API to support adding in new upgrade items for machines

I have some ideas for upgrade items- so that I can get people off their Advanced Machine dependency. Unfortunately at present it looks like there's no way to hook TileEntityMachine when there are upgrade items.

What I would like to be able to do is create new "Upgrader" items, probably event driven, with visibility into the base TileEntityMachine.

Here's a simple proposal.

public interface MachineUpgradeItem {
 /** Called with the current itemstack when the upgrade stack is modified 
 * Returns true if this is now a locked slot (cannot have more inserted)
*/
  public boolean installUpgradeItem(ItemStack upgradeItemStack, TileEntityMachine machine);
/** Called to compute the current effect of this stack on the machine. Generally would set the overclock rate and maybe have other effects.
 * Returns maybe a new value for some parameter?
*/
  public int evaluateOverclock(ItemStack upgradeItemStack, TileEntityMachine machine);
/** Called whenever an operation cycle is about to start (new item being smelted or something)
* This should come before the machine decides if it wants to smelt something - so I could insert something into the machine at the last second.
* Returns true if the operation can proceed.
*/
  public boolean beforeOperation(ItemStack upgradeItemStack, TileEntityMachine machine);
/** Called after an operation cycle is complete. (Item has finished smelting for example).
* This allows for me to e.g. remove the item from the machine and put it somewhere else.
*/
  public boolean afterOperation(ItemStack upgradeItemStack, TileEntityMachine machine);
}

This is just a sketch of an idea for a new API to support modders creating new upgrade items without having to hack base IC2 code. Thoughts?

Alblaka,
It's not hard to deal with the TileEntityMachine not being in the API itself- you provide an interface with some typical accessors as an interface that IS in the API and use that instead.

I realise that crops are planned for API extension and IC2 core isn't, but I've actually had to do exactly this kind of API retrofitting for my day job, on oh, about half a dozen occasions.

I agree that there might be some constraints to the other poster's point, but to be honest, I think it's a shame if we cannot code up new upgrade modules. It means I have to go back to the old, not very fun, way of doing something like an advanced machine. I suspect, Alblaka, to your point about "we would add in all the upgrade modules", are you planning a redstone engine based "extractor" module to automatically put output into a neighbouring chest or BC pipe (this was my idea for replacing the old advanced machines mod by the way)?

I also had ideas about "lockin" type modules, whereby you could lockin certain types of machine for certain jobs. For example: 1 macerator per ore type - to try and help prevent overload. Also a miniature input extension module. I think all of these are possible simply with the api ideas above.