Open hyperlinks in PDF in a new tab when middle mouse clicking.

pdf/pdfium/pdfium_engine.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "pdf/pdfium/pdfium_engine.h"
 
 #include <math.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1509 matching lines @@
                            &selection_rect_vector);
     pp::Point point = event.GetPosition();
     for (const auto& rect : selection_rect_vector) {
       if (rect.Contains(point.x(), point.y()))
         return false;
     }
     SelectionChangeInvalidator selection_invalidator(this);
     selection_.clear();
     return true;
   }
-  if (event.GetButton() != PP_INPUTEVENT_MOUSEBUTTON_LEFT)
+
+  if (event.GetButton() != PP_INPUTEVENT_MOUSEBUTTON_LEFT &&
+      event.GetButton() != PP_INPUTEVENT_MOUSEBUTTON_MIDDLE) {
     return false;
+  }
 
   SelectionChangeInvalidator selection_invalidator(this);
   selection_.clear();
 
   int page_index = -1;
   int char_index = -1;
   int form_type = FPDF_FORMFIELD_UNKNOWN;
   PDFiumPage::LinkTarget target;
   PDFiumPage::Area area =
       GetCharIndex(event, &page_index, &char_index, &form_type, &target);
   mouse_down_state_.Set(area, target);
 
   // Decide whether to open link or not based on user action in mouse up and
   // mouse move events.
   if (area == PDFiumPage::WEBLINK_AREA)
     return true;
 
+  if (event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_MIDDLE)

[Lei Zhang, 2016/07/14 00:03:39]

Add a comment to explain why we return here.

[jaepark, 2016/07/14 00:59:40]

Done.

+    return false;
+
   if (area == PDFiumPage::DOCLINK_AREA) {

[Lei Zhang, 2016/07/14 00:03:40]

What about middle clicks on DOCLINK_AREAs? How do they compare with (shift +)
left clicks?

[jaepark, 2016/07/14 00:59:40]

I assume you mean ctrl + left (not shift + left) click which triggers the link
to open in a new tab.
For DOCLINK_AREAs, ctrl + left click behaves exactly the same as left click. It
navigates within the tab.

For middle mouse clicking, nothing happens when clicked on the DOCLINK AREAs.

[Lei Zhang, 2016/07/14 01:25:04]

Yes, I meant ctrl, though I just discovered what shift + left click does on a
regular webpage... and now we have https://crbug.com/628057, wee!

     client_->ScrollToPage(target.page);
     client_->FormTextFieldFocusChange(false);
     return true;
   }
 
   if (page_index != -1) {
     last_page_mouse_down_ = page_index;
     double page_x, page_y;
     pp::Point point = event.GetPosition();
     DeviceToPage(page_index, point.x(), point.y(), &page_x, &page_y);
@@ skipping 53 matching lines @@
     base::char16 cur = pages_[page_index]->GetCharAtIndex(end_index);
     if (cur == '\n' || (click_count == 2 && (cur == ' ' || cur == '\t')))
       break;
   }
 
   selection_.push_back(PDFiumRange(
       pages_[page_index], start_index, end_index - start_index));
 }
 
 bool PDFiumEngine::OnMouseUp(const pp::MouseInputEvent& event) {
-  if (event.GetButton() != PP_INPUTEVENT_MOUSEBUTTON_LEFT)
+
+  if (event.GetButton() != PP_INPUTEVENT_MOUSEBUTTON_LEFT &&
+      event.GetButton() != PP_INPUTEVENT_MOUSEBUTTON_MIDDLE) {
     return false;
+  }
 
   int page_index = -1;
   int char_index = -1;
   int form_type = FPDF_FORMFIELD_UNKNOWN;
   PDFiumPage::LinkTarget target;
   PDFiumPage::Area area =
       GetCharIndex(event, &page_index, &char_index, &form_type, &target);
 
   // Open link on mouse up for same link for which mouse down happened earlier.
   if (mouse_down_state_.Matches(area, target)) {
     if (area == PDFiumPage::WEBLINK_AREA) {
-      bool open_in_new_tab = !!(event.GetModifiers() & kDefaultKeyModifier);
+      bool open_in_new_tab = !!(event.GetModifiers() & kDefaultKeyModifier) ||
+          !!(event.GetModifiers() & PP_INPUTEVENT_MODIFIER_MIDDLEBUTTONDOWN);
       client_->NavigateTo(target.url, open_in_new_tab);
       client_->FormTextFieldFocusChange(false);
       return true;
     }
   }
 
+  if (event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_MIDDLE)
+    return false;
+
   if (page_index != -1) {
     double page_x, page_y;
     pp::Point point = event.GetPosition();
     DeviceToPage(page_index, point.x(), point.y(), &page_x, &page_y);
     FORM_OnLButtonUp(
         form_, pages_[page_index]->GetPage(), 0, page_x, page_y);
   }
 
   if (!selecting_)
     return false;
@@ skipping 2240 matching lines @@
   FPDF_DOCUMENT doc =
       FPDF_LoadMemDocument(pdf_buffer, pdf_buffer_size, nullptr);
   if (!doc)
     return false;
   bool success = FPDF_GetPageSizeByIndex(doc, page_number, width, height) != 0;
   FPDF_CloseDocument(doc);
   return success;
 }
 
 }  // namespace chrome_pdf