- // ==UserScript==
- // @name Style shadowRoot
- // @namespace https://github.com/Procyon-b
- // @version 0.1
- // @description Allow stylus to target elements in shadow-root
- // @author Achernar
- // @match http://NOTHING/
- // @run-at document-start
- // @grant none
- // ==/UserScript==
-
- (function() {
- "use strict";
- var id=Date.now()
-
- //console.info('%c shadow CSS ', 'background: lightblue', {document}, {'body':document ? document.body:'-'}, {dE:document ? document.documentElement : '-'})
-
- // patch attachShadow()
- var AS=HTMLElement.prototype.attachShadow;
- //console.info('%c shadow CSS ', 'background: #6699FF', id,{AS},location.href);
-
- HTMLElement.prototype.attachShadow=function(m){/*[native */
- var e=this;
- //console.info('%c shadow CSS ', 'background: #6699FF', id,{e, m})
- e.sr=AS.call(e,m);
- shadows.push(e.sr);
- inject(e.sr);
- shadowMod(e.sr);
- return e.sr;
- }
- // END patch
-
- var sheets={}, order=[],
- shadows=[], sCSS={}, injCSS='', oldInjCSS='';
-
- // catch stylus injections
- const obs=new MutationObserver(function(muts){
- for (let mut of muts) {
- //console.info('%c shadow CSS ', 'background: #6699FF', {mut});
- for (let n of mut.addedNodes) {
- if ( (n.tagName == 'STYLE') && (n.className == 'stylus') && n.id.startsWith('stylus-') ) {
- addCSS(n);
- }
- }
-
- for (let n of mut.removedNodes) {
- if ( (n.tagName == 'STYLE') && (n.className == 'stylus') && n.id.startsWith('stylus-') ) {
- remCSS(n);
- }
- }
- }
- });
- // END catch
-
- function init() {
- if (!document.documentElement) {
- setTimeout(init, 0);
- return;
- }
-
- obs.observe(document.documentElement, {attributes: false, subtree: false, childList: true });
- // check for stylesheets
- document.documentElement.querySelectorAll('style[id^="stylus-"].stylus').forEach( (e) => addCSS(e,2) );
- }
-
- init();
-
- // get only shadow-specific css
- function parseSheet(s) {
- var R=s.sheet.cssRules, sels, sel, shCSS='';
- for (let i=0; i < R.length; i++) {
- sel=R[i].selectorText;
- //console.info('%c shadow CSS ', 'background: #6699FF', sel);
- if (!sel.includes(':host')) continue;
- //console.info('%c shadow CSS ', 'background: #6699FF', {sels, f:sels.filter(function(v){ return v.includes(':host') })} );
- sels=sel.split(',').filter(function(v){ return v.includes(':host') }).join(',');
- shCSS+=sels.trim()+ R[i].cssText.substr(sel.length)+'\n';
- }
-
- if (shCSS) shCSS='/*'+s.id+'*/\n'+shCSS;
- //console.info('%c shadow CSS ', 'background: lightgreen', shCSS)
- return shCSS;
- }
-
- // inject in this shadow
- function inject(e) {
- if (injCSS == '') {
- if (e._inj_) {
- e._inj_.remove();
- delete e._inj_;
- }
- return;
- }
- if (!e._inj_ || !e._inj_.parentNode ) {
- let s=e._inj_=document.createElement('style');
- s.className='sh-stylus';
- e.appendChild(s);
- }
- e._inj_.textContent=injCSS;
- }
-
- // inject style
- function injectAll() {
- for (let i=0; i < shadows.length; i++) inject(shadows[i]);
- }
-
- // create & inject style in shadows
- function injUpd() {
- oldInjCSS=injCSS;
- injCSS='';
- for (let i=0; i < order.length; i++) injCSS+=sCSS[order[i]];
- if (injCSS !== oldInjCSS) injectAll();
- }
-
- // get stylus stylesheet order
- function getStylusOrder() {
- order=[];
- for (let i=0; i < document.styleSheets.length; i++) {
- let s=document.styleSheets[i].ownerNode;
- if (s.className == 'stylus') order.push(s.id);
- }
- }
-
- // handle new stylesheet
- function addCSS(n, k=1) {
- if (n.id in sheets) return;
- sheets[n.id]=n;
- if (n.__k__) ;//console.info('%c shadow CSS ', 'background: #6699FF', 'already known', n.id, n.__k__, k);
- else {
- n.__k__=k;
-
- // monitor modification
- const obs=new MutationObserver(function(muts){
- if (muts[0].addedNodes.length) {
- // === reparse stylesheet and reinject it
- sCSS[muts[0].target.id]=parseSheet(muts[0].target);
- injUpd();
- }
- });
- obs.observe(n, {attributes: false, subtree: false, childList: true });
- }
-
- sCSS[n.id]=parseSheet(n);
- getStylusOrder();
- injUpd();
- }
-
- // handle stylesheet removal
- function remCSS(n) {
- // is it only moved?
- if (n.parentNode == null) delete sheets[n.id];
- getStylusOrder();
- injUpd();
- }
-
- // monitor shadow modification
- function shadowMod(e) {
- const obs=new MutationObserver(function(muts){
- if (e._inj_ && (!e._inj_.parentNode || e._inj_.nextElementSibling) ) e.appendChild(e._inj_);
- });
- obs.observe(e, {attributes: false, subtree: false, childList: true });
- }
-
- })();