components/font_service/public/cpp/font_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_FONT_SERVICE_PUBLIC_CPP_FONT_LOADER_H_
   6 #define COMPONENTS_FONT_SERVICE_PUBLIC_CPP_FONT_LOADER_H_
   7
   8 #include "base/containers/hash_tables.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/synchronization/lock.h"
  11 #include "components/font_service/public/cpp/mapped_font_file.h"
  12 #include "components/font_service/public/interfaces/font_service.mojom.h"
  13 #include "third_party/skia/include/core/SkStream.h"
  14 #include "third_party/skia/include/core/SkTypeface.h"
  15 #include "third_party/skia/include/ports/SkFontConfigInterface.h"
  16
  17 namespace mojo {
  18 class ApplicationImpl;
  19 class Shell;
  20 }
  21
  22 namespace font_service {
  23 namespace internal {
  24 class FontServiceThread;
  25 }
  26
  27 // FontConfig implementation for Skia which proxies to the font service to get
  28 // out of the sandbox. This methods of this class (as imposed by blink
  29 // requirements) may be called on any thread. (Because of this restriction,
  30 // also see the FontServiceThread class.)
  31 //
  32 // This is the mojo equivalent to content/common/font_config_ipc_linux.h
  33 class FontLoader : public SkFontConfigInterface,
  34                    public internal::MappedFontFile::Observer {
  35  public:
  36   explicit FontLoader(mojo::Shell* shell);
  37   explicit FontLoader(mojo::ApplicationImpl* application_impl);
  38   ~FontLoader() override;
  39
  40   // Shuts down the background thread.
  41   void Shutdown();
  42
  43   // SkFontConfigInterface:
  44   bool matchFamilyName(const char family_name[],
  45                        SkTypeface::Style requested,
  46                        FontIdentity* out_font_identifier,
  47                        SkString* out_family_name,
  48                        SkTypeface::Style* out_style) override;
  49   SkStreamAsset* openStream(const FontIdentity& identity) override;
  50
  51  private:
  52   // internal::MappedFontFile::Observer:
  53   void OnMappedFontFileDestroyed(internal::MappedFontFile* f) override;
  54
  55   // Thread to own the mojo message pipe. Because FontLoader can be called on
  56   // multiple threads, we create a dedicated thread to send and receive mojo
  57   // message calls.
  58   scoped_refptr<internal::FontServiceThread> thread_;
  59
  60   // Lock preventing multiple threads from opening font file and accessing
  61   // |mapped_font_files_| map at the same time.
  62   base::Lock lock_;
  63
  64   // Maps font identity ID to the memory-mapped file with font data.
  65   base::hash_map<uint32_t, internal::MappedFontFile*> mapped_font_files_;
  66
  67   DISALLOW_COPY_AND_ASSIGN(FontLoader);
  68 };
  69
  70 }  // namespace font_service
  71
  72 #endif  // COMPONENTS_FONT_SERVICE_PUBLIC_CPP_FONT_LOADER_H_