Refactors StackingController::GetDefaultParent to ash/wm/common

ash/wm/common/container_finder.cc

Index: ash/wm/common/container_finder.cc
diff --git a/ash/wm/common/container_finder.cc b/ash/wm/common/container_finder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..12b776cf9845733d21f22c956549f5a7ffe88eeb
--- /dev/null
+++ b/ash/wm/common/container_finder.cc
@@ -0,0 +1,110 @@
+// Copyright 2016 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/common/container_finder.h"
+
+#include "ash/wm/common/always_on_top_controller.h"
+#include "ash/wm/common/root_window_finder.h"
+#include "ash/wm/common/window_state.h"
+#include "ash/wm/common/wm_globals.h"
+#include "ash/wm/common/wm_root_window_controller.h"
+#include "ash/wm/common/wm_shell_window_ids.h"
+#include "ash/wm/common/wm_window.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace ash {
+namespace wm {
+namespace {
+
+WmWindow* FindContainerRoot(WmGlobals* globals, const gfx::Rect& bounds) {
+  if (bounds == gfx::Rect())
+    return globals->GetRootWindowForNewWindows();
+  return GetRootWindowMatching(bounds);
+}
+
+bool HasTransientParentWindow(const WmWindow* window) {
+  return window->GetTransientParent() &&
+         window->GetTransientParent()->GetType() != ui::wm::WINDOW_TYPE_UNKNOWN;
+}
+
+WmWindow* GetSystemModalContainer(WmWindow* root, WmWindow* window) {
+  DCHECK(window->IsSystemModal());
+
+  // If screen lock is not active and user session is active,
+  // all modal windows are placed into the normal modal container.
+  // In case of missing transient parent (it could happen for alerts from
+  // background pages) assume that the window belongs to user session.
+  if (!window->GetGlobals()->IsUserSessionBlocked() ||
+      !window->GetTransientParent()) {
+    return root->GetChildByShellWindowId(kShellWindowId_SystemModalContainer);
+  }
+
+  // Otherwise those that originate from LockScreen container and above are
+  // placed in the screen lock modal container.
+  int window_container_id =
+      window->GetTransientParent()->GetParent()->GetShellWindowId();
+  if (window_container_id < kShellWindowId_LockScreenContainer)
+    return root->GetChildByShellWindowId(kShellWindowId_SystemModalContainer);
+  return root->GetChildByShellWindowId(kShellWindowId_LockSystemModalContainer);
+}
+
+WmWindow* GetContainerFromAlwaysOnTopController(WmWindow* root,
+                                                WmWindow* window) {
+  return root->GetRootWindowController()
+      ->GetAlwaysOnTopController()
+      ->GetContainer(window);
+}
+
+}  // namespace
+
+WmWindow* GetContainerForWindow(WmWindow* window) {
+  WmWindow* container = window->GetParent();
+  while (container && container->GetType() != ui::wm::WINDOW_TYPE_UNKNOWN)
+    container = container->GetParent();
+  return container;
+}
+
+WmWindow* GetDefaultParent(WmWindow* context,
+                           WmWindow* window,
+                           const gfx::Rect& bounds) {
+  WmWindow* target_root = nullptr;
+  WmWindow* transient_parent = window->GetTransientParent();
+  if (transient_parent) {
+    // Transient window should use the same root as its transient parent.
+    target_root = transient_parent->GetRootWindow();
+  } else {
+    target_root = FindContainerRoot(context->GetGlobals(), bounds);
+  }
+
+  switch (window->GetType()) {
+    case ui::wm::WINDOW_TYPE_NORMAL:
+    case ui::wm::WINDOW_TYPE_POPUP:
+      if (window->IsSystemModal())
+        return GetSystemModalContainer(target_root, window);
+      if (HasTransientParentWindow(window))
+        return GetContainerForWindow(window->GetTransientParent());
+      return GetContainerFromAlwaysOnTopController(target_root, window);
+    case ui::wm::WINDOW_TYPE_CONTROL:
+      return target_root->GetChildByShellWindowId(
+          kShellWindowId_UnparentedControlContainer);
+    case ui::wm::WINDOW_TYPE_PANEL:
+      if (window->GetWindowState()->panel_attached())
+        return target_root->GetChildByShellWindowId(
+            kShellWindowId_PanelContainer);
+      return GetContainerFromAlwaysOnTopController(target_root, window);
+    case ui::wm::WINDOW_TYPE_MENU:
+      return target_root->GetChildByShellWindowId(kShellWindowId_MenuContainer);
+    case ui::wm::WINDOW_TYPE_TOOLTIP:
+      return target_root->GetChildByShellWindowId(
+          kShellWindowId_DragImageAndTooltipContainer);
+    default:
+      NOTREACHED() << "Window " << window->GetShellWindowId()
+                   << " has unhandled type " << window->GetType();
+      break;
+  }
+  return nullptr;
+}
+
+}  // namespace wm
+}  // namespace ash