Support modal windows

athena/screen/public/screen_manager.h

Index: athena/screen/public/screen_manager.h
diff --git a/athena/screen/public/screen_manager.h b/athena/screen/public/screen_manager.h
index e2637820ece499b8b7fda62bc0caa57363c268b6..8d6a3636bb1a7d54e7c0dc55f55d4abff60368a1 100644
--- a/athena/screen/public/screen_manager.h
+++ b/athena/screen/public/screen_manager.h
@@ -29,11 +29,34 @@ class ATHENA_EXPORT ScreenManager {
     // 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
@@ -44,11 +67,6 @@ class ATHENA_EXPORT ScreenManager {
 
   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;