Examples with CollectionWrapper ol.gwt.CollectionWrapper used on opensource projects

Example 1 with CollectionWrapper

use of ol.gwt.CollectionWrapper in project gwt-ol3 by TDesjardins.

the class OLUtil method getZoomLevel.

/**
 * Gets the current zoomlevel of the given {@link Map}.
 * @param map
 *            {@link Map}
 * @return zoomlevel on success, else {@link Double#NaN}
 */
public static double getZoomLevel(Map map) {
    View v = map.getView();
    // try to get zoom
    double z = getZoom(v);
    if (!Double.isNaN(z)) {
        return z;
    }
    // zoom is undefined, so check resolution
    double zoomResolution = v.getResolution();
    // walk layers to find resolution
    CollectionWrapper<Base> layers = new CollectionWrapper<Base>(map.getLayers());
    for (Base l : layers) {
        // get source if layer instance has it
        Source source = l.get("source");
        if (source != null) {
            // try to get a tilegrid from the source
            TileGrid tg = getTileGrid(source);
            if (tg != null) {
                // check resolutions
                double[] resolutions = tg.getResolutions();
                if (resolutions != null) {
                    double dPreviousResolution = 0;
                    for (int i = 0; i < resolutions.length; i++) {
                        // resolutions are sorted in descending order, so
                        // compare with actual one
                        double resolution = resolutions[i];
                        if (resolution <= zoomResolution) {
                            if (i > 1) {
                                // calculate the delta of the resolution
                                // compared to the current and the previous
                                // zoomlevel
                                double delta = (resolution - zoomResolution) / (dPreviousResolution - resolution);
                                // adjust the integer zoomlevel to the delta
                                return i + delta;
                            } else {
                                return 0;
                            }
                        }
                        dPreviousResolution = resolution;
                    }
                }
            }
        }
    }
    return Double.NaN;
}