Support modal windows

athena/screen/public/screen_manager.h

 // 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.
 
 #ifndef ATHENA_SCREEN_PUBLIC_SCREEN_MANAGER_H_
 #define ATHENA_SCREEN_PUBLIC_SCREEN_MANAGER_H_
 
 #include <string>
 
 #include "athena/athena_export.h"
@@ skipping 11 matching lines @@
 // create and manage their windows on the screen.
 class ATHENA_EXPORT ScreenManager {
  public:
   struct ContainerParams {
     ContainerParams(const std::string& name, int z_order_priority);
     std::string name;
 
     // True if the container can activate its child window.
     bool can_activate_children;
 
-    // True if the container will grab all of input events.
-    bool grab_inputs;
+    // True if the container will block evnets from containers behind it.
+    bool block_events;
 
     // Defines the z_order priority of the container.
     int z_order_priority;
+
+    // True if this container should be used as a default parent.
+    bool default_parent;
+
+    // The container priority used to open modal dialog window
+    // created from this container. Default is -1, and it will fallback
+    // to the container behind this container, that has the modal container
+    // proiroty.
+    //
+    // The modal container for modal window is selected as follows.
+    // 1) a window must be created with |aura::client::kModalKey| property
+    //   without explicit parent set.
+    // 2.a) If aura::client::kAlwaysOnTopKey is set, it searches the top most
+    //   container which has |modal_container_priority| != -1.
+    // 2.b) If aura::client::kAlwaysOnTopKey is NOT set, it searches the
+    //   container that has |modal_container_priority| != -1 downwards,
+    //   starting from this container.

[Jun Mukai, 2014/10/17 17:29:54]

I am not sure starting from which container.  Can you explain a bit more
verbose?

[oshima, 2014/10/17 18:20:04]

Updated the comment. 

+    // 3) Look for the container with |modal_container_priority|, and create
+    //   one if it doesn't exist.
+    //
+    // Created modal container will self destruct if last modal window
+    // is deleted.
+    int modal_container_priority;
   };
 
   // Creates, returns and deletes the singleton object of the ScreenManager
   // implementation.
   static ScreenManager* Create(aura::Window* root);
   static ScreenManager* Get();
   static void Shutdown();
 
   virtual ~ScreenManager() {}
 
-  // Creates the container window that is used when creating a normal
-  // widget without specific parent.
-  virtual aura::Window* CreateDefaultContainer(
-      const ContainerParams& params) = 0;
-
   // Creates the container window on the screen.
   virtual aura::Window* CreateContainer(const ContainerParams& params) = 0;
 
   // Return the context object to be used for widget creation.
   virtual aura::Window* GetContext() = 0;
 
   // Set screen rotation.
   // TODO(flackr): Extract and use ash DisplayManager to set rotation
   // instead: http://crbug.com/401044.
   virtual void SetRotation(gfx::Display::Rotation rotation) = 0;
   virtual void SetRotationLocked(bool rotation_locked) = 0;
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_SCREEN_PUBLIC_SCREEN_MANAGER_H_