canvas 绘点图
项目中需要一个记录点实时变动的信息，在此记录一下：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<script src="http://cdn.bootcss.com/jquery/3.0.0-beta1/jquery.min.js"></script>
</head> <body>
<canvas id="myCanvas2" class="pointCanvas" width="950" height="650"></canvas>
<canvas id="myCanvas" class="pointCanvas" width="950" height="650"></canvas>
<script type="text/javascript">
var data1 = {
"code": 0,
"msg": "Get complete!",
"data": {
"d3:35:c5:e7:62:27": [369.92, 425.31],
"20:29:73:d7:09:37": [575.07, 192.57],
}
}
jQuery(function() {
$.fn.extend({ // 将可选择的变量传递给方法
runingPoint: function(options) {
return this.each(function() {
var __this = this;
// console.log($(this));
var runingPoint = {
// 参数配置
options: {
// c: $(__this),
radius: 10,
url: null,
imgUrl: null,
points: [],
selectedCircle: null,
hoveredCircle: null
}, // 初始化方法
init: function(config) {
var _this = this,
o = this.options;
$.extend(true, _this.options, config);
console.log(_this.options);
// 第一次执行
_this.getData();
_this.eventsFn(); // 每5秒执行一次
setInterval(function() {
o.hoveredCircle = undefined;
_this.getData();
}, 5000); // 测试数据 start
// setInterval(function(){ // var arrData = [];
// var D = data1.data;
// o.hoveredCircle = undefined;
// for(var i in D){
// arrData.push({x:D[i][0],y:D[i][1],name:i})
// }
// // console.log('init',arrData); // _this.drawFn(arrData);
// }, 5000);//测试数据 end }, // 获取数据
getData: function() {
var _this = this,
o = this.options;
var arrData = [];
$.getJSON(o.url, function(data) {
// console.log('getData',data);
if (data.code == 0) {
var D = data.data;
for (var i in D) {
arrData.push({
x: D[i][0],
y: D[i][1],
name: i
})
}
// 调用绘图方法
_this.drawFn(arrData); }
});
}, //清除canvas
clear: function() {
var _this = this,
o = this.options;
var ctx = __this.getContext("2d");
ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
}, // 获取点的信息
getPointInfoFn: function(p) {
var _this = this,
o = this.options; console.log('getPointInfoFn', JSON.stringify(p)); // $.getJSON('/path/to/file', {param1: 'value1'}, function(json, textStatus) { // });
}, // 事件绑定
eventsFn: function() {
var _this = this,
o = this.options;
// 红点click事件
$(__this).on('click', function(e) {
var e = window.event || e
var rect = this.getBoundingClientRect();
var mouseX = e.clientX - rect.left; //获取鼠标在canvsa中的坐标
var mouseY = e.clientY - rect.top; o.hoveredCircle = undefined;
for (var i = 0; i < o.points.length; i++) { // 检查每一个圆，看鼠标是否滑过
var circleX = o.points[i].x;
var circleY = o.points[i].y;
var radius = o.radius;
if (Math.pow(mouseX - circleX, 2) + Math.pow(mouseY - circleY, 2) < Math.pow(radius, 2)) {
o.hoveredCircle = i;
// console.log('click',o.points[i]);
// 获取点信息
_this.getPointInfoFn(o.points[i]);
//点击放大
_this.drawFn(o.points);
break;
}
}
}); }, // 绘图方法
drawFn: function(data) {
var _this = this,
o = this.options;
var D = data;
var ctx = __this.getContext("2d");
var img = document.createElement('img');
img.src = o.imgUrl;
o.points = [];
_this.clear();
if(!o.imgUrl){
drawPointFn();
return;
}
img.onload = function() {
drawPointFn();
}
function drawPointFn(){
ctx.drawImage(img, 0, 0);
ctx.fillStyle = "#FF0000";
// console.log(D);
for (var i in D) {
// 记录点的数据
o.points.push({
x: D[i].x,
y: D[i].y,
name: D[i].name
}); ctx.beginPath();
ctx.arc(D[i].x, D[i].y, i == o.hoveredCircle ? o.radius * 1.5 : o.radius, 0, Math.PI * 2, true); //Math.PI*2是JS计算方法，是圆
ctx.closePath();
ctx.fill();
}
}
} }; // runingPoint End
console.log(options)
runingPoint.init(options); });
}
}); //extend end // 初始化
$(".pointCanvas").runingPoint({
radius: 10,
imgUrl: './img/img.jpg',
url: 'data.json'
}); })
</script>
</body> </html>