Make a pure mojo::View version of the aura::Window FocusController.

mojo/services/window_manager/basic_focus_rules.cc

+// Copyright 2014 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 "mojo/services/window_manager/basic_focus_rules.h"
+
+#include "base/macros.h"
+#include "mojo/services/public/cpp/view_manager/view.h"
+#include "mojo/services/window_manager/window_manager_app.h"
+
+namespace mojo {
+
+BasicFocusRules::BasicFocusRules(mojo::WindowManagerApp* window_manager_app,
+                           mojo::View* window_container)
+    : window_container_(window_container),
+      window_manager_app_(window_manager_app) {}
+
+BasicFocusRules::~BasicFocusRules() {}
+
+bool BasicFocusRules::IsToplevelView(mojo::View* view) const {
+  return view->parent() == window_container_;
+}
+
+bool BasicFocusRules::CanActivateView(mojo::View* view) const {
+  return view->parent() == window_container_;

[sky, 2014/11/10 20:45:30]

Don't you want to check visibility/drawn in any of these? If you don't need to
check here because it's done in FocusController, document in FocusRules that
subclasses don't need to check it.

[Elliot Glaysher, 2014/11/10 22:18:49]

You do, but right now this is a straight port of the focus rules as they exist
in mojo right now. I've documented that this needs to have a real implementation
in a followup patch.

+}
+
+bool BasicFocusRules::CanFocusView(mojo::View* view) const {
+  return true;
+}
+
+mojo::View* BasicFocusRules::GetToplevelView(mojo::View* view) const {
+  while (view->parent() != window_container_) {
+    view = view->parent();
+    // Unparented hierarchy, there is no "top level" window.
+    if (!view)
+      return NULL;

[sky, 2014/11/10 20:45:30]

nullptr every where.

+  }
+
+  return view;
+}
+
+mojo::View* BasicFocusRules::GetActivatableView(mojo::View* view) const {
+  return GetToplevelView(view);
+}
+
+mojo::View* BasicFocusRules::GetFocusableView(mojo::View* view) const {
+  return view;
+}
+
+mojo::View* BasicFocusRules::GetNextActivatableView(
+    mojo::View* activatable) const {
+  const mojo::View::Children& children = activatable->parent()->children();
+  for (mojo::View::Children::const_reverse_iterator it = children.rbegin();
+       it != children.rend(); ++it) {
+    if (*it != activatable)
+      return *it;
+  }
+  return NULL;
+}
+
+}  // namespace mojo