[WIP] ash/extensions: Add experimental extension support for window-management in ash.

ash/wm/window_manager_extension.cc

Index: ash/wm/window_manager_extension.cc
diff --git a/ash/wm/window_manager_extension.cc b/ash/wm/window_manager_extension.cc
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index 0000000000000000000000000000000000000000..37ffde77caf8cf680f82876749e91bcdf64307ab
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+++ b/ash/wm/window_manager_extension.cc
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+// 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 "ash/wm/window_manager_extension.h"
+
+#include "ash/shell.h"
+#include "ui/aura/client/activation_client.h"
+#include "ui/aura/env.h"
+#include "ui/aura/window.h"
+
+namespace ash {
+namespace internal {
+
+////////////////////////////////////////////////////////////////////////////////
+// WindowManagerExtension, public:
+
+WindowManagerExtension::WindowManagerExtension()
+    : delegate_(NULL) {
+  aura::Env::GetInstance()->AddObserver(this);
+  aura::client::GetActivationClient(
+      Shell::GetPrimaryRootWindow())->AddObserver(this);
+}
+
+WindowManagerExtension::~WindowManagerExtension() {
+  aura::client::GetActivationClient(
+      Shell::GetPrimaryRootWindow())->RemoveObserver(this);
+  aura::Env::GetInstance()->RemoveObserver(this);
+  for (size_t i = 0; i < windows_.size(); ++i)
+    windows_[i]->RemoveObserver(this);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// WindowManagerExtension, aura::EnvObserver implementation:
+
+void WindowManagerExtension::OnWindowInitialized(aura::Window* window) {
+  windows_.push_back(window);
+  window->AddObserver(this);
+
+  if (delegate_)
+    delegate_->OnWindowCreated(window);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// WindowManagerExtension, aura::WindowObserver implementation:
+
+void WindowManagerExtension::OnWindowVisibilityChanged(
+    aura::Window* window,
+    bool visible) {
+  if (delegate_) {
+    if (visible)
+      delegate_->OnWindowShown(window);
+    else
+      delegate_->OnWindowHidden(window);
+  }
+}
+
+void WindowManagerExtension::OnWindowDestroyed(aura::Window* window) {
+  windows_.erase(std::find(windows_.begin(), windows_.end(), window));
+  window->RemoveObserver(this);
+
+  if (delegate_)
+    delegate_->OnWindowClosed(window);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// WindowManagerExtension, aura::WindowObserver implementation:
+
+void WindowManagerExtension::OnWindowActivated(aura::Window* active,
+                                               aura::Window* old_active) {
+  if (delegate_)
+    delegate_->OnActiveWindowChanged(active);
+}
+
+}  // namespace internal
+}  // namespace ash