1 // Copyright 2019 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_OMNIBOX_BROWSER_LOCAL_HISTORY_ZERO_SUGGEST_PROVIDER_H_
6 #define COMPONENTS_OMNIBOX_BROWSER_LOCAL_HISTORY_ZERO_SUGGEST_PROVIDER_H_
7 
8 #include "base/memory/weak_ptr.h"
9 #include "base/strings/string16.h"
10 #include "base/task/cancelable_task_tracker.h"
11 #include "components/omnibox/browser/autocomplete_provider.h"
12 
13 class AutocompleteProviderClient;
14 class AutocompleteProviderListener;
15 
16 namespace history {
17 class QueryResults;
18 }  // namespace history
19 
20 // Autocomplete provider for on-focus zero-prefix query suggestions from local
21 // history when Google is the default search engine.
22 class LocalHistoryZeroSuggestProvider : public AutocompleteProvider {
23  public:
24   // Creates and returns an instance of this provider.
25   static LocalHistoryZeroSuggestProvider* Create(
26       AutocompleteProviderClient* client,
27       AutocompleteProviderListener* listener);
28 
29   // AutocompleteProvider:
30   void Start(const AutocompleteInput& input, bool minimal_changes) override;
31   void DeleteMatch(const AutocompleteMatch& match) override;
32 
33  private:
34   FRIEND_TEST_ALL_PREFIXES(LocalHistoryZeroSuggestProviderTest, Input);
35 
36   LocalHistoryZeroSuggestProvider(AutocompleteProviderClient* client,
37                                   AutocompleteProviderListener* listener);
38   ~LocalHistoryZeroSuggestProvider() override;
39   LocalHistoryZeroSuggestProvider(const LocalHistoryZeroSuggestProvider&) =
40       delete;
41   LocalHistoryZeroSuggestProvider& operator=(
42       const LocalHistoryZeroSuggestProvider&) = delete;
43 
44   // Queries the keyword search terms table of the in-memory URLDatabase for the
45   // recent search terms submitted to the default search provider.
46   void QueryURLDatabase(const AutocompleteInput& input);
47 
48   // Called when the query results from HistoryService::QueryHistory are ready.
49   // Deletes URLs in |results| that would generate |suggestion|. |query_time| is
50   // the time HistoryService was queried.
51   void OnHistoryQueryResults(const base::string16& suggestion,
52                              const base::TimeTicks& query_time,
53                              history::QueryResults results);
54 
55   // The maximum number of matches to return.
56   const size_t max_matches_;
57 
58   // Client for accessing TemplateUrlService, prefs, etc.
59   AutocompleteProviderClient* const client_;
60 
61   // Listener to notify when matches are available.
62   AutocompleteProviderListener* const listener_;
63 
64   // Used for the async tasks querying the HistoryService.
65   base::CancelableTaskTracker history_task_tracker_;
66 
67   base::WeakPtrFactory<LocalHistoryZeroSuggestProvider> weak_ptr_factory_{this};
68 };
69 
70 #endif  // COMPONENTS_OMNIBOX_BROWSER_LOCAL_HISTORY_ZERO_SUGGEST_PROVIDER_H_
71