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>

1 files changed, 32 insertions, 0 deletions

diff --git a/fpdfsdk/fpdf_formfill.cpp b/fpdfsdk/fpdf_formfill.cpp
index 7676463edc..b70bd9da50 100644
--- a/fpdfsdk/fpdf_formfill.cpp
+++ b/fpdfsdk/fpdf_formfill.cpp
@@ -465,6 +465,38 @@ FPDF_EXPORT void FPDF_CALLCONV FORM_ReplaceSelection(FPDF_FORMHANDLE hHandle,
   pPageView->ReplaceSelection(wide_str_text);
 }
 
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_CanUndo(FPDF_FORMHANDLE hHandle,
+                                                 FPDF_PAGE page) {
+  CPDFSDK_PageView* pPageView = FormHandleToPageView(hHandle, page);
+  if (!pPageView)
+    return false;
+  return pPageView->CanUndo();
+}
+
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_CanRedo(FPDF_FORMHANDLE hHandle,
+                                                 FPDF_PAGE page) {
+  CPDFSDK_PageView* pPageView = FormHandleToPageView(hHandle, page);
+  if (!pPageView)
+    return false;
+  return pPageView->CanRedo();
+}
+
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_Undo(FPDF_FORMHANDLE hHandle,
+                                              FPDF_PAGE page) {
+  CPDFSDK_PageView* pPageView = FormHandleToPageView(hHandle, page);
+  if (!pPageView)
+    return false;
+  return pPageView->Undo();
+}
+
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FORM_Redo(FPDF_FORMHANDLE hHandle,
+                                              FPDF_PAGE page) {
+  CPDFSDK_PageView* pPageView = FormHandleToPageView(hHandle, page);
+  if (!pPageView)
+    return false;
+  return pPageView->Redo();
+}
+
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
 FORM_ForceToKillFocus(FPDF_FORMHANDLE hHandle) {
   CPDFSDK_FormFillEnvironment* pFormFillEnv =