DropTargetDropEvent: Point => Position

[heidtmare]

I've implemented a DropTargetListener with the following:

PHP Code:

@Override
    public void drop(DropTargetDropEvent dtde) {
        if (dtde.isDataFlavorSupported(RenderableProvider.DATA_FLAVOR)) {
            try {
                Object transData = dtde.getTransferable().getTransferData(RenderableProvider.DATA_FLAVOR);
                if (transData instanceof RenderableProvider) {
                    dtde.acceptDrop(DnDConstants.ACTION_COPY_OR_MOVE);

                    RenderableProvider rp = (RenderableProvider) dtde.getTransferable().getTransferData(RenderableProvider.DATA_FLAVOR);

                    //get the layer
                    String ln = rp.getLayerName();
                    RenderableLayer layer = (RenderableLayer) wwm.getLayers().getLayerByName(ln);
                    if (layer == null) {
                        layer = new RenderableLayer();
                        layer.setName(ln);
                        wwm.getLayers().add(layer);
                    }

                    //calculate position
                    Globe globe = wwm.getWorldWindow().getModel().getGlobe();
                    Point p = dtde.getLocation();
                    Position pos = globe.computePositionFromPoint(new Vec4(p.getX(), p.getY()));
                    LOGGER.log(Level.INFO, "Position: {0}", pos);

                    //add the renderable
                    Renderable r = rp.getRenderable(pos);
                    if (r != null) {
                        layer.addRenderable(r);
                    }
                }
            } catch (UnsupportedFlavorException ufe) {
                Exceptions.printStackTrace(ufe);
                dtde.rejectDrop();
                dtde.dropComplete(true);
            } catch (IOException ioe) {
                Exceptions.printStackTrace(ioe);
                dtde.rejectDrop();
                dtde.dropComplete(false);
            }
        } else {
            LOGGER.warning("Unsupported Data Flavor");
            dtde.rejectDrop();
            dtde.dropComplete(false);
        }
    }
} 


It works if my goal is to have all my Renderables show up at the north pole... which it is not.

PHP Code:

Point p = dtde.getLocation();
Position pos = globe.computePositionFromPoint(new Vec4(p.getX(), p.getY()));
LOGGER.log(Level.INFO, "Position: {0}", pos); 


This always gives me a position close to the pole.
So I'm assuming there is an absolute vs relative issue here.
Is there a magical way to convert between java.awt.Point and gov.nasa.worldwind.geom.Position?

[dcollins]

heidtmare,

This looks like a simple oversight: the method Globe.computePositionFromPoint transforms a model-coordinate Cartesian point to spherical coordinates. Since you are specifying screen-coordinate values which happen to be small relative to model-coordiante values, the code above essentially transforms points near the center of the earth to their corresponding spherical value.

Please try replacing usage of Globe.computePointFromPosition with View.computePositionFromScreenPoint, and let us know if that resolves the issue. Note that View.computePositionFromScreenPoint returns null if the point is off the globe.

Thanks,
Dave

[workingDog]

I did the same DropTarget thing a while back using this:

Line lineRay = wwm.getWorldWindow().getView().computeRa yFromScreenPoint(p.x, p.y);
Position dropPosition = wwm.getWorldWindow().getView().getGlobe( ).getIntersectionPosition(lineRay);

[dcollins]

workingDog,

Please note that View.computePositionFromScreenPoint does exactly what you outline in your post. It would be worth using this method instead of your own, unless you have other logic that what you've shown above.

Thanks,
Dave

[heidtmare]

yep, i knew i was doing something silly... thanks guys.