blob: 62a8f8ea7abe245ac2a137a1306983ae1aad2032 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
// 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.
#ifndef CHROME_BROWSER_UI_TITLE_PREFIX_MATCHER_H_
#define CHROME_BROWSER_UI_TITLE_PREFIX_MATCHER_H_
#pragma once
#include <vector>
#include "base/string16.h"
#include "googleurl/src/gurl.h"
// This class exposes a static method that receives a vector of TitleInfo
// objects so that it can find the length of the common prefixes among all
// the titles. It can be used for tab titles for example so that the common
// prefixes can be elided.
// First, the caller needs to fill a vector of TitleInfo objects with the titles
// for which they want to find the common prefix lengths. They can also provide
// an optional caller_value where the index of the tabs could be saved
// for example. This way the caller can remember which tab this title belongs
// to, if not all tabs are passed into the vector.
// When CalculatePrefixLengths returns, the TitleInfo objects in the vector
// are set with the prefix_length that is common between this title
// and at least one other.
// Note that the prefix_length is only calculated at word boundaries.
class TitlePrefixMatcher {
public:
struct TitleInfo {
TitleInfo(const string16* title, const GURL& url, int caller_value);
~TitleInfo();
// We assume the title string will be valid throughout the execution of
// the prefix lengths calculation, and so we use a pointer to avoid an
// unnecessary string copy.
const string16* title;
// We only look for common prefix when the URL has the same hostname.
GURL url;
// This contains the number of characters at the beginning of title that
// are common with other titles in the TitleInfo vector.
size_t prefix_length;
// Utility data space for the caller. Unused by CalculatePrefixLengths.
int caller_value;
};
static void CalculatePrefixLengths(std::vector<TitleInfo>* title_infos);
// We want to show the last few common chars of a page title in the tab,
// so we only do it if the common prefix is at least kMinElidingLength,
// otherwise, we could be replacing less characters than the ellipsis take.
static const int kCommonCharsToShow;
static const size_t kMinElidingLength;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(TitlePrefixMatcher);
};
#endif // CHROME_BROWSER_UI_TITLE_PREFIX_MATCHER_H_
|
