1 files changed, 250 insertions, 0 deletions
diff --git a/layout/base/nsFrameManager.cpp b/layout/base/nsFrameManager.cpp
new file mode 100644
index 0000000000..87328ccb80
--- /dev/null
+++ b/layout/base/nsFrameManager.cpp
@@ -0,0 +1,250 @@
+/* -*- 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/. */
+
+/* storage of the frame tree and information about it */
+
+#include "nsFrameManager.h"
+
+#include "nscore.h"
+#include "nsCOMPtr.h"
+#include "plhash.h"
+#include "nsPlaceholderFrame.h"
+#include "nsGkAtoms.h"
+#include "nsILayoutHistoryState.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/PresState.h"
+#include "mozilla/ComputedStyle.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/Document.h"
+
+#include "nsError.h"
+#include "nsAbsoluteContainingBlock.h"
+#include "ChildIterator.h"
+
+#include "GeckoProfiler.h"
+#include "nsIStatefulFrame.h"
+#include "nsContainerFrame.h"
+#include "nsWindowSizes.h"
+
+#include "mozilla/MemoryReporting.h"
+
+// #define DEBUG_UNDISPLAYED_MAP
+// #define DEBUG_DISPLAY_CONTENTS_MAP
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+//----------------------------------------------------------------------
+
+nsFrameManager::~nsFrameManager() {
+  NS_ASSERTION(!mPresShell, "nsFrameManager::Destroy never called");
+}
+
+void nsFrameManager::Destroy() {
+  NS_ASSERTION(mPresShell, "Frame manager already shut down.");
+
+  // Destroy the frame hierarchy.
+  mPresShell->SetIgnoreFrameDestruction(true);
+
+  if (mRootFrame) {
+    FrameDestroyContext context(mPresShell);
+    mRootFrame->Destroy(context);
+    mRootFrame = nullptr;
+  }
+
+  mPresShell = nullptr;
+}
+
+//----------------------------------------------------------------------
+void nsFrameManager::AppendFrames(nsContainerFrame* aParentFrame,
+                                  FrameChildListID aListID,
+                                  nsFrameList&& aFrameList) {
+  if (aParentFrame->IsAbsoluteContainer() &&
+      aListID == aParentFrame->GetAbsoluteListID()) {
+    aParentFrame->GetAbsoluteContainingBlock()->AppendFrames(
+        aParentFrame, aListID, std::move(aFrameList));
+  } else {
+    aParentFrame->AppendFrames(aListID, std::move(aFrameList));
+  }
+}
+
+void nsFrameManager::InsertFrames(nsContainerFrame* aParentFrame,
+                                  FrameChildListID aListID,
+                                  nsIFrame* aPrevFrame,
+                                  nsFrameList&& aFrameList) {
+  MOZ_ASSERT(
+      !aPrevFrame ||
+          (!aPrevFrame->GetNextContinuation() ||
+           (aPrevFrame->GetNextContinuation()->HasAnyStateBits(
+                NS_FRAME_IS_OVERFLOW_CONTAINER) &&
+            !aPrevFrame->HasAnyStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER))),
+      "aPrevFrame must be the last continuation in its chain!");
+
+  if (aParentFrame->IsAbsoluteContainer() &&
+      aListID == aParentFrame->GetAbsoluteListID()) {
+    aParentFrame->GetAbsoluteContainingBlock()->InsertFrames(
+        aParentFrame, aListID, aPrevFrame, std::move(aFrameList));
+  } else {
+    aParentFrame->InsertFrames(aListID, aPrevFrame, nullptr,
+                               std::move(aFrameList));
+  }
+}
+
+void nsFrameManager::RemoveFrame(DestroyContext& aContext,
+                                 FrameChildListID aListID,
+                                 nsIFrame* aOldFrame) {
+  // In case the reflow doesn't invalidate anything since it just leaves
+  // a gap where the old frame was, we invalidate it here.  (This is
+  // reasonably likely to happen when removing a last child in a way
+  // that doesn't change the size of the parent.)
+  // This has to sure to invalidate the entire overflow rect; this
+  // is important in the presence of absolute positioning
+  aOldFrame->InvalidateFrameForRemoval();
+
+  NS_ASSERTION(!aOldFrame->GetPrevContinuation() ||
+                   // exception for
+                   // nsCSSFrameConstructor::RemoveFloatingFirstLetterFrames
+                   aOldFrame->IsTextFrame(),
+               "Must remove first continuation.");
+  NS_ASSERTION(!(aOldFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW) &&
+                 aOldFrame->GetPlaceholderFrame()),
+               "Must call RemoveFrame on placeholder for out-of-flows.");
+  nsContainerFrame* parentFrame = aOldFrame->GetParent();
+  if (parentFrame->IsAbsoluteContainer() &&
+      aListID == parentFrame->GetAbsoluteListID()) {
+    parentFrame->GetAbsoluteContainingBlock()->RemoveFrame(aContext, aListID,
+                                                           aOldFrame);
+  } else {
+    parentFrame->RemoveFrame(aContext, aListID, aOldFrame);
+  }
+}
+
+//----------------------------------------------------------------------
+
+// Capture state for a given frame.
+// Accept a content id here, in some cases we may not have content (scroll
+// position)
+void nsFrameManager::CaptureFrameStateFor(nsIFrame* aFrame,
+                                          nsILayoutHistoryState* aState) {
+  if (!aFrame || !aState) {
+    NS_WARNING("null frame, or state");
+    return;
+  }
+
+  // Only capture state for stateful frames
+  nsIStatefulFrame* statefulFrame = do_QueryFrame(aFrame);
+  if (!statefulFrame) {
+    return;
+  }
+
+  // Capture the state, exit early if we get null (nothing to save)
+  UniquePtr<PresState> frameState = statefulFrame->SaveState();
+  if (!frameState) {
+    return;
+  }
+
+  // Generate the hash key to store the state under
+  // Exit early if we get empty key
+  nsAutoCString stateKey;
+  nsIContent* content = aFrame->GetContent();
+  Document* doc = content ? content->GetUncomposedDoc() : nullptr;
+  statefulFrame->GenerateStateKey(content, doc, stateKey);
+  if (stateKey.IsEmpty()) {
+    return;
+  }
+
+  // Store the state. aState owns frameState now.
+  aState->AddState(stateKey, std::move(frameState));
+}
+
+void nsFrameManager::CaptureFrameState(nsIFrame* aFrame,
+                                       nsILayoutHistoryState* aState) {
+  MOZ_ASSERT(nullptr != aFrame && nullptr != aState,
+             "null parameters passed in");
+
+  CaptureFrameStateFor(aFrame, aState);
+
+  // Now capture state recursively for the frame hierarchy rooted at aFrame
+  for (const auto& childList : aFrame->ChildLists()) {
+    for (nsIFrame* child : childList.mList) {
+      if (child->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)) {
+        // We'll pick it up when we get to its placeholder
+        continue;
+      }
+      // Make sure to walk through placeholders as needed, so that we
+      // save state for out-of-flows which may not be our descendants
+      // themselves but whose placeholders are our descendants.
+      CaptureFrameState(nsPlaceholderFrame::GetRealFrameFor(child), aState);
+    }
+  }
+}
+
+// Restore state for a given frame.
+// Accept a content id here, in some cases we may not have content (scroll
+// position)
+void nsFrameManager::RestoreFrameStateFor(nsIFrame* aFrame,
+                                          nsILayoutHistoryState* aState) {
+  if (!aFrame || !aState) {
+    NS_WARNING("null frame or state");
+    return;
+  }
+
+  // Only restore state for stateful frames
+  nsIStatefulFrame* statefulFrame = do_QueryFrame(aFrame);
+  if (!statefulFrame) {
+    return;
+  }
+
+  // Generate the hash key the state was stored under
+  // Exit early if we get empty key
+  nsIContent* content = aFrame->GetContent();
+  // If we don't have content, we can't generate a hash
+  // key and there's probably no state information for us.
+  if (!content) {
+    return;
+  }
+
+  nsAutoCString stateKey;
+  Document* doc = content->GetUncomposedDoc();
+  statefulFrame->GenerateStateKey(content, doc, stateKey);
+  if (stateKey.IsEmpty()) {
+    return;
+  }
+
+  // Get the state from the hash
+  PresState* frameState = aState->GetState(stateKey);
+  if (!frameState) {
+    return;
+  }
+
+  // Restore it
+  nsresult rv = statefulFrame->RestoreState(frameState);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  // If we restore ok, remove the state from the state table
+  aState->RemoveState(stateKey);
+}
+
+void nsFrameManager::RestoreFrameState(nsIFrame* aFrame,
+                                       nsILayoutHistoryState* aState) {
+  MOZ_ASSERT(nullptr != aFrame && nullptr != aState,
+             "null parameters passed in");
+
+  RestoreFrameStateFor(aFrame, aState);
+
+  // Now restore state recursively for the frame hierarchy rooted at aFrame
+  for (const auto& childList : aFrame->ChildLists()) {
+    for (nsIFrame* child : childList.mList) {
+      RestoreFrameState(child, aState);
+    }
+  }
+}
+
+void nsFrameManager::AddSizeOfIncludingThis(nsWindowSizes& aSizes) const {
+  aSizes.mLayoutPresShellSize += aSizes.mState.mMallocSizeOf(this);
+}