index.js 4.84 KB
'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});

var _has = require('has');

var _has2 = _interopRequireDefault(_has);

var _postcss = require('postcss');

var _postcss2 = _interopRequireDefault(_postcss);

var _postcssValueParser = require('postcss-value-parser');

var _postcssValueParser2 = _interopRequireDefault(_postcssValueParser);

var _cssnanoUtilGetMatch = require('cssnano-util-get-match');

var _cssnanoUtilGetMatch2 = _interopRequireDefault(_cssnanoUtilGetMatch);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function getValues(list, { value }, index) {
    if (index % 2 === 0) {
        return [...list, parseFloat(value)];
    }

    return list;
}

function matrix3d(node, values) {
    // matrix3d(a, b, 0, 0, c, d, 0, 0, 0, 0, 1, 0, tx, ty, 0, 1) => matrix(a, b, c, d, tx, ty)
    if (values[15] && values[2] === 0 && values[3] === 0 && values[6] === 0 && values[7] === 0 && values[8] === 0 && values[9] === 0 && values[10] === 1 && values[11] === 0 && values[14] === 0 && values[15] === 1) {
        const { nodes } = node;

        node.value = 'matrix';
        node.nodes = [nodes[0], // a
        nodes[1], // ,
        nodes[2], // b
        nodes[3], // ,
        nodes[8], // c
        nodes[9], // ,
        nodes[10], // d
        nodes[11], // ,
        nodes[24], // tx
        nodes[25], // ,
        nodes[26]];
    }
}

const rotate3dMappings = [['rotateX', [1, 0, 0]], // rotate3d(1, 0, 0, a) => rotateX(a)
['rotateY', [0, 1, 0]], // rotate3d(0, 1, 0, a) => rotateY(a)
['rotate', [0, 0, 1]]];

const rotate3dMatch = (0, _cssnanoUtilGetMatch2.default)(rotate3dMappings);

function rotate3d(node, values) {
    const { nodes } = node;
    const match = rotate3dMatch(values.slice(0, 3));

    if (match.length) {
        node.value = match;
        node.nodes = [nodes[6]];
    }
}

function rotateZ(node) {
    // rotateZ(rz) => rotate(rz)
    node.value = 'rotate';
}

function scale(node, values) {
    const { nodes } = node;

    if (!nodes[2]) {
        return;
    }

    const [first, second] = values;

    // scale(sx, sy) => scale(sx)
    if (first === second) {
        node.nodes = [nodes[0]];

        return;
    }

    // scale(sx, 1) => scaleX(sx)
    if (second === 1) {
        node.value = 'scaleX';
        node.nodes = [nodes[0]];

        return;
    }

    // scale(1, sy) => scaleY(sy)
    if (first === 1) {
        node.value = 'scaleY';
        node.nodes = [nodes[2]];

        return;
    }
}

function scale3d(node, values) {
    const { nodes } = node;
    const [first, second, third] = values;

    // scale3d(sx, 1, 1) => scaleX(sx)
    if (second === 1 && third === 1) {
        node.value = 'scaleX';
        node.nodes = [nodes[0]];

        return;
    }

    // scale3d(1, sy, 1) => scaleY(sy)
    if (first === 1 && third === 1) {
        node.value = 'scaleY';
        node.nodes = [nodes[2]];

        return;
    }

    // scale3d(1, 1, sz) => scaleZ(sz)
    if (first === 1 && second === 1) {
        node.value = 'scaleZ';
        node.nodes = [nodes[4]];

        return;
    }
}

function translate(node, values) {
    const { nodes } = node;

    if (!nodes[2]) {
        return;
    }

    // translate(tx, 0) => translate(tx)
    if (values[1] === 0) {
        node.nodes = [nodes[0]];

        return;
    }

    // translate(0, ty) => translateY(ty)
    if (values[0] === 0) {
        node.value = 'translateY';
        node.nodes = [nodes[2]];

        return;
    }
}

function translate3d(node, values) {
    const { nodes } = node;

    // translate3d(0, 0, tz) => translateZ(tz)
    if (values[0] === 0 && values[1] === 0) {
        node.value = 'translateZ';
        node.nodes = [nodes[4]];
    }
}

const reducers = {
    matrix3d,
    rotate3d,
    rotateZ,
    scale,
    scale3d,
    translate,
    translate3d
};

function normalizeReducerName(name) {
    const lowerCasedName = name.toLowerCase();

    if (lowerCasedName === 'rotatez') {
        return 'rotateZ';
    }

    return lowerCasedName;
}

function reduce(node) {
    const { nodes, type, value } = node;
    const normalizedReducerName = normalizeReducerName(value);

    if (type === 'function' && (0, _has2.default)(reducers, normalizedReducerName)) {
        reducers[normalizedReducerName](node, nodes.reduce(getValues, []));
    }

    return false;
}

exports.default = _postcss2.default.plugin('postcss-reduce-transforms', () => {
    return css => {
        const cache = {};

        css.walkDecls(/transform$/i, decl => {
            const value = decl.value;

            if (cache[value]) {
                decl.value = cache[value];

                return;
            }

            const result = (0, _postcssValueParser2.default)(value).walk(reduce).toString();

            decl.value = result;
            cache[value] = result;
        });
    };
});
module.exports = exports['default'];