Bug 1466208 - part 11: Create PresShell::EventHandler::MaybeDiscardOrDelayKeyboardEvent() r=smaug

PresShell::EventHandler::HandleEvent() discards or puts off to dispatch
the handling event if it's a keyboard event and event dispatching is
suppressed by the document.

This patch moves the block into the new method for making HandleEvent() simpler.

Differential Revision: https://phabricator.services.mozilla.com/D18520

--HG--
extra : moz-landing-system : lando

layout/base/PresShell.cpp

@@ -6517,15 +6517,8 @@ nsresult PresShell::EventHandler::HandleEvent(nsIFrame* aFrame,
     }
   }
 
-  if (aGUIEvent->mClass == eKeyboardEventClass && GetDocument() &&
-      GetDocument()->EventHandlingSuppressed()) {
-    if (aGUIEvent->mMessage == eKeyDown) {
-      mPresShell->mNoDelayedKeyEvents = true;
-    } else if (!mPresShell->mNoDelayedKeyEvents) {
-      auto event = MakeUnique<DelayedKeyEvent>(aGUIEvent->AsKeyboardEvent());
-      PushDelayedEventIntoQueue(std::move(event));
-    }
-    aGUIEvent->mFlags.mIsSuppressedOrDelayed = true;
+  if (MaybeDiscardOrDelayKeyboardEvent(aGUIEvent)) {
+    // The event is discarded or put into the delayed event queue.
     return NS_OK;
   }
 
@@ -7273,6 +7266,30 @@ bool PresShell::EventHandler::MaybeHandleEventWithAnotherPresShell(
   return true;
 }
 
+bool PresShell::EventHandler::MaybeDiscardOrDelayKeyboardEvent(
+    WidgetGUIEvent* aGUIEvent) {
+  MOZ_ASSERT(aGUIEvent);
+
+  if (aGUIEvent->mClass != eKeyboardEventClass) {
+    return false;
+  }
+
+  Document* document = GetDocument();
+  if (!document || !document->EventHandlingSuppressed()) {
+    return false;
+  }
+
+  if (aGUIEvent->mMessage == eKeyDown) {
+    mPresShell->mNoDelayedKeyEvents = true;
+  } else if (!mPresShell->mNoDelayedKeyEvents) {
+    UniquePtr<DelayedKeyEvent> delayedKeyEvent =
+        MakeUnique<DelayedKeyEvent>(aGUIEvent->AsKeyboardEvent());
+    PushDelayedEventIntoQueue(std::move(delayedKeyEvent));
+  }
+  aGUIEvent->mFlags.mIsSuppressedOrDelayed = true;
+  return true;
+}
+
 Document* PresShell::GetPrimaryContentDocument() {
   nsPresContext* context = GetPresContext();
   if (!context || !context->IsRoot()) {

layout/base/PresShell.h

@@ -672,6 +672,17 @@ class PresShell final : public nsIPresShell,
     bool MaybeHandleEventWithAccessibleCaret(WidgetGUIEvent* aGUIEvent,
                                              nsEventStatus* aEventStatus);
 
+    /**
+     * MaybeDiscardOrDelayKeyboardEvent() may discared or put aGUIEvent into
+     * the delayed event queue if it's a keyboard event and if we should do so.
+     * If aGUIEvent is not a keyboard event, this does nothing.
+     *
+     * @param aGUIEvent         The handling event.
+     * @return                  true if this method discard the event or
+     *                          put it into the delayed event queue.
+     */
+    bool MaybeDiscardOrDelayKeyboardEvent(WidgetGUIEvent* aGUIEvent);
+
     /**
      * XXX Needs better name.
      * HandleEventInternal() dispatches aEvent into the DOM tree and