如何将信封移动到特定点？

Question

Point p = /*a point*/;
ReferencedEnvelope envelope = mapPane.getDisplayArea();
/*envelope.moveTo or something like that? */
mapPane.setDisplayArea(envelope);

How can I move the envelope so that the center position is the position of the given point? All I see are "expand"-methods.

Answer 1

The easiest way is to create a new envelope centred on your new point:

ReferencedEnvelope env = fr.getMapPane().getDisplayArea();
double x,y;//new centre
double w2 = env.getWidth()/2.0;
double h2 = env.getHeight()/2.0;
Coordinate c = new Coordinate(x,y);
ReferencedEnvelope renv = new ReferencedEnvelope(c.x-w2,c.x+w2,c.y-h2,c.y+h2,env.getCoordinateReferenceSystem());