帧动画
<animation-list>
AnimationDrawable
onWindowFocusChanged
补间动画
分类 平移(translate) 缩放(scale) 旋转(rotate) 透明度(alpha)
关键属性
translate fromXDelta fromYDelta toXDelta toYDelta
scale fromXScale fromYScale toXScale toYScale pivotX pivotY
rotate fromDegrees toDegrees pivotX pivotY
alpha fromAlpha toAlpha
AnimationListener