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Google API3 在地图上画圆圈，实现可拖动

2011-11-11 15:41 357 查看
<html xmlns="http://www.w3.org/1999/xhtml">
<head><title>API3_DrawCircle</title>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=true"></script>
<script type="text/javascript" language="JavaScript">
var myMap = null;

function displayMap(){
var myOptions = {
zoom: 14,
center: new google.maps.LatLng(41.967044,-73.835253),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
myMap = new google.maps.Map(document.getElementById("map"),myOptions);

google.maps.event.addListener(myMap, 'click', function(event) {
if (event) {
//singleClick = !singleClick;
//setTimeout("if (singleClick) createCircle(new google.maps.LatLng("+ event.latLng.lat() + ", " + event.latLng.lng() +"), 250);", 300);
createCircle(new google.maps.LatLng(event.latLng.lat(),event.latLng.lng()),450);
}

});
}

</script>

<style type="text/css">
@import url("http://www.google.com/uds/css/gsearch.css");
@import url("http://www.google.com/uds/solutions/localsearch/gmlocalsearch.css");

div#GQueryControl {
background-color: white;
width: 155;
}
</style>

</head>
<body onload="displayMap();" style="width: 100%; height: 100%; margin: 0px;">
<div id="map" style="width: 100%; height: 95%;"></div>
<!--<div style="font-family: arial, sans-serif;">Made by <a href="http://www.3rdcrust.com">3rdCrust.com</a></div>
<div id="QueryControl"></div>
<div id="ads">
</div -->
<script>
var metric = false;
var singleClick = false;
var infowindow = new google.maps.InfoWindow({
content: ""
});

function createCircle(point, radius) {
singleClick = false;
geoQuery = new GeoQuery();
geoQuery.initializeCircle(radius, point, myMap);
geoQuery.render();

alert(geoQuery._dragHandlePosition);
alert(geoQuery._radius);
}

/**
*
* 算法:通过原点、角度和距离计算目标点的坐标
* orig:原点坐标
* hdng:角度
* dist:原点的到目标点的距离
* @return 目标点坐标
*
*/
function destination(orig, hdng, dist) {
var R = 6371; // earth's mean radius in km
var oX, oY;
var x, y;
var d = dist/R;  // d = angular distance covered on earth's surface
hdng = hdng * Math.PI / 180; // degrees to radians
oX = orig.lng() * Math.PI / 180;
oY = orig.lat() * Math.PI / 180;

y = Math.asin( Math.sin(oY)*Math.cos(d) + Math.cos(oY)*Math.sin(d)*Math.cos(hdng) );
x = oX + Math.atan2(Math.sin(hdng)*Math.sin(d)*Math.cos(oY), Math.cos(d)-Math.sin(oY)*Math.sin(y));

y = y * 180 / Math.PI;
x = x * 180 / Math.PI;
return new google.maps.LatLng(y, x);
}

/**
*
* 算法:计算两个坐标点的距离
* point1:坐标点1
* point2:坐标点2
* @return 两点的距离
*
*/
function distance(point1, point2) {
var R = 6371; // earth's mean radius in km
var lon1 = point1.lng()* Math.PI / 180;
var lat1 = point1.lat() * Math.PI / 180;
var lon2 = point2.lng() * Math.PI / 180;
var lat2 = point2.lat() * Math.PI / 180;

var deltaLat = lat1 - lat2
var deltaLon = lon1 - lon2

var step1 = Math.pow(Math.sin(deltaLat/2), 2) + Math.cos(lat2) * Math.cos(lat1) * Math.pow(Math.sin(deltaLon/2), 2);
var step2 = 2 * Math.atan2(Math.sqrt(step1), Math.sqrt(1 - step1));
return step2 * R;
}

/**
* 画圆的类
*
*/
function GeoQuery() {

}

GeoQuery.prototype.CIRCLE='circle';        //画的形状
GeoQuery.prototype.COLORS=["#0000ff", "#00ff00", "#ff0000"];  //圆的颜色
var COLORI=0;             //默认颜色为0

GeoQuery.prototype = new GeoQuery();
GeoQuery.prototype._map;
GeoQuery.prototype._type;
GeoQuery.prototype._radius;
GeoQuery.prototype._dragHandle;
GeoQuery.prototype._centerHandle;
GeoQuery.prototype._polyline;
GeoQuery.prototype._color;
GeoQuery.prototype._control;
GeoQuery.prototype._points;
GeoQuery.prototype._dragHandlePosition;
GeoQuery.prototype._centerHandlePosition;

/**
*
* 圆的加载
*
*/
GeoQuery.prototype.initializeCircle = function(radius, point, map) {
this._type = this.CIRCLE;    //圆形
this._radius = radius;     //半径
this._map = map;      //地图

//计算扩大圆的点的位置
var distance1 = this._radius/1000;
var newPoint = destination(point,180,distance1);
distance1 = distance(point,newPoint);

this._dragHandlePosition = destination(point, 90, distance1);
//设置扩大圆的点的样式
this._dragHandle = new google.maps.Marker({
position: this._dragHandlePosition,
map: map,
draggable:true,
icon:"resizeArrow.png"
});

//中心点的位置
this._centerHandlePosition = point;
//设置中心点的样式
this._centerHandle = new google.maps.Marker({
position: this._centerHandlePosition,
map: map,
draggable:true,
icon:"centerArrow.png"
});

//随机获取颜色
this._color = this.COLORS[COLORI++ % 3];

//在地图上加载圆形
this._dragHandle.setMap(map);
this._centerHandle.setMap(map);

var myObject = this;
//扩大圆的点的拖拽停止事件
google.maps.event.addListener(myObject._dragHandle, 'dragend', function() {
myObject.updateCircle(1);

alert(myObject._dragHandlePosition);
alert(myObject._radius);
});
//扩大圆的点的拖拽事件
google.maps.event.addListener(myObject._dragHandle, 'drag', function() {myObject.updateCircle(1);});

//跳出的infowindow
google.maps.event.addListener(myObject._dragHandle, 'drag', function() {myObject.updateCircle(1);});

//圆的中心点的点击事件
google.maps.event.addListener(myObject._centerHandle, 'click', function() {
infowindow.setContent("我的窗口");
infowindow.open(myObject._centerHandle.get('map'), myObject._centerHandle);
});
//圆的中心点的拖拽停止事件
google.maps.event.addListener(myObject._centerHandle, 'dragend', function() {
myObject.updateCircle(2);

alert(myObject._dragHandlePosition);
alert(myObject._radius);
});
//圆的中心点的拖拽事件
google.maps.event.addListener(myObject._centerHandle, 'drag', function() {myObject.updateCircle(2);});
}

/**
*
* 圆的修改
* type:1为扩大缩小点，其他为中心点
*
*/
GeoQuery.prototype.updateCircle = function (type) {
this._polyline.setMap(null);
if (type==1) {
this._dragHandlePosition = this._dragHandle.getPosition();
this._radius = distance(this._centerHandlePosition, this._dragHandlePosition) * 1000;
this.render();
} else {
this._centerHandlePosition = this._centerHandle.getPosition();
this.render();
this._dragHandle.setPosition(this.getEast());
}

}

/**
*
* 圆的渲染
*
*/
GeoQuery.prototype.render = function() {
if (this._type == this.CIRCLE) {
this._points = [];

//var dis = distance(this._points[0],this._points[1])/2;
//var newPoint = destination(this._points[0],180,dis);

var distance = this._radius/1000;

for (i = 0; i < 72; i++) {
this._points.push(destination(this._centerHandlePosition, i * 360/72, distance) );
}
this._points.push(destination(this._centerHandlePosition, 0, distance) );

this._polyline = new google.maps.Polygon({
paths: this._points,
strokeColor: "#FF0000",
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: "#FF0000",
fillOpacity: 0.35
});
this._polyline.setMap(this._map);
}
}

/**
*
* 圆的删除
*
*/
GeoQuery.prototype.remove = function() {
this._polyline.setMap(null);
this._dragHandle.setMap(null);
this._centerHandle.setMap(null);
}

GeoQuery.prototype.getRadius = function() {
return this._radius;
}

GeoQuery.prototype.getHTML = function() {
return "<span><font color='"+ this._color + "''>" + this.getDistHtml() + "</font></span>";
}

GeoQuery.prototype.getDistHtml = function() {
result = "<img src='http://jfno.net/images/close.gif' onClick='myQueryControl.remove(" + this._control.getIndex(this) + ");'/>Radius ";
if (metric) {
if (this._radius < 1000) {
result += "in meters : " + this._radius.toFixed(1);
} else {
result += "in kilometers : " + (this._radius / 1000).toFixed(1);
}
} else {
var radius = this._radius * 3.2808399;
if (radius < 5280) {
result += "in feet : " + radius.toFixed(1);
} else {
result += "in miles : " + (radius / 5280).toFixed(1);
}
}
return result;
}

GeoQuery.prototype.getNorth = function() {
return this._points[0];
}

GeoQuery.prototype.getSouth = function() {
return this._points[(72/2)];
}

GeoQuery.prototype.getEast = function() {

var dis = distance(this._points[0],this._points[1])/2;
var newPoint = destination(this._points[0],180,dis);
return newPoint;
//return this._points[(72/4)];
}

GeoQuery.prototype.getWest = function() {
return this._points[(72/4*3)];
}

</script>
</body>
</html>
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