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

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 08e869de6e40c95f10dd6b9a4b9d46ea3c83b558..b829f4774f4c0cbb5d48ab879f65033573bdab4b 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1527,8 +1527,11 @@ bool PDFiumEngine::OnMouseDown(const pp::MouseInputEvent& event) {
     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();
@@ -1546,6 +1549,9 @@ bool PDFiumEngine::OnMouseDown(const pp::MouseInputEvent& event) {
   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);
@@ -1620,8 +1626,11 @@ void PDFiumEngine::OnMultipleClick(int click_count,
 }
 
 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;
@@ -1633,13 +1642,17 @@ bool PDFiumEngine::OnMouseUp(const pp::MouseInputEvent& event) {
   // 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();