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// Copyright (c) 2011 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.
//
// This file contains the keyword autocomplete provider. The keyword provider
// is responsible for remembering/suggesting user "search keyword queries"
// (e.g. "imdb Godzilla") and then fixing them up into valid URLs. An
// instance of it gets created and managed by the autocomplete controller.
// KeywordProvider uses a TemplateURLModel to find the set of keywords.
//
// For more information on the autocomplete system in general, including how
// the autocomplete controller and autocomplete providers work, see
// chrome/browser/autocomplete.h.
#ifndef CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_
#define CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_
#pragma once
#include <string>
#include "chrome/browser/autocomplete/autocomplete.h"
#include "content/common/notification_observer.h"
#include "content/common/notification_registrar.h"
class Profile;
class TemplateURL;
class TemplateURLModel;
// Autocomplete provider for keyword input.
//
// After construction, the autocomplete controller repeatedly calls Start()
// with some user input, each time expecting to receive a small set of the best
// matches (either synchronously or asynchronously).
//
// To construct these matches, the provider treats user input as a series of
// whitespace-delimited tokens and tries to match the first token as the prefix
// of a known "keyword". A keyword is some string that maps to a search query
// URL; the rest of the user's input is taken as the input to the query. For
// example, the keyword "bug" might map to the URL "http://b/issue?id=%s", so
// input like "bug 123" would become "http://b/issue?id=123".
//
// Because we do prefix matching, user input could match more than one keyword
// at once. (Example: the input "f jazz" matches all keywords starting with
// "f".) We return the best matches, up to three.
//
// The resulting matches are shown with content specified by the keyword
// (usually "Search [name] for %s"), description "(Keyword: [keyword])", and
// action "[keyword] %s". If the user has typed a (possibly partial) keyword
// but no search terms, the suggested result is shown greyed out, with
// "<enter term(s)>" as the substituted input, and does nothing when selected.
class KeywordProvider : public AutocompleteProvider,
public NotificationObserver {
public:
KeywordProvider(ACProviderListener* listener, Profile* profile);
// For testing.
KeywordProvider(ACProviderListener* listener, TemplateURLModel* model);
// Returns the replacement string from the user input. The replacement
// string is the portion of the input that does not contain the keyword.
// For example, the replacement string for "b blah" is blah.
// If |trim_leading_whitespace| is true then leading whitespace in
// replacement string will be trimmed.
static string16 SplitReplacementStringFromInput(
const string16& input,
bool trim_leading_whitespace);
// Returns the matching substituting keyword for |input|, or NULL if there
// is no keyword for the specified input.
static const TemplateURL* GetSubstitutingTemplateURLForInput(
Profile* profile,
const AutocompleteInput& input,
string16* remaining_input);
// AutocompleteProvider
virtual void Start(const AutocompleteInput& input, bool minimal_changes);
virtual void Stop();
private:
class ScopedEndExtensionKeywordMode;
friend class ScopedEndExtensionKeywordMode;
virtual ~KeywordProvider();
// Extracts the keyword from |input| into |keyword|. Any remaining characters
// after the keyword are placed in |remaining_input|. Returns true if |input|
// is valid and has a keyword. This makes use of SplitKeywordFromInput to
// extract the keyword and remaining string, and uses
// TemplateURLModel::CleanUserInputKeyword to remove unnecessary characters.
// In general use this instead of SplitKeywordFromInput.
// Leading whitespace in |*remaining_input| will be trimmed.
static bool ExtractKeywordFromInput(const AutocompleteInput& input,
string16* keyword,
string16* remaining_input);
// Extracts the next whitespace-delimited token from input and returns it.
// Sets |remaining_input| to everything after the first token (skipping over
// the first intervening whitespace).
// If |trim_leading_whitespace| is true then leading whitespace in
// |*remaining_input| will be trimmed.
static string16 SplitKeywordFromInput(const string16& input,
bool trim_leading_whitespace,
string16* remaining_input);
// Fills in the "destination_url" and "contents" fields of |match| with the
// provided user input and keyword data.
static void FillInURLAndContents(
const string16& remaining_input,
const TemplateURL* element,
AutocompleteMatch* match);
// Determines the relevance for some input, given its type, whether the user
// typed the complete keyword, and whether the user is in "prefer keyword
// matches" mode, and whether the keyword supports replacement.
// If |allow_exact_keyword_match| is false, the relevance for complete
// keywords that support replacements is degraded.
static int CalculateRelevance(AutocompleteInput::Type type,
bool complete,
bool support_replacement,
bool prefer_keyword,
bool allow_exact_keyword_match);
// Creates a fully marked-up AutocompleteMatch from the user's input.
// If |relevance| is negative, calculate a relevance based on heuristics.
AutocompleteMatch CreateAutocompleteMatch(
TemplateURLModel* model,
const string16& keyword,
const AutocompleteInput& input,
size_t prefix_length,
const string16& remaining_input,
int relevance);
void EnterExtensionKeywordMode(const std::string& extension_id);
void MaybeEndExtensionKeywordMode();
// NotificationObserver interface.
virtual void Observe(NotificationType type,
const NotificationSource& source,
const NotificationDetails& details);
// Model for the keywords. This is only non-null when testing, otherwise the
// TemplateURLModel from the Profile is used.
TemplateURLModel* model_;
// Identifies the current input state. This is incremented each time the
// autocomplete edit's input changes in any way. It is used to tell whether
// suggest results from the extension are current.
int current_input_id_;
// The input state at the time we last asked the extension for suggest
// results.
AutocompleteInput extension_suggest_last_input_;
// We remember the last suggestions we've received from the extension in case
// we need to reset our matches without asking the extension again.
std::vector<AutocompleteMatch> extension_suggest_matches_;
// If non-empty, holds the ID of the extension whose keyword is currently in
// the URL bar while the autocomplete popup is open.
std::string current_keyword_extension_id_;
NotificationRegistrar registrar_;
DISALLOW_COPY_AND_ASSIGN(KeywordProvider);
};
#endif // CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_