Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 944 insertions, 0 deletions

diff --git a/layout/xul/nsSplitterFrame.cpp b/layout/xul/nsSplitterFrame.cpp
new file mode 100644
index 0000000000..79143df15e
--- /dev/null
+++ b/layout/xul/nsSplitterFrame.cpp
@@ -0,0 +1,944 @@
+/* -*- 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/. */
+
+//
+// Eric Vaughan
+// Netscape Communications
+//
+// See documentation in associated header file
+//
+
+#include "gfxContext.h"
+#include "nsSplitterFrame.h"
+#include "nsGkAtoms.h"
+#include "nsXULElement.h"
+#include "nsPresContext.h"
+#include "mozilla/dom/Document.h"
+#include "nsNameSpaceManager.h"
+#include "nsScrollbarButtonFrame.h"
+#include "nsIDOMEventListener.h"
+#include "nsFrameList.h"
+#include "nsHTMLParts.h"
+#include "mozilla/ComputedStyle.h"
+#include "mozilla/CSSOrderAwareFrameIterator.h"
+#include "nsBoxLayoutState.h"
+#include "nsContainerFrame.h"
+#include "nsContentCID.h"
+#include "nsLayoutUtils.h"
+#include "nsDisplayList.h"
+#include "nsContentUtils.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/Event.h"
+#include "mozilla/dom/MouseEvent.h"
+#include "mozilla/MouseEvents.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/UniquePtr.h"
+
+using namespace mozilla;
+
+using mozilla::dom::Element;
+using mozilla::dom::Event;
+
+class nsSplitterInfo {
+ public:
+  nscoord min;
+  nscoord max;
+  nscoord current;
+  nscoord changed;
+  nsCOMPtr<nsIContent> childElem;
+  int32_t flex;
+  int32_t index;
+};
+
+class nsSplitterFrameInner final : public nsIDOMEventListener {
+ protected:
+  virtual ~nsSplitterFrameInner();
+
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIDOMEVENTLISTENER
+
+  explicit nsSplitterFrameInner(nsSplitterFrame* aSplitter)
+      : mDidDrag(false),
+        mDragStart(0),
+        mParentBox(nullptr),
+        mChildInfosBeforeCount(0),
+        mChildInfosAfterCount(0),
+        mState(Open),
+        mSplitterPos(0),
+        mDragging(false) {
+    mOuter = aSplitter;
+    mPressed = false;
+  }
+
+  void Disconnect() { mOuter = nullptr; }
+
+  nsresult MouseDown(Event* aMouseEvent);
+  nsresult MouseUp(Event* aMouseEvent);
+  nsresult MouseMove(Event* aMouseEvent);
+
+  void MouseDrag(nsPresContext* aPresContext, WidgetGUIEvent* aEvent);
+  void MouseUp(nsPresContext* aPresContext, WidgetGUIEvent* aEvent);
+
+  void AdjustChildren(nsPresContext* aPresContext);
+  void AdjustChildren(nsPresContext* aPresContext, nsSplitterInfo* aChildInfos,
+                      int32_t aCount, bool aIsHorizontal);
+
+  void AddRemoveSpace(nscoord aDiff, nsSplitterInfo* aChildInfos,
+                      int32_t aCount, int32_t& aSpaceLeft);
+
+  void ResizeChildTo(nscoord& aDiff, nsSplitterInfo* aChildrenBeforeInfos,
+                     nsSplitterInfo* aChildrenAfterInfos,
+                     int32_t aChildrenBeforeCount, int32_t aChildrenAfterCount,
+                     bool aBounded);
+
+  void UpdateState();
+
+  void AddListener();
+  void RemoveListener();
+
+  enum ResizeType { Closest, Farthest, Flex, Grow };
+  enum State { Open, CollapsedBefore, CollapsedAfter, Dragging };
+  enum CollapseDirection { Before, After };
+
+  ResizeType GetResizeBefore();
+  ResizeType GetResizeAfter();
+  State GetState();
+
+  void Reverse(UniquePtr<nsSplitterInfo[]>& aIndexes, int32_t aCount);
+  bool SupportsCollapseDirection(CollapseDirection aDirection);
+
+  void EnsureOrient();
+  void SetPreferredSize(nsBoxLayoutState& aState, nsIFrame* aChildBox,
+                        nscoord aOnePixel, bool aIsHorizontal, nscoord* aSize);
+
+  nsSplitterFrame* mOuter;
+  bool mDidDrag;
+  nscoord mDragStart;
+  nsIFrame* mParentBox;
+  bool mPressed;
+  UniquePtr<nsSplitterInfo[]> mChildInfosBefore;
+  UniquePtr<nsSplitterInfo[]> mChildInfosAfter;
+  int32_t mChildInfosBeforeCount;
+  int32_t mChildInfosAfterCount;
+  State mState;
+  nscoord mSplitterPos;
+  bool mDragging;
+
+  const Element* SplitterElement() const {
+    return mOuter->GetContent()->AsElement();
+  }
+};
+
+NS_IMPL_ISUPPORTS(nsSplitterFrameInner, nsIDOMEventListener)
+
+nsSplitterFrameInner::ResizeType nsSplitterFrameInner::GetResizeBefore() {
+  static Element::AttrValuesArray strings[] = {nsGkAtoms::farthest,
+                                               nsGkAtoms::flex, nullptr};
+  switch (SplitterElement()->FindAttrValueIn(
+      kNameSpaceID_None, nsGkAtoms::resizebefore, strings, eCaseMatters)) {
+    case 0:
+      return Farthest;
+    case 1:
+      return Flex;
+  }
+  return Closest;
+}
+
+nsSplitterFrameInner::~nsSplitterFrameInner() = default;
+
+nsSplitterFrameInner::ResizeType nsSplitterFrameInner::GetResizeAfter() {
+  static Element::AttrValuesArray strings[] = {
+      nsGkAtoms::farthest, nsGkAtoms::flex, nsGkAtoms::grow, nullptr};
+  switch (SplitterElement()->FindAttrValueIn(
+      kNameSpaceID_None, nsGkAtoms::resizeafter, strings, eCaseMatters)) {
+    case 0:
+      return Farthest;
+    case 1:
+      return Flex;
+    case 2:
+      return Grow;
+  }
+  return Closest;
+}
+
+nsSplitterFrameInner::State nsSplitterFrameInner::GetState() {
+  static Element::AttrValuesArray strings[] = {nsGkAtoms::dragging,
+                                               nsGkAtoms::collapsed, nullptr};
+  static Element::AttrValuesArray strings_substate[] = {
+      nsGkAtoms::before, nsGkAtoms::after, nullptr};
+  switch (SplitterElement()->FindAttrValueIn(
+      kNameSpaceID_None, nsGkAtoms::state, strings, eCaseMatters)) {
+    case 0:
+      return Dragging;
+    case 1:
+      switch (SplitterElement()->FindAttrValueIn(
+          kNameSpaceID_None, nsGkAtoms::substate, strings_substate,
+          eCaseMatters)) {
+        case 0:
+          return CollapsedBefore;
+        case 1:
+          return CollapsedAfter;
+        default:
+          if (SupportsCollapseDirection(After)) return CollapsedAfter;
+          return CollapsedBefore;
+      }
+  }
+  return Open;
+}
+
+//
+// NS_NewSplitterFrame
+//
+// Creates a new Toolbar frame and returns it
+//
+nsIFrame* NS_NewSplitterFrame(PresShell* aPresShell, ComputedStyle* aStyle) {
+  return new (aPresShell) nsSplitterFrame(aStyle, aPresShell->GetPresContext());
+}
+
+NS_IMPL_FRAMEARENA_HELPERS(nsSplitterFrame)
+
+nsSplitterFrame::nsSplitterFrame(ComputedStyle* aStyle,
+                                 nsPresContext* aPresContext)
+    : nsBoxFrame(aStyle, aPresContext, kClassID), mInner(0) {}
+
+void nsSplitterFrame::DestroyFrom(nsIFrame* aDestructRoot,
+                                  PostDestroyData& aPostDestroyData) {
+  if (mInner) {
+    mInner->RemoveListener();
+    mInner->Disconnect();
+    mInner->Release();
+    mInner = nullptr;
+  }
+  nsBoxFrame::DestroyFrom(aDestructRoot, aPostDestroyData);
+}
+
+nsresult nsSplitterFrame::AttributeChanged(int32_t aNameSpaceID,
+                                           nsAtom* aAttribute,
+                                           int32_t aModType) {
+  nsresult rv =
+      nsBoxFrame::AttributeChanged(aNameSpaceID, aAttribute, aModType);
+  if (aAttribute == nsGkAtoms::state) {
+    mInner->UpdateState();
+  }
+
+  return rv;
+}
+
+/**
+ * Initialize us. If we are in a box get our alignment so we know what direction
+ * we are
+ */
+void nsSplitterFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
+                           nsIFrame* aPrevInFlow) {
+  MOZ_ASSERT(!mInner);
+  mInner = new nsSplitterFrameInner(this);
+
+  mInner->AddRef();
+
+  // determine orientation of parent, and if vertical, set orient to vertical
+  // on splitter content, then re-resolve style
+  // XXXbz this is pretty messed up, since this can change whether we should
+  // have a frame at all.  This really needs a better solution.
+  if (aParent && aParent->IsXULBoxFrame()) {
+    if (!aParent->IsXULHorizontal()) {
+      if (!nsContentUtils::HasNonEmptyAttr(aContent, kNameSpaceID_None,
+                                           nsGkAtoms::orient)) {
+        aContent->AsElement()->SetAttr(kNameSpaceID_None, nsGkAtoms::orient,
+                                       u"vertical"_ns, false);
+      }
+    }
+  }
+
+  nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
+
+  mInner->mState = nsSplitterFrameInner::Open;
+  mInner->AddListener();
+  mInner->mParentBox = nullptr;
+}
+
+NS_IMETHODIMP
+nsSplitterFrame::DoXULLayout(nsBoxLayoutState& aState) {
+  if (HasAnyStateBits(NS_FRAME_FIRST_REFLOW)) {
+    mInner->mParentBox = nsIFrame::GetParentXULBox(this);
+    mInner->UpdateState();
+  }
+
+  return nsBoxFrame::DoXULLayout(aState);
+}
+
+void nsSplitterFrame::GetInitialOrientation(bool& aIsHorizontal) {
+  nsIFrame* box = nsIFrame::GetParentXULBox(this);
+  if (box) {
+    aIsHorizontal = !box->IsXULHorizontal();
+  } else
+    nsBoxFrame::GetInitialOrientation(aIsHorizontal);
+}
+
+NS_IMETHODIMP
+nsSplitterFrame::HandlePress(nsPresContext* aPresContext,
+                             WidgetGUIEvent* aEvent,
+                             nsEventStatus* aEventStatus) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSplitterFrame::HandleMultiplePress(nsPresContext* aPresContext,
+                                     WidgetGUIEvent* aEvent,
+                                     nsEventStatus* aEventStatus,
+                                     bool aControlHeld) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSplitterFrame::HandleDrag(nsPresContext* aPresContext, WidgetGUIEvent* aEvent,
+                            nsEventStatus* aEventStatus) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSplitterFrame::HandleRelease(nsPresContext* aPresContext,
+                               WidgetGUIEvent* aEvent,
+                               nsEventStatus* aEventStatus) {
+  return NS_OK;
+}
+
+void nsSplitterFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
+                                       const nsDisplayListSet& aLists) {
+  nsBoxFrame::BuildDisplayList(aBuilder, aLists);
+
+  // if the mouse is captured always return us as the frame.
+  if (mInner->mDragging && aBuilder->IsForEventDelivery()) {
+    // XXX It's probably better not to check visibility here, right?
+    aLists.Outlines()->AppendNewToTop<nsDisplayEventReceiver>(aBuilder, this);
+    return;
+  }
+}
+
+nsresult nsSplitterFrame::HandleEvent(nsPresContext* aPresContext,
+                                      WidgetGUIEvent* aEvent,
+                                      nsEventStatus* aEventStatus) {
+  NS_ENSURE_ARG_POINTER(aEventStatus);
+  if (nsEventStatus_eConsumeNoDefault == *aEventStatus) {
+    return NS_OK;
+  }
+
+  AutoWeakFrame weakFrame(this);
+  RefPtr<nsSplitterFrameInner> inner(mInner);
+  switch (aEvent->mMessage) {
+    case eMouseMove:
+      inner->MouseDrag(aPresContext, aEvent);
+      break;
+
+    case eMouseUp:
+      if (aEvent->AsMouseEvent()->mButton == MouseButton::ePrimary) {
+        inner->MouseUp(aPresContext, aEvent);
+      }
+      break;
+
+    default:
+      break;
+  }
+
+  NS_ENSURE_STATE(weakFrame.IsAlive());
+  return nsBoxFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
+}
+
+void nsSplitterFrameInner::MouseUp(nsPresContext* aPresContext,
+                                   WidgetGUIEvent* aEvent) {
+  if (mDragging && mOuter) {
+    AdjustChildren(aPresContext);
+    AddListener();
+    PresShell::ReleaseCapturingContent();  // XXXndeakin is this needed?
+    mDragging = false;
+    State newState = GetState();
+    // if the state is dragging then make it Open.
+    if (newState == Dragging) {
+      mOuter->mContent->AsElement()->SetAttr(kNameSpaceID_None,
+                                             nsGkAtoms::state, u""_ns, true);
+    }
+
+    mPressed = false;
+
+    // if we dragged then fire a command event.
+    if (mDidDrag) {
+      RefPtr<nsXULElement> element =
+          nsXULElement::FromNode(mOuter->GetContent());
+      element->DoCommand();
+    }
+
+    // printf("MouseUp\n");
+  }
+
+  mChildInfosBefore = nullptr;
+  mChildInfosAfter = nullptr;
+  mChildInfosBeforeCount = 0;
+  mChildInfosAfterCount = 0;
+}
+
+void nsSplitterFrameInner::MouseDrag(nsPresContext* aPresContext,
+                                     WidgetGUIEvent* aEvent) {
+  if (mDragging && mOuter) {
+    // printf("Dragging\n");
+
+    bool isHorizontal = !mOuter->IsXULHorizontal();
+    // convert coord to pixels
+    nsPoint pt = nsLayoutUtils::GetEventCoordinatesRelativeTo(
+        aEvent, RelativeTo{mParentBox});
+    nscoord pos = isHorizontal ? pt.x : pt.y;
+
+    // mDragStart is in frame coordinates
+    nscoord start = mDragStart;
+
+    // take our current position and subtract the start location
+    pos -= start;
+
+    // printf("Diff=%d\n", pos);
+
+    ResizeType resizeAfter = GetResizeAfter();
+
+    bool bounded;
+
+    if (resizeAfter == nsSplitterFrameInner::Grow)
+      bounded = false;
+    else
+      bounded = true;
+
+    int i;
+    for (i = 0; i < mChildInfosBeforeCount; i++)
+      mChildInfosBefore[i].changed = mChildInfosBefore[i].current;
+
+    for (i = 0; i < mChildInfosAfterCount; i++)
+      mChildInfosAfter[i].changed = mChildInfosAfter[i].current;
+
+    nscoord oldPos = pos;
+
+    ResizeChildTo(pos, mChildInfosBefore.get(), mChildInfosAfter.get(),
+                  mChildInfosBeforeCount, mChildInfosAfterCount, bounded);
+
+    State currentState = GetState();
+    bool supportsBefore = SupportsCollapseDirection(Before);
+    bool supportsAfter = SupportsCollapseDirection(After);
+
+    const bool isRTL =
+        mOuter->StyleVisibility()->mDirection == StyleDirection::Rtl;
+    bool pastEnd = oldPos > 0 && oldPos > pos;
+    bool pastBegin = oldPos < 0 && oldPos < pos;
+    if (isRTL) {
+      // Swap the boundary checks in RTL mode
+      bool tmp = pastEnd;
+      pastEnd = pastBegin;
+      pastBegin = tmp;
+    }
+    const bool isCollapsedBefore = pastBegin && supportsBefore;
+    const bool isCollapsedAfter = pastEnd && supportsAfter;
+
+    // if we are in a collapsed position
+    if (isCollapsedBefore || isCollapsedAfter) {
+      // and we are not collapsed then collapse
+      if (currentState == Dragging) {
+        if (pastEnd) {
+          // printf("Collapse right\n");
+          if (supportsAfter) {
+            RefPtr<Element> outer = mOuter->mContent->AsElement();
+            outer->SetAttr(kNameSpaceID_None, nsGkAtoms::substate, u"after"_ns,
+                           true);
+            outer->SetAttr(kNameSpaceID_None, nsGkAtoms::state, u"collapsed"_ns,
+                           true);
+          }
+
+        } else if (pastBegin) {
+          // printf("Collapse left\n");
+          if (supportsBefore) {
+            RefPtr<Element> outer = mOuter->mContent->AsElement();
+            outer->SetAttr(kNameSpaceID_None, nsGkAtoms::substate, u"before"_ns,
+                           true);
+            outer->SetAttr(kNameSpaceID_None, nsGkAtoms::state, u"collapsed"_ns,
+                           true);
+          }
+        }
+      }
+    } else {
+      // if we are not in a collapsed position and we are not dragging make sure
+      // we are dragging.
+      if (currentState != Dragging) {
+        mOuter->mContent->AsElement()->SetAttr(
+            kNameSpaceID_None, nsGkAtoms::state, u"dragging"_ns, true);
+      }
+      AdjustChildren(aPresContext);
+    }
+
+    mDidDrag = true;
+  }
+}
+
+void nsSplitterFrameInner::AddListener() {
+  mOuter->GetContent()->AddEventListener(u"mouseup"_ns, this, false, false);
+  mOuter->GetContent()->AddEventListener(u"mousedown"_ns, this, false, false);
+  mOuter->GetContent()->AddEventListener(u"mousemove"_ns, this, false, false);
+  mOuter->GetContent()->AddEventListener(u"mouseout"_ns, this, false, false);
+}
+
+void nsSplitterFrameInner::RemoveListener() {
+  NS_ENSURE_TRUE_VOID(mOuter);
+  mOuter->GetContent()->RemoveEventListener(u"mouseup"_ns, this, false);
+  mOuter->GetContent()->RemoveEventListener(u"mousedown"_ns, this, false);
+  mOuter->GetContent()->RemoveEventListener(u"mousemove"_ns, this, false);
+  mOuter->GetContent()->RemoveEventListener(u"mouseout"_ns, this, false);
+}
+
+nsresult nsSplitterFrameInner::HandleEvent(dom::Event* aEvent) {
+  nsAutoString eventType;
+  aEvent->GetType(eventType);
+  if (eventType.EqualsLiteral("mouseup")) return MouseUp(aEvent);
+  if (eventType.EqualsLiteral("mousedown")) return MouseDown(aEvent);
+  if (eventType.EqualsLiteral("mousemove") ||
+      eventType.EqualsLiteral("mouseout"))
+    return MouseMove(aEvent);
+
+  MOZ_ASSERT_UNREACHABLE("Unexpected eventType");
+  return NS_OK;
+}
+
+nsresult nsSplitterFrameInner::MouseUp(Event* aMouseEvent) {
+  NS_ENSURE_TRUE(mOuter, NS_OK);
+  mPressed = false;
+
+  PresShell::ReleaseCapturingContent();
+
+  return NS_OK;
+}
+
+nsresult nsSplitterFrameInner::MouseDown(Event* aMouseEvent) {
+  NS_ENSURE_TRUE(mOuter, NS_OK);
+  dom::MouseEvent* mouseEvent = aMouseEvent->AsMouseEvent();
+  if (!mouseEvent) {
+    return NS_OK;
+  }
+
+  // only if left button
+  if (mouseEvent->Button() != 0) return NS_OK;
+
+  if (SplitterElement()->AttrValueIs(kNameSpaceID_None, nsGkAtoms::disabled,
+                                     nsGkAtoms::_true, eCaseMatters))
+    return NS_OK;
+
+  mParentBox = nsIFrame::GetParentXULBox(mOuter);
+  if (!mParentBox) return NS_OK;
+
+  // get our index
+  nsPresContext* outerPresContext = mOuter->PresContext();
+  const nsFrameList& siblingList(mParentBox->PrincipalChildList());
+  int32_t childIndex = siblingList.IndexOf(mOuter);
+  // if it's 0 (or not found) then stop right here.
+  // It might be not found if we're not in the parent's primary frame list.
+  if (childIndex <= 0) return NS_OK;
+
+  int32_t childCount = siblingList.GetLength();
+  // if it's the last index then we need to allow for resizeafter="grow"
+  if (childIndex == childCount - 1 && GetResizeAfter() != Grow) return NS_OK;
+
+  RefPtr<gfxContext> rc =
+      outerPresContext->PresShell()->CreateReferenceRenderingContext();
+  nsBoxLayoutState state(outerPresContext, rc);
+  mPressed = true;
+
+  mDidDrag = false;
+
+  EnsureOrient();
+  bool isHorizontal = !mOuter->IsXULHorizontal();
+
+  ResizeType resizeBefore = GetResizeBefore();
+  ResizeType resizeAfter = GetResizeAfter();
+
+  mChildInfosBefore = MakeUnique<nsSplitterInfo[]>(childCount);
+  mChildInfosAfter = MakeUnique<nsSplitterInfo[]>(childCount);
+
+  // create info 2 lists. One of the children before us and one after.
+  int32_t count = 0;
+  mChildInfosBeforeCount = 0;
+  mChildInfosAfterCount = 0;
+
+  CSSOrderAwareFrameIterator iter(
+      mParentBox, layout::kPrincipalList,
+      CSSOrderAwareFrameIterator::ChildFilter::IncludeAll,
+      CSSOrderAwareFrameIterator::OrderState::Unknown,
+      CSSOrderAwareFrameIterator::OrderingProperty::BoxOrdinalGroup);
+  for (; !iter.AtEnd(); iter.Next()) {
+    nsIFrame* childBox = iter.get();
+    nsIContent* content = childBox->GetContent();
+
+    // skip over any splitters
+    if (content->NodeInfo()->NameAtom() != nsGkAtoms::splitter) {
+      nsSize prefSize = childBox->GetXULPrefSize(state);
+      nsSize minSize = childBox->GetXULMinSize(state);
+      nsSize maxSize = nsIFrame::XULBoundsCheckMinMax(
+          minSize, childBox->GetXULMaxSize(state));
+      prefSize = nsIFrame::XULBoundsCheck(minSize, prefSize, maxSize);
+
+      nsSplitterFrame::AddXULMargin(childBox, minSize);
+      nsSplitterFrame::AddXULMargin(childBox, prefSize);
+      nsSplitterFrame::AddXULMargin(childBox, maxSize);
+
+      nscoord flex = childBox->GetXULFlex();
+
+      nsMargin margin(0, 0, 0, 0);
+      childBox->GetXULMargin(margin);
+      nsRect r(childBox->GetRect());
+      r.Inflate(margin);
+
+      // We need to check for hidden attribute too, since treecols with
+      // the hidden="true" attribute are not really hidden, just collapsed
+      if (!content->IsElement() || (!content->AsElement()->AttrValueIs(
+                                        kNameSpaceID_None, nsGkAtoms::fixed,
+                                        nsGkAtoms::_true, eCaseMatters) &&
+                                    !content->AsElement()->AttrValueIs(
+                                        kNameSpaceID_None, nsGkAtoms::hidden,
+                                        nsGkAtoms::_true, eCaseMatters))) {
+        if (count < childIndex && (resizeBefore != Flex || flex > 0)) {
+          mChildInfosBefore[mChildInfosBeforeCount].childElem = content;
+          mChildInfosBefore[mChildInfosBeforeCount].min =
+              isHorizontal ? minSize.width : minSize.height;
+          mChildInfosBefore[mChildInfosBeforeCount].max =
+              isHorizontal ? maxSize.width : maxSize.height;
+          mChildInfosBefore[mChildInfosBeforeCount].current =
+              isHorizontal ? r.width : r.height;
+          mChildInfosBefore[mChildInfosBeforeCount].flex = flex;
+          mChildInfosBefore[mChildInfosBeforeCount].index = count;
+          mChildInfosBefore[mChildInfosBeforeCount].changed =
+              mChildInfosBefore[mChildInfosBeforeCount].current;
+          mChildInfosBeforeCount++;
+        } else if (count > childIndex && (resizeAfter != Flex || flex > 0)) {
+          mChildInfosAfter[mChildInfosAfterCount].childElem = content;
+          mChildInfosAfter[mChildInfosAfterCount].min =
+              isHorizontal ? minSize.width : minSize.height;
+          mChildInfosAfter[mChildInfosAfterCount].max =
+              isHorizontal ? maxSize.width : maxSize.height;
+          mChildInfosAfter[mChildInfosAfterCount].current =
+              isHorizontal ? r.width : r.height;
+          mChildInfosAfter[mChildInfosAfterCount].flex = flex;
+          mChildInfosAfter[mChildInfosAfterCount].index = count;
+          mChildInfosAfter[mChildInfosAfterCount].changed =
+              mChildInfosAfter[mChildInfosAfterCount].current;
+          mChildInfosAfterCount++;
+        }
+      }
+    }
+    count++;
+  }
+
+  if (!mParentBox->IsXULNormalDirection()) {
+    // The before array is really the after array, and the order needs to be
+    // reversed. First reverse both arrays.
+    Reverse(mChildInfosBefore, mChildInfosBeforeCount);
+    Reverse(mChildInfosAfter, mChildInfosAfterCount);
+
+    // Now swap the two arrays.
+    std::swap(mChildInfosBeforeCount, mChildInfosAfterCount);
+    std::swap(mChildInfosBefore, mChildInfosAfter);
+  }
+
+  // if resizebefore is not Farthest, reverse the list because the first child
+  // in the list is the farthest, and we want the first child to be the closest.
+  if (resizeBefore != Farthest)
+    Reverse(mChildInfosBefore, mChildInfosBeforeCount);
+
+  // if the resizeafter is the Farthest we must reverse the list because the
+  // first child in the list is the closest we want the first child to be the
+  // Farthest.
+  if (resizeAfter == Farthest) Reverse(mChildInfosAfter, mChildInfosAfterCount);
+
+  // grow only applys to the children after. If grow is set then no space should
+  // be taken out of any children after us. To do this we just set the size of
+  // that list to be 0.
+  if (resizeAfter == Grow) mChildInfosAfterCount = 0;
+
+  int32_t c;
+  nsPoint pt =
+      nsLayoutUtils::GetDOMEventCoordinatesRelativeTo(mouseEvent, mParentBox);
+  if (isHorizontal) {
+    c = pt.x;
+    mSplitterPos = mOuter->mRect.x;
+  } else {
+    c = pt.y;
+    mSplitterPos = mOuter->mRect.y;
+  }
+
+  mDragStart = c;
+
+  // printf("Pressed mDragStart=%d\n",mDragStart);
+
+  PresShell::SetCapturingContent(mOuter->GetContent(),
+                                 CaptureFlags::IgnoreAllowedState);
+
+  return NS_OK;
+}
+
+nsresult nsSplitterFrameInner::MouseMove(Event* aMouseEvent) {
+  NS_ENSURE_TRUE(mOuter, NS_OK);
+  if (!mPressed) return NS_OK;
+
+  if (mDragging) return NS_OK;
+
+  nsCOMPtr<nsIDOMEventListener> kungfuDeathGrip(this);
+  mOuter->mContent->AsElement()->SetAttr(kNameSpaceID_None, nsGkAtoms::state,
+                                         u"dragging"_ns, true);
+
+  RemoveListener();
+  mDragging = true;
+
+  return NS_OK;
+}
+
+void nsSplitterFrameInner::Reverse(UniquePtr<nsSplitterInfo[]>& aChildInfos,
+                                   int32_t aCount) {
+  UniquePtr<nsSplitterInfo[]> infos(new nsSplitterInfo[aCount]);
+
+  for (int i = 0; i < aCount; i++) infos[i] = aChildInfos[aCount - 1 - i];
+
+  aChildInfos = std::move(infos);
+}
+
+bool nsSplitterFrameInner::SupportsCollapseDirection(
+    nsSplitterFrameInner::CollapseDirection aDirection) {
+  static Element::AttrValuesArray strings[] = {
+      nsGkAtoms::before, nsGkAtoms::after, nsGkAtoms::both, nullptr};
+
+  switch (SplitterElement()->FindAttrValueIn(
+      kNameSpaceID_None, nsGkAtoms::collapse, strings, eCaseMatters)) {
+    case 0:
+      return (aDirection == Before);
+    case 1:
+      return (aDirection == After);
+    case 2:
+      return true;
+  }
+
+  return false;
+}
+
+void nsSplitterFrameInner::UpdateState() {
+  // State Transitions:
+  //   Open            -> Dragging
+  //   Open            -> CollapsedBefore
+  //   Open            -> CollapsedAfter
+  //   CollapsedBefore -> Open
+  //   CollapsedBefore -> Dragging
+  //   CollapsedAfter  -> Open
+  //   CollapsedAfter  -> Dragging
+  //   Dragging        -> Open
+  //   Dragging        -> CollapsedBefore (auto collapse)
+  //   Dragging        -> CollapsedAfter (auto collapse)
+
+  State newState = GetState();
+
+  if (newState == mState) {
+    // No change.
+    return;
+  }
+
+  if ((SupportsCollapseDirection(Before) || SupportsCollapseDirection(After)) &&
+      mOuter->GetParent()->IsXULBoxFrame()) {
+    // Find the splitter's immediate sibling.
+    nsIFrame* splitterSibling;
+    if (newState == CollapsedBefore || mState == CollapsedBefore) {
+      splitterSibling = mOuter->GetPrevSibling();
+    } else {
+      splitterSibling = mOuter->GetNextSibling();
+    }
+
+    if (splitterSibling) {
+      nsCOMPtr<nsIContent> sibling = splitterSibling->GetContent();
+      if (sibling && sibling->IsElement()) {
+        if (mState == CollapsedBefore || mState == CollapsedAfter) {
+          // CollapsedBefore -> Open
+          // CollapsedBefore -> Dragging
+          // CollapsedAfter -> Open
+          // CollapsedAfter -> Dragging
+          nsContentUtils::AddScriptRunner(new nsUnsetAttrRunnable(
+              sibling->AsElement(), nsGkAtoms::collapsed));
+        } else if ((mState == Open || mState == Dragging) &&
+                   (newState == CollapsedBefore ||
+                    newState == CollapsedAfter)) {
+          // Open -> CollapsedBefore / CollapsedAfter
+          // Dragging -> CollapsedBefore / CollapsedAfter
+          nsContentUtils::AddScriptRunner(new nsSetAttrRunnable(
+              sibling->AsElement(), nsGkAtoms::collapsed, u"true"_ns));
+        }
+      }
+    }
+  }
+  mState = newState;
+}
+
+void nsSplitterFrameInner::EnsureOrient() {
+  bool isHorizontal = !mParentBox->HasAnyStateBits(NS_STATE_IS_HORIZONTAL);
+  if (isHorizontal)
+    mOuter->AddStateBits(NS_STATE_IS_HORIZONTAL);
+  else
+    mOuter->RemoveStateBits(NS_STATE_IS_HORIZONTAL);
+}
+
+void nsSplitterFrameInner::AdjustChildren(nsPresContext* aPresContext) {
+  EnsureOrient();
+  bool isHorizontal = !mOuter->IsXULHorizontal();
+
+  AdjustChildren(aPresContext, mChildInfosBefore.get(), mChildInfosBeforeCount,
+                 isHorizontal);
+  AdjustChildren(aPresContext, mChildInfosAfter.get(), mChildInfosAfterCount,
+                 isHorizontal);
+}
+
+static nsIFrame* GetChildBoxForContent(nsIFrame* aParentBox,
+                                       nsIContent* aContent) {
+  nsIFrame* childBox = nsIFrame::GetChildXULBox(aParentBox);
+
+  while (childBox) {
+    if (childBox->GetContent() == aContent) {
+      return childBox;
+    }
+    childBox = nsIFrame::GetNextXULBox(childBox);
+  }
+  return nullptr;
+}
+
+void nsSplitterFrameInner::AdjustChildren(nsPresContext* aPresContext,
+                                          nsSplitterInfo* aChildInfos,
+                                          int32_t aCount, bool aIsHorizontal) {
+  /// printf("------- AdjustChildren------\n");
+
+  nsBoxLayoutState state(aPresContext);
+
+  nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
+
+  // first set all the widths.
+  nsIFrame* child = nsIFrame::GetChildXULBox(mOuter);
+  while (child) {
+    SetPreferredSize(state, child, onePixel, aIsHorizontal, nullptr);
+    child = nsIFrame::GetNextXULBox(child);
+  }
+
+  // now set our changed widths.
+  for (int i = 0; i < aCount; i++) {
+    nscoord pref = aChildInfos[i].changed;
+    nsIFrame* childBox =
+        GetChildBoxForContent(mParentBox, aChildInfos[i].childElem);
+
+    if (childBox) {
+      SetPreferredSize(state, childBox, onePixel, aIsHorizontal, &pref);
+    }
+  }
+}
+
+void nsSplitterFrameInner::SetPreferredSize(nsBoxLayoutState& aState,
+                                            nsIFrame* aChildBox,
+                                            nscoord aOnePixel,
+                                            bool aIsHorizontal,
+                                            nscoord* aSize) {
+  nsRect rect(aChildBox->GetRect());
+  nscoord pref = 0;
+
+  if (!aSize) {
+    if (aIsHorizontal)
+      pref = rect.width;
+    else
+      pref = rect.height;
+  } else {
+    pref = *aSize;
+  }
+
+  nsMargin margin(0, 0, 0, 0);
+  aChildBox->GetXULMargin(margin);
+
+  RefPtr<nsAtom> attribute;
+
+  if (aIsHorizontal) {
+    pref -= (margin.left + margin.right);
+    attribute = nsGkAtoms::width;
+  } else {
+    pref -= (margin.top + margin.bottom);
+    attribute = nsGkAtoms::height;
+  }
+
+  nsIContent* content = aChildBox->GetContent();
+  if (!content->IsElement()) {
+    return;
+  }
+
+  // set its preferred size.
+  nsAutoString prefValue;
+  prefValue.AppendInt(pref / aOnePixel);
+  if (content->AsElement()->AttrValueIs(kNameSpaceID_None, attribute, prefValue,
+                                        eCaseMatters)) {
+    return;
+  }
+
+  AutoWeakFrame weakBox(aChildBox);
+  content->AsElement()->SetAttr(kNameSpaceID_None, attribute, prefValue, true);
+  NS_ENSURE_TRUE_VOID(weakBox.IsAlive());
+  aState.PresShell()->FrameNeedsReflow(aChildBox, IntrinsicDirty::StyleChange,
+                                       NS_FRAME_IS_DIRTY);
+}
+
+void nsSplitterFrameInner::AddRemoveSpace(nscoord aDiff,
+                                          nsSplitterInfo* aChildInfos,
+                                          int32_t aCount, int32_t& aSpaceLeft) {
+  aSpaceLeft = 0;
+
+  for (int i = 0; i < aCount; i++) {
+    nscoord min = aChildInfos[i].min;
+    nscoord max = aChildInfos[i].max;
+    nscoord& c = aChildInfos[i].changed;
+
+    // figure our how much space to add or remove
+    if (c + aDiff < min) {
+      aDiff += (c - min);
+      c = min;
+    } else if (c + aDiff > max) {
+      aDiff -= (max - c);
+      c = max;
+    } else {
+      c += aDiff;
+      aDiff = 0;
+    }
+
+    // there is not space left? We are done
+    if (aDiff == 0) break;
+  }
+
+  aSpaceLeft = aDiff;
+}
+
+/**
+ * Ok if we want to resize a child we will know the actual size in pixels we
+ * want it to be. This is not the preferred size. But they only way we can
+ * change a child is my manipulating its preferred size. So give the actual
+ * pixel size this return method will return figure out the preferred size and
+ * set it.
+ */
+
+void nsSplitterFrameInner::ResizeChildTo(nscoord& aDiff,
+                                         nsSplitterInfo* aChildrenBeforeInfos,
+                                         nsSplitterInfo* aChildrenAfterInfos,
+                                         int32_t aChildrenBeforeCount,
+                                         int32_t aChildrenAfterCount,
+                                         bool aBounded) {
+  nscoord spaceLeft;
+  AddRemoveSpace(aDiff, aChildrenBeforeInfos, aChildrenBeforeCount, spaceLeft);
+
+  // if there is any space left over remove it from the dif we were originally
+  // given
+  aDiff -= spaceLeft;
+  AddRemoveSpace(-aDiff, aChildrenAfterInfos, aChildrenAfterCount, spaceLeft);
+
+  if (spaceLeft != 0) {
+    if (aBounded) {
+      aDiff += spaceLeft;
+      AddRemoveSpace(spaceLeft, aChildrenBeforeInfos, aChildrenBeforeCount,
+                     spaceLeft);
+    }
+  }
+}