PMTweening Protocol Reference

Conforms to	NSObject
Declared in	PMTweening.h

Overview

The PMTweening protocol declares methods and properties that must be adopted by custom tweening classes in order to participate in PMTween.

In addition to adopting the required methods, custom tweening classes must also post the PMTweenDidCompleteNotification notification in order to properly interact with other PMTween classes.

Tasks

Controlling a Tween

– stopTween required method
– startTween required method
– pauseTween required method
– resumeTween required method
reversing property required method
tempo property required method

Updating a Tween

– updateWithTimeInterval: required method

Properties

reversing

A Boolean which determines whether a tween operation, when it has tweened to the ending value, should tween from the ending value back to the starting value.

@property (nonatomic, assign, getter=isReversing) BOOL reversing

Discussion

@remarks When set to YES, the tween plays in reverse after completing a forward tween. In this state, a tween cycle represents the combination of the forward and back tweens. The default value is NO.

Declared In

PMTweening.h

tempo

A concrete PMTweenTempo subclass that provides an update “beat” while a tween operation occurs.

@property (nonatomic, strong) PMTweenTempo *tempo

Discussion

@remarks While you don’t have to implement PMTweenTempo for your own class updating, other tween collection classes like PMTweenGroup will try to remove any tempos of tween objects added to them.

Declared In

PMTweening.h

Instance Methods

pauseTween

Pauses a tween that is currently tweening. (required)

- (void)pauseTween

Discussion

@remarks When this method is called, a tween should only enter a paused state if it is currently tweening.

Declared In

PMTweening.h

resumeTween

Resumes a tween that is currently paused. (required)

- (void)resumeTween

Discussion

@remarks When this method is called, a tween should only resume tweening if it is currently paused.

Declared In

PMTweening.h

startTween

Starts a tween that is currently stopped. (required)

- (void)startTween

Discussion

@remarks When this method is called, a tween should only start tweening if it is stopped.

Declared In

PMTweening.h

stopTween

Stops a tween that is currently tweening. (required)

- (void)stopTween

Discussion

@remarks When this method is called, a tween should only enter a stopped state if it currently tweening.

Declared In

PMTweening.h

updateWithTimeInterval:

This method is called to prompt a tweening class to update its current tween values.

- (void)updateWithTimeInterval:(NSTimeInterval)currentTime

Parameters

currentTime: A timestamp that can be used in easing calculations.

Declared In

PMTweening.h