Rename folder + first build

Twitch Notes/background.js

@@ -0,0 +1,48 @@
+const activeTabs = {};
+let contentScriptRerunner = null;
+
+function runContentScript(tabId) {
+  chrome.tabs.executeScript(tabId, {
+    allFrames: true,
+    file: 'run.js',
+  });
+}
+
+function rerunContentScripts() {
+  // unfortunately we need to rerun periodically to handle iframes changing..
+  // eventually fixed when we require the new host permission or chrome releases a content script api
+  for (const tabId of Object.keys(activeTabs)) {
+    runContentScript(parseInt(tabId, 10));
+  }
+}
+
+function registerDynamicContentScript() {
+  chrome.tabs.onUpdated.addListener((tabId, {status}, {url}) => {
+    if (!status || !url) {
+      return;
+    }
+
+    runContentScript(tabId);
+    activeTabs[tabId] = true;
+
+    if (contentScriptRerunner == null) {
+      contentScriptRerunner = setInterval(rerunContentScripts, 5000);
+    }
+  });
+  chrome.tabs.onRemoved.addListener((tabId) => {
+    delete activeTabs[tabId];
+
+    if (contentScriptRerunner != null && Object.keys(activeTabs).length === 0) {
+      clearInterval(contentScriptRerunner);
+      contentScriptRerunner = null;
+    }
+  });
+}
+
+chrome.runtime.onInstalled.addListener(({reason}) => {
+  if (reason !== 'install') {
+    return;
+  }
+});
+
+registerDynamicContentScript();