mirror of
https://github.com/material-components/material-web.git
synced 2024-09-11 13:46:10 +03:00
175 lines
5.1 KiB
TypeScript
175 lines
5.1 KiB
TypeScript
/**
|
|
* @license
|
|
* Copyright 2021 Google LLC
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
/**
|
|
* Array of pseudo classes to transform by default. These pseudo classes
|
|
* represent state interactions from the user (such as :hover) or the browser
|
|
* (such as :autofill) that cannot be reproduced with HTML markup.
|
|
*/
|
|
export const defaultTransformPseudoClasses = [
|
|
':active',
|
|
':autofill',
|
|
':focus',
|
|
':focus-visible',
|
|
':focus-within',
|
|
':hover',
|
|
':invalid',
|
|
':link',
|
|
':paused',
|
|
':playing',
|
|
':user-invalid',
|
|
':valid',
|
|
':visited',
|
|
];
|
|
|
|
/**
|
|
* Retrieves the transformed class name for a given pseudo class.
|
|
*
|
|
* @param pseudoClass The pseudo class to transform.
|
|
* @return The transform pseudo class string.
|
|
*/
|
|
export function getTransformedPseudoClass(pseudoClass: string) {
|
|
return `_${pseudoClass.substring(1)}`;
|
|
}
|
|
|
|
/**
|
|
* A weak set of stylesheets to use as reference for whether or not a stylesheet
|
|
* has been transformed.
|
|
*/
|
|
const transformedStyleSheets = new WeakSet<CSSStyleSheet>();
|
|
|
|
/**
|
|
* Transforms a document's stylesheets' pseudo classes into normal classes with
|
|
* a new stylesheet.
|
|
*
|
|
* Pseudo classes are given an underscore in their transformation. For example,
|
|
* `:hover` transforms to `._hover`.
|
|
*
|
|
* ```css
|
|
* .mdc-foo:hover {
|
|
* color: teal;
|
|
* }
|
|
* ```
|
|
* ```css
|
|
* .mdc-foo._hover {
|
|
* color: teal;
|
|
* }
|
|
* ```
|
|
*
|
|
* @param pseudoClasses An optional array of pseudo class names to transform.
|
|
*/
|
|
export function transformPseudoClasses(
|
|
stylesheets: Iterable<CSSStyleSheet>,
|
|
pseudoClasses = defaultTransformPseudoClasses) {
|
|
for (const stylesheet of stylesheets) {
|
|
if (transformedStyleSheets.has(stylesheet)) {
|
|
continue;
|
|
}
|
|
|
|
let rules: CSSRuleList;
|
|
try {
|
|
rules = stylesheet.cssRules;
|
|
} catch {
|
|
continue;
|
|
}
|
|
|
|
for (let j = rules.length - 1; j >= 0; j--) {
|
|
visitRule(rules[j], stylesheet, j, pseudoClasses);
|
|
}
|
|
|
|
transformedStyleSheets.add(stylesheet);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Visits a rule for the given stylesheet and adds a rule that replaces any
|
|
* pseudo classes with a regular transformed class for simulation styling.
|
|
*
|
|
* @param rule The CSS rule to transform.
|
|
* @param stylesheet The rule's parent stylesheet to update.
|
|
* @param index The index of the rule in the parent stylesheet.
|
|
* @param pseudoClasses An array of pseudo classes to search for and replace.
|
|
*/
|
|
function visitRule(
|
|
rule: CSSRule, stylesheet: CSSStyleSheet|CSSGroupingRule, index: number,
|
|
pseudoClasses: string[]) {
|
|
if (rule instanceof CSSMediaRule || rule instanceof CSSSupportsRule) {
|
|
for (let i = rule.cssRules.length - 1; i >= 0; i--) {
|
|
visitRule(rule.cssRules[i], rule, i, pseudoClasses);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (!(rule instanceof CSSStyleRule)) {
|
|
return;
|
|
}
|
|
|
|
try {
|
|
let {selectorText} = rule;
|
|
// match :foo, ensuring that it does not have a paren at the end
|
|
// (no pseudo class functions like :foo())
|
|
const regex = /(:(?![\w-]+\()[\w-]+)/g;
|
|
const matches = Array.from(selectorText.matchAll(regex)).filter(match => {
|
|
// don't match pseudo elements like ::foo
|
|
if (match.index != null && selectorText[match.index - 1] === ':') {
|
|
return false;
|
|
}
|
|
return pseudoClasses.includes(match[1]);
|
|
});
|
|
|
|
if (!matches.length) {
|
|
return;
|
|
}
|
|
|
|
matches.reverse();
|
|
selectorText = rearrangePseudoElements(selectorText);
|
|
for (const match of matches) {
|
|
selectorText = selectorText.substring(0, match.index!) +
|
|
`.${getTransformedPseudoClass(match[1])}` +
|
|
selectorText.substring(match.index! + match[1].length);
|
|
}
|
|
|
|
const css = `${selectorText} {${rule.style.cssText}}`;
|
|
stylesheet.insertRule(css, index + 1);
|
|
} catch (error: unknown) {
|
|
// Catch exception to skip the rule that cannot be parsed.
|
|
console.error(error);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Re-arranges a selector's pseudo elements to appear at the end of the
|
|
* selector. This prevents invalid CSS when replacing pseudo classes that
|
|
* appear after a pseudo element.
|
|
*
|
|
* @example
|
|
* // '.foo::before:hover' -> '.foo::before._hover' is invalid
|
|
*
|
|
* rearrangePseudoElements('.foo::before:hover'); // '.foo:hover::before'
|
|
* // '.foo:hover::before' -> '.foo._hover::before' is valid
|
|
*
|
|
* @param selectorText The selector text string to re-arrange.
|
|
* @return The re-arranged selector text.
|
|
*/
|
|
function rearrangePseudoElements(selectorText: string) {
|
|
const pseudoElementsBeforeClasses =
|
|
Array.from(selectorText.matchAll(/(?:::[\w-]+)+(?=:[\w-])/g));
|
|
pseudoElementsBeforeClasses.reverse();
|
|
for (const match of pseudoElementsBeforeClasses) {
|
|
const pseudoElement = match[0];
|
|
const pseudoElementIndex = match.index!;
|
|
const endOfCompoundSelector = selectorText.substring(pseudoElementIndex)
|
|
.match(/(\s(?!([^\s].)*\))|,|$)/)!;
|
|
const index = endOfCompoundSelector.index! + pseudoElementIndex;
|
|
selectorText = selectorText.substring(0, index) + pseudoElement +
|
|
selectorText.substring(index);
|
|
selectorText = selectorText.substring(0, pseudoElementIndex) +
|
|
selectorText.substring(pseudoElementIndex + pseudoElement.length);
|
|
}
|
|
|
|
return selectorText;
|
|
}
|