Bug 1792741 - Remove nsDocElementBoxFrame. r=TYLin

After bug 1665476, it's pretty much a regular XUL box with a couple
special-cases that we can use IsRootElementStyle for. Do that, and allow
using nsFlexContainerFrame when using flexbox emulation.

Differential Revision: https://phabricator.services.mozilla.com/D158288

layout/base/nsCSSFrameConstructor.cpp

@@ -209,9 +209,6 @@ static FrameCtorDebugFlags gFlags[] = {
 
 //------------------------------------------------------------------
 
-nsContainerFrame* NS_NewDocElementBoxFrame(PresShell* aPresShell,
-                                           ComputedStyle* aStyle);
-
 nsIFrame* NS_NewLeafBoxFrame(PresShell* aPresShell, ComputedStyle* aStyle);
 
 nsIFrame* NS_NewRangeFrame(PresShell* aPresShell, ComputedStyle* aStyle);
@@ -2420,14 +2417,7 @@ nsIFrame* nsCSSFrameConstructor::ConstructDocElementFrame(
 
   nsFrameConstructorSaveState absoluteSaveState;
 
-  // Check whether we need to build a XUL box or SVG root frame
-  if (aDocElement->IsXULElement()) {
-    contentFrame = NS_NewDocElementBoxFrame(mPresShell, computedStyle);
-    InitAndRestoreFrame(state, aDocElement, mDocElementContainingBlock,
-                        contentFrame);
-    frameList = {contentFrame, contentFrame};
-    processChildren = true;
-  } else if (aDocElement->IsSVGElement()) {
+  if (aDocElement->IsSVGElement()) {
     if (!aDocElement->IsSVGElement(nsGkAtoms::svg)) {
       return nullptr;
     }
@@ -2447,11 +2437,19 @@ nsIFrame* nsCSSFrameConstructor::ConstructDocElementFrame(
   } else if (display->mDisplay == StyleDisplay::Flex ||
              display->mDisplay == StyleDisplay::WebkitBox ||
              display->mDisplay == StyleDisplay::Grid ||
-             (display->mDisplay == StyleDisplay::MozBox &&
-              computedStyle->StyleVisibility()->EmulateMozBoxWithFlex())) {
-    auto func = display->mDisplay == StyleDisplay::Grid
-                    ? NS_NewGridContainerFrame
-                    : NS_NewFlexContainerFrame;
+             display->mDisplay == StyleDisplay::MozBox ||
+             display->mDisplay == StyleDisplay::MozPopup) {
+    auto func = [&] {
+      if (display->mDisplay == StyleDisplay::Grid) {
+        return NS_NewGridContainerFrame;
+      }
+      if ((display->mDisplay == StyleDisplay::MozBox ||
+           display->mDisplay == StyleDisplay::MozPopup) &&
+          !computedStyle->StyleVisibility()->EmulateMozBoxWithFlex()) {
+        return NS_NewBoxFrame;
+      }
+      return NS_NewFlexContainerFrame;
+    }();
     contentFrame = func(mPresShell, computedStyle);
     InitAndRestoreFrame(
         state, aDocElement,
@@ -2602,19 +2600,14 @@ void nsCSSFrameConstructor::SetUpDocElementContainingBlock(
   /*
     how the root frame hierarchy should look
 
-  Galley presentation, non-XUL, with scrolling:
+  Galley presentation, with scrolling:
 
       ViewportFrame [fixed-cb]
-        nsHTMLScrollFrame
+        nsHTMLScrollFrame (if needed)
           nsCanvasFrame [abs-cb]
             root element frame (nsBlockFrame, SVGOuterSVGFrame,
-                                nsTableWrapperFrame, nsPlaceholderFrame)
-
-  Galley presentation, XUL
-
-      ViewportFrame [fixed-cb]
-        nsCanvasFrame [abs-cb]
-          root element frame (nsDocElementBoxFrame)
+                                nsTableWrapperFrame, nsPlaceholderFrame,
+                                nsBoxFrame)
 
   Print presentation, non-XUL
 
@@ -4472,7 +4465,8 @@ nsCSSFrameConstructor::FindDisplayData(const nsStyleDisplay& aDisplay,
       if (aMozBoxLayout == StyleMozBoxLayout::Legacy ||
           aElement.IsXULElement(nsGkAtoms::scrollcorner)) {
         static constexpr FrameConstructionData data =
-            SCROLLABLE_ABSPOS_CONTAINER_XUL_FCDATA(NS_NewBoxFrame);
+            SCROLLABLE_ABSPOS_CONTAINER_XUL_FCDATA(
+                ToCreationFunc(NS_NewBoxFrame));
         return &data;
       }
       [[fallthrough]];

layout/generic/FrameClasses.py

@@ -22,7 +22,6 @@ FRAME_CLASSES = [
     Frame("nsComboboxDisplayFrame", "ComboboxDisplay", NOT_LEAF),
     Frame("nsContinuingTextFrame", "Text", LEAF),
     Frame("nsDateTimeControlFrame", "DateTimeControl", NOT_LEAF),
-    Frame("nsDocElementBoxFrame", "DocElementBox", NOT_LEAF),
     Frame("nsFieldSetFrame", "FieldSet", NOT_LEAF),
     Frame("nsFileControlFrame", "Block", LEAF),
     Frame("nsFirstLetterFrame", "Letter", NOT_LEAF),

layout/generic/nsContainerFrame.cpp

@@ -810,7 +810,7 @@ void nsContainerFrame::SyncWindowProperties(nsPresContext* aPresContext,
 
   nsSize minSize(0, 0);
   nsSize maxSize(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);
-  if (rootElement->IsXULElement()) {
+  if (rootFrame->IsXULBoxFrame()) {
     nsBoxLayoutState aState(aPresContext, aRC);
     minSize = rootFrame->GetXULMinSize(aState);
     maxSize = rootFrame->GetXULMaxSize(aState);

layout/generic/nsFrameStateBits.h

@@ -320,11 +320,9 @@ FRAME_STATE_GROUP(Box, nsBoxFrame)
 FRAME_STATE_BIT(Box, 20, NS_STATE_BOX_CHILD_RESERVED)
 FRAME_STATE_BIT(Box, 22, NS_STATE_IS_HORIZONTAL)
 FRAME_STATE_BIT(Box, 23, NS_STATE_AUTO_STRETCH)
-FRAME_STATE_BIT(Box, 24, NS_STATE_IS_ROOT)
-/* Bits 25, 26, and 27 were used for xul debug flags but are now unused */
-FRAME_STATE_BIT(Box, 28, NS_STATE_MENU_HAS_POPUP_LIST)
-FRAME_STATE_BIT(Box, 29, NS_STATE_EQUAL_SIZE)
-FRAME_STATE_BIT(Box, 30, NS_STATE_IS_DIRECTION_NORMAL)
+FRAME_STATE_BIT(Box, 24, NS_STATE_MENU_HAS_POPUP_LIST)
+FRAME_STATE_BIT(Box, 25, NS_STATE_EQUAL_SIZE)
+FRAME_STATE_BIT(Box, 26, NS_STATE_IS_DIRECTION_NORMAL)
 
 // == Frame state bits that apply to flex container frames ====================
 

layout/generic/nsGfxScrollFrame.cpp

@@ -1576,7 +1576,7 @@ NS_IMPL_FRAMEARENA_HELPERS(nsXULScrollFrame)
 
 nsXULScrollFrame::nsXULScrollFrame(ComputedStyle* aStyle,
                                    nsPresContext* aPresContext, bool aIsRoot)
-    : nsBoxFrame(aStyle, aPresContext, kClassID, aIsRoot),
+    : nsBoxFrame(aStyle, aPresContext, kClassID),
       mHelper(ALLOW_THIS_IN_INITIALIZER_LIST(this), aIsRoot) {
   SetXULLayoutManager(nullptr);
 }

layout/painting/nsDisplayList.cpp

@@ -837,12 +837,12 @@ void nsDisplayListBuilder::MarkFrameForDisplayIfVisible(
 void nsDisplayListBuilder::SetGlassDisplayItem(nsDisplayItem* aItem) {
   // Web pages or extensions could trigger the "Multiple glass backgrounds
   // found?" warning by using -moz-appearance:win-borderless-glass etc on their
-  // own elements (as long as they are DocElementBoxFrames, which is rare as
-  // each xul doc only gets one near the root). We only care about first one,
-  // since that will be the background of the root window.
+  // own elements (as long as they are root frames, which is rare as each doc
+  // only gets one near the root). We only care about the first one, since that
+  // will be the background of the root window.
 
   if (IsPartialUpdate()) {
-    if (aItem->Frame()->IsDocElementBoxFrame()) {
+    if (aItem->Frame()->Style()->IsRootElementStyle()) {
 #ifdef DEBUG
       if (mHasGlassItemDuringPartial) {
         NS_WARNING("Multiple glass backgrounds found?");
@@ -856,7 +856,7 @@ void nsDisplayListBuilder::SetGlassDisplayItem(nsDisplayItem* aItem) {
     return;
   }
 
-  if (aItem->Frame()->IsDocElementBoxFrame()) {
+  if (aItem->Frame()->Style()->IsRootElementStyle()) {
 #ifdef DEBUG
     if (mGlassDisplayItem) {
       NS_WARNING("Multiple glass backgrounds found?");

layout/xul/moz.build

@@ -23,7 +23,6 @@ UNIFIED_SOURCES += [
     "nsBoxFrame.cpp",
     "nsBoxLayout.cpp",
     "nsBoxLayoutState.cpp",
-    "nsDocElementBoxFrame.cpp",
     "nsImageBoxFrame.cpp",
     "nsLeafBoxFrame.cpp",
     "nsMenuBarFrame.cpp",

layout/xul/nsBoxFrame.cpp

@@ -87,14 +87,7 @@ using namespace mozilla;
 using namespace mozilla::dom;
 using namespace mozilla::gfx;
 
-nsIFrame* NS_NewBoxFrame(PresShell* aPresShell, ComputedStyle* aStyle,
-                         bool aIsRoot, nsBoxLayout* aLayoutManager) {
-  return new (aPresShell)
-      nsBoxFrame(aStyle, aPresShell->GetPresContext(), nsBoxFrame::kClassID,
-                 aIsRoot, aLayoutManager);
-}
-
-nsIFrame* NS_NewBoxFrame(PresShell* aPresShell, ComputedStyle* aStyle) {
+nsContainerFrame* NS_NewBoxFrame(PresShell* aPresShell, ComputedStyle* aStyle) {
   return new (aPresShell) nsBoxFrame(aStyle, aPresShell->GetPresContext());
 }
 
@@ -107,22 +100,16 @@ NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
 #endif
 
 nsBoxFrame::nsBoxFrame(ComputedStyle* aStyle, nsPresContext* aPresContext,
-                       ClassID aID, bool aIsRoot, nsBoxLayout* aLayoutManager)
+                       ClassID aID)
     : nsContainerFrame(aStyle, aPresContext, aID), mAscent(0) {
   AddStateBits(NS_STATE_IS_HORIZONTAL | NS_STATE_AUTO_STRETCH);
 
-  if (aIsRoot) AddStateBits(NS_STATE_IS_ROOT);
-
   mValign = vAlign_Top;
   mHalign = hAlign_Left;
 
-  // if no layout manager specified us the static sprocket layout
-  nsCOMPtr<nsBoxLayout> layout = aLayoutManager;
-
-  if (layout == nullptr) {
-    NS_NewSprocketLayout(layout);
-  }
-
+  // Use the static sprocket layout
+  nsCOMPtr<nsBoxLayout> layout;
+  NS_NewSprocketLayout(layout);
   SetXULLayoutManager(layout);
 }
 
@@ -538,7 +525,7 @@ void nsBoxFrame::Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize,
 
   // getting the ascent could be a lot of work. Don't get it if
   // we are the root. The viewport doesn't care about it.
-  if (!(mState & NS_STATE_IS_ROOT)) {
+  if (!Style()->IsRootElementStyle()) {
     ascent = GetXULBoxAscent(state);
   }
 
@@ -707,7 +694,7 @@ nsBoxFrame::DoXULLayout(nsBoxLayoutState& aState) {
 
     // getting the ascent could be a lot of work. Don't get it if
     // we are the root. The viewport doesn't care about it.
-    if (!(mState & NS_STATE_IS_ROOT)) {
+    if (!Style()->IsRootElementStyle()) {
       ascent = GetXULBoxAscent(aState);
     }
     desiredSize.SetBlockStartAscent(ascent);

layout/xul/nsBoxFrame.h

@@ -29,11 +29,8 @@ class DrawTarget;
 }  // namespace gfx
 }  // namespace mozilla
 
-nsIFrame* NS_NewBoxFrame(mozilla::PresShell* aPresShell,
-                         mozilla::ComputedStyle* aStyle, bool aIsRoot,
-                         nsBoxLayout* aLayoutManager);
-nsIFrame* NS_NewBoxFrame(mozilla::PresShell* aPresShell,
-                         mozilla::ComputedStyle* aStyle);
+nsContainerFrame* NS_NewBoxFrame(mozilla::PresShell* aPresShell,
+                                 mozilla::ComputedStyle* aStyle);
 
 class nsBoxFrame : public nsContainerFrame {
  protected:
@@ -45,11 +42,8 @@ class nsBoxFrame : public nsContainerFrame {
   NS_DECL_QUERYFRAME
 #endif
 
-  friend nsIFrame* NS_NewBoxFrame(mozilla::PresShell* aPresShell,
-                                  ComputedStyle* aStyle, bool aIsRoot,
-                                  nsBoxLayout* aLayoutManager);
-  friend nsIFrame* NS_NewBoxFrame(mozilla::PresShell* aPresShell,
-                                  ComputedStyle* aStyle);
+  friend nsContainerFrame* NS_NewBoxFrame(mozilla::PresShell* aPresShell,
+                                          ComputedStyle* aStyle);
 
   // gets the rect inside our border and debug border. If you wish to paint
   // inside a box call this method to get the rect so you don't draw on the
@@ -150,11 +144,10 @@ class nsBoxFrame : public nsContainerFrame {
 
  private:
   explicit nsBoxFrame(ComputedStyle* aStyle, nsPresContext* aPresContext)
-      : nsBoxFrame(aStyle, aPresContext, kClassID, false, nullptr) {}
+      : nsBoxFrame(aStyle, aPresContext, kClassID) {}
 
  protected:
-  nsBoxFrame(ComputedStyle* aStyle, nsPresContext* aPresContext, ClassID aID,
-             bool aIsRoot = false, nsBoxLayout* aLayoutManager = nullptr);
+  nsBoxFrame(ComputedStyle* aStyle, nsPresContext* aPresContext, ClassID aID);
   virtual ~nsBoxFrame();
 
   virtual bool GetInitialEqualSize(bool& aEqualSize);

layout/xul/nsDocElementBoxFrame.cpp

@@ -1,61 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-#include "mozilla/PresShell.h"
-#include "mozilla/dom/Document.h"
-#include "mozilla/dom/Element.h"
-#include "mozilla/dom/FromParser.h"
-#include "mozilla/dom/NodeInfo.h"
-#include "nsHTMLParts.h"
-#include "nsContainerFrame.h"
-#include "nsCSSRendering.h"
-#include "nsPageFrame.h"
-#include "nsStyleConsts.h"
-#include "nsGkAtoms.h"
-#include "nsBoxFrame.h"
-#include "nsNodeInfoManager.h"
-#include "nsContentCreatorFunctions.h"
-
-using namespace mozilla;
-using namespace mozilla::dom;
-
-class nsDocElementBoxFrame final : public nsBoxFrame {
- public:
-  friend nsIFrame* NS_NewBoxFrame(mozilla::PresShell* aPresShell,
-                                  ComputedStyle* aStyle);
-
-  explicit nsDocElementBoxFrame(ComputedStyle* aStyle,
-                                nsPresContext* aPresContext)
-      : nsBoxFrame(aStyle, aPresContext, kClassID, true) {}
-
-  NS_DECL_FRAMEARENA_HELPERS(nsDocElementBoxFrame)
-
-  bool IsFrameOfType(uint32_t aFlags) const override {
-    // Override nsBoxFrame.
-    if (aFlags & (nsIFrame::eReplacedContainsBlock | nsIFrame::eReplaced))
-      return false;
-    return nsBoxFrame::IsFrameOfType(aFlags);
-  }
-
-#ifdef DEBUG_FRAME_DUMP
-  nsresult GetFrameName(nsAString& aResult) const override;
-#endif
-};
-
-//----------------------------------------------------------------------
-
-nsContainerFrame* NS_NewDocElementBoxFrame(PresShell* aPresShell,
-                                           ComputedStyle* aStyle) {
-  return new (aPresShell)
-      nsDocElementBoxFrame(aStyle, aPresShell->GetPresContext());
-}
-
-NS_IMPL_FRAMEARENA_HELPERS(nsDocElementBoxFrame)
-
-#ifdef DEBUG_FRAME_DUMP
-nsresult nsDocElementBoxFrame::GetFrameName(nsAString& aResult) const {
-  return MakeFrameName(u"DocElementBox"_ns, aResult);
-}
-#endif