createPainter method
Creates a DecorationImagePainterToo for this DecorationImageToo.
The onChanged
argument must not be null
.
It will be called whenever the image needs to be repainted,
e.g. because it is loading incrementally or because it is animated.
Implementation
@override
DecorationImagePainter createPainter(VoidCallback onChanged) =>
DecorationImagePainterToo._(this, onChanged);