@Override
	public boolean onBlockActivated(World worldIn, BlockPos pos, IBlockState state, EntityPlayer playerIn, EnumHand hand, @Nullable ItemStack heldItem, EnumFacing side, float hitX, float hitY, float hitZ)
	{
		ItemStack stack = playerIn.getHeldItem(hand);
		ItemStack stacktoAdd = new ItemStack(Items.BOOK);

		final IBlockState set0 = IntegratedBlocks.bookcases.getDefaultState().withProperty(BlockBookcaseMulti.TYPE, EnumBookshelf.one1);  // Empty
		final IBlockState set1 = IntegratedBlocks.bookcases.getDefaultState().withProperty(BlockBookcaseMulti.TYPE, EnumBookshelf.two2);  // 1/3 full
		final IBlockState set2 = IntegratedBlocks.bookcases.getDefaultState().withProperty(BlockBookcaseMulti.TYPE, EnumBookshelf.two3);  // 2/3 full
		final IBlockState set3 = IntegratedBlocks.bookcases.getDefaultState().withProperty(BlockBookcaseMulti.TYPE, EnumBookshelf.three1);// full

		if(stack != null && playerIn.getHeldItemMainhand().getItem() == Items.BOOK)
		{
			if (state.getValue(BlockBookcaseMulti.TYPE) == EnumBookshelf.one1)
			{
				if (!worldIn.isRemote)
				{
					System.out.println("changed into +1");
					worldIn.setBlockState(pos, set1);
					--stack.stackSize;
					return true;
				}
				else
				{
					return false;
				}
			}
			if (state.getValue(BlockBookcaseMulti.TYPE) == EnumBookshelf.two2)
			{
				if (!worldIn.isRemote)
				{
					System.out.println("changed into +2");
					worldIn.setBlockState(pos, set2);
					--stack.stackSize;
					return true;
				}
				else
				{
					return false;
				}
			}
			if (state.getValue(BlockBookcaseMulti.TYPE) == EnumBookshelf.two3)
			{
				if (!worldIn.isRemote)
				{
					System.out.println("changed into +3");
					worldIn.setBlockState(pos, Blocks.BOOKSHELF.getDefaultState());
					--stack.stackSize;
					return true;
				}
				else
				{
					return false;
				}
			}
			else
			{
				return false;
			}
		}
		else if(stack == null)
		{
			if (state.getValue(BlockBookcaseMulti.TYPE) == EnumBookshelf.two3)// 2/3 full
			{
				if (!worldIn.isRemote)
				{
					System.out.println("changed back into -2");
					worldIn.setBlockState(pos, set1);
					playerIn.inventory.addItemStackToInventory(stacktoAdd);
					return true;
				}
				else
				{
					return false;
				}
			}
			if (state.getValue(BlockBookcaseMulti.TYPE) == EnumBookshelf.two2) //back to empty
			{
				if (!worldIn.isRemote)
				{
					System.out.println("changed back into -1");
					worldIn.setBlockState(pos, set0);
					playerIn.inventory.addItemStackToInventory(stacktoAdd);
					return true;
				}
				else
				{
					return false;
				}
			}
			else
			{
				return false;
			}
		}
		else
		{
			return false;
		}
	}