Bug 1641085 Part 3 - Add APIs to manipulate excess overflow containers list. r=mats

This patch is similar to Part 2, but for adding APIs for
ExcessOverflowContainersProperty().

Differential Revision: https://phabricator.services.mozilla.com/D88457

layout/forms/nsFieldSetFrame.cpp

@@ -914,12 +914,10 @@ void nsFieldSetFrame::EnsureChildContinuation(nsIFrame* aChild,
       }
     }
     if (aStatus.IsOverflowIncomplete()) {
-      if (nsFrameList* eoc =
-              GetPropTableFrames(ExcessOverflowContainersProperty())) {
+      if (nsFrameList* eoc = GetExcessOverflowContainers()) {
         eoc->AppendFrames(nullptr, nifs);
       } else {
-        SetPropTableFrames(new (PresShell()) nsFrameList(nifs),
-                           ExcessOverflowContainersProperty());
+        SetExcessOverflowContainers(std::move(nifs));
       }
     } else {
       if (nsFrameList* oc = GetOverflowFrames()) {

layout/generic/nsBlockFrame.cpp

@@ -5169,8 +5169,7 @@ bool nsBlockFrame::DrainOverflowLines() {
       // prev-in-flow. We'll append these to mFrames to ensure the continuations
       // are ordered.
       auto HasOverflowContainers = [this]() -> bool {
-        return GetOverflowContainers() ||
-               GetPropTableFrames(ExcessOverflowContainersProperty());
+        return GetOverflowContainers() || GetExcessOverflowContainers();
       };
       nsFrameList ocContinuations;
       if (HasOverflowContainers()) {

layout/generic/nsContainerFrame.cpp

@@ -305,8 +305,7 @@ const nsFrameList& nsContainerFrame::GetChildList(ChildListID aListID) const {
       return list ? *list : nsFrameList::EmptyList();
     }
     case kExcessOverflowContainersList: {
-      nsFrameList* list =
-          GetPropTableFrames(ExcessOverflowContainersProperty());
+      nsFrameList* list = GetExcessOverflowContainers();
       return list ? *list : nsFrameList::EmptyList();
     }
     case kBackdropList: {
@@ -1441,7 +1440,7 @@ nsresult nsContainerFrame::StealFrame(nsIFrame* aChild) {
     if (!list || !list->ContainsFrame(aChild)) {
       list = GetOverflowContainers();
       if (!list || !list->ContainsFrame(aChild)) {
-        list = GetProperty(ExcessOverflowContainersProperty());
+        list = GetExcessOverflowContainers();
         MOZ_ASSERT(list && list->ContainsFrame(aChild),
                    "aChild isn't our child"
                    " or on a frame list not supported by StealFrame");
@@ -2053,12 +2052,10 @@ void nsContainerFrame::MergeSortedExcessOverflowContainers(nsFrameList& aList) {
       aList.FirstChild()->HasAnyStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER),
       "this is the wrong list to put this child frame");
   MOZ_ASSERT(aList.FirstChild()->GetParent() == this);
-  nsFrameList* eoc = GetPropTableFrames(ExcessOverflowContainersProperty());
-  if (eoc) {
+  if (nsFrameList* eoc = GetExcessOverflowContainers()) {
     MergeSortedFrameLists(*eoc, aList, GetContent());
   } else {
-    SetPropTableFrames(new (PresShell()) nsFrameList(aList),
-                       ExcessOverflowContainersProperty());
+    SetExcessOverflowContainers(std::move(aList));
   }
 }
 
@@ -2248,7 +2245,7 @@ nsFrameList* nsContainerFrame::DrainExcessOverflowContainersList(
 
   NS_ASSERTION(!(overflowContainers && GetPrevInFlow() &&
                  static_cast<nsContainerFrame*>(GetPrevInFlow())
-                     ->GetPropTableFrames(ExcessOverflowContainersProperty())),
+                     ->GetExcessOverflowContainers()),
                "conflicting overflow containers lists");
 
   if (!overflowContainers) {
@@ -2940,8 +2937,7 @@ void nsOverflowContinuationTracker::SetupOverflowContList() {
     }
   }
   if (!mOverflowContList) {
-    mOverflowContList = mParent->GetPropTableFrames(
-        nsContainerFrame::ExcessOverflowContainersProperty());
+    mOverflowContList = mParent->GetExcessOverflowContainers();
     if (mOverflowContList) {
       SetUpListWalker();
     }
@@ -3044,10 +3040,14 @@ nsresult nsOverflowContinuationTracker::Insert(nsIFrame* aOverflowCont,
       aOverflowCont->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
     }
     if (!mOverflowContList) {
+      // Note: We don't use SetExcessOverflowContainers() since it requires
+      // setting a non-empty list. It's OK to manually set an empty list to
+      // ExcessOverflowContainersProperty() because we are going to insert
+      // aOverflowCont to mOverflowContList below, which guarantees an nonempty
+      // list in ExcessOverflowContainersProperty().
       mOverflowContList = new (presContext->PresShell()) nsFrameList();
-      mParent->SetPropTableFrames(
-          mOverflowContList,
-          nsContainerFrame::ExcessOverflowContainersProperty());
+      mParent->SetProperty(nsContainerFrame::ExcessOverflowContainersProperty(),
+                           mOverflowContList);
       SetUpListWalker();
     }
     if (aOverflowCont->GetParent() != mParent) {
@@ -3137,8 +3137,7 @@ void nsOverflowContinuationTracker::EndFinish(nsIFrame* aChild) {
     return;
   }
   // Forget mOverflowContList if it was deleted.
-  nsFrameList* eoc = mParent->GetProperty(
-      nsContainerFrame::ExcessOverflowContainersProperty());
+  nsFrameList* eoc = mParent->GetExcessOverflowContainers();
   if (eoc != mOverflowContList) {
     nsFrameList* oc = mParent->GetOverflowContainers();
     if (oc != mOverflowContList) {
@@ -3200,10 +3199,8 @@ void nsContainerFrame::SanityCheckChildListsBeforeReflow() const {
   const auto* pif = static_cast<nsContainerFrame*>(GetPrevInFlow());
   if (pif) {
     const nsFrameList* oc = GetOverflowContainers();
-    const nsFrameList* eoc =
-        GetPropTableFrames(ExcessOverflowContainersProperty());
-    const nsFrameList* pifEOC =
-        pif->GetPropTableFrames(ExcessOverflowContainersProperty());
+    const nsFrameList* eoc = GetExcessOverflowContainers();
+    const nsFrameList* pifEOC = pif->GetExcessOverflowContainers();
     for (const nsIFrame* child : pif->GetChildList(kPrincipalList)) {
       const nsIFrame* childNIF = child->GetNextInFlow();
       MOZ_ASSERT(!childNIF || mFrames.ContainsFrame(childNIF) ||

layout/generic/nsContainerFrame.h

@@ -536,10 +536,12 @@ class nsContainerFrame : public nsSplittableFrame {
    */
 
   /**
-   * Get the frames on the overflow list.  Can return null if there are no
-   * overflow frames.  The caller does NOT take ownership of the list; it's
-   * still owned by this frame.  A non-null return value indicates that the
-   * list is nonempty.
+   * Get the frames on the overflow list, overflow containers list, or excess
+   * overflow containers list. Can return null if there are no frames in the
+   * list.
+   *
+   * The caller does NOT take ownership of the list; it's still owned by this
+   * frame. A non-null return value indicates that the list is non-empty.
    */
   [[nodiscard]] nsFrameList* GetOverflowFrames() const {
     nsFrameList* list = GetProperty(OverflowProperty());
@@ -552,14 +554,22 @@ class nsContainerFrame : public nsSplittableFrame {
                  "Unexpected empty overflow containers list");
     return list;
   }
+  [[nodiscard]] nsFrameList* GetExcessOverflowContainers() const {
+    nsFrameList* list = GetProperty(ExcessOverflowContainersProperty());
+    NS_ASSERTION(!list || !list->IsEmpty(),
+                 "Unexpected empty overflow containers list");
+    return list;
+  }
 
   /**
-   * As GetOverflowFrames, but removes the overflow frames property.  The
-   * caller is responsible for deleting nsFrameList and either passing
-   * ownership of the frames to someone else or destroying the frames.
-   * A non-null return value indicates that the list is nonempty.  The
-   * recommended way to use this function it to assign its return value
-   * into an AutoFrameListPtr.
+   * Same as the Get methods above, but also remove and the property from this
+   * frame.
+   *
+   * The caller is responsible for deleting nsFrameList and either passing
+   * ownership of the frames to someone else or destroying the frames. A
+   * non-null return value indicates that the list is non-empty. The recommended
+   * way to use this function it to assign its return value into an
+   * AutoFrameListPtr.
    */
   [[nodiscard]] nsFrameList* StealOverflowFrames() {
     nsFrameList* list = TakeProperty(OverflowProperty());
@@ -571,9 +581,17 @@ class nsContainerFrame : public nsSplittableFrame {
     NS_ASSERTION(!list || !list->IsEmpty(), "Unexpected empty overflow list");
     return list;
   }
+  [[nodiscard]] nsFrameList* StealExcessOverflowContainers() {
+    nsFrameList* list = TakeProperty(ExcessOverflowContainersProperty());
+    NS_ASSERTION(!list || !list->IsEmpty(), "Unexpected empty overflow list");
+    return list;
+  }
 
   /**
-   * Set the overflow list.  aOverflowFrames must not be an empty list.
+   * Set the overflow list, overflow containers list, or excess overflow
+   * containers list. The argument must be a *non-empty* list.
+   *
+   * After this operation, the argument becomes an empty list.
    */
   void SetOverflowFrames(nsFrameList&& aOverflowFrames) {
     MOZ_ASSERT(aOverflowFrames.NotEmpty(), "Shouldn't be called");
@@ -589,9 +607,25 @@ class nsContainerFrame : public nsSplittableFrame {
     SetProperty(OverflowContainersProperty(),
                 new (PresShell()) nsFrameList(std::move(aOverflowContainers)));
   }
+  void SetExcessOverflowContainers(nsFrameList&& aExcessOverflowContainers) {
+    MOZ_ASSERT(aExcessOverflowContainers.NotEmpty(),
+               "Shouldn't set an empty list!");
+    MOZ_ASSERT(!GetProperty(ExcessOverflowContainersProperty()),
+               "Shouldn't override existing list!");
+    MOZ_ASSERT(IsFrameOfType(nsIFrame::eCanContainOverflowContainers),
+               "This type of frame can't have overflow containers!");
+    SetProperty(ExcessOverflowContainersProperty(),
+                new (PresShell())
+                    nsFrameList(std::move(aExcessOverflowContainers)));
+  }
 
   /**
-   * Destroy the overflow list, which must be empty.
+   * Destroy the overflow list, overflow containers list, or excess overflow
+   * containers list.
+   *
+   * The list to be destroyed must be empty. That is, the caller is responsible
+   * for either passing ownership of the frames to someone else or destroying
+   * the frames before calling these methods.
    */
   void DestroyOverflowList() {
     nsFrameList* list = RemovePropTableFrames(OverflowProperty());
@@ -603,6 +637,11 @@ class nsContainerFrame : public nsSplittableFrame {
     MOZ_ASSERT(list && list->IsEmpty());
     list->Delete(PresShell());
   }
+  void DestroyExcessOverflowContainers() {
+    nsFrameList* list = TakeProperty(ExcessOverflowContainersProperty());
+    MOZ_ASSERT(list && list->IsEmpty());
+    list->Delete(PresShell());
+  }
 
   /**
    * Moves any frames on both the prev-in-flow's overflow list and the