jtopo

CanvasRenderingContext2D.prototype.wrapText = function(str,x,y){
var index = str.indexOf('-');
str2= str.substr(index+1,str.length);
str1= str.substr(0,index);
var textArray = new Array(str1,str2);
if(textArray==undefined||textArray==null)return false;
var rowCnt = textArray.length;
var i = 0,imax  = rowCnt,maxLength = 0;maxText = textArray[0];
for(;i<imax;i++){
var nowText = textArray[i],textLength = nowText.length;
if(textLength >=maxLength){
maxLength = textLength;
maxText = nowText;
}
}
var maxWidth = this.measureText(maxText).width;
var lineHeight = this.measureText("元").width;
x-= lineHeight*2;
for(var j= 0;j<textArray.length;j++){
var words = textArray[j];
this.fillText(words,x,y);
y+= lineHeight;
}
};

node.paintText = function(a){
a.beginPath(),
a.font = this.font,
a.wrapText(this.text,this.height/2,this.height);
a.closePath()
}