Bug 1634619 - Back out focusable state changes on overflow events. r=Jamie

Differential Revision: https://phabricator.services.mozilla.com/D74487

accessible/generic/RootAccessible.cpp

@@ -145,7 +145,7 @@ const char* const kEventTypes[] = {
     // HTMLInputElement.cpp & radio.js)
     "RadioStateChange", "popupshown", "popuphiding", "DOMMenuInactive",
     "DOMMenuItemActive", "DOMMenuItemInactive", "DOMMenuBarActive",
-    "DOMMenuBarInactive", "scroll", "overflow", "underflow"};
+    "DOMMenuBarInactive", "scroll"};
 
 nsresult RootAccessible::AddEventListeners() {
   // EventTarget interface allows to register event listeners to
@@ -446,19 +446,6 @@ void RootAccessible::ProcessDOMEvent(Event* aDOMEvent, nsINode* aTarget) {
                             accessible);
   }
 #endif
-  else if (eventType.EqualsLiteral("overflow") ||
-           eventType.EqualsLiteral("underflow")) {
-    // An overflow or underflow may mean the element's focusable state has
-    // changed.
-    if (accessible->IsContent() && !accessible->GetContent()->IsFocusable()) {
-      // If the element is not focusable for other DOM reasons (input, tabindex,
-      // etc.), dispatch a focusable state change event.
-      RefPtr<AccEvent> event = new AccStateChangeEvent(
-          accessible, states::FOCUSABLE,
-          (accessible->NativeInteractiveState() & states::FOCUSABLE) != 0);
-      targetDocument->FireDelayedEvent(event);
-    }
-  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////

accessible/tests/mochitest/events/test_focusable_statechange.html

@@ -66,62 +66,6 @@
       getNode("div").removeAttribute("tabindex");
       await p;
 
-      // When an element that has overflow content gets set to
-      // "auto", scrollbars appear and the element should become focusable.
-      info("change to overflow:auto");
-      p = waitForEvent(...focusableStateChange("scrollable1", true));
-      getNode("scrollable1").style.overflow = "auto";
-      await p;
-
-      // If an overflow:auto element's children change to fit
-      // within its bounds, the scrollability goes away and the
-      // element becomes not focusable.
-      info("clamp height to parent");
-      p = waitForEvent(...focusableStateChange("scrollable1", false));
-      getNode("in-scrollable1").style.height = "100%";
-      await p;
-
-      // If an overflow:auto element's children become larger
-      // than its bounding box, it becomes scrollable and focusable
-      // again. If the element is contenteditable, it is already focusable,
-      // so we don't expect an event for that.
-      info("unclamp height from parent");
-      p = waitForEvents({
-        expected: [focusableStateChange("scrollable1", true)],
-        unexpected: [focusableStateChange("scrollable2")]
-      });
-      getNode("in-scrollable2").style.height = "200%";
-      getNode("in-scrollable1").style.height = "200%";
-      await p;
-
-      // overflow:hidden disables scrollability and focusability.
-      // An overflowing textarea should not fire an event since it
-      // is always focusable.
-      info("change to overflow:hidden");
-      p = waitForEvents({
-        expected: [focusableStateChange("scrollable1", false)],
-        unexpected: [focusableStateChange("textarea")]
-      });
-      getNode("textarea").value = "one\ntwo\nthree\nfour\nfive";
-      getNode("scrollable1").style.overflow = "hidden";
-      await p;
-
-      // contenteditable makes things focusable
-      p = waitForEvent(...focusableStateChange("scrollable1", true));
-      getNode("scrollable1").contentEditable = "true";
-      await p;
-
-      // A disabled textarea will file a focusable state change event.
-      // A disabled overflow:auto div won't.
-      info("change to overflow:hidden");
-      p = waitForEvents({
-        expected: [focusableStateChange("textarea", false)],
-        unexpected: [focusableStateChange("scrollable2")]
-      });
-      getNode("textarea").disabled = true;
-      getNode("scrollable2").setAttribute("disabled", "true");
-      await p;
-
       p = waitForEvent(...focusableStateChange("link", false));
       getNode("link").removeAttribute("href");
       await p;
@@ -146,16 +90,6 @@
 
   <div id="div">Hello</div>
 
-  <div id="scrollable1" role="group" style="width: 50px; height: 50px; overflow: hidden;">
-    <div id="in-scrollable1" style="width: 100%; height: 200%;"></div>
-  </div>
-
-  <div id="scrollable2" role="group" style="width: 50px; height: 50px; overflow: auto;" contenteditable="true">
-    <div id="in-scrollable2" style="width: 100%; height: 100%;"></div>
-  </div>
-
-  <textarea id="textarea" rows="3" cols="30"></textarea>
-
   <a id="link" href="#">A link</a>
 
 </body>