Add FORM_GetSelectedText() function.

This function copies the selected text from a form text field or
form combobox text field into the buffer parameter and returns the
length of the selected text string. When buffer is a nullptr or
buflen is less than the length of the selected text, this function
does not modify the buffer and only returns the selected text length.

BUG=chromium:59266

Change-Id: Ie77de38e45bbe6f9ea033826c961435304eedfc7
Reviewed-on: https://pdfium-review.googlesource.com/6413
Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

4 files changed, 22 insertions, 0 deletions

diff --git a/fpdfsdk/formfiller/cffl_formfiller.cpp b/fpdfsdk/formfiller/cffl_formfiller.cpp
index 297d5b78d6..526f4b947d 100644
--- a/fpdfsdk/formfiller/cffl_formfiller.cpp
+++ b/fpdfsdk/formfiller/cffl_formfiller.cpp
@@ -239,6 +239,17 @@ bool CFFL_FormFiller::OnChar(CPDFSDK_Annot* pAnnot,
   return false;
 }
 
+CFX_WideString CFFL_FormFiller::GetSelectedText(CPDFSDK_Annot* pAnnot) {
+  if (!IsValid())
+    return CFX_WideString();
+
+  CPDFSDK_PageView* pPageView = GetCurPageView(true);
+  ASSERT(pPageView);
+
+  CPWL_Wnd* pWnd = GetPDFWindow(pPageView, false);
+  return pWnd ? pWnd->GetSelectedText() : CFX_WideString();
+}
+
 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 445e86fb3c..2ddbdf2d6e 100644
--- a/fpdfsdk/formfiller/cffl_formfiller.h
+++ b/fpdfsdk/formfiller/cffl_formfiller.h
@@ -74,6 +74,8 @@ class CFFL_FormFiller : public IPWL_Provider, public CPWL_TimerHandler {
                          uint32_t nFlags);
   virtual bool OnChar(CPDFSDK_Annot* pAnnot, uint32_t nChar, uint32_t nFlags);
 
+  CFX_WideString GetSelectedText(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 7647fb19ff..69c74bc587 100644
--- a/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
+++ b/fpdfsdk/formfiller/cffl_interactiveformfiller.cpp
@@ -522,6 +522,13 @@ void CFFL_InteractiveFormFiller::RemoveFormFiller(CPDFSDK_Annot* pAnnot) {
     UnRegisterFormFiller(pAnnot);
 }
 
+CFX_WideString CFFL_InteractiveFormFiller::GetSelectedText(
+    CPDFSDK_Annot* pAnnot) {
+  ASSERT(pAnnot->GetPDFAnnot()->GetSubtype() == CPDF_Annot::Subtype::WIDGET);
+  CFFL_FormFiller* pFormFiller = GetFormFiller(pAnnot, false);
+  return pFormFiller ? pFormFiller->GetSelectedText(pAnnot) : CFX_WideString();
+}
+
 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 f72dfbcc61..b7724a32e3 100644
--- a/fpdfsdk/formfiller/cffl_interactiveformfiller.h
+++ b/fpdfsdk/formfiller/cffl_interactiveformfiller.h
@@ -82,6 +82,8 @@ class CFFL_InteractiveFormFiller : public IPWL_Filler_Notify {
   CFFL_FormFiller* GetFormFiller(CPDFSDK_Annot* pAnnot, bool bRegister);
   void RemoveFormFiller(CPDFSDK_Annot* pAnnot);
 
+  CFX_WideString GetSelectedText(CPDFSDK_Annot* pAnnot);
+
   static bool IsVisible(CPDFSDK_Widget* pWidget);
   static bool IsReadOnly(CPDFSDK_Widget* pWidget);
   static bool IsFillingAllowed(CPDFSDK_Widget* pWidget);