Creating Property Animations

Android 3.0 introduced an animation framework called property animation. This framework allows you to change any object, not just views, and it actually changes an object’s values, not just the way it is drawn. It may seem strange to animate something that is not a view; after all, views are what the user sees. But you can think of property animation as a framework for changing any value over time. Generally, these values will cause some animation on the screen, but this is not strictly necessary. Property animation is very powerful and can make some animations much easier.

ValueAnimator

The base class for all property animation is ValueAnimator. This class takes a starting value, an ending value, and a duration, and it calculates a new value at each time step of an animation; the time steps are determined by the speed of the animation thread. The ValueAnimator requires an Interpolator and a TypeEvaluator to compute the property values. Here is a brief explanation of each class: