[1.10.2] Slabs & FACING - doesn't work on double slabs

public abstract class SlabBase extends BlockSlab {
  public static final PropertyDirection FACING = BlockHorizontal.FACING;

  public SlabBase(String unlocalizedName) {
    super(Material.IRON);
    this.setUnlocalizedName(unlocalizedName);
    this.setCreativeTab(Main.tabBirchware);
    this.setRegistryName(new ResourceLocation(Ref.MODID,unlocalizedName));
    this.setHardness(1);
    this.setResistance(2);
    this.useNeighborBrightness = true;

    IBlockState state;
    if (!this.isDouble()) state = this.blockState.getBaseState().withProperty(FACING,EnumFacing.NORTH).withProperty(HALF,EnumBlockHalf.BOTTOM);
    else                  state = this.blockState.getBaseState().withProperty(FACING,EnumFacing.NORTH);
    this.setDefaultState(state);
  }

  @Override
  public String getUnlocalizedName(int meta) { return this.getUnlocalizedName(); }

  @Override
  public IProperty<?> getVariantProperty() {
    return HALF;
  }

  @Override
  public Comparable<?> getTypeForItem(ItemStack stack) {
    return EnumBlockHalf.BOTTOM;
  }

  @Override
  public int damageDropped(IBlockState state) {
    return 0;
  }

  @Override
  protected BlockStateContainer createBlockState() {
    return new BlockStateContainer(this,new IProperty[]{FACING,HALF});
  }

  @Override
  public IBlockState getStateFromMeta(int meta) {
    EnumFacing enumfacing = EnumFacing.getFront(meta & 7);
    if (enumfacing.getAxis() == EnumFacing.Axis.Y) {
      enumfacing = EnumFacing.NORTH;
    }
    IBlockState state = this.getDefaultState().withProperty(FACING,enumfacing.values()[meta & 7]);
    if (!this.isDouble()) state = state.withProperty(HALF,(meta & 8) == 0 ? EnumBlockHalf.BOTTOM : EnumBlockHalf.TOP);
    return state;
  }

  @Override
  public int getMetaFromState(IBlockState state) {
    int meta = 0;
    meta = ((EnumFacing)state.getValue(FACING)).getIndex();
    if (isDouble()) meta |= 8;
    return meta;
  }

  @Override
  public IBlockState onBlockPlaced(World worldIn,BlockPos pos,EnumFacing facing,float hitX,float hitY,float hitZ,int meta,EntityLivingBase placer) {
    Boolean bTop;
    if      (facing == EnumFacing.DOWN) bTop = true;  // Under a block.
    else if (facing == EnumFacing.UP  ) bTop = false; // On a block.
    else bTop = (double)hitY > 0.5D;                  // Any side, hitY is where you clicked.
    if (!this.isDouble()) return this.getDefaultState().withProperty(FACING,placer.getHorizontalFacing().getOpposite()).withProperty(HALF,bTop ? EnumBlockHalf.TOP : EnumBlockHalf.BOTTOM);
    else                  return this.getDefaultState().withProperty(FACING,placer.getHorizontalFacing().getOpposite());
  }

  @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)
  {
    //  Meta debugging.
    if ((playerIn.isSneaking()) && (!worldIn.isRemote)) {
      Logg.info("onBlockActivated Meta: " + getMetaFromState(state));
      return true;
    }
    return false;
  }
}

public abstract class SlabAsphaltLine extends SlabBase
{
  SlabAsphaltLine(String unlocalizedName) {
    super(unlocalizedName);
  }

  @Override
  public Item getItemDropped(IBlockState state, Random rand, int fortune) {
    return Item.getItemFromBlock(slabAsphaltLineHalf);
  }
}

public class SlabAsphaltLineHalf extends SlabAsphaltLine {
  public SlabAsphaltLineHalf(String unlocalizedName) { super(unlocalizedName); }

  @Override
  public boolean isDouble() { return false; }
}

public class SlabAsphaltLineDouble extends SlabAsphaltLine {
  public SlabAsphaltLineDouble(String unlocalizedName) { super(unlocalizedName); }

  @Override
  public boolean isDouble() { return true; }
}