js封装成插件_Canvas统计图插件编写实例

之前就说过，我想写一个canvas画统计图的插件，现在写好了

先说下实现的功能吧：

　　1.可以通过自定义X轴坐标属性和Y轴坐标属性按比例画出统计图

　　2.可以选择画折现图还是柱形统计图，或者两者都实现

　　3.可以自由定义折现颜色，坐标颜色，柱形图颜色和canvas边框颜色，当然边框你也可以选择要或者不要

　　4.可以选择是否实现柱形图和折现图的动画实现

实现过程

画坐标——画箭头——做X轴和Y轴的标注——画柱形图——画折现图

话不多说，上代码

数量和对应得名称以及百分比 "yChartData" :[],//y轴的数量及名称 "axisColor" : "white",//坐标轴颜色 "columnChartColor" : "#EEE685",//柱形图颜色 "isNeedAnimation" : true,//是否需要动画 "isNeedLineChart" : true,//是否需要折线图 "isNeedColumnChart" : true,//是否需要柱形图 "lineChartColor" : "#90EE90",//折线图颜色，当isNeedLineChart=true时有效 "isNeedBorder" : false,//canvas是否需要外边框 "borderColor" : "white" //外边框颜色 },options); if(this.options.canvasWidth<=500) { this.axisBorderWidth = 3; this.fontSize = 8; } else if(this.options.canvasWidth<=800){ this.axisBorderWidth = 4; this.fontSize = 12; } else{ this.axisBorderWidth = 5; this.fontSize = 16; } var self = this; _init(); function _init(){ var canvasDom = document.createElement("canvas"); canvasDom.id = self.options.containerId+"_"+"canvas"; canvasDom.width = self.options.canvasWidth; canvasDom.height = self.options.canvasHeight; if(self.options.isNeedBorder){ canvasDom.style.borderWidth = 1; canvasDom.style.borderStyle = "solid"; canvasDom.style.borderColor = self.options.borderColor; } document.getElementById(self.options.containerId).appendChild(canvasDom); self.context = document.getElementById(self.options.containerId+"_"+"canvas"); self.ctx = self.context.getContext("2d"); _drawAxis(); }

function _drawCoordinatePoints(){
self.reactAngleWidth = (1-20.04)(self.options.canvasWidth-(2self.options.paddingLeft))/(self.options.columnChartData.length2-1);
self.lineDataList = [];
for(var i = 0;i<self.options.columnChartData.length;i++)
{
drawXText(self.ctx,2self.options.columnChartData[i].NOself.reactAngleWidth+self.options.paddingLeft+0.04(self.options.canvasWidth-(2self.options.paddingLeft))+self.reactAngleWidth/2,self.options.paddingTop/2,self.options.columnChartData[i].Name);
self.lineDataList.push({
x:2self.options.columnChartData[i].NOself.reactAngleWidth+self.options.paddingLeft+0.04(self.options.canvasWidth-(2self.options.paddingLeft))+self.reactAngleWidth/2,y:self.options.canvasHeight-(self.options.paddingTop+(self.options.canvasHeight-2self.options.paddingTop)self.options.columnChartData[i].PT)
})
}

//画Y轴title 画y轴虚线
self.reactAngleHeight = (self.options.canvasHeight-2self.options.paddingTop)/(self.options.yChartData.length+1);
for(var j = 0;j<self.options.yChartData.length;j++)
{
drawYText(self.ctx,3self.options.paddingLeft/4,self.options.paddingTop+self.reactAngleHeight(j+1),self.options.yChartData[j].Name);
//画虚线
drawDottedLine(self.ctx,self.options.paddingLeft,self.options.canvasWidth-self.options.paddingLeft,self.options.canvasWidth-2self.options.paddingLeft,10,self.axisBorderWidth/2);
}
_drawColumnChart();
}

function transformAxis(data)
{
var newData=[];
for(var i=0;i<data.length;i++){
newData.push({
x:data[i].x,y:self.options.canvasHeight-data[i].y
})
}
return newData;
}

//画y轴title
function drawYText(context,str) {
context.beginPath();
context.font = '{fontSize} Microsoft Yahei'.replace("{fontSize}",self.fontSize+"px");
context.fillStyle = 'white';
context.textAlign = 'right';
context.fillText(str,self.options.canvasHeight-y);
context.closePath();
}
//画x轴title
function drawXText(context,self.fontSize+"px");
context.fillStyle = 'white';
context.textAlign = 'center';
context.fillText(str,self.options.canvasHeight-y);
context.closePath();
}
function drawDottedLine(context,x1,y1,x2,y2,totalLength,length,lineWidth){
y1 = self.options.canvasHeight-y1;
y2 = self.options.canvasHeight-y2;
var dashLen = length === undefined ? 5 : length;
//计算有多少个线段
context.beginPath();
var num = Math.floor(totalLength/dashLen);
context.lineWidth = lineWidth;
for(var i = 0 ; i < num; i++)
{
contexti%2==0 ? 'moveTo' : 'lineTo';
}
context.stroke();
}
};
window.ChartDraws = ChartDraws;
}(window,document));

下面还有一个是实现requestAnimationFrame浏览器兼容的

var requestAnimationFrame = window.requestAnimationFrame;
var cancelAnimationFrame = window.cancelAnimationFrame;

var prefix;
//通过遍历各浏览器前缀，来得到requestAnimationFrame和cancelAnimationFrame在当前浏览器的实现形式
for( var i = 0; i < prefixes.length; i++ ) {
if ( requestAnimationFrame && cancelAnimationFrame ) {
break;
}
prefix = prefixes[i];
requestAnimationFrame = requestAnimationFrame || window[ prefix + 'RequestAnimationFrame' ];
cancelAnimationFrame = cancelAnimationFrame || window[ prefix + 'CancelAnimationFrame' ] || window[ prefix + 'CancelRequestAnimationFrame' ];
}

//如果当前浏览器不支持requestAnimationFrame和cancelAnimationFrame，则会退到setTimeout
if ( !requestAnimationFrame || !cancelAnimationFrame ) {
requestAnimationFrame = function( callback,element ) {
var currTime = new Date().getTime();
//为了使setTimteout的尽可能的接近每秒60帧的效果
var timeToCall = Math.max( 0,16 - ( currTime - lastTime ) );
var id = window.setTimeout( function() {
callback( currTime + timeToCall );
},timeToCall );
lastTime = currTime + timeToCall;
return id;
};
cancelAnimationFrame = function( id ) {
window.clearTimeout( id );
};
}

window.requestAnimationFrame = requestAnimationFrame;
window.cancelAnimationFrame = cancelAnimationFrame;
}());

附上

js封装成插件_Canvas统计图插件编写实例

先说下实现的功能吧：

实现过程

话不多说，上代码

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