components/resource_provider/public/cpp/resource_loader.h

   1 // Copyright 2015 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_RESOURCE_PROVIDER_PUBLIC_CPP_RESOURCE_LOADER_H_
   6 #define COMPONENTS_RESOURCE_PROVIDER_PUBLIC_CPP_RESOURCE_LOADER_H_
   7
   8 #include <map>
   9 #include <set>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/basictypes.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "components/resource_provider/public/interfaces/resource_provider.mojom.h"
  16 #include "mojo/application/public/interfaces/service_provider.mojom.h"
  17 #include "mojo/platform_handle/platform_handle.h"
  18 #include "third_party/mojo/src/mojo/public/cpp/bindings/array.h"
  19 #include "third_party/mojo/src/mojo/public/cpp/system/handle.h"
  20
  21 namespace base {
  22 class File;
  23 }
  24
  25 namespace mojo {
  26 class Shell;
  27 }
  28
  29 namespace resource_provider {
  30
  31 // ResourceLoader handles making a request to ResourceProvider and blocking
  32 // until the resources are available. Expected use is to create a ResourceLoader
  33 // and shortly thereafter call BlockUntilLoaded() to wait until the resources
  34 // have been obtained.
  35 class ResourceLoader {
  36  public:
  37   ResourceLoader(mojo::Shell* shell, const std::set<std::string>& paths);
  38   ~ResourceLoader();
  39
  40   // Uses WaitForIncomingMessage() to block until the results are available, or
  41   // an error occurs. Returns true if the resources were obtained, false on
  42   // error. This immediately returns if the resources have already been
  43   // obtained.
  44   bool BlockUntilLoaded();
  45
  46   // Releases and returns the file wrapping the handle.
  47   base::File ReleaseFile(const std::string& path);
  48
  49   bool loaded() const { return loaded_; }
  50
  51  private:
  52   using ResourceMap = std::map<std::string, scoped_ptr<base::File>>;
  53
  54   // Callback when resources have loaded.
  55   void OnGotResources(const std::vector<std::string>& paths,
  56                       mojo::Array<mojo::ScopedHandle> resources);
  57
  58   mojo::ServiceProviderPtr resource_provider_service_provider_;
  59
  60   ResourceProviderPtr resource_provider_;
  61
  62   ResourceMap resource_map_;
  63
  64   bool loaded_;
  65   bool did_block_;
  66
  67   DISALLOW_COPY_AND_ASSIGN(ResourceLoader);
  68 };
  69
  70 }  // namespace resource_provider
  71
  72 #endif  // COMPONENTS_RESOURCE_PROVIDER_PUBLIC_CPP_RESOURCE_LOADER_H_