mojo/services/view_manager/ids.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 MOJO_SERVICES_VIEW_MANAGER_IDS_H_
   6 #define MOJO_SERVICES_VIEW_MANAGER_IDS_H_
   7
   8 #include "mojo/services/public/cpp/view_manager/types.h"
   9 #include "mojo/services/public/cpp/view_manager/util.h"
  10 #include "mojo/services/view_manager/view_manager_export.h"
  11
  12 namespace mojo {
  13 namespace service {
  14
  15 // Connection id is used to indicate no connection. That is, no
  16 // ViewManagerServiceImpl ever gets this id.
  17 const ConnectionSpecificId kInvalidConnectionId = 0;
  18
  19 // TODO(sky): remove this, temporary while window manager API is in existing
  20 // api.
  21 const ConnectionSpecificId kWindowManagerConnection = 1;
  22
  23 // Adds a bit of type safety to view ids.
  24 struct MOJO_VIEW_MANAGER_EXPORT ViewId {
  25   ViewId(ConnectionSpecificId connection_id, ConnectionSpecificId view_id)
  26       : connection_id(connection_id),
  27         view_id(view_id) {}
  28   ViewId() : connection_id(0), view_id(0) {}
  29
  30   bool operator==(const ViewId& other) const {
  31     return other.connection_id == connection_id &&
  32         other.view_id == view_id;
  33   }
  34
  35   bool operator!=(const ViewId& other) const {
  36     return !(*this == other);
  37   }
  38
  39   ConnectionSpecificId connection_id;
  40   ConnectionSpecificId view_id;
  41 };
  42
  43 inline ViewId ViewIdFromTransportId(Id id) {
  44   return ViewId(HiWord(id), LoWord(id));
  45 }
  46
  47 inline Id ViewIdToTransportId(const ViewId& id) {
  48   return (id.connection_id << 16) | id.view_id;
  49 }
  50
  51 inline ViewId RootViewId() {
  52   return ViewId(kInvalidConnectionId, 1);
  53 }
  54
  55 // Returns a ViewId that is reserved to indicate no view. That is, no view will
  56 // ever be created with this id.
  57 inline ViewId InvalidViewId() {
  58   return ViewId(kInvalidConnectionId, 0);
  59 }
  60
  61 }  // namespace service
  62 }  // namespace mojo
  63
  64 #endif  // MOJO_SERVICES_VIEW_MANAGER_IDS_H_