Sets the size of the area the content should clip to.
void setViewArea(float width,
Sets the size of the area the content should clip to. In the default clipping, this
has no effect (it relies solely on the clipped group surrounding the content).
This will always be called prior to setPosition.
void setPosition(float x,
Sets the translation of the content, based on scroll bar positions. Both numbers will
be non-positive, up to the maximum position of the content such that its right or
bottom edge aligns with the width or height of the view area, respectively. For the
default clipping, this just sets the translation of the content's layer.