UIView

UIView is the root class of all UI elements.

Getting View Hierarchy Info

There are 2 ways of getting the view hierarchy info, the "human readable" -[UIView recursiveDescription] and "machine readable" -[UIView scriptingInfoWithChildren].

-recursiveDescription

Signature	-(NSString*)recursiveDescription;
Available in	3.0 – 3.1

Returns the description of the view and its subviews.

Example output:

<UIWebView: 0x4116bb0; frame = (0 100; 320 230); layer = <CALayer: 0x4116c20>>
   <UIScroller: 0x411e110; frame = (0 0; 320 230); clipsToBounds = YES; autoresize = H; layer = <CALayer: 0x411e4d0>>
       <UIImageView: 0x411f460; frame = (0 0; 54 54); transform = [-1, 0, -0, -1, 0, 0]; alpha = 0; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x411f490>>
       <UIWebDocumentView: 0x4812c00; frame = (0 0; 320 230); layer = <UIWebLayer: 0x41171c0>>

-scriptingInfoWithChildren

Signature	-(NSDictionary*)scriptingInfoWithChildren;
Available in	2.0 – 3.1

This function returns an NSDictionary with contains some information e.g. geometry, class name, etc.

Animation Blocks

Further information: UIViewAnimationState

Animation blocks are implemented by the UIViewAnimationState class with the following correspondences:

UIView methods	Equivalent call
[UIView beginAnimations:identifier context:context];	[UIViewAnimationState pushViewAnimationState:identifier context:context];
[UIView commitAnimations];	[UIViewAnimationState popAnimationState];
[UIView setAnimationStartDate:date];	__currentViewAnimationState->_start = [date timeIntervalSinceReferenceDate];
[UIView setAnimationsEnabled:enabled];	__animate = enabled;
[UIView setAnimationDelegate:delegate];	if (__currentViewAnimationState->_delegate != delegate) {   [__currentViewAnimationState->_delegate release];   __currentViewAnimationState->_delegate = [delegate retain]; }
[UIView setAnimationWillStartSelector:selector];	__currentViewAnimationState->_willStartSelector = selector;
[UIView setAnimationDidStopSelector:selector];	__currentViewAnimationState->_didEndSelector = selector;
[UIView setAnimationDuration:duration];	__currentViewAnimationState->_duration = duration;
[UIView setAnimationDelay:delay];	__currentViewAnimationState->_delay = delay;
[UIView setAnimationCurve:curve];	__currentViewAnimationState->_curve = curve;
[UIView setAnimationRepeatCount:repeatCount];	__currentViewAnimationState->_repeatCount = repeatCount;
[UIView setAnimationRepeatAutoreverses:autoreverses];	__currentViewAnimationState->_autoreverses = autoreverses;
[UIView setAnimationBeginsFromCurrentState:value];	__currentViewAnimationState->_useCurrentLayerState = value;
[UIView setAnimationTransition:transVal forView:container cache:cache];	__currentViewAnimationState->_transition = transVal; __currentViewAnimationState->_transitionView = [container retain]; __currentViewAnimationState->_cacheTransition = cache;
[UIView areAnimationsEnabled];	__animate;

In above, __currentViewAnimationState is a global variable, which is a UIViewAnimationState. This value is automatically updated after calling +pushViewAnimationState:context: and +popAnimationState. NULL checks were omitted in the above codes for simplicity.

There are also a few undocumented methods:

UIView method	Equivalent call
[UIView beginAnimations:identifier];	[UIView beginAnimations:identifier context:NULL];
[UIView _pendingAnimations];	__currentViewAnimationState != nil;
[UIView setAnimationPosition:position];	__currentViewAnimationState->_position = position;
[UIView disableAnimation];	__animate = NO;
[UIView enableAnimation];	__animate = YES;
[UIView setAnimationFrameInterval:interval];	__currentViewAnimationState->_frameInterval = interval;
[UIView setAnimationStartTime:time];	__currentViewAnimationState->_start = time;
[UIView setAnimationRoundsToInteger:rounds];	__currentViewAnimationState->_roundsToInteger = rounds;

There are also a few equivalent (probably deprecated) selectors:

• +endAnimations = +commitAnimations
• +setAnimationAutoreverses: = +setAnimationRepeatAutoreverses:
• +setAnimationFromCurrentState: = +setAnimationBeginsFromCurrentState:

References

• Official documentation: UIView
• Header: http://github.com/kennytm/iphone-private-frameworks/blob/master/UIKit/UIView2.h