUI's inventory</p>
+     * @param inventoryName <p>The name of the inventory</p>
+     */
+    public ArenaGUI(int inventorySize, String inventoryName) {
+        super(inventorySize, inventoryName, null);
+    }
+
+    /**
+     * Gets an item describing player visibility toggling
+     *
+     * @return <p>A player toggle item</p>
+     */
+    protected ItemStack getTogglePlayersItem() {
+        GUIItemFactory togglePlayersItemFactory = new GUIItemFactory(Material.PLAYER_HEAD);
+        List<String> loreLines = getLoreLines();
+        loreLines.add(ChatColor.GRAY + "Use this item to toggle the visibility");
+        loreLines.add(ChatColor.GRAY + "of other players");
+        togglePlayersItemFactory.setName(ChatColor.BLUE + "Toggle Players");
+        togglePlayersItemFactory.setLore(loreLines);
+        return togglePlayersItemFactory.build();
+    }
+
+    /**
+     * Gets an item describing a leave arena action
+     *
+     * @return <p>A leave item</p>
+     */
+    protected ItemStack getLeaveItem() {
+        GUIItemFactory leaveItemFactory = new GUIItemFactory(Material.BARRIER);
+        List<String> loreLines = getLoreLines();
+        loreLines.add(ChatColor.GRAY + "Use this item to leave the arena");
+        leaveItemFactory.setName(ChatColor.DARK_RED + "Leave");
+        leaveItemFactory.setLore(loreLines);
+        return leaveItemFactory.build();
+    }
+
+    /**
+     * Gets an arraylist with one blank line lore-lines can be added to
+     *
+     * @return <p>An arraylist with one blank line</p>
+     */
+    protected List<String> getLoreLines() {
+        List<String> loreLines = new ArrayList<>();
+        loreLines.add("");
+        return loreLines;
+    }
+
+    /**
+     * Sets a click action for both right-click and left-click
+     *
+     * @param inventorySlot <p>The inventory slot the action should be added to</p>
+     * @param action        <p>The action to register</p>
+     */
+    protected void setAnyClickAction(int inventorySlot, GUIAction action) {
+        setClickAction(inventorySlot, ClickType.LEFT, action);
+        setClickAction(inventorySlot, ClickType.RIGHT, action);
+    }
+
+    /**
+     * Gets the action to run when triggering the leave item
+     *
+     * @return <p>The leave action</p>
+     */
+    protected GUIAction getLeaveAction() {
+        return (player) -> {
+            ArenaSession session = MiniGames.getInstance().getSession(player.getUniqueId());
+            if (session != null) {
+                session.triggerQuit(false);
+            }
+        };
+    }
+
+}