tooltip_manager.cc revision 58537e28ecd584eab876aee8be7156509866d23a 
1// Copyright (c) 2011 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#include "ui/views/widget/tooltip_manager.h"
6
7#include <vector>
8
9#include "base/strings/string_split.h"
10#include "base/strings/utf_string_conversions.h"
11#include "ui/gfx/text_elider.h"
12#include "ui/gfx/text_utils.h"
13
14// Maximum number of characters we allow in a tooltip.
15const size_t kMaxTooltipLength = 1024;
16
17// Maximum number of lines we allow in the tooltip.
18const size_t kMaxLines = 6;
19
20namespace views {
21
22// static
23void TooltipManager::TrimTooltipToFit(string16* text,
24                                      int* max_width,
25                                      int* line_count,
26                                      int x,
27                                      int y,
28                                      gfx::NativeView context) {
29  *max_width = 0;
30  *line_count = 0;
31
32  // Clamp the tooltip length to kMaxTooltipLength so that we don't
33  // accidentally DOS the user with a mega tooltip.
34  if (text->length() > kMaxTooltipLength)
35    *text = text->substr(0, kMaxTooltipLength);
36
37  // Determine the available width for the tooltip.
38  int available_width = GetMaxWidth(x, y, context);
39
40  // Split the string into at most kMaxLines lines.
41  std::vector<string16> lines;
42  base::SplitString(*text, '\n', &lines);
43  if (lines.size() > kMaxLines)
44    lines.resize(kMaxLines);
45  *line_count = static_cast<int>(lines.size());
46
47  // Format each line to fit.
48  const gfx::FontList& font_list = GetDefaultFontList();
49  string16 result;
50  for (std::vector<string16>::iterator i = lines.begin(); i != lines.end();
51       ++i) {
52    string16 elided_text =
53        gfx::ElideText(*i, font_list, available_width, gfx::ELIDE_AT_END);
54    *max_width = std::max(*max_width,
55                          gfx::GetStringWidth(elided_text, font_list));
56    if (!result.empty())
57      result.push_back('\n');
58    result.append(elided_text);
59  }
60  *text = result;
61}
62
63}  // namespace views
64