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 afc8b71633bcd2bbab24880da6b033316bfe63a9..5a301f2d47669d0677dbf6ff724e47849b68f882 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1625,6 +1625,30 @@ void PDFiumEngine::FitContentsToPrintableAreaIfRequired(
 void PDFiumEngine::SaveSelectedFormForPrint() {
   FORM_ForceToKillFocus(form_);
   client_->FormTextFieldFocusChange(false);
+  SetInFormTextField(false);
+  SetInFormComboboxTextField(false);
+}
+
+void PDFiumEngine::SetFormSelectedText(const FPDF_FORMHANDLE& form_handle,

[Lei Zhang, 2017/06/17 02:21:17]

We don't do this consistently, so let's try to be consistent and pass by value,
since all of these types are void* underneath.

[drgage, 2017/06/19 21:53:52]

Done.

+                                       const FPDF_PAGE& page) {
+  size_t form_sel_text_len =
+      FORM_GetSelectedText(form_handle, page, nullptr, 0);
+
+  // Initial length = 2 (not 0) because text is CFX_WideString and

[Lei Zhang, 2017/06/17 02:21:18]

CFX_WideString is suppose to be an implementation detail. Shhh!

[drgage, 2017/06/19 21:53:52]

Done.

+  // sentinel char is included in count.

[Lei Zhang, 2017/06/17 02:21:17]

By "sentinel char" do you really mean NUL character?

[drgage, 2017/06/19 21:53:52]

Done.

+  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(
+      form_handle, 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() {
@@ -1721,18 +1745,33 @@ 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);
+      if (form_type == FPDF_FORMFIELD_TEXTFIELD)
+        mouse_down_state_.Set(PDFiumPage::FORM_TEXT_AREA, target);
+      else if (form_type == FPDF_FORMFIELD_COMBOBOX)
+        mouse_down_state_.Set(PDFiumPage::FORM_COMBOBOX_TEXT_AREA, target);
+      else
+        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): figure out selection and copying
+// for XFA fields
 #if defined(PDF_ENABLE_XFA)
       is_valid_control |= (form_type == FPDF_FORMFIELD_XFA);
 #endif
+
+      // TODO(drgage): implement copying for comboboxes
       client_->FormTextFieldFocusChange(is_valid_control);
+      SetInFormTextField(form_type == FPDF_FORMFIELD_TEXTFIELD);
+      SetInFormComboboxTextField(form_type == FPDF_FORMFIELD_COMBOBOX);
       return true;  // Return now before we get into the selection code.
     }
   }
 
   client_->FormTextFieldFocusChange(false);
+  SetInFormTextField(false);
+  SetInFormComboboxTextField(false);
 
   if (area != PDFiumPage::TEXT_AREA)
     return true;  // Return true so WebKit doesn't do its own highlighting.
@@ -1808,11 +1847,15 @@ bool PDFiumEngine::OnMouseUp(const pp::MouseInputEvent& event) {
 
       client_->NavigateTo(target.url, disposition);
       client_->FormTextFieldFocusChange(false);
+      SetInFormTextField(false);
+      SetInFormComboboxTextField(false);
       return true;
     }
     if (area == PDFiumPage::DOCLINK_AREA) {
       client_->ScrollToPage(target.page);
       client_->FormTextFieldFocusChange(false);
+      SetInFormTextField(false);
+      SetInFormComboboxTextField(false);
       return true;
     }
   }
@@ -1828,6 +1871,11 @@ 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 ||
+      area == PDFiumPage::FORM_COMBOBOX_TEXT_AREA) {
+    SetFormSelectedText(form_, pages_[last_page_mouse_down_]->GetPage());
+  }
+
   if (!selecting_)
     return false;
 
@@ -1859,6 +1907,8 @@ bool PDFiumEngine::OnMouseMove(const pp::MouseInputEvent& event) {
         cursor = PP_CURSORTYPE_HAND;
         break;
       case PDFiumPage::NONSELECTABLE_AREA:
+      case PDFiumPage::FORM_TEXT_AREA:
+      case PDFiumPage::FORM_COMBOBOX_TEXT_AREA:
       default:
         switch (form_type) {
           case FPDF_FORMFIELD_PUSHBUTTON:
@@ -1992,6 +2042,17 @@ bool PDFiumEngine::OnKeyUp(const pp::KeyboardInputEvent& event) {
   if (last_page_mouse_down_ == -1)
     return false;
 
+  if (in_form_text_field_ || in_form_combobox_text_field_) {
+    if (event.GetKeyCode() == ui::VKEY_SHIFT)
+      SetFormSelectedText(form_, pages_[last_page_mouse_down_]->GetPage());
+    else {
+      // If a key other than shift is released while shift is not also
+      // being held down, selection of form field text should be cleared.
+      if (event.GetModifiers() & ~PP_INPUTEVENT_MODIFIER_SHIFTKEY)
+        pp::PDF::SetSelectedText(GetPluginInstance(), "");

[Lei Zhang, 2017/06/17 02:21:17]

Are you sure the key up event is the best time to do this? With a regular HTML
text form, if there is selected text, and I let go of the shift key. The moment
I press an arrow key, the cursor starts moving and the visual selection goes
away. It does not wait for the arrow key to be released.

[drgage, 2017/06/19 21:53:52]

Done.

+    }
+  }
+
   return !!FORM_OnKeyUp(form_, pages_[last_page_mouse_down_]->GetPage(),
                         event.GetKeyCode(), event.GetModifiers());
 }
@@ -3553,6 +3614,15 @@ 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::SetInFormComboboxTextField(
+    bool in_form_combobox_text_field) {
+  in_form_combobox_text_field_ = in_form_combobox_text_field;
+}
+
 void PDFiumEngine::ScheduleTouchTimer(const pp::TouchInputEvent& evt) {
   touch_timers_[++next_touch_timer_id_] = evt;
   client_->ScheduleTouchTimerCallback(next_touch_timer_id_,