components/view_manager/public/cpp/view_manager_delegate.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_VIEW_MANAGER_PUBLIC_CPP_VIEW_MANAGER_DELEGATE_H_
   6 #define COMPONENTS_VIEW_MANAGER_PUBLIC_CPP_VIEW_MANAGER_DELEGATE_H_
   7
   8 #include <string>
   9
  10 #include "components/view_manager/public/interfaces/view_manager.mojom.h"
  11 #include "mojo/application/public/interfaces/service_provider.mojom.h"
  12 #include "mojo/services/network/public/interfaces/url_loader.mojom.h"
  13
  14 namespace mojo {
  15
  16 class View;
  17 class ViewManager;
  18
  19 // Interface implemented by an application using the view manager.
  20 //
  21 // Each call to OnEmbed() results in a new ViewManager and new root View.
  22 // ViewManager is deleted by any of the following:
  23 // . If the root of the connection is destroyed. This happens if the owner
  24 //   of the root Embed()s another app in root, or the owner explicitly deletes
  25 //   root.
  26 // . The connection to the viewmanager is lost.
  27 // . Explicitly by way of calling delete.
  28 //
  29 // When the ViewManager is deleted all views are deleted (and observers
  30 // notified). This is followed by notifying the delegate by way of
  31 // OnViewManagerDestroyed().
  32 class ViewManagerDelegate {
  33  public:
  34   // Called when the application implementing this interface is embedded at
  35   // |root|.
  36   //
  37   // |services| exposes the services offered by the embedder to the delegate.
  38   //
  39   // |exposed_services| is an object that the delegate can add services to
  40   // expose to the embedder.
  41   //
  42   // Note that if a different application is subsequently embedded at |root|,
  43   // the pipes connecting |services| and |exposed_services| to the embedder and
  44   // any services obtained from them are not broken and will continue to be
  45   // valid.
  46   virtual void OnEmbed(View* root) = 0;
  47
  48   // Sent when another app is embedded in the same View as this connection.
  49   // Subsequently the root View and this object are destroyed (observers are
  50   // notified appropriately).
  51   virtual void OnUnembed();
  52
  53   // Only invoked if the connection has been marked as an embed root. This
  54   // allows the delegate to disallow the embed (return false), or change
  55   // the ServiceProviders that would be exposed to the new client.
  56   //
  57   // This implementation returns true (allowing the embed), and does not alter
  58   // the supplied ServiceProviders.
  59   //
  60   // See the mojom for more details.
  61   virtual void OnEmbedForDescendant(View* view,
  62                                     URLRequestPtr request,
  63                                     ViewManagerClientPtr* client);
  64
  65   // Called from the destructor of ViewManager after all the Views have been
  66   // destroyed. |view_manager| is no longer valid after this call.
  67   virtual void OnViewManagerDestroyed(ViewManager* view_manager) = 0;
  68
  69  protected:
  70   virtual ~ViewManagerDelegate() {}
  71 };
  72
  73 }  // namespace mojo
  74
  75 #endif  // COMPONENTS_VIEW_MANAGER_PUBLIC_CPP_VIEW_MANAGER_DELEGATE_H_