content/browser/renderer_host/dwrite_font_proxy_impl_win.h

// 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.

#ifndef CONTENT_BROWSER_RENDERER_HOST_DWRITE_FONT_PROXY_IMPL_WIN_H_
#define CONTENT_BROWSER_RENDERER_HOST_DWRITE_FONT_PROXY_IMPL_WIN_H_

#include <dwrite.h>
#include <dwrite_2.h>
#include <wrl.h>
#include <set>
#include <utility>
#include <vector>

#include "base/location.h"
#include "base/macros.h"
#include "base/memory/read_only_shared_memory_region.h"
#include "base/memory/ref_counted.h"
#include "base/strings/string16.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_message_filter.h"
#include "content/public/browser/browser_thread.h"
#include "third_party/blink/public/mojom/dwrite_font_proxy/dwrite_font_proxy.mojom.h"

namespace service_manager {
struct BindSourceInfo;
}

namespace content {

// Implements a message filter that handles the dwrite font proxy messages.
// If DWrite is enabled, calls into the system font collection to obtain
// results. Otherwise, acts as if the system collection contains no fonts.
class CONTENT_EXPORT DWriteFontProxyImpl
    : public blink::mojom::DWriteFontProxy {
 public:
  DWriteFontProxyImpl();
  ~DWriteFontProxyImpl() override;

  static void Create(blink::mojom::DWriteFontProxyRequest request,
                     const service_manager::BindSourceInfo& source_info);

  void SetWindowsFontsPathForTesting(base::string16 path);
  void SetSlowDownIndexingForTesting(bool);

 protected:
  // blink::mojom::DWriteFontProxy:
  void FindFamily(const base::string16& family_name,
                  FindFamilyCallback callback) override;
  void GetFamilyCount(GetFamilyCountCallback callback) override;
  void GetFamilyNames(uint32_t family_index,
                      GetFamilyNamesCallback callback) override;
  void GetFontFiles(uint32_t family_index,
                    GetFontFilesCallback callback) override;
  void MapCharacters(const base::string16& text,
                     blink::mojom::DWriteFontStylePtr font_style,
                     const base::string16& locale_name,
                     uint32_t reading_direction,
                     const base::string16& base_family_name,
                     MapCharactersCallback callback) override;

  void GetUniqueNameLookupTable(
      GetUniqueNameLookupTableCallback callback) override;

  void InitializeDirectWrite();

 private:
  // Checks if the unique font table has been built already, and if not, builds
  // it by enumerating fonts from the collection, extracting their file
  // locations, ttc indices and names.
  bool EnsureFontUniqueNameTable();
  bool IsLastResortFallbackFont(uint32_t font_index);

 private:
  bool IsFontUniqueNameTableValid();
  bool direct_write_initialized_ = false;
  Microsoft::WRL::ComPtr<IDWriteFontCollection> collection_;
  Microsoft::WRL::ComPtr<IDWriteFactory2> factory2_;
  Microsoft::WRL::ComPtr<IDWriteFontFallback> font_fallback_;
  base::string16 windows_fonts_path_;
  bool slow_down_indexing_for_testing_;
  base::MappedReadOnlyRegion font_unique_name_table_memory_;

  // Temp code to help track down crbug.com/561873
  std::vector<uint32_t> last_resort_fonts_;

  DISALLOW_COPY_AND_ASSIGN(DWriteFontProxyImpl);
};

}  // namespace content

#endif  // CONTENT_BROWSER_RENDERER_HOST_DWRITE_FONT_PROXY_MESSAGE_FILTER_WIN_H_