Add public APIs for undo / redo in forms.

Add FORM_CanUndo(), FORM_CanRedo(), FORM_Undo(), and FORM_Redo().

BUG=chromium:764260

Change-Id: I1d9ea67152d9b35d9b8e1d7ef7d019706fdfa30a
Reviewed-on: https://pdfium-review.googlesource.com/30872
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

6 files changed, 52 insertions, 12 deletions

diff --git a/fpdfsdk/pwl/cpwl_combo_box.cpp b/fpdfsdk/pwl/cpwl_combo_box.cpp
index 1576b022fd..2e6e56c52b 100644
--- a/fpdfsdk/pwl/cpwl_combo_box.cpp
+++ b/fpdfsdk/pwl/cpwl_combo_box.cpp
@@ -196,6 +196,22 @@ void CPWL_ComboBox::ReplaceSelection(const WideString& text) {
     m_pEdit->ReplaceSelection(text);
 }
 
+bool CPWL_ComboBox::CanUndo() {
+  return m_pEdit && m_pEdit->CanUndo();
+}
+
+bool CPWL_ComboBox::CanRedo() {
+  return m_pEdit && m_pEdit->CanRedo();
+}
+
+bool CPWL_ComboBox::Undo() {
+  return m_pEdit && m_pEdit->Undo();
+}
+
+bool CPWL_ComboBox::Redo() {
+  return m_pEdit && m_pEdit->Redo();
+}
+
 WideString CPWL_ComboBox::GetText() {
   return m_pEdit ? m_pEdit->GetText() : WideString();
 }
diff --git a/fpdfsdk/pwl/cpwl_combo_box.h b/fpdfsdk/pwl/cpwl_combo_box.h
index 28c063d5fd..a4e823c4dc 100644
--- a/fpdfsdk/pwl/cpwl_combo_box.h
+++ b/fpdfsdk/pwl/cpwl_combo_box.h
@@ -63,6 +63,10 @@ class CPWL_ComboBox : public CPWL_Wnd {
   WideString GetText() override;
   WideString GetSelectedText() override;
   void ReplaceSelection(const WideString& text) override;
+  bool CanUndo() override;
+  bool CanRedo() override;
+  bool Undo() override;
+  bool Redo() override;
 
   void SetFillerNotify(IPWL_Filler_Notify* pNotify);
 
diff --git a/fpdfsdk/pwl/cpwl_edit_ctrl.cpp b/fpdfsdk/pwl/cpwl_edit_ctrl.cpp
index 5e2f7acda6..579a587175 100644
--- a/fpdfsdk/pwl/cpwl_edit_ctrl.cpp
+++ b/fpdfsdk/pwl/cpwl_edit_ctrl.cpp
@@ -401,22 +401,20 @@ void CPWL_EditCtrl::Backspace() {
     m_pEdit->Backspace();
 }
 
-bool CPWL_EditCtrl::CanUndo() const {
+bool CPWL_EditCtrl::CanUndo() {
   return !IsReadOnly() && m_pEdit->CanUndo();
 }
 
-bool CPWL_EditCtrl::CanRedo() const {
+bool CPWL_EditCtrl::CanRedo() {
   return !IsReadOnly() && m_pEdit->CanRedo();
 }
 
-void CPWL_EditCtrl::Redo() {
-  if (CanRedo())
-    m_pEdit->Redo();
+bool CPWL_EditCtrl::Undo() {
+  return CanUndo() && m_pEdit->Undo();
 }
 
-void CPWL_EditCtrl::Undo() {
-  if (CanUndo())
-    m_pEdit->Undo();
+bool CPWL_EditCtrl::Redo() {
+  return CanRedo() && m_pEdit->Redo();
 }
 
 int32_t CPWL_EditCtrl::GetCharSet() const {
diff --git a/fpdfsdk/pwl/cpwl_edit_ctrl.h b/fpdfsdk/pwl/cpwl_edit_ctrl.h
index 544464770f..a21c8a2700 100644
--- a/fpdfsdk/pwl/cpwl_edit_ctrl.h
+++ b/fpdfsdk/pwl/cpwl_edit_ctrl.h
@@ -36,10 +36,10 @@ class CPWL_EditCtrl : public CPWL_Wnd {
   void SetCharSet(uint8_t nCharSet) { m_nCharSet = nCharSet; }
   int32_t GetCharSet() const;
 
-  bool CanUndo() const;
-  bool CanRedo() const;
-  void Redo();
-  void Undo();
+  bool CanUndo() override;
+  bool CanRedo() override;
+  bool Undo() override;
+  bool Redo() override;
 
   void SetReadyToInput();
 
diff --git a/fpdfsdk/pwl/cpwl_wnd.cpp b/fpdfsdk/pwl/cpwl_wnd.cpp
index c6d6b79136..8782e85a14 100644
--- a/fpdfsdk/pwl/cpwl_wnd.cpp
+++ b/fpdfsdk/pwl/cpwl_wnd.cpp
@@ -365,6 +365,22 @@ WideString CPWL_Wnd::GetSelectedText() {
 
 void CPWL_Wnd::ReplaceSelection(const WideString& text) {}
 
+bool CPWL_Wnd::CanUndo() {
+  return false;
+}
+
+bool CPWL_Wnd::CanRedo() {
+  return false;
+}
+
+bool CPWL_Wnd::Undo() {
+  return false;
+}
+
+bool CPWL_Wnd::Redo() {
+  return false;
+}
+
 bool CPWL_Wnd::OnMouseWheel(short zDelta,
                             const CFX_PointF& point,
                             uint32_t nFlag) {
diff --git a/fpdfsdk/pwl/cpwl_wnd.h b/fpdfsdk/pwl/cpwl_wnd.h
index 9c790eb5b8..a24635fa1f 100644
--- a/fpdfsdk/pwl/cpwl_wnd.h
+++ b/fpdfsdk/pwl/cpwl_wnd.h
@@ -184,6 +184,12 @@ class CPWL_Wnd : public CPWL_TimerHandler, public Observable<CPWL_Wnd> {
   virtual WideString GetText();
   virtual WideString GetSelectedText();
   virtual void ReplaceSelection(const WideString& text);
+
+  virtual bool CanUndo();
+  virtual bool CanRedo();
+  virtual bool Undo();
+  virtual bool Redo();
+
   virtual CFX_FloatRect GetFocusRect() const;
   virtual CFX_FloatRect GetClientRect() const;