1 files changed, 162 insertions, 0 deletions
diff --git a/layout/base/nsLayoutHistoryState.cpp b/layout/base/nsLayoutHistoryState.cpp
new file mode 100644
index 0000000000..f79545fb3b
--- /dev/null
+++ b/layout/base/nsLayoutHistoryState.cpp
@@ -0,0 +1,162 @@
+/* -*- 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/. */
+
+/*
+ * container for information saved in session history when the document
+ * is not
+ */
+
+#include "nsILayoutHistoryState.h"
+#include "nsWeakReference.h"
+#include "mozilla/PresState.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/UniquePtr.h"
+#include "nsTHashMap.h"
+
+using namespace mozilla;
+
+class nsLayoutHistoryState final : public nsILayoutHistoryState,
+                                   public nsSupportsWeakReference {
+ public:
+  nsLayoutHistoryState() : mScrollPositionOnly(false) {}
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSILAYOUTHISTORYSTATE
+
+ private:
+  ~nsLayoutHistoryState() = default;
+  bool mScrollPositionOnly;
+
+  nsTHashMap<nsCString, UniquePtr<PresState>> mStates;
+};
+
+already_AddRefed<nsILayoutHistoryState> NS_NewLayoutHistoryState() {
+  RefPtr<nsLayoutHistoryState> state = new nsLayoutHistoryState();
+  return state.forget();
+}
+
+NS_IMPL_ISUPPORTS(nsLayoutHistoryState, nsILayoutHistoryState,
+                  nsISupportsWeakReference)
+
+NS_IMETHODIMP
+nsLayoutHistoryState::GetHasStates(bool* aHasStates) {
+  *aHasStates = HasStates();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLayoutHistoryState::GetKeys(nsTArray<nsCString>& aKeys) {
+  if (!HasStates()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  AppendToArray(aKeys, mStates.Keys());
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLayoutHistoryState::GetPresState(const nsACString& aKey, float* aScrollX,
+                                   float* aScrollY,
+                                   bool* aAllowScrollOriginDowngrade,
+                                   float* aRes) {
+  PresState* state = GetState(nsCString(aKey));
+
+  if (!state) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *aScrollX = state->scrollState().x;
+  *aScrollY = state->scrollState().y;
+  *aAllowScrollOriginDowngrade = state->allowScrollOriginDowngrade();
+  *aRes = state->resolution();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsLayoutHistoryState::AddNewPresState(const nsACString& aKey, float aScrollX,
+                                      float aScrollY,
+                                      bool aAllowScrollOriginDowngrade,
+                                      float aRes) {
+  UniquePtr<PresState> newState = NewPresState();
+  newState->scrollState() = nsPoint(aScrollX, aScrollY);
+  newState->allowScrollOriginDowngrade() = aAllowScrollOriginDowngrade;
+  newState->resolution() = aRes;
+
+  mStates.InsertOrUpdate(nsCString(aKey), std::move(newState));
+
+  return NS_OK;
+}
+
+void nsLayoutHistoryState::AddState(const nsCString& aStateKey,
+                                    UniquePtr<PresState> aState) {
+  mStates.InsertOrUpdate(aStateKey, std::move(aState));
+}
+
+PresState* nsLayoutHistoryState::GetState(const nsCString& aKey) {
+  auto statePtr = mStates.Lookup(aKey);
+  if (!statePtr) {
+    return nullptr;
+  }
+  PresState* state = statePtr->get();
+
+  if (mScrollPositionOnly) {
+    // Ensure any state that shouldn't be restored is removed
+    state->contentData() = void_t();
+    state->disabledSet() = false;
+  }
+
+  return state;
+}
+
+void nsLayoutHistoryState::RemoveState(const nsCString& aKey) {
+  mStates.Remove(aKey);
+}
+
+bool nsLayoutHistoryState::HasStates() { return mStates.Count() != 0; }
+
+void nsLayoutHistoryState::SetScrollPositionOnly(const bool aFlag) {
+  mScrollPositionOnly = aFlag;
+}
+
+void nsLayoutHistoryState::ResetScrollState() {
+  for (const auto& state : mStates.Values()) {
+    if (state) {
+      state->scrollState() = nsPoint(0, 0);
+    }
+  }
+}
+
+void nsLayoutHistoryState::GetContents(bool* aScrollPositionOnly,
+                                       nsTArray<nsCString>& aKeys,
+                                       nsTArray<mozilla::PresState>& aStates) {
+  *aScrollPositionOnly = mScrollPositionOnly;
+  aKeys.SetCapacity(mStates.Count());
+  aStates.SetCapacity(mStates.Count());
+  for (const auto& entry : mStates) {
+    aKeys.AppendElement(entry.GetKey());
+    aStates.AppendElement(*(entry.GetData().get()));
+  }
+}
+
+void nsLayoutHistoryState::Reset() {
+  mScrollPositionOnly = false;
+  mStates.Clear();
+}
+
+namespace mozilla {
+UniquePtr<PresState> NewPresState() {
+  return MakeUnique<PresState>(
+      /* contentData */ mozilla::void_t(),
+      /* scrollState */ nsPoint(0, 0),
+      /* allowScrollOriginDowngrade */ true,
+      /* resolution */ 1.0,
+      /* disabledSet */ false,
+      /* disabled */ false,
+      /* droppedDown */ false);
+}
+}  // namespace mozilla