Implement Bookmark Autocomplete Provider

chrome/browser/autocomplete/bookmark_provider.h

+// Copyright (c) 2012 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.
+
+#ifndef CHROME_BROWSER_AUTOCOMPLETE_BOOKMARK_PROVIDER_H_
+#define CHROME_BROWSER_AUTOCOMPLETE_BOOKMARK_PROVIDER_H_
+
+#include <string>
+
+#include "chrome/browser/autocomplete/autocomplete_input.h"
+#include "chrome/browser/autocomplete/autocomplete_match.h"
+#include "chrome/browser/autocomplete/autocomplete_provider.h"
+#include "chrome/browser/bookmarks/bookmark_utils.h"
+#include "chrome/browser/history/snippet.h"
+
+class BookmarkModel;
+class Profile;
+
+// This class is an autocomplete provider which quickly (and synchronously)
+// provides autocomplete suggestions based on the titles of bookmarks. Page
+// titles, URLs, and typed and visit counts of the bookmarks are not taken into

[Peter Kasting, 2012/10/10 18:29:06]

The old comment said "Page titles and URLs are not matched", which makes sense
given this larger comment.  But I don't get the bit about typed and visit counts
you added.  Why wouldn't we still use typed/visit counts as an input to our
scoring algorithm?  After all, the real goal of this provider is to match
bookmarks whose titles differ from their URL/page title, and thus would be
missed by the HQP.  Right?

[mrossetti, 2012/10/15 19:22:46]

Exactly right. But I wanted to get this basic implementation into place before
complicating it with interactions with the HQP (or, potentially, the History
database—not my preferred option). I am sorry I did not make that intention
clear initially.

I'm also trying to figure out how to best coordinate the results form the BP
with those from the HQP and think I'll have a better handle on that once this
gets landed. This might be done in the merge phase by the
AutocompleteController. Or it might be done by the BP while indexing a bookmark
by recognizing that the HQP also knows about the URL. Or it might be done by the
HQP during indexing by recognizing that the URL is also referenced by a bookmark
and adding the bookmark title to the indexed corpus. There are a number of
options and I'm not prepared to choose one at the moment.

And finally, I'm trying to avoid tossing a massive change onto your lap for
review; as I've been known to do in the past.

I'll add a TODO hinting at this.

If it's okay with you, I'd like to get this settled as-is and then propose in a
future CL how to best coordinate with the history.

On 2012/10/10 18:29:06, Peter Kasting wrote:

+// consideration as those factors will have been used by the
+// HistoryQuickProvider in identifying suggestions.
+class BookmarkProvider : public AutocompleteProvider {
+ public:
+  BookmarkProvider(AutocompleteProviderListener* listener, Profile* profile);
+
+  // AutocompleteProvider. When |minimal_changes| is true short circuit any
+  // additional searching and leave the previous matches for this provider
+  // unchanged.
+  virtual void Start(const AutocompleteInput& input,
+                     bool minimal_changes) OVERRIDE;
+
+  // Sets the BookmarkModel for unit tests.
+  void set_bookmark_model_for_testing(BookmarkModel* bookmark_model) {
+    bookmark_model_ = bookmark_model;
+  }
+
+ private:
+  virtual ~BookmarkProvider();
+
+  // Performs the actual matching of |input| over the bookmarks and fills in
+  // |matches_|. If |best_match| then only suggest the single best match,
+  // otherwise suggest the top |kMaxMatches| matches.
+  void DoAutocomplete(const AutocompleteInput& input, bool best_match);
+
+  // Calculates a relevance for |title_match|, converts it to an
+  // AutocompleteMatch and returns the converted match.
+  AutocompleteMatch TitleMatchToACMatch(
+      const bookmark_utils::TitleMatch& title_match);
+
+  // Converts |positions| into ACMatchClassifications and returns the
+  // classifications. |text_length| is used to determine the need to add an
+  // 'unhighlighted' classification span so the tail of the source string
+  // properly highlighted.
+  static ACMatchClassifications ClassificationsFromMatch(
+      const Snippet::MatchPositions& positions,
+      size_t text_length);
+
+  BookmarkModel* bookmark_model_;
+
+  // Languages used during the URL formatting.
+  std::string languages_;
+
+  DISALLOW_COPY_AND_ASSIGN(BookmarkProvider);
+};
+
+#endif  // CHROME_BROWSER_AUTOCOMPLETE_BOOKMARK_PROVIDER_H_