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

pdf/pdfium/pdfium_engine.h

Index: pdf/pdfium/pdfium_engine.h
diff --git a/pdf/pdfium/pdfium_engine.h b/pdf/pdfium/pdfium_engine.h
index 6620c77cb6bad9313550bdb79835ac494e61afdb..2a0aba6305d61cc785a5384f24ed86cfdfd53a91 100644
--- a/pdf/pdfium/pdfium_engine.h
+++ b/pdf/pdfium/pdfium_engine.h
@@ -318,6 +318,10 @@ class PDFiumEngine : public PDFEngine,
       const PP_PrintSettings_Dev& print_settings);
   void SaveSelectedFormForPrint();
 
+  // Sets plugin's selected text to be selected text in form text field

[Lei Zhang, 2017/06/20 00:26:24]

I don't know why I didn't notice earlier. What does it mean for selected text to
be "available" ?

[Lei Zhang, 2017/06/20 18:34:57]

How about this?

Checks if |page| has selected text in a form element. If so, sets that as the
plugin's text selection.

[drgage, 2017/06/20 23:14:27]

Done.

[drgage, 2017/06/20 23:14:27]

What I meant by available is if selected text in a form text field or form
combobox text field exists, then this function will set the plugin's selected
text to be that.

+  // or form combobox text field if available.
+  void SetFormSelectedText(FPDF_FORMHANDLE form_handle, FPDF_PAGE page);
+
   // Given a mouse event, returns which page and character location it's closest
   // to.
   PDFiumPage::Area GetCharIndex(const pp::MouseInputEvent& event,
@@ -437,9 +441,14 @@ class PDFiumEngine : public PDFEngine,
   // Common code shared by RotateClockwise() and RotateCounterclockwise().
   void RotateInternal();
 
-  // Setting selection status of document.
+  // Setting text selection status of document. This does not include text

[Lei Zhang, 2017/06/20 18:34:58]

Let's use "Sets ..." here for consistency.

[drgage, 2017/06/20 23:14:27]

Done.

+  // within form text fields.
   void SetSelecting(bool selecting);
 
+  // Sets status of whether or not focus is in form text field or form combobox

[Lei Zhang, 2017/06/20 00:26:24]

You can probably omit "status of" here.

[drgage, 2017/06/20 23:14:27]

Done.

+  // text field.
+  void SetInFormTextArea(bool in_form_text_area);
+
   bool PageIndexInBounds(int index) const;
 
   void ScheduleTouchTimer(const pp::TouchInputEvent& event);
@@ -640,12 +649,15 @@ class PDFiumEngine : public PDFEngine,
   bool defer_page_unload_;
   std::vector<int> deferred_page_unloads_;
 
-  // Used for selection.  There could be more than one range if selection spans
-  // more than one page.
+  // Used for text selection, but does not include text within form text fields.
+  // There could be more than one range if selection spans more than one page.
   std::vector<PDFiumRange> selection_;
-  // True if we're in the middle of selection.
+  // True if we're in the middle of text selection.
   bool selecting_;
 
+  // True if focus is on form text field or form combobox text field.

[Lei Zhang, 2017/06/20 00:26:24]

Line 448 says "focus is in". Be consistent?

[drgage, 2017/06/20 23:14:27]

Done.

+  bool in_form_text_area_;
+
   MouseDownState mouse_down_state_;
 
   // Used for searching.