MacViews: Implement Full Keyboard Access.

ui/views/focus/focus_search.cc

 // Copyright (c) 2011 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 "base/logging.h"
 #include "ui/views/focus/focus_manager.h"
 #include "ui/views/focus/focus_search.h"
 #include "ui/views/view.h"
 
 namespace views {
@@ skipping 80 matching lines @@
   // Nothing found.
   return NULL;
 }
 
 bool FocusSearch::IsViewFocusableCandidate(View* v, int skip_group_id) {
   return IsFocusable(v) &&
       (v->IsGroupFocusTraversable() || skip_group_id == -1 ||
        v->GetGroup() != skip_group_id);
 }
 
+// On Mac, we also need to read system preferences for "Full Keyboard Access" to

[tapted, 2016/02/12 02:56:45]

Can we instead expose the |accessibility_mode_| data member?

Then BridgedNativeWidget can simply call
native_widget_mac_->GetWidget()->GetFocusSearch()->SetAccessibilityMode([NSApp
isFullKeyboardAccessEnabled]);

(probably at the end of SetRootView)

There also should be a system notification that we listen for when the user
presses Ctrl+F7, so that we can toggle this on the fly. SetAccessibilityMode(..)
should then advance focus if it's currently on a non-focusable view, to match
OSX behaviour.

[karandeepb, 2016/02/22 07:15:37]

Done. Instead of setting the accessibility mode on the FocusSearch, I am setting
it on the FocusManager. This is because, each widget in the widget hierarchy
will have its own separate FocusSearch (corresponding to its root view) but all
of them will have the same FocusManager.

+// decide whether accessibility mode should be enabled or not.
+#if !defined(OS_MACOSX)
 bool FocusSearch::IsFocusable(View* v) {
   if (accessibility_mode_)
     return v && v->IsAccessibilityFocusable();
   return v && v->IsFocusable();
 }
+#endif
 
 View* FocusSearch::FindSelectedViewForGroup(View* view) {
   if (view->IsGroupFocusTraversable() ||
       view->GetGroup() == -1)  // No group for that view.
     return view;
 
   View* selected_view = view->GetSelectedViewForGroup(view->GetGroup());
   if (selected_view)
     return selected_view;
 
@@ skipping 150 matching lines @@
                                            skip_group_id,
                                            focus_traversable,
                                            focus_traversable_view);
   }
 
   // We found nothing.
   return NULL;
 }
 
 }  // namespace views