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..9fead52b6667a8c7ccad8d9bd7e98b1ca4bec670 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1624,6 +1624,26 @@ 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);
+
+  if (form_sel_text_len) {

[Lei Zhang, 2017/06/10 01:55:49]

Invert + early return.

[drgage, 2017/06/12 18:57:47]

Done.

+    base::string16 selected_form_text;

[Lei Zhang, 2017/06/10 01:55:49]

How about calling the std::string version selected_form_text, and this
selected_form_text16?

[drgage, 2017/06/12 18:57:47]

Done.

+    PDFiumAPIStringBufferSizeInBytesAdapter<base::string16> string_adapter(
+        &selected_form_text, form_sel_text_len, false);
+    string_adapter.Close(FORM_GetSelectedText(
+        hHandle, page, string_adapter.GetData(), form_sel_text_len));
+
+    std::string str_selected_form_text = UTF16ToUTF8(selected_form_text);
+    if (str_selected_form_text.c_str() && str_selected_form_text != "") {

[Lei Zhang, 2017/06/10 01:55:49]

I think you just want to check: !str_selected_form_text.empty()

[drgage, 2017/06/12 18:57:47]

Done.

+      pp::PDF::SetSelectedText(GetPluginInstance(),
+                               str_selected_form_text.c_str());
+    }
+  }
 }
 
 void PDFiumEngine::PrintEnd() {
@@ -1720,18 +1740,20 @@ 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);
+      mouse_down_state_.Set(PDFiumPage::FORM_TEXT_AREA, target);
       bool is_valid_control = (form_type == FPDF_FORMFIELD_TEXTFIELD ||
                                form_type == FPDF_FORMFIELD_COMBOBOX);
 #if defined(PDF_ENABLE_XFA)
       is_valid_control |= (form_type == FPDF_FORMFIELD_XFA);
 #endif
       client_->FormTextFieldFocusChange(is_valid_control);
+      SetInFormTextField(is_valid_control);

[Lei Zhang, 2017/06/10 01:55:49]

Isn't this also going to be true for a combo box?

[drgage, 2017/06/12 18:57:47]

Yeah, you're right. Do you think I should change how is_valid_control is set so
that it's clear which form type it is?

       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 +1829,13 @@ 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 +1851,10 @@ 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 +2019,13 @@ bool PDFiumEngine::OnKeyUp(const pp::KeyboardInputEvent& event) {
   if (last_page_mouse_down_ == -1)
     return false;
 
+  uint32_t modifiers = event.GetModifiers();
+  bool shift_key = !!(modifiers & PP_INPUTEVENT_MODIFIER_SHIFTKEY);
+
+  if (in_form_text_field_ && shift_key) {

[Lei Zhang, 2017/06/10 01:55:49]

If |in_form_text_field_| is false, then it is not necessary to even look up the
keyboard modifier. So this can be written as:

if (in_form_text_field_) {
  uint32_t modifiers = event.GetModifiers();
  if (modifiers & PP_INPUTEVENT_MODIFIER_SHIFTKEY)
    SetFormSelectedText(form_, pages_[last_page_mouse_down_]->GetPage());
}

[drgage, 2017/06/12 18:57:47]

Done.

+    SetFormSelectedText(form_, pages_[last_page_mouse_down_]->GetPage());
+  }
+
   return !!FORM_OnKeyUp(form_, pages_[last_page_mouse_down_]->GetPage(),
                         event.GetKeyCode(), event.GetModifiers());
 }
@@ -3552,6 +3587,10 @@ 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_,