chrome/browser/android/contextualsearch/contextual_search_delegate.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 CHROME_BROWSER_ANDROID_CONTEXTUALSEARCH_CONTEXTUAL_SEARCH_DELEGATE_H_
   6 #define CHROME_BROWSER_ANDROID_CONTEXTUALSEARCH_CONTEXTUAL_SEARCH_DELEGATE_H_
   7
   8 #include "base/callback.h"
   9 #include "base/gtest_prod_util.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "chrome/browser/android/contextualsearch/contextual_search_context.h"
  13 #include "content/public/browser/android/content_view_core.h"
  14 #include "net/url_request/url_fetcher_delegate.h"
  15
  16 namespace net {
  17 class URLRequestContextGetter;
  18 }  // namespace net
  19
  20 class Profile;
  21 class TemplateURLService;
  22
  23 // Handles tasks for the ContextualSearchManager in a separable and testable
  24 // way, without the complication of being connected to a Java object.
  25 class ContextualSearchDelegate
  26     : public net::URLFetcherDelegate,
  27       public base::SupportsWeakPtr<ContextualSearchDelegate> {
  28  public:
  29   typedef base::Callback<
  30       void(bool, int, const std::string&, const std::string&,
  31            const std::string&, bool)>
  32       SearchTermResolutionCallback;
  33   typedef base::Callback<
  34       void(const std::string&, const std::string&)> SurroundingTextCallback;
  35   typedef base::Callback<
  36       void(const base::string16&, int, int)>
  37       HandleSurroundingsCallback;
  38   typedef base::Callback<
  39       void(const std::string&, const base::string16&, size_t, size_t)>
  40       IcingCallback;
  41
  42   // ID used in creating URLFetcher for Contextual Search results.
  43   static const int kContextualSearchURLFetcherID;
  44
  45   // Constructs a delegate that will always call back to the given callbacks
  46   // when search term resolution or surrounding text responses are available.
  47   ContextualSearchDelegate(
  48       net::URLRequestContextGetter* url_request_context,
  49       TemplateURLService* template_url_service,
  50       const SearchTermResolutionCallback& search_term_callback,
  51       const SurroundingTextCallback& surrounding_callback,
  52       const IcingCallback& icing_callback);
  53   ~ContextualSearchDelegate() override;
  54
  55   // Gathers surrounding text and starts an asynchronous search term resolution
  56   // request. The "search term" is the best query to issue for a section of text
  57   // in the context of a web page. When the response is available the callback
  58   // specified in the constructor is run.
  59   void StartSearchTermResolutionRequest(
  60       const std::string& selection,
  61       bool use_resolved_search_term,
  62       content::ContentViewCore* content_view_core);
  63
  64   // Gathers surrounding text and saves it locally for a future query.
  65   void GatherAndSaveSurroundingText(
  66       const std::string& selection,
  67       bool use_resolved_search_term,
  68       content::ContentViewCore* content_view_core);
  69
  70   // Continues making a Search Term Resolution request based on the context
  71   // set up through calling |GatherAndSaveSurroundingText|.
  72   // When the response is available the callback specified in the constructor
  73   // is run.
  74   void ContinueSearchTermResolutionRequest();
  75
  76   // For testing.
  77   void set_context_for_testing(ContextualSearchContext* context) {
  78     context_.reset(context);
  79   }
  80
  81  private:
  82   FRIEND_TEST_ALL_PREFIXES(ContextualSearchDelegateTest,
  83                            SurroundingTextHighMaximum);
  84   FRIEND_TEST_ALL_PREFIXES(ContextualSearchDelegateTest,
  85                            SurroundingTextLowMaximum);
  86   FRIEND_TEST_ALL_PREFIXES(ContextualSearchDelegateTest,
  87                            SurroundingTextNoBeforeText);
  88   FRIEND_TEST_ALL_PREFIXES(ContextualSearchDelegateTest,
  89                            SurroundingTextForIcing);
  90   FRIEND_TEST_ALL_PREFIXES(ContextualSearchDelegateTest,
  91                            SurroundingTextForIcingNegativeLimit);
  92   FRIEND_TEST_ALL_PREFIXES(ContextualSearchDelegateTest,
  93                            DecodeSearchTermsFromJsonResponse);
  94
  95   // net::URLFetcherDelegate:
  96   void OnURLFetchComplete(const net::URLFetcher* source) override;
  97
  98   // Builds the search term resolution request URL from the current context.
  99   GURL BuildRequestUrl();
 100
 101   // Uses the TemplateURL service to construct a search term resolution URL from
 102   // the given parameters.
 103   std::string GetSearchTermResolutionUrlString(
 104       const std::string& selected_text,
 105       const std::string& base_page_url,
 106       const bool use_resolved_search_term);
 107
 108   // Will gather the surrounding text from the |content_view_core| and call the
 109   // |callback|.
 110   void GatherSurroundingTextWithCallback(
 111       const std::string& selection,
 112       bool use_resolved_search_term,
 113       content::ContentViewCore* content_view_core,
 114       HandleSurroundingsCallback callback);
 115
 116   // Callback for GatherSurroundingTextWithCallback(). Will start the search
 117   // term resolution request.
 118   void StartSearchTermRequestFromSelection(
 119       const base::string16& surrounding_text,
 120       int start_offset,
 121       int end_offset);
 122
 123   void SaveSurroundingText(
 124     const base::string16& surrounding_text,
 125     int start_offset,
 126     int end_offset);
 127
 128   // Will call back to the manager with the proper surrounding text to be shown
 129   // in the UI. Will return a maximum of |max_surrounding_chars| characters for
 130   // each of the segments.
 131   void SendSurroundingText(int max_surrounding_chars);
 132
 133   // Populates the discourse context and adds it to the HTTP header of the
 134   // search term resolution request.
 135   void SetDiscourseContextAndAddToHeader(
 136       const ContextualSearchContext& context);
 137
 138   // Checks if we can send the URL for this user. Several conditions are checked
 139   // to make sure it's OK to send the url.  These fall into two categories:
 140   // 1) check if it's allowed by our policy, and 2) ensure that the user is
 141   // already sending their URL browsing activity to Google.
 142   bool CanSendPageURL(const GURL& current_page_url,
 143                       Profile* profile,
 144                       TemplateURLService* template_url_service);
 145
 146   // Decodes the given json response string and extracts parameters.
 147   void DecodeSearchTermsFromJsonResponse(const std::string& response,
 148                                          std::string* search_term,
 149                                          std::string* display_text,
 150                                          std::string* alternate_term,
 151                                          std::string* prevent_preload);
 152
 153   // Returns the surrounding size to use for the search term resolution
 154   // request.
 155   int GetSearchTermSurroundingSize();
 156
 157   // Returns the size of the surroundings to be sent to Icing.
 158   int GetIcingSurroundingSize();
 159
 160   // Generates a subset of the given surrounding_text string, for Icing
 161   // integration.
 162   // |surrounding_text| the entire text context that contains the selection.
 163   // |padding_each_side| the number of characters of padding desired on each
 164   // side of the selection (negative values treated as 0).
 165   // |start| the start offset of the selection, updated to reflect the new
 166   // position
 167   // of the selection in the function result.
 168   // |end| the end offset of the selection, updated to reflect the new position
 169   // of the selection in the function result.
 170   // |return| the trimmed surrounding text with selection at the
 171   // updated start/end offsets.
 172   base::string16 SurroundingTextForIcing(const base::string16& surrounding_text,
 173                                          int padding_each_side,
 174                                          size_t* start,
 175                                          size_t* end);
 176
 177   // The current request in progress, or NULL.
 178   scoped_ptr<net::URLFetcher> search_term_fetcher_;
 179
 180   // Holds the URL request context. Not owned.
 181   net::URLRequestContextGetter* url_request_context_;
 182
 183   // Holds the TemplateURLService. Not owned.
 184   TemplateURLService* template_url_service_;
 185
 186   // The callback for notifications of completed URL fetches.
 187   SearchTermResolutionCallback search_term_callback_;
 188
 189   // The callback for notifications of surrounding text being available.
 190   SurroundingTextCallback surrounding_callback_;
 191
 192   // The callback for notifications of Icing selection being available.
 193   IcingCallback icing_callback_;
 194
 195   // Used to hold the context until an upcoming search term request is started.
 196   scoped_ptr<ContextualSearchContext> context_;
 197
 198   DISALLOW_COPY_AND_ASSIGN(ContextualSearchDelegate);
 199 };
 200
 201 #endif  // CHROME_BROWSER_ANDROID_CONTEXTUALSEARCH_CONTEXTUAL_SEARCH_DELEGATE_H_