PageAction: display on init and tab switch if activated

src/background.js

@@ -30,8 +30,38 @@ function shareCurrentTab(tab) {
   });
 }
 
+/**
+ * Show Page Action on current page if activated
+ * @param  {string} tabId - Current tab id
+ * @return {void}         -
+ */
+function showPageAction(tabId){
+  browser.storage.local.get().then((storage) => {
+    if(storage.pageAction){
+      browser.pageAction.show(tabId);
+    }
+  });
+}
+
+/**
+ * Show page action with given active information
+ * @param  {object} activeInfo  -
+ * @return {void}               -
+ */
+function tabActivation(activeInfo){
+  showPageAction(activeInfo.tabId);
+}
+
+/*
+Initialize
+ */
+browser.tabs.query({active: true, currentWindow: true}).then((tabs) => {
+  showPageAction(tabs[0].id);
+});
+
 /*
 Listeners
  */
+browser.tabs.onActivated.addListener(tabActivation);
 browser.browserAction.onClicked.addListener(shareCurrentTab);
 browser.pageAction.onClicked.addListener(shareCurrentTab);