components/omnibox/browser/autocomplete_classifier.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_OMNIBOX_BROWSER_AUTOCOMPLETE_CLASSIFIER_H_
#define COMPONENTS_OMNIBOX_BROWSER_AUTOCOMPLETE_CLASSIFIER_H_

#include <memory>
#include <string>

#include "components/keyed_service/core/keyed_service.h"
#include "components/omnibox/browser/autocomplete_scheme_classifier.h"
#include "third_party/metrics_proto/omnibox_event.pb.h"

class AutocompleteController;
struct AutocompleteMatch;
class GURL;

class AutocompleteClassifier : public KeyedService {
 public:
  AutocompleteClassifier() = delete;

  AutocompleteClassifier(
      std::unique_ptr<AutocompleteController> controller_,
      std::unique_ptr<AutocompleteSchemeClassifier> scheme_classifier);

  AutocompleteClassifier(const AutocompleteClassifier&) = delete;
  AutocompleteClassifier& operator=(const AutocompleteClassifier&) = delete;

  ~AutocompleteClassifier() override;

  // KeyedService:
  void Shutdown() override;

  // Bitmap of AutocompleteProvider::Type values describing the default set of
  // providers queried for the omnibox.  Intended to be passed to
  // AutocompleteController().
  // The parameter |is_low_memory_device| permits suppression of certain
  // Autocomplete providers on devices where memory is scarce. This is
  // particularly relevant for Android, where visually rich suggestions should
  // be suppressed to reduce memory pressure.
  static int DefaultOmniboxProviders(bool is_low_memory_device = false);

  // Given some string |text| that the user wants to use for navigation,
  // determines how it should be interpreted.
  // |prefer_keyword| should be true the when keyword UI is onscreen; see
  // comments on AutocompleteController::Start().
  // |allow_exact_keyword_match| should be true when treating the string as a
  // potential keyword search is valid; see
  // AutocompleteInput::allow_exact_keyword_match().
  // |page_classification| gives information about the context (e.g., is the
  // user on a search results page doing search term replacement); this may
  // be useful in deciding how the input should be interpreted.
  // |match| should be a non-NULL outparam that will be set to the default
  // match for this input, if any (for invalid input, there will be no default
  // match, and |match| will be left unchanged).  |alternate_nav_url| is a
  // possibly-NULL outparam that, if non-NULL, will be set to the navigational
  // URL (if any) in case of an accidental search; see comments on
  // AutocompleteResult::alternate_nav_url_ in autocomplete.h.
  void Classify(
      const std::u16string& text,
      bool prefer_keyword,
      bool allow_exact_keyword_match,
      metrics::OmniboxEventProto::PageClassification page_classification,
      AutocompleteMatch* match,
      GURL* alternate_nav_url);

  AutocompleteController* autocomplete_controller() {
    return controller_.get();
  }

 private:
  std::unique_ptr<AutocompleteController> controller_;
  std::unique_ptr<AutocompleteSchemeClassifier> scheme_classifier_;

  // Are we currently in Classify? Used to verify Classify isn't invoked
  // recursively, since this can corrupt state and cause crashes.
  bool inside_classify_;
};

#endif  // COMPONENTS_OMNIBOX_BROWSER_AUTOCOMPLETE_CLASSIFIER_H_