ZoomChangedListener.java

/*
 * $Id: org.eclipse.jdt.ui.prefs 5004 2006-03-17 20:47:08 -0800 (Fri, 17 Mar 2006) eelco12 $
 * $Revision: 5004 $
 * $Date: 2006-03-17 20:47:08 -0800 (Fri, 17 Mar 2006) $
 *
 * ==============================================================================
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package wicket.contrib.gmap3.mapevent;

import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.request.Request;
import org.apache.wicket.request.cycle.RequestCycle;
import wicket.contrib.gmap3.GMap;

/**
 * See "zoomend" in the event section of <a
 * href="http://www.google.com/apis/maps/documentation/reference.html#GMap2"
 * >GMap2</a>.
 */
public abstract class ZoomChangedListener extends GMapEventListenerBehavior {

    private static final long serialVersionUID = -5092475688071699463L;

    @Override
    protected String getEvent() {
        return Event.ZOOM_CHANGED.toString();
    }

    @Override
    protected void onEvent( final AjaxRequestTarget target ) {
        final Request request = RequestCycle.get().getRequest();
        int oldLevel = 0;
        int newLevel = 0;
        final String oldZoomLevelParameter = request.getRequestParameters().getParameterValue( "argument0" ).toString();
        final String newZoomLevelParameter = request.getRequestParameters().getParameterValue( "argument1" ).toString();
        if ( oldZoomLevelParameter == null || newZoomLevelParameter == null ) {
            return;
        }
        oldLevel = Integer.parseInt( oldZoomLevelParameter );
        newLevel = Integer.parseInt( newZoomLevelParameter );
        onZoomEnd( target, oldLevel, newLevel );
    }

    /**
     * Override this method to provide handling of a zoomEnd.<br>
     * You can get the new center coordinates of the map by calling
     * {@link GMap#getCenter()}.
     *
     * @param target
     *            the target that initiated the move
     */
    protected abstract void onZoomEnd( AjaxRequestTarget target, int oldLevel, int newLevel );

}