Viewport.java 文件源码

/**
 * Zoom to the given coordinates with the given width and height.
 * 
 * @param x
 *            upper left corner X coordinate
 * @param y
 *            upper left corner Y coordinate
 * @param widthOfNewView
 *            widht of the new view
 * @param heightOfNewView
 *            height of the new view
 * @throws NoninvertibleTransformException
 *             throws an exception when the transformation fails
 */
public final void zoom(final int x, final int y,
        final double widthOfNewView, final double heightOfNewView)
        throws NoninvertibleTransformException {
    LayerViewPanel lvp = this.layerViewPanels.iterator().next();
    double zoomFactor = Math.min(lvp.getWidth() / widthOfNewView,
            lvp.getHeight() / heightOfNewView);
    double realWidthOfNewView = lvp.getWidth() / zoomFactor;
    double realHeightOfNewView = lvp.getHeight() / zoomFactor;
    IEnvelope zoomEnvelope;
    try {
        zoomEnvelope = this.toModelEnvelope(x - Viewport.ZERO_POINT_FIVE
                * realWidthOfNewView, x + Viewport.ZERO_POINT_FIVE
                * realWidthOfNewView, y - Viewport.ZERO_POINT_FIVE
                * realHeightOfNewView, y + Viewport.ZERO_POINT_FIVE
                * realHeightOfNewView);
    } catch (NoninvertibleTransformException ex) {
        this.zoomToFullExtent();
        return;
    }
    this.zoom(zoomEnvelope);
}