| /* @flow */ |
| "use strict"; |
| |
| const isNumbery = require("./isNumbery"); |
| const isStandardSyntaxValue = require("./isStandardSyntaxValue"); |
| const isValidFontSize = require("./isValidFontSize"); |
| const isVariable = require("./isVariable"); |
| const keywordSets = require("../reference/keywordSets"); |
| const postcssValueParser = require("postcss-value-parser"); |
| |
| const nodeTypesToCheck = new Set(["word", "string", "space", "div"]); |
| |
| function joinValueNodes(firstNode, secondNode, charactersBetween) { |
| firstNode.value = firstNode.value + charactersBetween + secondNode.value; |
| |
| return firstNode; |
| } |
| |
| /** |
| * Get the font-families within a `font` shorthand property value. |
| * |
| * @param {string} value |
| * @return {object} Collection font-family nodes |
| */ |
| module.exports = function findFontFamily( |
| value /*: string*/ |
| ) /*: Array<Object>*/ { |
| const fontFamilies = []; |
| |
| const valueNodes = postcssValueParser(value); |
| |
| // Handle `inherit`, `initial` and etc |
| if ( |
| valueNodes.nodes.length === 1 && |
| keywordSets.basicKeywords.has(valueNodes.nodes[0].value.toLowerCase()) |
| ) { |
| return [valueNodes.nodes[0]]; |
| } |
| |
| let needMergeNodesByValue = false; |
| let mergeCharacters = null; |
| |
| valueNodes.walk((valueNode, index, nodes) => { |
| if (valueNode.type === "function") { |
| return false; |
| } |
| |
| if (!nodeTypesToCheck.has(valueNode.type)) { |
| return; |
| } |
| |
| const valueLowerCase = valueNode.value.toLowerCase(); |
| |
| // Ignore non standard syntax |
| if (!isStandardSyntaxValue(valueLowerCase)) { |
| return; |
| } |
| |
| // Ignore variables |
| if (isVariable(valueLowerCase)) { |
| return; |
| } |
| |
| // Ignore keywords for other font parts |
| if ( |
| keywordSets.fontShorthandKeywords.has(valueLowerCase) && |
| !keywordSets.fontFamilyKeywords.has(valueLowerCase) |
| ) { |
| return; |
| } |
| |
| // Ignore font-sizes |
| if (isValidFontSize(valueNode.value)) { |
| return; |
| } |
| |
| // Ignore anything come after a <font-size>/, because it's a line-height |
| if ( |
| nodes[index - 1] && |
| nodes[index - 1].value === "/" && |
| nodes[index - 2] && |
| isValidFontSize(nodes[index - 2].value) |
| ) { |
| return; |
| } |
| |
| // Ignore number values |
| if (isNumbery(valueLowerCase)) { |
| return; |
| } |
| |
| // Detect when a space or comma is dividing a list of font-families, and save the joining character. |
| if ( |
| (valueNode.type === "space" || |
| (valueNode.type === "div" && valueNode.value !== ",")) && |
| fontFamilies.length !== 0 |
| ) { |
| needMergeNodesByValue = true; |
| mergeCharacters = valueNode.value; |
| |
| return; |
| } else if (valueNode.type === "space" || valueNode.type === "div") { |
| return; |
| } |
| |
| const fontFamily = valueNode; |
| |
| if (needMergeNodesByValue) { |
| joinValueNodes( |
| fontFamilies[fontFamilies.length - 1], |
| valueNode, |
| mergeCharacters |
| ); |
| needMergeNodesByValue = false; |
| mergeCharacters = null; |
| } else { |
| fontFamilies.push(fontFamily); |
| } |
| }); |
| |
| return fontFamilies; |
| }; |