Hotbar command and tag

src/main/java/com/denizenscript/denizen2sponge/Denizen2Sponge.java

@@ -136,6 +136,7 @@ public void onServerStart(GamePreInitializationEvent event) {
         Denizen2Core.register(new BanCommand());
         Denizen2Core.register(new FeedCommand());
         Denizen2Core.register(new GiveCommand());
+        Denizen2Core.register(new HotbarCommand());
         Denizen2Core.register(new KickCommand());
         Denizen2Core.register(new NarrateCommand());
         Denizen2Core.register(new PardonCommand());

src/main/java/com/denizenscript/denizen2sponge/commands/player/HotbarCommand.java

@@ -0,0 +1,101 @@
+package com.denizenscript.denizen2sponge.commands.player;
+
+import com.denizenscript.denizen2core.commands.AbstractCommand;
+import com.denizenscript.denizen2core.commands.CommandEntry;
+import com.denizenscript.denizen2core.commands.CommandQueue;
+import com.denizenscript.denizen2core.tags.objects.IntegerTag;
+import com.denizenscript.denizen2core.utilities.CoreUtilities;
+import com.denizenscript.denizen2core.utilities.debugging.ColorSet;
+import com.denizenscript.denizen2sponge.tags.objects.PlayerTag;
+import org.spongepowered.api.item.inventory.entity.Hotbar;
+import org.spongepowered.api.item.inventory.entity.PlayerInventory;
+
+public class HotbarCommand extends AbstractCommand {
+
+    // <--[command]
+    // @Name hotbar
+    // @Arguments <player> <value>
+    // @Short changes the hotbar slot currently selected by the player.
+    // @Updated 2017/04/20
+    // @Group Player
+    // @Minimum 2
+    // @Maximum 2
+    // @Named operation (TextTag) Sets whether the command will add or set the value.
+    // @Description
+    // Changes the hotbar slot currently selected by the player. Optionally specify
+    // whether the command will 'add' or 'set' the value. Defaults to 'set'.
+    // @Example
+    // # This example sets the selected hotbar slot of the player to the first one
+    // - hotbar <player> 1
+    // -->
+
+    @Override
+    public String getName() {
+        return "hotbar";
+    }
+
+    @Override
+    public String getArguments() {
+        return "<player> <value>";
+    }
+
+    @Override
+    public int getMinimumArguments() {
+        return 2;
+    }
+
+    @Override
+    public int getMaximumArguments() {
+        return 2;
+    }
+
+    @Override
+    public void execute(CommandQueue queue, CommandEntry entry) {
+        PlayerTag player = PlayerTag.getFor(queue.error, entry.getArgumentObject(queue, 0));
+        IntegerTag value = IntegerTag.getFor(queue.error, entry.getArgumentObject(queue, 1));
+        Hotbar hotbar = ((PlayerInventory) player.getInternal().getInventory()).getHotbar();
+        String operation;
+        if (entry.namedArgs.containsKey("operation")) {
+            operation = CoreUtilities.toLowerCase(entry.getNamedArgumentObject(queue, "operation").toString());
+            int index;
+            switch (operation) {
+                case "set":
+                    index = (int) value.getInternal();
+                    if (index > 9 || index < 1) {
+                        queue.handleError(entry, "Invalid slot index: '" + index + "'. It must be inside the 1-9 range!");
+                        return;
+                    }
+                    hotbar.setSelectedSlotIndex(index - 1);
+                    break;
+                case "add":
+                    index = hotbar.getSelectedSlotIndex() + (int) value.getInternal();
+                    if (index > 9) {
+                        index -= 9;
+                    }
+                    else if (index < 1) {
+                        index += 9;
+                    }
+                    hotbar.setSelectedSlotIndex(index);
+                    break;
+                default:
+                    queue.handleError(entry, "Invalid operation: '" + operation + "'!");
+                    return;
+            }
+        }
+        else {
+            operation = "set";
+            int index = (int) value.getInternal();
+            if (index > 9 || index < 1) {
+                queue.handleError(entry, "Invalid slot index: '" + index + "'. It must be inside the 1-9 range!");
+                return;
+            }
+            hotbar.setSelectedSlotIndex(index - 1);
+        }
+        if (queue.shouldShowGood()) {
+            queue.outGood(ColorSet.emphasis + (operation.equals("add") ? "Scrolling" : "Setting")
+                    + ColorSet.good + " the selected hotbar slot of " + ColorSet.emphasis
+                    + player.debug() + ColorSet.good + (operation.equals("add") ? " by " : " to ")
+                    + ColorSet.emphasis + value.debug() + ColorSet.good + "!");
+        }
+    }
+}

src/main/java/com/denizenscript/denizen2sponge/tags/objects/PlayerTag.java

@@ -11,6 +11,7 @@
 import org.spongepowered.api.entity.Entity;
 import org.spongepowered.api.entity.living.player.Player;
 import org.spongepowered.api.entity.living.player.gamemode.GameModes;
+import org.spongepowered.api.item.inventory.entity.PlayerInventory;
 import org.spongepowered.api.util.blockray.BlockRay;
 import org.spongepowered.api.world.extent.EntityUniverse;
 
@@ -151,6 +152,14 @@ public Player getInternal() {
         // @Returns the current latency of the player, in milliseconds.
         // -->
         handlers.put("latency", (dat, obj) -> new IntegerTag(((PlayerTag) obj).internal.getConnection().getLatency()));
+        // <--[tag]
+        // @Name PlayerTag.selected_slot
+        // @Updated 2017/04/20
+        // @Group Properties
+        // @ReturnType IntegerTag
+        // @Returns the index of the hotbar slot that is currently selected by the player.
+        // -->
+        handlers.put("selected_slot", (dat, obj) -> new IntegerTag(((PlayerInventory)((PlayerTag) obj).internal.getInventory()).getHotbar().getSelectedSlotIndex() + 1));
     }
 
     public static PlayerTag getFor(Action<String> error, String text) {