OptionalblockingWhether the panel swallows pointer events aimed at what is behind it.
true by default, which is what a dialog wants: a click on the panel,
or on the dimmed scene it covers, must not reach the game underneath.
Children are unaffected either way, because the dispatcher asks a child
before the container holding it.
Set false for a panel that is only a backdrop, such as a HUD frame
drawn over a playfield that still has to receive clicks.
OptionalbobHow far the panel drifts up and down, in pixels. 0, the default,
leaves it still.
See UIPanel#bobAmplitude.
OptionalbobHow long one full up and down cycle takes, in milliseconds.
See UIPanel#bobPeriod.
Optionalborderdrawn around the edge; null for none
Optionalborderhow thick that border is
OptionalfillThe fill behind the children; null leaves it transparent.
NOT backgroundColor, which a Container already has and which does
something else entirely: that one is handed to clearColor and wipes
the whole render target, so a panel setting it would repaint the
screen. The name here matches ProgressBarSettings instead.
the panel's height, in pixels
Optionalradiuscorner radius; 0 is square
the panel's width, in pixels
Everything UIPanel takes.