using iOS 6.0 SDK and building for iOS 5 Target causes UIScrollView setMinimumZoomScale to fail when running on iOS 5 simulator

Question

i upgraded to Xcode 4.5 and have started using the iOS SDK 6.0:

i have a unive

Answer 1

answering my own question …

the complexity of my original question involved additional gesture recognizers.

under iOS 5.1 SDK (and some prior), it was possible to add a gesture recognizer to UIScrollView and be able to have it work in conjunction with panGestureRecognizer and pinchGestureRecognizer that are built into the UIScrollView.

under iOS 6.0 SDK, this behavior is apparently no longer really supported. the relevant documentation does not so much explicitly forbid the behavior as it does define what the UIScrollView will do for touches that may or may not be related to pan and pinch.

Because a scroll view has no scroll bars, it must know whether a touch signals an intent to scroll versus an intent to track a subview in the content. To make this determination, it temporarily intercepts a touch-down event by starting a timer and, before the timer fires, seeing if the touching finger makes any movement. If the timer fires without a significant change in position, the scroll view sends tracking events to the touched subview of the content view. If the user then drags their finger far enough before the timer elapses, the scroll view cancels any tracking in the subview and performs the scrolling itself. Subclasses can override the touchesShouldBegin:withEvent:inContentView:, pagingEnabled, and touchesShouldCancelInContentView: methods (which are called by the scroll view) to affect how the scroll view handles scrolling gestures.

in order to rectify the problem, i had to make sure that the gesture recognizers in the storyboard are no longer part of the collection associated with the scrollview, and instead associate them with the content-view of the scrollview.

(in my case, in order to do this, i had to manually add them using addGestureRecognizer: for each gesture-recognizer i am interested in, since the content-view is for images that aren't known at storyboard time.)