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, 16 insertions, 0 deletions

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) {