添加地图滚轮放大缩小的动画效果

ZommAnimation=OpenLayers.Class(OpenLayers.Control.Navigation,{
size:null,
offset:null,
uricon:null,
ulicon:null,
bricon:null,
blicon:null,
imgPath:APIAdress + "/jsapi/theme/img/gis/navi/",
// 拖动的滑动效果必须使enableKinetic为true
dragPanOptions: {enableKinetic: false},
isCenterMouseWheel:true,
isCartoonPlay:false,
initialize: function(options) {
OpenLayers.Control.Navigation.prototype.initialize.apply(this, arguments);
this.size = new OpenLayers.Size(7,7);//10,6
this.offset = new OpenLayers.Pixel(-(this.size.w/2), -(this.size.h/2));

this.uricon = new OpenLayers.Icon(this.imgPath+"ur.png",this.size,this.offset);
this.ulicon = new OpenLayers.Icon(this.imgPath+"ul.png",this.size,this.offset);
this.bricon = new OpenLayers.Icon(this.imgPath+"br.png",this.size,this.offset);
this.blicon = new OpenLayers.Icon(this.imgPath+"bl.png",this.size,this.offset);
},

wheelUp: function(evt) {
var newZoom = this.map.getZoom();
if (newZoom<this.map.getNumZoomLevels()-1 && !this.isCartoonPlay) {
this.isCartoonPlay = true;
var markers=new OpenLayers.Layer.Markers("Zoomin",{displayInLayerSwitcher: false});
var x=evt.xy.x;
var y=evt.xy.y;
var marker1=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x+30,y+23)),this.bricon.clone());
var marker2=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x-30,y+23)),this.blicon.clone());
var marker3=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x+30,y-23)),this.uricon.clone());
var marker4=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x-30,y-23)),this.ulicon.clone());
marker1.map=this.map;
marker2.map=this.map;
marker3.map=this.map;
marker4.map=this.map;
markers.addMarker(marker1);
markers.addMarker(marker2);
markers.addMarker(marker3);
markers.addMarker(marker4);
map.addLayer(markers);
var j=0;
var t;

var _self = this;
var movemarker=function(){
j++;
marker1.moveTo(new OpenLayers.Pixel(x+30+6*j,y+23+4*j));
marker2.moveTo(new OpenLayers.Pixel(x-30-6*j,y+23+4*j));
marker3.moveTo(new OpenLayers.Pixel(x+30+6*j,y-23-4*j));
marker4.moveTo(new OpenLayers.Pixel(x-30-6*j,y-23-4*j));
if(j==5){
_self.isCartoonPlay = false;
map.removeLayer(markers);
markers.clearMarkers();
markers.destroy();
window.clearInterval(t);
}
};
t=window.setInterval(function(){movemarker();}, 100);
}
this.wheelChange(evt, 1);
},

wheelDown: function(evt) {
var newZoom = this.map.getZoom();
if (newZoom>this.map.minLevel && !this.isCartoonPlay) {
this.isCartoonPlay = true;
var markers=new OpenLayers.Layer.Markers("Zoomout",{displayInLayerSwitcher: false});
var x=evt.xy.x;
var y=evt.xy.y;
var marker1=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x+60,y+45)),this.ulicon.clone());
var marker2=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x-60,y+45)),this.uricon.clone());
var marker3=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x+60,y-45)),this.blicon.clone());
var marker4=new OpenLayers.Marker(map.getLonLatFromPixel(new OpenLayers.Pixel(x-60,y-45)),this.bricon.clone());
marker1.map=this.map;
marker2.map=this.map;
marker3.map=this.map;
marker4.map=this.map;
markers.addMarker(marker1);
markers.addMarker(marker2);
markers.addMarker(marker3);
markers.addMarker(marker4);
map.addLayer(markers);
var j=0;
var t;
var _self = this;
var movemarker=function(){
j++;
marker1.moveTo(new OpenLayers.Pixel(x+60-6*j,y+45-4*j));
marker2.moveTo(new OpenLayers.Pixel(x-60+6*j,y+45-4*j));
marker3.moveTo(new OpenLayers.Pixel(x+60-6*j,y-45+4*j));
marker4.moveTo(new OpenLayers.Pixel(x-60+6*j,y-45+4*j));
if(j==5){
_self.isCartoonPlay = false;
map.removeLayer(markers);
markers.clearMarkers();
markers.destroy();
window.clearInterval(t);
}
};
t=window.setInterval(function(){movemarker();}, 100);
}
this.wheelChange(evt, -1);
},
wheelChange: function(evt, deltaZ) {
var currentZoom = this.map.getZoom();
var newZoom = this.map.getZoom() + Math.round(deltaZ);
newZoom = Math.max(newZoom, 0);
newZoom = Math.min(newZoom, this.map.getNumZoomLevels());
if (newZoom === currentZoom) {
return;
}
var size = this.map.getSize();
var deltaX = size.w/2 - evt.xy.x;
var deltaY = evt.xy.y - size.h/2;
var newRes = this.map.baseLayer.getResolutionForZoom(newZoom);
var zoomPoint = this.map.getLonLatFromPixel(evt.xy);
var newCenter = new OpenLayers.LonLat(
zoomPoint.lon + deltaX * newRes,
zoomPoint.lat + deltaY * newRes );
if(this.isCenterMouseWheel)
this.map.setCenter( newCenter, newZoom );
else
this.map.setCenter(this.map.getCenter(), this.map.getZoom() + Math.round(deltaZ));

}
});