Add basic GUI framework

src/main/java/com/cjburkey/claimchunk/ClaimChunk.java

@@ -10,6 +10,7 @@
 import com.cjburkey.claimchunk.data.newdata.*;
 import com.cjburkey.claimchunk.data.sqlite.SqLiteDataHandler;
 import com.cjburkey.claimchunk.event.*;
+import com.cjburkey.claimchunk.gui.CCGuiHandler;
 import com.cjburkey.claimchunk.i18n.V2JsonMessages;
 import com.cjburkey.claimchunk.layer.PlaceholderInitLayer;
 import com.cjburkey.claimchunk.layer.PrereqsInitLayer;
@@ -108,6 +109,7 @@ public final class ClaimChunk extends JavaPlugin implements IClaimChunkPlugin {
     // The main handler (may not always be here, please don't rely on this)
     @Getter private MainHandler mainHandler;
     @Getter private ChunkOutlineHandler chunkOutlineHandler;
+    @Getter private CCGuiHandler guiHandler;
 
     // Config conversion storage
     private FromPre0023 fromPre0023;
@@ -533,10 +535,13 @@ private void setupConfig() {
     }
 
     private void setupEvents() {
+        guiHandler = new CCGuiHandler();
+
         // Register all the event handlers
         getServer().getPluginManager().registerEvents(new PlayerConnectionHandler(this), this);
         getServer().getPluginManager().registerEvents(new PlayerMovementHandler(this), this);
         getServer().getPluginManager().registerEvents(new WorldProfileEventHandler(this), this);
+        getServer().getPluginManager().registerEvents(guiHandler, this);
     }
 
     private void setupNewCommands() {

src/main/java/com/cjburkey/claimchunk/gui/CCGuiHandler.java

@@ -0,0 +1,76 @@
+package com.cjburkey.claimchunk.gui;
+
+import com.cjburkey.claimchunk.Utils;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.bukkit.inventory.Inventory;
+
+import java.util.HashMap;
+import java.util.UUID;
+
+/**
+ * The handler behind ClaimChunk GUI screens. This class acts as the interface for opening GUIs as
+ * well as the event listener for players clicking in/closing the screens.
+ *
+ * @since 0.0.26
+ */
+public class CCGuiHandler implements Listener {
+
+    private final HashMap<UUID, CCOpenGui> openGuis = new HashMap<>();
+
+    @EventHandler
+    public void onGuiClick(InventoryClickEvent e) {
+        UUID uuid = e.getWhoClicked().getUniqueId();
+        CCOpenGui openGui = openGuis.get(uuid);
+        if (openGui != null) {
+            if (e.getInventory().equals(openGui.inventory())) {
+                openGui.gui()
+                        .onClick(
+                                openGui.inventory(),
+                                (Player) e.getWhoClicked(),
+                                e.getSlot(),
+                                e.getClick(),
+                                e.getCurrentItem());
+            }
+            e.setCancelled(true);
+        }
+    }
+
+    @EventHandler
+    public void onGuiClose(InventoryCloseEvent e) {
+        if (openGuis.containsKey(e.getPlayer().getUniqueId())) {
+            closeGui((Player) e.getPlayer());
+        }
+    }
+
+    @SuppressWarnings("unused")
+    public void openGui(Player player, ICCGui gui) {
+        if (openGuis.containsKey(player.getUniqueId())) {
+            closeGui(player);
+        }
+        openGuis.put(player.getUniqueId(), new CCOpenGui(gui, createAndShowGui(player, gui)));
+        gui.onOpen(openGuis.get(player.getUniqueId()).inventory(), player);
+    }
+
+    public void closeGui(Player player) {
+        if (openGuis.containsKey(player.getUniqueId())) {
+            openGuis.get(player.getUniqueId())
+                    .gui()
+                    .onClose(openGuis.get(player.getUniqueId()).inventory(), player);
+            openGuis.remove(player.getUniqueId());
+        }
+    }
+
+    private static Inventory createAndShowGui(Player player, ICCGui gui) {
+        int rowCount = Math.min(Math.max(gui.getRows(), 1), 6);
+        Inventory inventory =
+                Bukkit.createInventory(player, rowCount * 9, Utils.color(gui.getName()));
+        player.openInventory(inventory);
+        return inventory;
+    }
+}

src/main/java/com/cjburkey/claimchunk/gui/CCOpenGui.java

@@ -0,0 +1,5 @@
+package com.cjburkey.claimchunk.gui;
+
+import org.bukkit.inventory.Inventory;
+
+record CCOpenGui(ICCGui gui, Inventory inventory) {}

src/main/java/com/cjburkey/claimchunk/gui/ICCGui.java

@@ -0,0 +1,59 @@
+package com.cjburkey.claimchunk.gui;
+
+import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.ClickType;
+import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Interface representing a ClaimChunk GUI screen.
+ *
+ * @since 0.0.26
+ */
+public interface ICCGui {
+
+    /**
+     * Called when this screen is shown to a player.
+     *
+     * @param inventory The inventory behind this GUI
+     * @param player The player the GUI is shown to
+     */
+    void onOpen(@NotNull Inventory inventory, @NotNull Player player);
+
+    /**
+     * Called when this screen is being closed.
+     *
+     * @param inventory The inventory behind this GUI
+     * @param player The player closing the GUI
+     */
+    void onClose(@NotNull Inventory inventory, @NotNull Player player);
+
+    /**
+     * Called when the player clicks on a given slot within the inventory.
+     *
+     * @param inventory The inventory behind this GUI
+     * @param player The player clicking in the GUI being shown to them.
+     * @param slot The index of the slot being clicked.
+     * @param clickType Which type of click the player performed.
+     * @param stack The stack on which the player clicked.
+     */
+    void onClick(
+            @NotNull Inventory inventory,
+            @NotNull Player player,
+            int slot,
+            @NotNull ClickType clickType,
+            @Nullable ItemStack stack);
+
+    /**
+     * @return The name to be shown at the top of the GUI
+     */
+    @NotNull
+    String getName();
+
+    /**
+     * @return The number of rows this GUI should have
+     */
+    int getRows();
+}

src/main/java/com/cjburkey/claimchunk/gui/screens/MainMenu.java

@@ -0,0 +1,36 @@
+package com.cjburkey.claimchunk.gui.screens;
+
+import com.cjburkey.claimchunk.gui.ICCGui;
+
+import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.ClickType;
+import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+public class MainMenu implements ICCGui {
+
+    @Override
+    public void onOpen(@NotNull Inventory inventory, @NotNull Player player) {}
+
+    @Override
+    public void onClose(@NotNull Inventory inventory, @NotNull Player player) {}
+
+    @Override
+    public void onClick(
+            @NotNull Inventory inventory,
+            @NotNull Player player,
+            int slot,
+            @NotNull ClickType clickType,
+            @NotNull ItemStack stack) {}
+
+    @Override
+    public @NotNull String getName() {
+        return "ClaimChunk GUI";
+    }
+
+    @Override
+    public int getRows() {
+        return 0;
+    }
+}

src/main/java/com/cjburkey/claimchunk/i18n/V2JsonMessages.java

@@ -202,6 +202,7 @@ public final class V2JsonMessages {
     public String cmdClaim = "Claim the chunk you're standing in";
     public String cmdHelp = "Display ClaimChunk help (for [command], if supplied)";
     public String cmdInfo = "Display information about the current chunk";
+    public String cmdGui = "Open the ClaimChunk GUI";
     public String cmdList = "Display a paginated list of all your claims in the world";
     public String cmdName = "Change the name that appears when someone enters your land";
     public String cmdReload = "Reload the config for ClaimChunk";

src/main/java/com/cjburkey/claimchunk/smartcommand/ClaimChunkBaseCommand.java

@@ -74,7 +74,9 @@ public ClaimChunkBaseCommand(ClaimChunk claimChunk) {
                 // `/chunk unclaim`
                 new CommandStr(new UnclaimCmd(claimChunk), "unclaim"),
                 // `/chunk scan`
-                new CommandStr(new ScanCmd(claimChunk), "scan"));
+                new CommandStr(new ScanCmd(claimChunk), "scan"),
+                // `/chunk gui`
+                new CommandStr(new GuiCmd(claimChunk), "gui"));
 
         // Admin commands
         registerCmds(

src/main/java/com/cjburkey/claimchunk/smartcommand/sub/ply/GuiCmd.java

@@ -0,0 +1,43 @@
+package com.cjburkey.claimchunk.smartcommand.sub.ply;
+
+import com.cjburkey.claimchunk.ClaimChunk;
+import com.cjburkey.claimchunk.gui.screens.MainMenu;
+import com.cjburkey.claimchunk.smartcommand.CCSubCommand;
+
+import de.goldmensch.commanddispatcher.Executor;
+
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * @since 0.0.23
+ */
+public class GuiCmd extends CCSubCommand {
+
+    public GuiCmd(ClaimChunk claimChunk) {
+        super(claimChunk, Executor.PLAYER, true, "player");
+    }
+
+    @Override
+    public @Nullable String getDescription() {
+        return claimChunk.getMessages().cmdGui;
+    }
+
+    @Override
+    public CCArg[] getPermittedArguments() {
+        return new CCArg[0];
+    }
+
+    @Override
+    public int getRequiredArguments() {
+        return 0;
+    }
+
+    @Override
+    public boolean onCall(@NotNull String cmdUsed, @NotNull CommandSender executor, String[] args) {
+        claimChunk.getGuiHandler().openGui((Player) executor, new MainMenu());
+        return true;
+    }
+}