ant-design/components/progress/Line.tsx

import * as React from 'react';
import { validProgress } from './utils';
import { ProgressProps, ProgressGradient, StringGradients } from './progress';

interface LineProps extends ProgressProps {
  prefixCls: string;
  children: React.ReactNode;
}

/**
 * {
 *   '0%': '#afc163',
 *   '75%': '#009900',
 *   '50%': 'green',     ====>     '#afc163 0%, #66FF00 25%, #00CC00 50%, #009900 75%, #ffffff 100%'
 *   '25%': '#66FF00',
 *   '100%': '#ffffff'
 * }
 */
export const sortGradient = (gradients: ProgressGradient) => {
  let tempArr = [];
  for (const [key, value] of Object.entries(gradients)) {
    const formatKey = parseFloat(key.replace(/%/g, ''));
    if (isNaN(formatKey)) {
      return {};
    }
    tempArr.push({
      key: formatKey,
      value,
    });
  }
  tempArr = tempArr.sort((a, b) => a.key - b.key);
  return tempArr.map(({ key, value }) => `${value} ${key}%`).join(', ');
};

/**
 * {
 *   '0%': '#afc163',
 *   '25%': '#66FF00',
 *   '50%': '#00CC00',     ====>  linear-gradient(to right, #afc163 0%, #66FF00 25%,
 *   '75%': '#009900',              #00CC00 50%, #009900 75%, #ffffff 100%)
 *   '100%': '#ffffff'
 * }
 *
 * Then this man came to realize the truth:
 * Besides six pence, there is the moon.
 * Besides bread and butter, there is the bug.
 * And...
 * Besides women, there is the code.
 */
export const handleGradient = (strokeColor: ProgressGradient) => {
  const { from = '#1890ff', to = '#1890ff', direction = 'to right', ...rest } = strokeColor;
  if (Object.keys(rest).length !== 0) {
    const sortedGradients = sortGradient(rest as StringGradients);
    return { backgroundImage: `linear-gradient(${direction}, ${sortedGradients})` };
  }
  return { backgroundImage: `linear-gradient(${direction}, ${from}, ${to})` };
};

const Line: React.SFC<LineProps> = props => {
  const {
    prefixCls,
    percent,
    successPercent,
    strokeWidth,
    size,
    strokeColor,
    strokeLinecap,
    children,
  } = props;
  let backgroundProps;
  if (strokeColor && typeof strokeColor !== 'string') {
    backgroundProps = handleGradient(strokeColor);
  } else {
    backgroundProps = {
      background: strokeColor,
    };
  }
  const percentStyle = {
    width: `${validProgress(percent)}%`,
    height: strokeWidth || (size === 'small' ? 6 : 8),
    borderRadius: strokeLinecap === 'square' ? 0 : '100px',
    ...backgroundProps,
  };
  const successPercentStyle = {
    width: `${validProgress(successPercent)}%`,
    height: strokeWidth || (size === 'small' ? 6 : 8),
    borderRadius: strokeLinecap === 'square' ? 0 : '100px',
  };
  const successSegment =
    successPercent !== undefined ? (
      <div className={`${prefixCls}-success-bg`} style={successPercentStyle} />
    ) : null;
  return (
    <div>
      <div className={`${prefixCls}-outer`}>
        <div className={`${prefixCls}-inner`}>
          <div className={`${prefixCls}-bg`} style={percentStyle} />
          {successSegment}
        </div>
      </div>
      {children}
    </div>
  );
};

export default Line;