Reify view ownership as a message pipe.

examples/ui/tile/tile_view.cc

 // 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.
 
 #include "base/bind.h"
 #include "examples/ui/tile/tile_view.h"
 #include "mojo/services/geometry/cpp/geometry_util.h"
 
 namespace examples {
 
 namespace {
 constexpr uint32_t kViewResourceIdBase = 100;
 constexpr uint32_t kViewResourceIdSpacing = 100;
 
 constexpr uint32_t kRootNodeId = mojo::gfx::composition::kSceneRootNodeId;
 constexpr uint32_t kViewNodeIdBase = 100;
 constexpr uint32_t kViewNodeIdSpacing = 100;
 constexpr uint32_t kViewSceneNodeIdOffset = 1;
 constexpr uint32_t kViewFallbackNodeIdOffset = 2;
 }  // namespace
 
-TileView::TileView(mojo::ApplicationImpl* app_impl,
-                   const std::vector<std::string>& view_urls,
-                   const mojo::ui::ViewProvider::CreateViewCallback& callback)
-    : BaseView(app_impl, "Tile", callback), view_urls_(view_urls) {
+TileView::TileView(
+    mojo::ApplicationImpl* app_impl,
+    mojo::InterfaceRequest<mojo::ui::ViewOwner> view_owner_request,
+    const std::vector<std::string>& view_urls)
+    : BaseView(app_impl, view_owner_request.Pass(), "Tile"),
+      view_urls_(view_urls) {
   ConnectViews();
 }
 
 TileView::~TileView() {}
 
 void TileView::ConnectViews() {
   uint32_t child_key = 0;
   for (const auto& url : view_urls_) {
     // Start connecting to the view provider.
     mojo::ui::ViewProviderPtr provider;
     app_impl()->ConnectToService(url, &provider);
-    provider.set_connection_error_handler(
-        base::Bind(&TileView::OnChildConnectionError, base::Unretained(this),
-                   child_key, url));
 
-    // Create the view.
-    // We include the provider reference in the callback so that the
-    // binding will be kept alive until the callback completes.
     LOG(INFO) << "Connecting to view: child_key=" << child_key
               << ", url=" << url;
-    provider->CreateView(
-        nullptr, nullptr,
-        base::Bind(&TileView::OnChildCreated, base::Unretained(this), child_key,
-                   url, base::Passed(provider.Pass())));
+    mojo::ui::ViewOwnerPtr child_view_owner;
+    provider->CreateView(mojo::GetProxy(&child_view_owner), nullptr, nullptr);
+
+    view_host()->AddChild(child_key, child_view_owner.Pass());
+    views_.emplace(std::make_pair(
+        child_key, std::unique_ptr<ViewData>(new ViewData(url, child_key))));
+
     child_key++;
   }
 }
 
-void TileView::OnChildConnectionError(uint32_t child_key,
-                                      const std::string& url) {
-  LOG(ERROR) << "Could not connect to view: child_key=" << child_key
-             << ", url=" << url;
-}
-
-void TileView::OnChildCreated(uint32_t child_key,
-                              const std::string& url,
-                              mojo::ui::ViewProviderPtr provider,
-                              mojo::ui::ViewTokenPtr token) {
-  DCHECK(views_.find(child_key) == views_.end());
-  LOG(INFO) << "View created: child_key=" << child_key << ", url=" << url;
-
-  view_host()->AddChild(child_key, token.Pass());
-  views_.emplace(std::make_pair(
-      child_key, std::unique_ptr<ViewData>(new ViewData(url, child_key))));
-
-  // Note that the view provider will be destroyed once this function
-  // returns which is fine now that we are done creating the view.
-}
-
 void TileView::OnChildUnavailable(uint32_t child_key,
                                   const OnChildUnavailableCallback& callback) {
   auto it = views_.find(child_key);
   DCHECK(it != views_.end());
   LOG(ERROR) << "View died unexpectedly: child_key=" << child_key
              << ", url=" << it->second->url;
 
   std::unique_ptr<ViewData> view_data = std::move(it->second);
   views_.erase(it);
 
-  view_host()->RemoveChild(child_key);
+  view_host()->RemoveChild(child_key, nullptr);
 
   if (view_data->layout_pending) {
     DCHECK(pending_child_layout_count_);
     pending_child_layout_count_--;
     FinishLayout();
   }
 
   callback.Run();
 }
 
@@ skipping 168 matching lines @@
   pending_layout_callback_.Run(info.Pass());
   pending_layout_callback_.reset();
 }
 
 TileView::ViewData::ViewData(const std::string& url, uint32_t key)
     : url(url), key(key), layout_pending(false) {}
 
 TileView::ViewData::~ViewData() {}
 
 }  // namespace examples