gradientColor.js 2.97 KB
// 实现渐变色
export default class gradientColor {
    constructor (startColor, endColor, step) {
        this.startColor = startColor;
        this.endColor = endColor;
        this.step = step;
    }

    exgColor() {
        var startRGB, startR, startG, startB;
        startRGB = this.colorRgb(this.startColor);//转换为rgb数组模式
        startR = startRGB[0];
        startG = startRGB[1];
        startB = startRGB[2];
        var endRGB, endR, endG, endB;
        endRGB = this.colorRgb(this.endColor);
        endR = endRGB[0];
        endG = endRGB[1];
        endB = endRGB[2];
        var sR, sG, sB;
        sR = (endR - startR) / this.step;//总差值
        sG = (endG - startG) / this.step;
        sB = (endB - startB) / this.step;

        var colorArr = [];
        for (var i = 0; i < this.step; i++) {
            //计算每一步的hex值 
            var hex = this.colorHex('rgb('+ parseInt((sR * i + startR))+ ',' + parseInt((sG * i + startG))+ ',' + parseInt((sB * i + startB)) + ')');
            colorArr.push(hex);
        }
        return colorArr;
    }

    colorRgb (sColor) {
        var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
        var sColor = sColor.toLowerCase();
        if (sColor && reg.test(sColor)) {
            if (sColor.length === 4) {
                var sColorNew = "#";
                for (var i = 1; i < 4; i += 1) {
                    sColorNew += sColor.slice(i, i + 1).concat(sColor.slice(i, i + 1));
                }
                sColor = sColorNew;
            }
            //处理六位的颜色值
            var sColorChange = [];
            for (var i = 1; i < 7; i += 2) {
                sColorChange.push(parseInt("0x" + sColor.slice(i, i + 2)));
            }
            return sColorChange;
        } else {
            return sColor;
        }
    }
    colorHex (rgb) {
        var _this = rgb;
        var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
        if (/^(rgb|RGB)/.test(_this)) {
            var aColor = _this.replace(/(?:(|)|rgb|RGB)*/g, "").split(",");
            var strHex = "#";
            for (var i = 0; i < aColor.length; i++) {
                var hex = Number(aColor[i]).toString(16);
                hex = hex < 10 ? 0 + '' + hex : hex;// 保证每个rgb的值为2位
                if (hex === "0") {
                    hex += hex;
                }
                strHex += hex;
            }
            if (strHex.length !== 7) {
                strHex = _this;
            }
            return strHex;
        } else if (reg.test(_this)) {
            var aNum = _this.replace(/#/, "").split("");
            if (aNum.length === 6) {
                return _this;
            } else if (aNum.length === 3) {
                var numHex = "#";
                for (var i = 0; i < aNum.length; i += 1) {
                    numHex += (aNum[i] + aNum[i]);
                }
                return numHex;
            }
        } else {
            return _this;
        }
    }
}

// export default gradientColor;