Re: superview
Re: superview
- Subject: Re: superview
- From: Conrad Shultz <email@hidden>
- Date: Sun, 08 May 2011 18:09:03 -0700
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On 5/8/11 5:37 PM, Kyle Sluder wrote:
> On Sun, May 8, 2011 at 5:08 PM, Nelson Hazeltine <email@hidden> wrote:
>> Since the value of superview is the next responder (the receiver, most often a view controller in iPhone applications)
>
> Where did you get this idea? See the documentation for -[UIResponder
> nextResponder]:
> http://developer.apple.com/library/ios/documentation/uikit/reference/UIResponder_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40006783-CH4-SW12
It seems likely the the OP generalized from Figure 1-1 at
http://developer.apple.com/library/ios/#documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/EventsiPhoneOS/EventsiPhoneOS.html#//apple_ref/doc/uid/TP40009541-CH2-SW5
(or a similar diagram) and erroneously concluded that superview and
nextResponder are synonymous.
To answer the question I _think_ the OP is asking:
UIView descends from UIResponder, not the other way around.
Since a superview is always going to be a UIView, -superview returns
UIView*, not the more general UIResponder*.
Any superview can of course then, in principle, serve as nextResponder.
But this is going to depend on how you linked up the responder chain,
what is getting returned from -canBecomeFirstResponder, etc. _By
default_ the superview is also nextResponder, but this can be changed,
and often is. Quoting from the UIResponder docs for -nextResponder:
"UIView implements this method by returning the UIViewController object
that manages it (if it has one) or its superview (if it doesn?t)."
On iOS the responder chain seems a little more locked down than on OS X
since the former does not implement (publicly) the -setNextResponder
method that is present in NSResponder. However, as noted in the
UIResponder documentation, you certainly can override -nextResponder
("Subclasses must override this method to set the next responder") to
insert objects into the responder chain yourself if needed.
- --
Conrad Shultz
Synthetiq Solutions
www.synthetiqsolutions.com
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| References: | |
| | >superview (From: Nelson Hazeltine <email@hidden>) |
| | >Re: superview (From: Kyle Sluder <email@hidden>) |