Paper/src/main/java/net/minecraft/server/ItemBlock.java

package net.minecraft.server;

public class ItemBlock extends Item {

    private int id;

    public ItemBlock(int i) {
        super(i);
        this.id = i + 256;
        this.c(Block.byId[i + 256].a(2));
    }

    public int g() {
        return this.id;
    }

    public boolean interactWith(ItemStack itemstack, EntityHuman entityhuman, World world, int i, int j, int k, int l, float f, float f1, float f2) {
        int i1 = world.getTypeId(i, j, k);

        if (i1 == Block.SNOW.id) {
            l = 1;
        } else if (i1 != Block.VINE.id && i1 != Block.LONG_GRASS.id && i1 != Block.DEAD_BUSH.id) {
            if (l == 0) {
                --j;
            }

            if (l == 1) {
                ++j;
            }

            if (l == 2) {
                --k;
            }

            if (l == 3) {
                ++k;
            }

            if (l == 4) {
                --i;
            }

            if (l == 5) {
                ++i;
            }
        }

        if (itemstack.count == 0) {
            return false;
        } else if (!entityhuman.a(i, j, k, l, itemstack)) {
            return false;
        } else if (j == 255 && Block.byId[this.id].material.isBuildable()) {
            return false;
        } else if (world.mayPlace(this.id, i, j, k, false, l, entityhuman)) {
            Block block = Block.byId[this.id];
            int j1 = this.filterData(itemstack.getData());
            int k1 = Block.byId[this.id].getPlacedData(world, i, j, k, l, f, f1, f2, j1);

            // CraftBukkit start - redirect to common function handler
            /*
            if (world.setTypeIdAndData(i, j, k, this.id, k1)) {
                if (world.getTypeId(i, j, k) == this.id) {
                    Block.byId[this.id].postPlace(world, i, j, k, entityhuman);
                    Block.byId[this.id].postPlace(world, i, j, k, k1);
                }

                world.makeSound((double) ((float) i + 0.5F), (double) ((float) j + 0.5F), (double) ((float) k + 0.5F), block.stepSound.getPlaceSound(), (block.stepSound.getVolume1() + 1.0F) / 2.0F, block.stepSound.getVolume2() * 0.8F);
                --itemstack.count;
            }
            */
            return processBlockPlace(world, entityhuman, itemstack, i, j, k, this.id, k1);
            // CraftBukkit end
        } else {
            return false;
        }
    }

    // CraftBukkit start - add method to process block placement
    static boolean processBlockPlace(final World world, final EntityHuman entityhuman, final ItemStack itemstack, final int x, final int y, final int z, final int id, final int data) {
        org.bukkit.block.BlockState blockstate = org.bukkit.craftbukkit.block.CraftBlockState.getBlockState(world, x, y, z);

        world.suppressPhysics = true;
        world.setTypeIdAndData(x, y, z, id, data);

        org.bukkit.event.block.BlockPlaceEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callBlockPlaceEvent(world, entityhuman, blockstate, x, y, z);
        if (event.isCancelled() || !event.canBuild()) {
            blockstate.update(true);
            world.suppressPhysics = false;
            return false;
        }

        world.suppressPhysics = false;
        world.applyPhysics(x, y, z, world.getTypeId(x, y, z));

        Block block = Block.byId[world.getTypeId(x, y, z)];
        if (block != null) {
            block.postPlace(world, x, y, z, entityhuman);
            block.postPlace(world, x, y, z, world.getData(x, y, z));

            world.makeSound((double) ((float) x + 0.5F), (double) ((float) y + 0.5F), (double) ((float) z + 0.5F), block.stepSound.getPlaceSound(), (block.stepSound.getVolume1() + 1.0F) / 2.0F, block.stepSound.getVolume2() * 0.8F);
        }

        if (itemstack != null) {
            --itemstack.count;
        }

        return true;
    }
    // CraftBukkit end

    public String d(ItemStack itemstack) {
        return Block.byId[this.id].a();
    }

    public String getName() {
        return Block.byId[this.id].a();
    }
}