Simplify CPWL_EditImpl_Undo.

Change-Id: I15307562fcf8f0aebd6e14293b46a10106c4ace7
Reviewed-on: https://pdfium-review.googlesource.com/10858
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

2 files changed, 9 insertions, 20 deletions

diff --git a/fpdfsdk/pwl/cpwl_edit_impl.cpp b/fpdfsdk/pwl/cpwl_edit_impl.cpp
index 1f3aa21130..808eddb7cb 100644
--- a/fpdfsdk/pwl/cpwl_edit_impl.cpp
+++ b/fpdfsdk/pwl/cpwl_edit_impl.cpp
@@ -211,12 +211,10 @@ void CPWL_EditImpl_Refresh::EndRefresh() {
   m_RefreshRects.Clear();
 }
 
-CPWL_EditImpl_Undo::CPWL_EditImpl_Undo(int32_t nBufsize)
-    : m_nCurUndoPos(0), m_nBufSize(nBufsize), m_bWorking(false) {}
+CPWL_EditImpl_Undo::CPWL_EditImpl_Undo()
+    : m_nCurUndoPos(0), m_bWorking(false) {}
 
-CPWL_EditImpl_Undo::~CPWL_EditImpl_Undo() {
-  Reset();
-}
+CPWL_EditImpl_Undo::~CPWL_EditImpl_Undo() {}
 
 bool CPWL_EditImpl_Undo::CanUndo() const {
   return m_nCurUndoPos > 0;
@@ -224,7 +222,7 @@ bool CPWL_EditImpl_Undo::CanUndo() const {
 
 void CPWL_EditImpl_Undo::Undo() {
   m_bWorking = true;
-  if (m_nCurUndoPos > 0) {
+  if (CanUndo()) {
     m_UndoItemStack[m_nCurUndoPos - 1]->Undo();
     m_nCurUndoPos--;
   }
@@ -237,7 +235,7 @@ bool CPWL_EditImpl_Undo::CanRedo() const {
 
 void CPWL_EditImpl_Undo::Redo() {
   m_bWorking = true;
-  if (m_nCurUndoPos < m_UndoItemStack.size()) {
+  if (CanRedo()) {
     m_UndoItemStack[m_nCurUndoPos]->Redo();
     m_nCurUndoPos++;
   }
@@ -247,11 +245,10 @@ void CPWL_EditImpl_Undo::Redo() {
 void CPWL_EditImpl_Undo::AddItem(std::unique_ptr<IFX_Edit_UndoItem> pItem) {
   ASSERT(!m_bWorking);
   ASSERT(pItem);
-  ASSERT(m_nBufSize > 1);
-  if (m_nCurUndoPos < m_UndoItemStack.size())
+  if (CanRedo())
     RemoveTails();
 
-  if (m_UndoItemStack.size() >= m_nBufSize)
+  if (m_UndoItemStack.size() >= kEditUndoMaxItems)
     RemoveHeads();
 
   m_UndoItemStack.push_back(std::move(pItem));
@@ -264,15 +261,10 @@ void CPWL_EditImpl_Undo::RemoveHeads() {
 }
 
 void CPWL_EditImpl_Undo::RemoveTails() {
-  while (m_UndoItemStack.size() > m_nCurUndoPos)
+  while (CanRedo())
     m_UndoItemStack.pop_back();
 }
 
-void CPWL_EditImpl_Undo::Reset() {
-  m_UndoItemStack.clear();
-  m_nCurUndoPos = 0;
-}
-
 CFXEU_InsertWord::CFXEU_InsertWord(CPWL_EditImpl* pEdit,
                                    const CPVT_WordPlace& wpOldPlace,
                                    const CPVT_WordPlace& wpNewPlace,
@@ -575,7 +567,6 @@ void CPWL_EditImpl::DrawEdit(CFX_RenderDevice* pDevice,
 CPWL_EditImpl::CPWL_EditImpl()
     : m_pVT(pdfium::MakeUnique<CPDF_VariableText>()),
       m_bEnableScroll(false),
-      m_Undo(kEditUndoMaxItems),
       m_nAlignment(0),
       m_bNotifyFlag(false),
       m_bEnableOverflow(false),
diff --git a/fpdfsdk/pwl/cpwl_edit_impl.h b/fpdfsdk/pwl/cpwl_edit_impl.h
index d65610dc43..80c68050f5 100644
--- a/fpdfsdk/pwl/cpwl_edit_impl.h
+++ b/fpdfsdk/pwl/cpwl_edit_impl.h
@@ -103,7 +103,7 @@ class CPWL_EditImpl_Select {
 
 class CPWL_EditImpl_Undo {
  public:
-  explicit CPWL_EditImpl_Undo(int32_t nBufsize);
+  CPWL_EditImpl_Undo();
   ~CPWL_EditImpl_Undo();
 
   void AddItem(std::unique_ptr<IFX_Edit_UndoItem> pItem);
@@ -111,7 +111,6 @@ class CPWL_EditImpl_Undo {
   void Redo();
   bool CanUndo() const;
   bool CanRedo() const;
-  void Reset();
 
  private:
   void RemoveHeads();
@@ -119,7 +118,6 @@ class CPWL_EditImpl_Undo {
 
   std::deque<std::unique_ptr<IFX_Edit_UndoItem>> m_UndoItemStack;
   size_t m_nCurUndoPos;
-  size_t m_nBufSize;
   bool m_bWorking;
 };