Primefaces GMap，如何在pointSelect事件后更新缩放

Question

I have ap:gmap component. It gets the zoom attribute from a bean, and adds a Marker on pointSelect

The usual User interaction is like this :

1. User zooms in, to find his desired Location
2. User Clicks on map
3. Map reloads with a Marker right on the point where she clicked

My only problem is that after the map refresh, the map is zoomed out, as the zoom attribute is not getting updated

p:gmap code looks like this

<p:gmap
    binding="#{mapBean.gmap}"
    zoom="#{mapBean.zoom}"
    model="#{mapBean.poiMapModel}"
    widgetVar="poiMap"
    id="poiMapComponent"        
    >
    <p:ajax event="pointSelect" 
        listener="#{mapBean.onPointSelect}"  
        update=":#{p:component('poiMapComponent')}"
    />  
</p:gmap>

MapBean's relevant Code is :

public void onPointSelect(PointSelectEvent event) {  

        LatLng latlng = event.getLatLng();  


        int _zoom = this.getGmap().getZoom(); //This never gets changed
        System.out.println("NEW ZOOM = " + _zoom);

        //Creating a new Marker in the clicked area
        selectedMarker = new Marker(latlng, "");
        poiMapModel.addOverlay(selectedMarker);
    }


    public org.primefaces.component.gmap.GMap getGmap() {
        return gmap;
    }
    public void setGmap(org.primefaces.component.gmap.GMap gmap) {
        this.gmap = gmap;
    }

After some testing, I'm sure that the MapBean.setZoom() is never getting called.

As you can see, I even tried binding the component back to the bean, so I Could get the p:gmap's current zoom value. But it seems that the PointSelect event always resets the zoom value. I can't find a way to process the changed zoom whatsoever.

It seems like there's a one-way communication between the bean and the p:gmap component!

My question is : Is there any way to detect zoom changes and get the updated value? Have the p:gmap updating the bean's zoom attribute

Answer 1

The p:gmap event API has four events (user guide 4.0 ed.2.2 p.214):

1. markerDrag : Get dragged marker instance
2. overlaySelect : Get selected overlay instance
3. pointSelect : Get coordinates of selected point
4. stateChange : Get boundaries of map / zoom level of map

So you can get the zoom level with

<p:ajax event="stateChange" listener="#{mapBean.onStateChange}"/>

public void onStateChange(StateChangeEvent event) {  
   zoom = event.getZoomLevel();
}