example.java

    public boolean isInventoryOpen() {
        EntityPlayer handle = getHandle();
        return handle.activeContainer != handle.defaultContainer;
    }

    public void openInventory(Inventory inventory) {
        if(isInventoryOpen()) {
            EntityPlayer handle = getHandle();
            CraftPlayer craftPlayer = (CraftPlayer) player;
            CraftInventory craftInventory = (CraftInventory) inventory;
            PlayerInventory handleinventory = handle.inventory;
            IInventory iinventory = craftInventory.getInventory();
            Container container = new ContainerChest(handle.inventory, iinventory);
            container.checkReachable = false;

            sendPacket(new Packet101CloseWindow(handle.activeContainer.windowId));

            handle.activeContainer.transferTo(container, craftPlayer);
            if (handleinventory.getCarried() != null) {
                handle.updateInventory(container);
            }

            int counter = handle.nextContainerCounter();
            int windowType = CraftContainer.getNotchInventoryType(inventory.getType());
            String title = iinventory.getName();
            int size = iinventory.getSize();
            boolean useTitle = true;

            handle.playerConnection.sendPacket(new Packet100OpenWindow(counter, windowType, title, size, useTitle));
            handle.activeContainer = container;
            handle.activeContainer.windowId = counter;
            handle.activeContainer.addSlotListener(handle);
        } else {
            player.openInventory(inventory);
        }
    }