UIGestureRecognizer causes circular retain?

Question

I was thinking, if you assign the target as self in the gesture recogniser's initWithTarget:action: method, will you cause a circular retain? Since self will retain the recogniser in self.gestureRecognizers and it's possible the gesture recogniser to also retain self in initWithTarget:action.

Would the following be a solution for it?

__weak VRDrawer* weakSelf = self;
UIGestureRecognizer* tapRec = [[UITapGestureRecognizer alloc] initWithTarget:weakSelf
                                                                      action:@selector(handleTap:)];

Answer 1

I completely understand confirming something with the lack of documentation can feel unsettling. The important thing to note is that, by over a decade of convention, target-action relationships are never strong. Here's the relevant docs. Note the part that says:

Control objects do not (and should not) retain their targets.

"Retain…" in the MRC way of saying "Holds a strong reference to…"

Given this is the documented convention for this type of interaction, it's safe to assume that, if UIGestureRecognizer's target-action implementation did retain objects, that anomaly would be strange enough that it would show up in its docs.

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P.S. You don't have to worry about the note that refers to controls retaining targets in memory-managed environments. "Memory-managed" refers to the (now depricated) garbage collection in Cocoa. Neither MRC or ARC is memory-managed.

Answer 2

UIGestureRecognizer* tapRec = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];

This does not retain self. It would also be noted in the docs

You need to add a recognizer to a view. That view will retain the recognizer. no retain cycle.

[aView addGestureRecognizer:tapRec];

addGestureRecognizer: docs do mention, that the view retains the recognizer

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as you are using ARC, this is all you have to do

UIGestureRecognizer* tapRec = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];
[aView addGestureRecognizer:tapRec];