From c73140a5cf3fed4e0a422ba9e6f000551bbfa5dc Mon Sep 17 00:00:00 2001
From: Brian Hackett <bhackett1024@gmail.com>
Date: Thu, 3 Jan 2019 06:39:12 -1000
Subject: [PATCH] Bug 1177346 Part 1 - Add setSuppressedEventListener
 interface, r=smaug.

--HG--
extra : rebase_source : a01b747e49f06fe6ef7724e38648ea28601b2793
---
 dom/base/Document.cpp      | 13 +++++++++++++
 dom/base/Document.h        |  8 ++++++++
 dom/webidl/Document.webidl |  8 ++++++++
 layout/base/PresShell.cpp  | 22 ++++++++++++++++++++++
 4 files changed, 51 insertions(+)

diff --git a/dom/base/Document.cpp b/dom/base/Document.cpp
index c74f486389a7..d0fc811f7920 100644
--- a/dom/base/Document.cpp
+++ b/dom/base/Document.cpp
@@ -1746,6 +1746,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(Document)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAnonymousContents)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCommandDispatcher)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFeaturePolicy)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSuppressedEventListener)
 
   // Traverse all our nsCOMArrays.
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStyleSheets)
@@ -1837,6 +1838,7 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Document)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCommandDispatcher)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mDocumentL10n);
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mFeaturePolicy)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSuppressedEventListener)
 
   tmp->mParentDocument = nullptr;
 
@@ -8492,6 +8494,17 @@ void Document::AddSuspendedChannelEventQueue(net::ChannelEventQueue* aQueue) {
   mSuspendedQueues.AppendElement(aQueue);
 }
 
+static bool SetSuppressedEventListenerInSubDocument(Document* aDocument,
+                                                    void* aData) {
+  aDocument->SetSuppressedEventListener(static_cast<EventListener*>(aData));
+  return true;
+}
+
+void Document::SetSuppressedEventListener(EventListener* aListener) {
+  mSuppressedEventListener = aListener;
+  EnumerateSubDocuments(SetSuppressedEventListenerInSubDocument, aListener);
+}
+
 nsISupports* Document::GetCurrentContentSink() {
   return mParser ? mParser->GetContentSink() : nullptr;
 }
diff --git a/dom/base/Document.h b/dom/base/Document.h
index 672da1f8c6b4..b2bb6e79508b 100644
--- a/dom/base/Document.h
+++ b/dom/base/Document.h
@@ -2446,6 +2446,12 @@ class Document : public nsINode,
    */
   bool IsVisibleConsideringAncestors() const;
 
+  void SetSuppressedEventListener(EventListener* aListener);
+
+  EventListener* GetSuppressedEventListener() {
+    return mSuppressedEventListener;
+  }
+
   /**
    * Return true when this document is active, i.e., an active document
    * in a content viewer.  Note that this will return true for bfcached
@@ -4137,6 +4143,8 @@ class Document : public nsINode,
   // events were suppressed.
   nsTArray<RefPtr<mozilla::net::ChannelEventQueue>> mSuspendedQueues;
 
+  RefPtr<EventListener> mSuppressedEventListener;
+
   /**
    * https://html.spec.whatwg.org/#ignore-destructive-writes-counter
    */
diff --git a/dom/webidl/Document.webidl b/dom/webidl/Document.webidl
index 50d41efc9388..600d7609833d 100644
--- a/dom/webidl/Document.webidl
+++ b/dom/webidl/Document.webidl
@@ -505,6 +505,14 @@ partial interface Document {
   void notifyUserGestureActivation();
 };
 
+// Extension to give chrome JS the ability to set an event handler which is
+// called with certain events that happened while events were suppressed in the
+// document or one of its subdocuments.
+partial interface Document {
+  [ChromeOnly]
+  void setSuppressedEventListener(EventListener? aListener);
+};
+
 // Extension to give chrome and XBL JS the ability to determine whether
 // the document is sandboxed without permission to run scripts
 // and whether inline scripts are blocked by the document's CSP.
diff --git a/layout/base/PresShell.cpp b/layout/base/PresShell.cpp
index 5f2b9d24e119..17f39627a61b 100644
--- a/layout/base/PresShell.cpp
+++ b/layout/base/PresShell.cpp
@@ -6785,6 +6785,28 @@ nsresult PresShell::HandleEvent(nsIFrame* aFrame, WidgetGUIEvent* aEvent,
         auto event = MakeUnique<DelayedMouseEvent>(aEvent->AsMouseEvent());
         mDelayedEvents.AppendElement(std::move(event));
       }
+
+      // If there is a suppressed event listener associated with the document,
+      // notify it about the suppressed mouse event. This allows devtools
+      // features to continue receiving mouse events even when the devtools
+      // debugger has paused execution in a page.
+      RefPtr<EventListener> suppressedListener =
+        frame->PresContext()->Document()->GetSuppressedEventListener();
+      if (suppressedListener &&
+          aEvent->AsMouseEvent()->mReason != WidgetMouseEvent::eSynthesized) {
+        nsCOMPtr<nsIContent> targetContent;
+        frame->GetContentForEvent(aEvent, getter_AddRefs(targetContent));
+        if (targetContent) {
+          aEvent->mTarget = targetContent;
+        }
+
+        nsCOMPtr<EventTarget> et = aEvent->mTarget;
+        RefPtr<Event> event = EventDispatcher::CreateEvent(
+                et, frame->PresContext(), aEvent, EmptyString());
+
+        suppressedListener->HandleEvent(*event);
+      }
+
       return NS_OK;
     }