I need to be able to have an item that cannot break any blocks - that can be achieved with events or overriding the Item class' methods. However, the server is still telling the client to render the break animation (the block's break stages), and the client is also still spawning block-break particles. Is there a way to cancel everything before the block is broken (kind of like when the block is first clicked) so that it looks seamless as though the player had not clicked at all? I know ItemSword does this, although I cannot find any place where ItemSword is referenced in the Call Hierarchy (besides where instances of it are created for registration). If someone could please elaborate on how I would get this done, I would appreciate it Thanks.

Did you look inside the vanilla ItemSword class? It has this method in it (overriding the default behavior in class Item):

 

    public float getStrVsBlock(ItemStack stack, Block block)
    {
        if (block == Blocks.web)
        {
            return 15.0F;
        }
        else
        {
            Material material = block.getMaterial();
            return material != Material.plants && material != Material.vine && material != Material.coral && material != Material.leaves && material != Material.gourd ? 1.0F : 1.5F;
        }
    } 

Did you look inside the vanilla ItemSword class? It has this method in it (overriding the default behavior in class Item):

 

    public float getStrVsBlock(ItemStack stack, Block block)
    {
        if (block == Blocks.web)
        {
            return 15.0F;
        }
        else
        {
            Material material = block.getMaterial();
            return material != Material.plants && material != Material.vine && material != Material.coral && material != Material.leaves && material != Material.gourd ? 1.0F : 1.5F;
        }
    } 

 

This works when you return 0.0F - if you are in survival. My item does not need to be able to interact with blocks (or blocks with inventory / other capabilities on left / right click). diesieben07 gave the perfect solution, MouseEvents. This stops vanilla packets from being sent and rendering / particles from being spawned on the client. Perfect solution, considering the personal MouseListener I wrote for Forge is uninterrupted by canceling vanilla Mouse actions. Thanks for the help.