device_properties.h

// Copyright 2012 Google Inc. All Rights Reserved.

#ifndef NET_INSTAWEB_REWRITER_PUBLIC_DEVICE_PROPERTIES_H_
#define NET_INSTAWEB_REWRITER_PUBLIC_DEVICE_PROPERTIES_H_

#include <vector>

#include "pagespeed/kernel/base/basictypes.h"
#include "pagespeed/kernel/base/gtest_prod.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/base/string_util.h"
#include "pagespeed/kernel/http/user_agent_matcher.h"

namespace net_instaweb {

class RequestHeaders;

class DeviceProperties {
 public:
  explicit DeviceProperties(UserAgentMatcher* matcher);
  virtual ~DeviceProperties();

  void SetUserAgent(const StringPiece& user_agent_string);
  void ParseRequestHeaders(const RequestHeaders& request_headers);
  bool SupportsImageInlining() const;
  bool SupportsLazyloadImages() const;
  bool SupportsCriticalCss() const;
  bool SupportsCriticalImagesBeacon() const;
  bool SupportsJsDefer(bool enable_mobile) const;
  bool SupportsWebpInPlace() const;
  bool SupportsWebpRewrittenUrls() const;
  bool SupportsWebpLosslessAlpha() const;
  bool SupportsWebpAnimated() const;
  bool IsBot() const;
  bool AcceptsGzip() const;
  UserAgentMatcher::DeviceType GetDeviceType() const;
  bool IsMobile() const {
    return GetDeviceType() == UserAgentMatcher::kMobile;
  }
  bool IsTablet() const {
    return GetDeviceType() == UserAgentMatcher::kTablet;
  }

  enum ImageQualityPreference {
    kImageQualityDefault,
    kImageQualityLow,
    kImageQualityMedium,
    kImageQualityHigh,
  };
  static const int kMediumScreenWidthThreshold = 720;
  static const int kLargeScreenWidthThreshold = 1500;
  bool ForbidWebpInlining() const;

  bool RequestsSaveData() const;
  bool HasViaHeader() const;

 private:
  friend class ImageRewriteTest;
  friend class RequestProperties;

  GoogleString user_agent_;
  GoogleString accept_header_;
  UserAgentMatcher* ua_matcher_;

  mutable LazyBool supports_critical_css_;
  mutable LazyBool supports_image_inlining_;
  mutable LazyBool supports_js_defer_;
  mutable LazyBool supports_lazyload_images_;
  mutable LazyBool requests_save_data_;
  mutable LazyBool accepts_webp_;
  mutable LazyBool accepts_gzip_;
  mutable LazyBool supports_webp_rewritten_urls_;
  mutable LazyBool supports_webp_lossless_alpha_;
  mutable LazyBool supports_webp_animated_;
  mutable LazyBool is_bot_;
  mutable LazyBool is_mobile_user_agent_;
  mutable LazyBool supports_split_html_;
  mutable LazyBool supports_flush_early_;
  const std::vector<int>* preferred_webp_qualities_;
  const std::vector<int>* preferred_jpeg_qualities_;
  mutable LazyBool device_type_set_;
  mutable UserAgentMatcher::DeviceType device_type_;
  mutable LazyBool has_via_header_;

  
};

}  

#endif