Cancellable

Info

For a more in-depth explanation, see the MixinExtra's Wiki.

Cancellable lets you use CallbackInfo or CallbackInfoReturnable on any type of injection.

We can use Cancellable by adding either of the following to the mixin method arguments:

• @Cancellable CallbackInfo ci for a void method
• @Cancellable CallbackInfoReturnable<ReturnType> cir for a non-void method

Say we had the following code:

public void foo(int p) {
    int a = doSomething(p);
    int b = doSomething(p);
    doSomethingTwo(a + b); 
}

If we wanted to ModifyArgs the first doSomething, and potentially early return after it, we could do so with Cancellable:

@ModifyArgs(method = "foo", at = @At(value = "INVOKE", target = "doSomething(I)I"), ordinal = 0)
private void doSomethingElse(Args args, @Cancellable CallbackInfo ci) {
    int ret = (int) args.get(1) + 1
    args.set(0, ret);
    if (ret > 5) {
        ci.cancel();
    }
}

This results in:

public void foo(int p) {
    CallbackInfo ci = new CallbackInfo();
    int a = doSomething(p + 1);
    if (p + 1 > 5) {
        return;
    }
    int b = doSomething(p);
    doSomethingTwo(a + b); 
}