add initial marp implementation with sample content and build configuration

node_modules/@marp-team/marpit/lib/theme.js

@@ -0,0 +1,168 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var _postcss = _interopRequireDefault(require("postcss"));
+var _parse = _interopRequireDefault(require("./postcss/import/parse"));
+var _meta = _interopRequireDefault(require("./postcss/meta"));
+var _nesting = _interopRequireDefault(require("./postcss/nesting"));
+var _increasing_specificity = require("./postcss/root/increasing_specificity");
+var _replace = _interopRequireDefault(require("./postcss/root/replace"));
+var _section_size = _interopRequireDefault(require("./postcss/section_size"));
+var _symbol = _interopRequireDefault(require("./theme/symbol"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+const absoluteUnits = {
+  cm: v => v * 960 / 25.4,
+  in: v => v * 96,
+  mm: v => v * 96 / 25.4,
+  pc: v => v * 16,
+  pt: v => v * 4 / 3,
+  px: v => v,
+  q: v => v * 24 / 25.4
+};
+const convertToPixel = value => {
+  if (typeof value !== 'string') return undefined;
+  const matched = value.match(/^(-?[.0-9]+)([a-z]+)$/i);
+  if (!matched) return undefined;
+  const [, num, unit] = matched;
+  const parsed = Number.parseFloat(num);
+  if (Number.isNaN(parsed)) return undefined;
+  const conv = absoluteUnits[unit.toLowerCase()];
+  return conv ? conv(parsed) : undefined;
+};
+const memoizeProp = name => `${name}Memoized`;
+const reservedMetaType = {
+  theme: String
+};
+
+/**
+ * Marpit theme class.
+ */
+class Theme {
+  /**
+   * Create a Theme instance.
+   *
+   * You should use {@link Theme.fromCSS} unless there is some particular
+   * reason.
+   *
+   * @param {string} name The name of theme.
+   * @param {string} css The content of CSS.
+   * @hideconstructor
+   */
+  constructor(name, css) {
+    /**
+     * The name of theme.
+     * @type {string}
+     */
+    this.name = name;
+
+    /**
+     * The content of theme CSS.
+     * @type {string}
+     */
+    this.css = css;
+
+    /**
+     * Parsed metadata from CSS comments.
+     * @type {Object}
+     */
+    this.meta = Object.freeze({});
+
+    /**
+     * Parsed `@import` rules.
+     * @type {module:postcss/import/parse~ImportMeta[]}
+     */
+    this.importRules = [];
+
+    /**
+     * Slide width. It requires the absolute unit supported in CSS.
+     * @type {string}
+     */
+    this.width = undefined;
+
+    /**
+     * Slide height. It requires the absolute unit supported in CSS.
+     * @type {string}
+     */
+    this.height = undefined;
+    this.memoizeInit('width');
+    this.memoizeInit('height');
+  }
+
+  /**
+   * Create a Theme instance from Marpit theme CSS.
+   *
+   * @alias Theme.fromCSS
+   * @param {string} cssString The string of Marpit theme CSS. It requires
+   *     `@theme` meta comment.
+   * @param {Object} [opts]
+   * @param {Object} [opts.metaType] An object for defined types for metadata.
+   * @param {Object} [opts.cssNesting] Enable support for CSS nesting.
+   */
+  static fromCSS(cssString, opts = {}) {
+    const metaType = {
+      ...(opts.metaType || {}),
+      ...reservedMetaType
+    };
+    const {
+      css,
+      result
+    } = (0, _postcss.default)([!!opts.cssNesting && _nesting.default, (0, _meta.default)({
+      metaType
+    }), (0, _replace.default)({
+      pseudoClass: _increasing_specificity.pseudoClass
+    }), (0, _section_size.default)({
+      preferedPseudoClass: _increasing_specificity.pseudoClass
+    }), _parse.default].filter(p => p)).process(cssString);
+    if (!opts[_symbol.default] && !result.marpitMeta.theme) throw new Error('Marpit theme CSS requires @theme meta.');
+    const theme = new Theme(result.marpitMeta.theme, css);
+    theme.importRules = [...result.marpitImport];
+    theme.meta = Object.freeze({
+      ...result.marpitMeta
+    });
+    Object.assign(theme, {
+      ...result.marpitSectionSize
+    });
+    return Object.freeze(theme);
+  }
+
+  /**
+   * The converted width into pixel.
+   *
+   * @alias Theme#widthPixel
+   * @type {number}
+   * @readonly
+   */
+  get widthPixel() {
+    return this.memoize('width', convertToPixel);
+  }
+
+  /**
+   * The converted height into pixel.
+   *
+   * @alias Theme#heightPixel
+   * @type {number}
+   * @readonly
+   */
+  get heightPixel() {
+    return this.memoize('height', convertToPixel);
+  }
+
+  /** @private */
+  memoize(prop, func) {
+    if (this[memoizeProp(prop)].has(this[prop])) return this[memoizeProp(prop)].get(this[prop]);
+    const converted = func(this[prop]);
+    this[memoizeProp(prop)].set(this[prop], converted);
+    return converted;
+  }
+
+  /** @private */
+  memoizeInit(prop) {
+    if (!this[memoizeProp(prop)]) Object.defineProperty(this, memoizeProp(prop), {
+      value: new Map()
+    });
+  }
+}
+var _default = exports.default = Theme;