So, vanilla minecraft has an advancement trigger for when the content of a players inventory were changed, and it would be very nice to have this within the spigot-api aswell, like a InventoryChangeEvent.

Some methods this may include:

Player getPlayer();

List<ItemStack> getPreviousContent();

List<ItemStack> getNewContent();

ChangeReason getChangeReason(); // if the event was triggered by dropping items, collecting, taking out of other inv, command, plugin etc