Specifies location and attributes for views over the course of the motion
sequence. By default, motion proceeds from the initial state to the end state.
By using <KeyFrameSet>, you can build more complex motions.
The <KeyFrameSet> contains
<KeyPosition> or
<KeyAttribute>
nodes. These nodes specify the position or attributes of a target view
at a specific point in the motion.
MotionLayout
smoothly animates the view from the starting point to each intermediate
point and then to the final destination.
Suppose the initial state of the motion sequence has an opaque ball
in the lower-left corner of the view, and the final state makes the ball
transparent in the
upper-right corner. By default, the MotionLayout
moves the ball smoothly in a diagonal line, gradually becoming transparent
until it vanishes when it reaches its destination. By using <KeyFrameSet>, you
can change this behavior. For example, you can make the ball move vertically
to the upper-left corner while remaining entirely opaque, then move horizontally
to the upper-right corner while fading out. You can do this by creating a
<KeyFrameSet> and adding a <KeyPosition> and <KeyAttribute> inside it.
The <KeyPosition> specifies the intermediate location of the ball, and the
<KeyAttribute> specifies that the ball remains opaque at the midpoint of
the motion.
Syntax
<KeyFrameSet>
[ <KeyPosition/>... ]
[ <KeyAttribute/>...]
</KeyFrameSet>
Contained in
Contains
<KeyPosition>- Specifies a view's position at a specific moment during the motion sequence.
<KeyAttribute>- Specifies view attributes at a specific moment during the motion sequence.