Create a RegisterViewAssociate method in ViewManager

mojo/services/ui/views/interfaces/view_associates.mojom

 // Copyright 2015 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.
 
 [DartPackage="mojo_services"]
 module mojo.ui;
 
 import "mojo/public/interfaces/application/service_provider.mojom";
 import "mojo/services/gfx/composition/interfaces/hit_tests.mojom";
 import "mojo/services/gfx/composition/interfaces/scene_token.mojom";
 import "mojo/services/ui/views/interfaces/view_token.mojom";
 import "mojo/services/ui/views/interfaces/view_tree_token.mojom";
 
 // View associates are trusted components that are attached to a view manager
 // instance with the purpose of offering additional services to views and
 // view trees registered beyond the basic operations performed by the
 // view manager itself.  Associates may be used to implement input,
 // accessibility, editing, and other capabilities.
 //
 // Associates are coupled to a view manager instance for the entire life
 // of that view manager.  Associates cannot be dynamically added or removed
 // since applications rely on the services that they offer and expect them
 // to be available for the lifetime of their views.  Moreover, all views and
 // view trees registered with a particular view manager instance share
 // the same set of associates.
 //
 // This mechanism is designed to avoid a potential explosion in complexity
 // if all features which depend on the state of views were implemented
 // in one place.
-//
-// TODO(jeffbrown): In the current implementation, the view manager binds
-// to a hard coded set of associates at start up time which can be overridden
-// from the command-line.  We should find a better way to register associates
-// once we decide how the system as a whole should be initialized.
 [ServiceName="mojo::ui::ViewAssociate"]
 interface ViewAssociate {
   // Connects to the associate.
   //
   // The |inspector| provides a means for the view associate to query state
   // from the view manager.
   //
   // The associate must return information about the services that it
   // offers in |info|.
   Connect(ViewInspector inspector) => (ViewAssociateInfo info);
@@ skipping 13 matching lines @@
   // the caller.  If the associate is not willing or able to provide the
   // requested service, it should close the |pipe|.
   //
   // The |view_tree_token| is the token of the view tree which requested
   // the service.
   ConnectToViewTreeService(ViewTreeToken view_tree_token,
                            string service_name,
                            handle<message_pipe> pipe);
 };
 
+// ViewAssociateOwner is used as a transferable reference which can
+// be passed to a ViewAssociate's intended container as part of a request to
+// register the ViewAssociate with the ViewManager. The ViewAssociateOwner will
+// get a connection error callback if the corresponding ViewAssociate is
+// destroyed, and similarly the ViewAssociate that it owns will be killed if
+// this object is destroyed.
+[ServiceName="mojo::ui::ViewAssociateOwner"]
+interface ViewAssociateOwner {};
+
 // Provides information about the services offered by an associate.
 struct ViewAssociateInfo {
   // The names of view services offered by the associate.
   // May be null if none.
   array<string>? view_service_names;
 
   // The names of view tree services offered by the associate.
   // May be null if none.
   array<string>? view_tree_service_names;
 };
@@ skipping 19 matching lines @@
   // Given an array of scene tokens, produces an array of view tokens
   // of equal size containing the view to which the scene belongs or null
   // if the scene token does not belong to any view.
   //
   // It is safe to cache the results of this operation because a scene will
   // only ever be associated with at most one view although a view may
   // create several scenes during its lifetime.
   ResolveScenes(array<mojo.gfx.composition.SceneToken> scene_tokens)
       => (array<ViewToken?> view_tokens);
 };