Add functionality for copying text within form text fields and form combobox text fields

pdf/pdfium/pdfium_engine.cc

Index: pdf/pdfium/pdfium_engine.cc
diff --git a/pdf/pdfium/pdfium_engine.cc b/pdf/pdfium/pdfium_engine.cc
index 37c01618778ebd942421fbab1c4c6f6b8a3affcf..2a65c283114a0aabc6c9609f881a8c157438de6d 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1624,6 +1624,28 @@ void PDFiumEngine::FitContentsToPrintableAreaIfRequired(
 void PDFiumEngine::SaveSelectedFormForPrint() {
   FORM_ForceToKillFocus(form_);
   client_->FormTextFieldFocusChange(false);
+  SetInFormTextField(false);
+}
+
+void PDFiumEngine::SetFormSelectedText(const FPDF_FORMHANDLE& hHandle,
+                                       const FPDF_PAGE& page) {
+  size_t form_sel_text_len = FORM_GetSelectedText(hHandle, page, nullptr, 0);
+
+  // Initial length = 2 (not 0) because text is CFX_WideString and
+  // sentinel char is included in count.
+  if (form_sel_text_len <= 2)
+    return;
+
+  base::string16 selected_form_text16;
+  PDFiumAPIStringBufferSizeInBytesAdapter<base::string16> string_adapter(
+      &selected_form_text16, form_sel_text_len, false);
+  string_adapter.Close(FORM_GetSelectedText(
+      hHandle, page, string_adapter.GetData(), form_sel_text_len));
+
+  std::string selected_form_text = UTF16ToUTF8(selected_form_text16);
+  if (!selected_form_text.empty()) {
+    pp::PDF::SetSelectedText(GetPluginInstance(), selected_form_text.c_str());
+  }
 }
 
 void PDFiumEngine::PrintEnd() {
@@ -1720,18 +1742,28 @@ bool PDFiumEngine::OnMouseDown(const pp::MouseInputEvent& event) {
 
     FORM_OnLButtonDown(form_, pages_[page_index]->GetPage(), 0, page_x, page_y);
     if (form_type > FPDF_FORMFIELD_UNKNOWN) {  // returns -1 sometimes...
-      mouse_down_state_.Set(PDFiumPage::NONSELECTABLE_AREA, target);
+      (form_type == FPDF_FORMFIELD_TEXTFIELD)

[Lei Zhang, 2017/06/15 18:11:28]

style: With a ternary operator, write this as:

mouse_down_state_.Set(form_type == FPDF_FORMFIELD_TEXTFIELD 
? PDFiumPage::FORM_TEXT_AREA : PDFiumPage::NONSELECTABLE_AREA, target);

so there's no need to repeat most of the statment. Otherwise, write:

if (form_type == FPDF_FORMFIELD_TEXTFIELD)
  ...
else
  ...

[drgage, 2017/06/16 01:49:21]

Done.

+          ? mouse_down_state_.Set(PDFiumPage::FORM_TEXT_AREA, target)
+          : mouse_down_state_.Set(PDFiumPage::NONSELECTABLE_AREA, target);
+
       bool is_valid_control = (form_type == FPDF_FORMFIELD_TEXTFIELD ||
                                form_type == FPDF_FORMFIELD_COMBOBOX);
+
+// TODO (bug_62400): come back to this to figure out selection and copying
+// for XFA fields
 #if defined(PDF_ENABLE_XFA)
       is_valid_control |= (form_type == FPDF_FORMFIELD_XFA);
 #endif
+
+      // TODO (drgage): come back and implement copying for comboboxes
       client_->FormTextFieldFocusChange(is_valid_control);
+      SetInFormTextField(is_valid_control);
       return true;  // Return now before we get into the selection code.
     }
   }
 
   client_->FormTextFieldFocusChange(false);
+  SetInFormTextField(false);
 
   if (area != PDFiumPage::TEXT_AREA)
     return true;  // Return true so WebKit doesn't do its own highlighting.
@@ -1807,11 +1839,13 @@ bool PDFiumEngine::OnMouseUp(const pp::MouseInputEvent& event) {
 
       client_->NavigateTo(target.url, disposition);
       client_->FormTextFieldFocusChange(false);
+      SetInFormTextField(false);
       return true;
     }
     if (area == PDFiumPage::DOCLINK_AREA) {
       client_->ScrollToPage(target.page);
       client_->FormTextFieldFocusChange(false);
+      SetInFormTextField(false);
       return true;
     }
   }
@@ -1827,6 +1861,10 @@ bool PDFiumEngine::OnMouseUp(const pp::MouseInputEvent& event) {
     FORM_OnLButtonUp(form_, pages_[page_index]->GetPage(), 0, page_x, page_y);
   }
 
+  if (area == PDFiumPage::FORM_TEXT_AREA) {
+    SetFormSelectedText(form_, pages_[last_page_mouse_down_]->GetPage());
+  }
+
   if (!selecting_)
     return false;
 
@@ -1991,6 +2029,12 @@ bool PDFiumEngine::OnKeyUp(const pp::KeyboardInputEvent& event) {
   if (last_page_mouse_down_ == -1)
     return false;
 
+  if (in_form_text_field_) {
+    uint32_t modifiers = event.GetModifiers();
+    if (modifiers & PP_INPUTEVENT_MODIFIER_SHIFTKEY)
+      SetFormSelectedText(form_, pages_[last_page_mouse_down_]->GetPage());
+  }
+
   return !!FORM_OnKeyUp(form_, pages_[last_page_mouse_down_]->GetPage(),
                         event.GetKeyCode(), event.GetModifiers());
 }
@@ -3552,6 +3596,10 @@ void PDFiumEngine::SetSelecting(bool selecting) {
     client_->IsSelectingChanged(selecting);
 }
 
+void PDFiumEngine::SetInFormTextField(bool in_form_text_field) {
+  in_form_text_field_ = in_form_text_field;
+}
+
 void PDFiumEngine::ScheduleTouchTimer(const pp::TouchInputEvent& evt) {
   touch_timers_[++next_touch_timer_id_] = evt;
   client_->ScheduleTouchTimerCallback(next_touch_timer_id_,