Add current sketch point to sketch feature if the latter exists, else create it.
Clear the drawing
Finish drawing. If there's a sketch point, it's added first.
Return whether the interaction is currently dirty. It is if the sketch
feature has its geometry last coordinate set to the center without the
use of the
true if the interaction is dirty,
Return whether the interaction is currently drawing.
true if the interaction is drawing,
Returns the current sketch feature.
The sketch feature, or null if none.
Return whether the interaction as a valid sketch feature, i.e. its geometry is valid.
true if the interaction has a valid sketch feature,