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>

4 files changed, 78 insertions, 0 deletions

diff --git a/fpdfsdk/formfiller/cffl_formfiller.cpp b/fpdfsdk/formfiller/cffl_formfiller.cpp
index 32bbcb73d2..ac82e3ed47 100644
--- a/fpdfsdk/formfiller/cffl_formfiller.cpp
+++ b/fpdfsdk/formfiller/cffl_formfiller.cpp
@@ -256,6 +256,50 @@ void CFFL_FormFiller::ReplaceSelection(CPDFSDK_Annot* pAnnot,
   pWnd->ReplaceSelection(text);
 }
 
+bool CFFL_FormFiller::CanUndo(CPDFSDK_Annot* pAnnot) {
+  if (!IsValid())
+    return false;
+
+  CPDFSDK_PageView* pPageView = GetCurPageView(true);
+  ASSERT(pPageView);
+
+  CPWL_Wnd* pWnd = GetPDFWindow(pPageView, false);
+  return pWnd && pWnd->CanUndo();
+}
+
+bool CFFL_FormFiller::CanRedo(CPDFSDK_Annot* pAnnot) {
+  if (!IsValid())
+    return false;
+
+  CPDFSDK_PageView* pPageView = GetCurPageView(true);
+  ASSERT(pPageView);
+
+  CPWL_Wnd* pWnd = GetPDFWindow(pPageView, false);
+  return pWnd && pWnd->CanRedo();
+}
+
+bool CFFL_FormFiller::Undo(CPDFSDK_Annot* pAnnot) {
+  if (!IsValid())
+    return false;
+
+  CPDFSDK_PageView* pPageView = GetCurPageView(true);
+  ASSERT(pPageView);
+
+  CPWL_Wnd* pWnd = GetPDFWindow(pPageView, false);
+  return pWnd && pWnd->Undo();
+}
+
+bool CFFL_FormFiller::Redo(CPDFSDK_Annot* pAnnot) {
+  if (!IsValid())
+    return false;
+
+  CPDFSDK_PageView* pPageView = GetCurPageView(true);
+  ASSERT(pPageView);
+
+  CPWL_Wnd* pWnd = GetPDFWindow(pPageView, false);
+  return pWnd && pWnd->Redo();
+}
+
 void CFFL_FormFiller::SetFocusForAnnot(CPDFSDK_Annot* pAnnot, uint32_t nFlag) {
   CPDFSDK_Widget* pWidget = (CPDFSDK_Widget*)pAnnot;
   UnderlyingPageType* pPage = pWidget->GetUnderlyingPage();
diff --git a/fpdfsdk/formfiller/cffl_formfiller.h b/fpdfsdk/formfiller/cffl_formfiller.h
index a9d90ab902..bad42ecaf4 100644
--- a/fpdfsdk/formfiller/cffl_formfiller.h
+++ b/fpdfsdk/formfiller/cffl_formfiller.h
@@ -79,6 +79,11 @@ class CFFL_FormFiller : public CPWL_Wnd::ProviderIface,
   WideString GetSelectedText(CPDFSDK_Annot* pAnnot);
   void ReplaceSelection(CPDFSDK_Annot* pAnnot, const WideString& text);
 
+  bool CanUndo(CPDFSDK_Annot* pAnnot);
+  bool CanRedo(CPDFSDK_Annot* pAnnot);
+  bool Undo(CPDFSDK_Annot* pAnnot);
+  bool Redo(CPDFSDK_Annot* pAnnot);
+
   void SetFocusForAnnot(CPDFSDK_Annot* pAnnot, uint32_t nFlag);
   void KillFocusForAnnot(CPDFSDK_Annot* pAnnot, uint32_t nFlag);
 
diff --git a/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp b/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
index 5972d1dd67..6b34ca3ae2 100644
--- a/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
+++ b/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
@@ -533,6 +533,30 @@ void CFFL_InteractiveFormFiller::ReplaceSelection(CPDFSDK_Annot* pAnnot,
   pFormFiller->ReplaceSelection(pAnnot, text);
 }
 
+bool CFFL_InteractiveFormFiller::CanUndo(CPDFSDK_Annot* pAnnot) {
+  ASSERT(pAnnot->GetPDFAnnot()->GetSubtype() == CPDF_Annot::Subtype::WIDGET);
+  CFFL_FormFiller* pFormFiller = GetFormFiller(pAnnot, false);
+  return pFormFiller && pFormFiller->CanUndo(pAnnot);
+}
+
+bool CFFL_InteractiveFormFiller::CanRedo(CPDFSDK_Annot* pAnnot) {
+  ASSERT(pAnnot->GetPDFAnnot()->GetSubtype() == CPDF_Annot::Subtype::WIDGET);
+  CFFL_FormFiller* pFormFiller = GetFormFiller(pAnnot, false);
+  return pFormFiller && pFormFiller->CanRedo(pAnnot);
+}
+
+bool CFFL_InteractiveFormFiller::Undo(CPDFSDK_Annot* pAnnot) {
+  ASSERT(pAnnot->GetPDFAnnot()->GetSubtype() == CPDF_Annot::Subtype::WIDGET);
+  CFFL_FormFiller* pFormFiller = GetFormFiller(pAnnot, false);
+  return pFormFiller && pFormFiller->Undo(pAnnot);
+}
+
+bool CFFL_InteractiveFormFiller::Redo(CPDFSDK_Annot* pAnnot) {
+  ASSERT(pAnnot->GetPDFAnnot()->GetSubtype() == CPDF_Annot::Subtype::WIDGET);
+  CFFL_FormFiller* pFormFiller = GetFormFiller(pAnnot, false);
+  return pFormFiller && pFormFiller->Redo(pAnnot);
+}
+
 void CFFL_InteractiveFormFiller::UnRegisterFormFiller(CPDFSDK_Annot* pAnnot) {
   auto it = m_Maps.find(pAnnot);
   if (it == m_Maps.end())
diff --git a/fpdfsdk/formfiller/cffl_interactiveformfiller.h b/fpdfsdk/formfiller/cffl_interactiveformfiller.h
index bb0d2233fc..1f049d03ef 100644
--- a/fpdfsdk/formfiller/cffl_interactiveformfiller.h
+++ b/fpdfsdk/formfiller/cffl_interactiveformfiller.h
@@ -86,6 +86,11 @@ class CFFL_InteractiveFormFiller : public IPWL_Filler_Notify {
   WideString GetSelectedText(CPDFSDK_Annot* pAnnot);
   void ReplaceSelection(CPDFSDK_Annot* pAnnot, const WideString& text);
 
+  bool CanUndo(CPDFSDK_Annot* pAnnot);
+  bool CanRedo(CPDFSDK_Annot* pAnnot);
+  bool Undo(CPDFSDK_Annot* pAnnot);
+  bool Redo(CPDFSDK_Annot* pAnnot);
+
   static bool IsVisible(CPDFSDK_Widget* pWidget);
   static bool IsReadOnly(CPDFSDK_Widget* pWidget);
   static bool IsFillingAllowed(CPDFSDK_Widget* pWidget);