player selects hotbar slot, fixes #557

src/main/java/carpet/commands/PlayerCommand.java

@@ -58,6 +58,9 @@ public class PlayerCommand
                         .then(makeActionCommand("dropStack", EntityPlayerActionPack.ActionType.DROP_STACK))
                         .then(makeDropCommand("dropStack", true))
                         .then(makeActionCommand("swapHands", EntityPlayerActionPack.ActionType.SWAP_HANDS))
+                        .then(literal("hotbar")
+                                .then(argument("slot", IntegerArgumentType.integer(1, 9))
+                                        .executes(c -> manipulate(c, ap -> ap.setSlot(IntegerArgumentType.getInteger(c, "slot"))))))
                         .then(literal("kill").executes(PlayerCommand::kill))
                         .then(literal("shadow"). executes(PlayerCommand::shadow))
                         .then(literal("mount").executes(manipulation(ap -> ap.mount(true)))

src/main/java/carpet/helpers/EntityPlayerActionPack.java

@@ -10,6 +10,7 @@ import net.minecraft.entity.player.PlayerInventory;
 import net.minecraft.entity.vehicle.BoatEntity;
 import net.minecraft.entity.vehicle.MinecartEntity;
 import net.minecraft.item.ItemStack;
+import net.minecraft.network.packet.s2c.play.HeldItemChangeS2CPacket;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.network.packet.c2s.play.PlayerActionC2SPacket;
 import net.minecraft.server.world.ServerWorld;
@@ -276,6 +277,12 @@ public class EntityPlayerActionPack
         }
     }
 
+    public void setSlot(int slot)
+    {
+        player.inventory.selectedSlot = slot-1;
+        player.networkHandler.sendPacket(new HeldItemChangeS2CPacket(slot-1));
+    }
+
     public enum ActionType
     {
         USE(true)