eventPage.js

const mainRegex104 = '*://www.104.com.tw/*';
const memberCenterRegex104 = '*://pda.104.com.tw/*';
// onInstalled  
chrome.runtime.onInstalled.addListener(function () {
    queryTabsAndShowPageActions({
        "active": false,
        "currentWindow": true,
        "url": [mainRegex104, memberCenterRegex104]
    });
});

// tabs.onUpdated
chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {
    queryTabsAndShowPageActions({
        "active": true,
        "currentWindow": true,
        "url": [mainRegex104, memberCenterRegex104]
    });
});

// tabs.onActivated
chrome.tabs.onActivated.addListener(function (tabId, changeInfo, tab) {
    queryTabsAndShowPageActions({
        "active": true,
        "currentWindow": true,
        "url": [mainRegex104, memberCenterRegex104]
    });
});

// find all tabs on the browser
function queryTabsAndShowPageActions(queryObject) {
    chrome.tabs.query(queryObject, (tabs) => {
        if (tabs && tabs.length > 0) {
            for (var i = 0; i < tabs.length; i++) {
                // pageAction.show on loaded tabs
                if (tabs[i].status === "complete") chrome.pageAction.show(tabs[i].id);
            }
        }
    }
    );
}