Issue 5542: Implement tooltips for new options page

desktop-options.js

Index: desktop-options.js
===================================================================
--- a/desktop-options.js
+++ b/desktop-options.js
@@ -533,18 +533,12 @@
 
   function findParentData(element, dataName, returnElement)
   {
-    while (element)
-    {
-      if (element.hasAttribute("data-" + dataName))
-      {
-        if (returnElement)
-          return element;
-        return element.getAttribute("data-" + dataName);
-      }
-
-      element = element.parentElement;
-    }
-    return null;
+    element = element.closest(`[data-${dataName}]`);
+    if (!element)
+      return null;
+    if (returnElement)
+      return element;
+    return element.getAttribute(`data-${dataName}`);
   }
 
   function sendMessageHandleErrors(message, onSuccess)
@@ -1295,7 +1289,7 @@
         updateSubscription(subscription);
         break;
       case "added":
-        let {url, recommended} = subscription;
+        let {url} = subscription;
         // Handle custom subscription
         if (/^~user/.test(url))
         {
@@ -1401,30 +1395,42 @@
 
   function updateTooltips()
   {
-    let anchors = document.querySelectorAll(":not(.tooltip) > [data-tooltip]");
-    for (let anchor of anchors)
+    const anchors = document.querySelectorAll("[data-tooltip]");
+    for (const anchor of anchors)
     {
       let id = anchor.getAttribute("data-tooltip");
 
-      let wrapper = document.createElement("div");
-      wrapper.setAttribute("aria-describedby", id);
-      wrapper.setAttribute("tabindex", "0");
-      wrapper.className = "icon tooltip";
-      anchor.parentNode.replaceChild(wrapper, anchor);
-      wrapper.appendChild(anchor);
+      // instead of replacing the whole node
+      // just make it non discoverable for
+      // the next updateTooltips call
+      anchor.removeAttribute("data-tooltip");
+      anchor.classList.add("icon", "tooltip");
 
-      let tooltip = document.createElement("div");
-      tooltip.id = id;
+      const tooltip = document.createElement("div");
       tooltip.setAttribute("role", "tooltip");
+      // needed by aria-describedby
+      tooltip.id = id;
 
-      let paragraph = document.createElement("p");
+      const paragraph = document.createElement("p");
       paragraph.textContent = getMessage(id);
       tooltip.appendChild(paragraph);
 
-      wrapper.appendChild(tooltip);
+      anchor.appendChild(tooltip);
+      anchor.setAttribute("aria-describedby", id);
+
+      // if focused and the mouse reaches another (?)
+      // blur the active element to drop previous tooltip
+      anchor.addEventListener("mouseover", dropActiveElement);
     }
   }
 
+  function dropActiveElement(event)
+  {
+    const active = event.target.ownerDocument.activeElement;
+    if (active)
+      active.blur();
+  }
+
   ext.onMessage.addListener((message) =>
   {
     switch (message.type)