调整圈大小时获取半径 [英] Get radius while resizing circle
问题描述
谷歌地图没有大小调整事件,只有触发器可以触发在用户停止调整大小后 radius_changed
事件。
我想我可以设置一个时间间隔并获得半径而圆圈正在调整大小,但 .getRadius()
在用户停止调整大小之前不会显示当前半径。
在Google Maps JavaScript API v3文档中曾经有过一篇名为Fun with MVC的文章。
SO上的这个问题:如何编辑可编辑的圈子在Google地图中的控件中有一个例子,该文章在圆圈被调整大小时输出半径。
代码段:
function init(){var mapDiv = document.getElementById('map-canvas'); var map = new google.maps.Map(mapDiv,{center:new google.maps.LatLng(37.790234970864,-122.39031314844),zoom:8,mapTypeId:google.maps.MapTypeId.ROADMAP}); var distanceWidget = new DistanceWidget(map); google.maps.event.addListener(distanceWidget,'distance_changed',function(){displayInfo(distanceWidget);}); google.maps.event.addListener(distanceWidget,'position_changed',function(){displayInfo(distanceWidget);}); } google.maps.event.addDomListener(window,'load',init); / ** *一个距离小部件,它将显示一个可以调整大小的圆,并以*为单位提供半径。 * * @param {google.maps.Map}地图附加距离小部件的地图。 * * @constructor * / function DistanceWidget(map){this.set('map',map); this.set('position',map.getCenter()); var marker = new google.maps.Marker({draggable:true,icon:{url:https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png,size:new google.maps .Size(7,7),anchor:new google.maps.Point(4,4)},title:'Move me!'}); //将标记贴图属性绑定到DistanceWidget贴图属性marker.bindTo('map',this); //将标记位置属性绑定到DistanceWidget位置// property marker.bindTo('position',this); //创建一个新的半径小部件var radiusWidget = new RadiusWidget(); //将radiusWidget地图绑定到DistanceWidget地图radiusWidget.bindTo('map',this); //将radiusWidget中心绑定到DistanceWidget位置radiusWidget.bindTo('center',this,'position'); //绑定到radiusWidgets的distance属性this.bindTo('distance',radiusWidget); //绑定到radiusWidgets的边界属性this.bindTo('bounds',radiusWidget); } DistanceWidget.prototype = new google.maps.MVCObject(); / ** *一个半径小部件,它向地图添加一个圆,并以标记为中心。 * * @constructor * / function RadiusWidget(){var circle = new google.maps.Circle({strokeWeight:2}); //设置距离属性值,默认为50km。 this.set('distance',50); //将RadiusWidget bounds属性绑定到circle bounds属性。 this.bindTo('bounds',circle); //将圆心绑定到RadiusWidget中心属性circle.bindTo('center',this); //将圆地图绑定到RadiusWidget地图circle.bindTo('map',this); //将圆半径属性绑定到RadiusWidget的半径属性circle.bindTo('radius',this); this.addSizer_(); } RadiusWidget.prototype = new google.maps.MVCObject(); / ** *当距离发生变化时更新半径。 * / RadiusWidget.prototype.distance_changed = function(){this.set('radius',this.get('distance')* 1000); }; / ** *将sizer标记添加到地图。 * * @private * / RadiusWidget.prototype.addSizer_ = function(){var sizer = new google.maps.Marker({draggable:true,icon:{url:https://maps.gstatic.com/intl/zh-cn /mapfiles/markers2/measle_blue.png,size:new google.maps.Size(7,7),anchor:new google.maps.Point(4,4)},title:'Drag me!'}); sizer.bindTo('map',this); sizer.bindTo('position',this,'sizer_position'); var me = this; google.maps.event.addListener(sizer,'drag',function(){//设置圆距(半径)me.setDistance();}); }; / ** *更新圆的中心,并将sizer放回原位。 * *位置与DistanceWidget绑定,因此当*距离小部件的位置发生更改时,预计会更改此位置。 * / RadiusWidget.prototype.center_changed = function(){var bounds = this.get('bounds'); //边界可能并不总是如此,因此请检查它是否存在。 if(bounds){var lng = bounds.getNorthEast()。lng(); //将sizer放置在圆心的正中。 var position = new google.maps.LatLng(this.get('center')。lat(),lng); this.set('sizer_position',position); }}; / ** *以km为单位计算两个latlng位置之间的距离。 * @see http://www.movable-type.co.uk/scripts/latlong.html * * @param {google.maps.LatLng} p1第一个经典点。 * @param {google.maps.LatLng} p2第二个经济点。 * @return {number}以km为单位的两点之间的距离。 * @private * / RadiusWidget.prototype.distanceBetweenPoints_ = function(p1,p2){if(!p1 ||!p2){return 0; } var R = 6371; //以公里为单位的地球半径var dLat =(p2.lat() - p1.lat())* Math.PI / 180; var dLon =(p2.lng() - p1.lng())* Math.PI / 180; Math.sin(dLat / 2)* Math.sin(dLat / 2)+ Math.cos(p1.lat()* Math.PI / 180)* Math.cos(p2.lat()* Math。 PI / 180)* Math.sin(dLon / 2)* Math.sin(dLon / 2); var c = 2 * Math.atan2(Math.sqrt(a),Math.sqrt(1 - a)); var d = R * c;返回d; }; / ** *根据分割器的位置设置圆的距离。 * / RadiusWidget.prototype.setDistance = function(){//当sizer被拖动时,其位置发生变化。因为// RadiusWidget的sizer_position绑定到sizer的位置,它也会改变。 var pos = this.get('sizer_position'); var center = this.get('center'); var distance = this.distanceBetweenPoints_(center,pos); //设置绑定到它的任何对象的distance属性this.set('distance',distance); };函数displayInfo(widget){var info = document.getElementById('info'); to.Value(3)+',distance:'+ widget.get('distance')。toFixed(3); } html,body,#map-canvas {height: 100%; margin:0px; < script src =https:// < / div>< div id =map-canvas >< / div>
Is it possible to get the radius of an existing circle while the circle is being resized?
Google maps doesn't have a "resizing" event and only triggers the radius_changed
event after the user stops resizing.
I figured I could get set up an interval and get the radius while the circle was being resized, but .getRadius()
doesn't show the current radius until the user stops resizing.
There used to be an "article" in the Google Maps Javascript API v3 documentation that did this called "Fun with MVC".
This question on SO: How to style editable circle controls in Google Maps has an example from that article that outputs the radius as the circle is resized.
fiddle (from my answer to that question)
code snippet:
function init() {
var mapDiv = document.getElementById('map-canvas');
var map = new google.maps.Map(mapDiv, {
center: new google.maps.LatLng(37.790234970864, -122.39031314844),
zoom: 8,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var distanceWidget = new DistanceWidget(map);
google.maps.event.addListener(distanceWidget, 'distance_changed', function() {
displayInfo(distanceWidget);
});
google.maps.event.addListener(distanceWidget, 'position_changed', function() {
displayInfo(distanceWidget);
});
}
google.maps.event.addDomListener(window, 'load', init);
/**
* A distance widget that will display a circle that can be resized and will
* provide the radius in km.
*
* @param {google.maps.Map} map The map on which to attach the distance widget.
*
* @constructor
*/
function DistanceWidget(map) {
this.set('map', map);
this.set('position', map.getCenter());
var marker = new google.maps.Marker({
draggable: true,
icon: {
url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
size: new google.maps.Size(7, 7),
anchor: new google.maps.Point(4, 4)
},
title: 'Move me!'
});
// Bind the marker map property to the DistanceWidget map property
marker.bindTo('map', this);
// Bind the marker position property to the DistanceWidget position
// property
marker.bindTo('position', this);
// Create a new radius widget
var radiusWidget = new RadiusWidget();
// Bind the radiusWidget map to the DistanceWidget map
radiusWidget.bindTo('map', this);
// Bind the radiusWidget center to the DistanceWidget position
radiusWidget.bindTo('center', this, 'position');
// Bind to the radiusWidgets' distance property
this.bindTo('distance', radiusWidget);
// Bind to the radiusWidgets' bounds property
this.bindTo('bounds', radiusWidget);
}
DistanceWidget.prototype = new google.maps.MVCObject();
/**
* A radius widget that add a circle to a map and centers on a marker.
*
* @constructor
*/
function RadiusWidget() {
var circle = new google.maps.Circle({
strokeWeight: 2
});
// Set the distance property value, default to 50km.
this.set('distance', 50);
// Bind the RadiusWidget bounds property to the circle bounds property.
this.bindTo('bounds', circle);
// Bind the circle center to the RadiusWidget center property
circle.bindTo('center', this);
// Bind the circle map to the RadiusWidget map
circle.bindTo('map', this);
// Bind the circle radius property to the RadiusWidget radius property
circle.bindTo('radius', this);
this.addSizer_();
}
RadiusWidget.prototype = new google.maps.MVCObject();
/**
* Update the radius when the distance has changed.
*/
RadiusWidget.prototype.distance_changed = function() {
this.set('radius', this.get('distance') * 1000);
};
/**
* Add the sizer marker to the map.
*
* @private
*/
RadiusWidget.prototype.addSizer_ = function() {
var sizer = new google.maps.Marker({
draggable: true,
icon: {
url: "https://maps.gstatic.com/intl/en_us/mapfiles/markers2/measle_blue.png",
size: new google.maps.Size(7, 7),
anchor: new google.maps.Point(4, 4)
},
title: 'Drag me!'
});
sizer.bindTo('map', this);
sizer.bindTo('position', this, 'sizer_position');
var me = this;
google.maps.event.addListener(sizer, 'drag', function() {
// Set the circle distance (radius)
me.setDistance();
});
};
/**
* Update the center of the circle and position the sizer back on the line.
*
* Position is bound to the DistanceWidget so this is expected to change when
* the position of the distance widget is changed.
*/
RadiusWidget.prototype.center_changed = function() {
var bounds = this.get('bounds');
// Bounds might not always be set so check that it exists first.
if (bounds) {
var lng = bounds.getNorthEast().lng();
// Put the sizer at center, right on the circle.
var position = new google.maps.LatLng(this.get('center').lat(), lng);
this.set('sizer_position', position);
}
};
/**
* Calculates the distance between two latlng locations in km.
* @see http://www.movable-type.co.uk/scripts/latlong.html
*
* @param {google.maps.LatLng} p1 The first lat lng point.
* @param {google.maps.LatLng} p2 The second lat lng point.
* @return {number} The distance between the two points in km.
* @private
*/
RadiusWidget.prototype.distanceBetweenPoints_ = function(p1, p2) {
if (!p1 || !p2) {
return 0;
}
var R = 6371; // Radius of the Earth in km
var dLat = (p2.lat() - p1.lat()) * Math.PI / 180;
var dLon = (p2.lng() - p1.lng()) * Math.PI / 180;
var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(p1.lat() * Math.PI / 180) * Math.cos(p2.lat() * Math.PI / 180) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
var d = R * c;
return d;
};
/**
* Set the distance of the circle based on the position of the sizer.
*/
RadiusWidget.prototype.setDistance = function() {
// As the sizer is being dragged, its position changes. Because the
// RadiusWidget's sizer_position is bound to the sizer's position, it will
// change as well.
var pos = this.get('sizer_position');
var center = this.get('center');
var distance = this.distanceBetweenPoints_(center, pos);
// Set the distance property for any objects that are bound to it
this.set('distance', distance);
};
function displayInfo(widget) {
var info = document.getElementById('info');
info.innerHTML = 'Position: ' + widget.get('position').toUrlValue(3) + ', distance: ' + widget.get('distance').toFixed(3);
}
html,
body,
#map-canvas {
height: 100%;
margin: 0px;
padding: 0px
}
<script src="https://maps.googleapis.com/maps/api/js?libraries=geometry"></script>
<div id="info"></div>
<div id="map-canvas"></div>
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