I have made a custom Slab and Double slab, but it seems, when in Creative mode, and one middle-clicks it on an empty slot, it gives me a Stone Slab, instead of my Block.

This is my ItemSlab Code

package com.strebornella.adrtwo.blocks.slabs.compressed;

import net.minecraft.block.Block;
import net.minecraft.block.BlockSlab;
import net.minecraft.item.ItemSlab;

public class CCobblestone_ItemSlab extends ItemSlab {
public CCobblestone_ItemSlab(Block block){
	super(block, (BlockSlab)CCobblestone_Slabs.ccslab, (BlockSlab)CCobblestone_Slabs.ccDoubleSlab, false);
	setHasSubtypes(true);
}
}

 

and this is the Slab code

 

package com.strebornella.adrtwo.blocks.slabs.compressed;

import java.util.Random;
import com.strebornella.adrtwo.StringRefs;
import com.strebornella.adrtwo.tabs.creative.ADRTabs;
import cpw.mods.fml.common.registry.GameRegistry;
import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;
import net.minecraft.block.Block;
import net.minecraft.block.BlockSlab;
import net.minecraft.block.material.Material;
import net.minecraft.client.renderer.texture.IIconRegister;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.util.IIcon;
import net.minecraft.world.World;

public class CCobblestone_Slabs extends BlockSlab{
public CCobblestone_Slabs(boolean isDouble, Material material) {
	super(isDouble, material);
	setLightOpacity(0);
	useNeighborBrightness = true;
}

public static Block ccslab;
public static Block ccDoubleSlab;
public static IIcon bottom;
public static IIcon top;
public static IIcon side1;
public static IIcon side2;
public static IIcon side3;
public static IIcon side4;

public static void mainRegistry(){
	ccslab = new CCobblestone_Slabs(false, Material.rock)
		.setBlockName("compcobblestoneslab")
		.setHardness(20.0F)
		.setResistance(280.0F)
		.setCreativeTab(ADRTabs.adrBlocks)
		.setStepSound(soundTypeStone);
	ccslab.setHarvestLevel("pickaxe", 1);
	ccslab.isToolEffective("pickaxe", 1);

	ccDoubleSlab = new CCobblestone_Slabs(true, Material.rock)
		.setBlockName("compcobblestonedoubleslab")
		.setHardness(16.0F)
		.setResistance(240.0F)
		.setStepSound(soundTypeStone);
	ccDoubleSlab.setHarvestLevel("pickaxe", 1);
	ccDoubleSlab.isToolEffective("pickaxe", 1);

	GameRegistry.registerBlock(ccslab, CCobblestone_ItemSlab.class, ccslab.getUnlocalizedName());
	GameRegistry.registerBlock(ccDoubleSlab, CCobblestone_ItemSlab.class, ccDoubleSlab.getUnlocalizedName());
}

@SideOnly(Side.CLIENT)
@Override
public void registerBlockIcons(IIconRegister icon){
	this.bottom = icon.registerIcon(StringRefs.MODID + ":comp/compressed_cobblestone");
	this.top = icon.registerIcon(StringRefs.MODID + ":comp/compressed_cobblestone");
	this.side1 = icon.registerIcon(StringRefs.MODID + ":compressed_cobblestone_slab_side");
	this.side2 = icon.registerIcon(StringRefs.MODID + ":compressed_cobblestone_slab_side");
	this.side3 = icon.registerIcon(StringRefs.MODID + ":compressed_cobblestone_slab_side");
	this.side4 = icon.registerIcon(StringRefs.MODID + ":compressed_cobblestone_slab_side");
}

@SideOnly(Side.CLIENT)
@Override
public IIcon getIcon(int side, int meta){
	if (side == 0) return bottom;
	else if (side == 1) return top;
	else if (side == 2) return side1;
	else if (side == 3) return side2;
	else if (side == 4) return side3;
	else if (side == 5) return side4;
	else return bottom;
}

public Item getItemDropped(int meta, Random random, int fortune) {
	return Item.getItemFromBlock(ccslab);
}

protected ItemStack createStackedBlock() {
	return new ItemStack(Item.getItemFromBlock(ccslab), 2);
}

public String getFullSlabName(int par1) {
	return getUnlocalizedName();
}

@Override
public String func_150002_b(int par1) {
	return getFullSlabName(par1);
}
}

 

Why this is happening, I don't know.

 

Override createStackedBlock for your Block class.