html2canvas/src/parsing/textDecoration.js

/* @flow */
'use strict';

import Color from '../Color';

export const TEXT_DECORATION_STYLE = {
    SOLID: 0,
    DOUBLE: 1,
    DOTTED: 2,
    DASHED: 3,
    WAVY: 4
};

export const TEXT_DECORATION = {
    NONE: null
};

export const TEXT_DECORATION_LINE = {
    UNDERLINE: 1,
    OVERLINE: 2,
    LINE_THROUGH: 3,
    BLINK: 4
};

export type TextDecorationStyle = $Values<typeof TEXT_DECORATION_STYLE>;
export type TextDecorationLine = $Values<typeof TEXT_DECORATION_LINE>;
type TextDecorationLineType = Array<TextDecorationLine> | null;
export type TextDecoration = {
    textDecorationLine: Array<TextDecorationLine>,
    textDecorationStyle: TextDecorationStyle,
    textDecorationColor: Color | null
};

const parseLine = (line: string): TextDecorationLine => {
    switch (line) {
        case 'underline':
            return TEXT_DECORATION_LINE.UNDERLINE;
        case 'overline':
            return TEXT_DECORATION_LINE.OVERLINE;
        case 'line-through':
            return TEXT_DECORATION_LINE.LINE_THROUGH;
    }
    return TEXT_DECORATION_LINE.BLINK;
};

const parseTextDecorationLine = (line: string): TextDecorationLineType => {
    if (line === 'none') {
        return null;
    }

    return line.split(' ').map(parseLine);
};

const parseTextDecorationStyle = (style: string): TextDecorationStyle => {
    switch (style) {
        case 'double':
            return TEXT_DECORATION_STYLE.DOUBLE;
        case 'dotted':
            return TEXT_DECORATION_STYLE.DOTTED;
        case 'dashed':
            return TEXT_DECORATION_STYLE.DASHED;
        case 'wavy':
            return TEXT_DECORATION_STYLE.WAVY;
    }
    return TEXT_DECORATION_STYLE.SOLID;
};

export const parseTextDecoration = (style: CSSStyleDeclaration): TextDecoration | null => {
    const textDecorationLine = parseTextDecorationLine(
        style.textDecorationLine ? style.textDecorationLine : style.textDecoration
    );
    if (textDecorationLine === null) {
        return TEXT_DECORATION.NONE;
    }

    const textDecorationColor = style.textDecorationColor
        ? new Color(style.textDecorationColor)
        : null;
    const textDecorationStyle = parseTextDecorationStyle(style.textDecorationStyle);

    return {
        textDecorationLine,
        textDecorationColor,
        textDecorationStyle
    };
};