1 // Copyright 2013 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/controls/styled_label.h"
6
7 #include <vector>
8
9 #include "base/strings/string_util.h"
10 #include "ui/gfx/text_elider.h"
11 #include "ui/native_theme/native_theme.h"
12 #include "ui/views/controls/label.h"
13 #include "ui/views/controls/link.h"
14 #include "ui/views/controls/styled_label_listener.h"
15
16 namespace views {
17
18 namespace {
19
20 // Calculates the height of a line of text. Currently returns the height of
21 // a label.
CalculateLineHeight()22 int CalculateLineHeight() {
23 Label label;
24 return label.GetPreferredSize().height();
25 }
26
CreateLabelRange(const string16 & text,const StyledLabel::RangeStyleInfo & style_info,views::LinkListener * link_listener)27 scoped_ptr<Label> CreateLabelRange(
28 const string16& text,
29 const StyledLabel::RangeStyleInfo& style_info,
30 views::LinkListener* link_listener) {
31 scoped_ptr<Label> result;
32
33 if (style_info.is_link) {
34 Link* link = new Link(text);
35 link->set_listener(link_listener);
36 link->SetUnderline((style_info.font_style & gfx::Font::UNDERLINE) != 0);
37 result.reset(link);
38 } else {
39 Label* label = new Label(text);
40 // Give the label a focus border so that its preferred size matches
41 // links' preferred sizes
42 label->SetHasFocusBorder(true);
43
44 result.reset(label);
45 }
46
47 result->SetEnabledColor(style_info.color);
48
49 if (!style_info.tooltip.empty())
50 result->SetTooltipText(style_info.tooltip);
51 if (style_info.font_style != gfx::Font::NORMAL)
52 result->SetFont(result->font().DeriveFont(0, style_info.font_style));
53
54 return scoped_ptr<Label>(result.release());
55 }
56
57 } // namespace
58
RangeStyleInfo()59 StyledLabel::RangeStyleInfo::RangeStyleInfo()
60 : font_style(gfx::Font::NORMAL),
61 color(ui::NativeTheme::instance()->GetSystemColor(
62 ui::NativeTheme::kColorId_LabelEnabledColor)),
63 disable_line_wrapping(false),
64 is_link(false) {}
65
~RangeStyleInfo()66 StyledLabel::RangeStyleInfo::~RangeStyleInfo() {}
67
68 // static
CreateForLink()69 StyledLabel::RangeStyleInfo StyledLabel::RangeStyleInfo::CreateForLink() {
70 RangeStyleInfo result;
71 result.disable_line_wrapping = true;
72 result.is_link = true;
73 result.color = Link::GetDefaultEnabledColor();
74 return result;
75 }
76
operator <(const StyledLabel::StyleRange & other) const77 bool StyledLabel::StyleRange::operator<(
78 const StyledLabel::StyleRange& other) const {
79 // Intentionally reversed so the priority queue is sorted by smallest first.
80 return range.start() > other.range.start();
81 }
82
StyledLabel(const string16 & text,StyledLabelListener * listener)83 StyledLabel::StyledLabel(const string16& text, StyledLabelListener* listener)
84 : listener_(listener),
85 displayed_on_background_color_set_(false),
86 auto_color_readability_enabled_(true) {
87 TrimWhitespace(text, TRIM_TRAILING, &text_);
88 }
89
~StyledLabel()90 StyledLabel::~StyledLabel() {}
91
SetText(const string16 & text)92 void StyledLabel::SetText(const string16& text) {
93 text_ = text;
94 style_ranges_ = std::priority_queue<StyleRange>();
95 RemoveAllChildViews(true);
96 PreferredSizeChanged();
97 }
98
AddStyleRange(const gfx::Range & range,const RangeStyleInfo & style_info)99 void StyledLabel::AddStyleRange(const gfx::Range& range,
100 const RangeStyleInfo& style_info) {
101 DCHECK(!range.is_reversed());
102 DCHECK(!range.is_empty());
103 DCHECK(gfx::Range(0, text_.size()).Contains(range));
104
105 style_ranges_.push(StyleRange(range, style_info));
106
107 PreferredSizeChanged();
108 }
109
SetDefaultStyle(const RangeStyleInfo & style_info)110 void StyledLabel::SetDefaultStyle(const RangeStyleInfo& style_info) {
111 default_style_info_ = style_info;
112 PreferredSizeChanged();
113 }
114
SetDisplayedOnBackgroundColor(SkColor color)115 void StyledLabel::SetDisplayedOnBackgroundColor(SkColor color) {
116 displayed_on_background_color_ = color;
117 displayed_on_background_color_set_ = true;
118 }
119
GetInsets() const120 gfx::Insets StyledLabel::GetInsets() const {
121 gfx::Insets insets = View::GetInsets();
122 const gfx::Insets focus_border_padding(1, 1, 1, 1);
123 insets += focus_border_padding;
124 return insets;
125 }
126
GetHeightForWidth(int w)127 int StyledLabel::GetHeightForWidth(int w) {
128 if (w != calculated_size_.width())
129 calculated_size_ = gfx::Size(w, CalculateAndDoLayout(w, true));
130
131 return calculated_size_.height();
132 }
133
Layout()134 void StyledLabel::Layout() {
135 CalculateAndDoLayout(GetLocalBounds().width(), false);
136 }
137
PreferredSizeChanged()138 void StyledLabel::PreferredSizeChanged() {
139 calculated_size_ = gfx::Size();
140 View::PreferredSizeChanged();
141 }
142
LinkClicked(Link * source,int event_flags)143 void StyledLabel::LinkClicked(Link* source, int event_flags) {
144 if (listener_)
145 listener_->StyledLabelLinkClicked(link_targets_[source], event_flags);
146 }
147
CalculateAndDoLayout(int width,bool dry_run)148 int StyledLabel::CalculateAndDoLayout(int width, bool dry_run) {
149 if (!dry_run) {
150 RemoveAllChildViews(true);
151 link_targets_.clear();
152 }
153
154 width -= GetInsets().width();
155 if (width <= 0 || text_.empty())
156 return 0;
157
158 const int line_height = CalculateLineHeight();
159 // The index of the line we're on.
160 int line = 0;
161 // The x position (in pixels) of the line we're on, relative to content
162 // bounds.
163 int x = 0;
164
165 string16 remaining_string = text_;
166 std::priority_queue<StyleRange> style_ranges = style_ranges_;
167
168 // Iterate over the text, creating a bunch of labels and links and laying them
169 // out in the appropriate positions.
170 while (!remaining_string.empty()) {
171 // Don't put whitespace at beginning of a line with an exception for the
172 // first line (so the text's leading whitespace is respected).
173 if (x == 0 && line > 0)
174 TrimWhitespace(remaining_string, TRIM_LEADING, &remaining_string);
175
176 gfx::Range range(gfx::Range::InvalidRange());
177 if (!style_ranges.empty())
178 range = style_ranges.top().range;
179
180 const size_t position = text_.size() - remaining_string.size();
181
182 const gfx::Rect chunk_bounds(x, 0, width - x, 2 * line_height);
183 std::vector<string16> substrings;
184 gfx::FontList text_font_list;
185 // If the start of the remaining text is inside a styled range, the font
186 // style may differ from the base font. The font specified by the range
187 // should be used when eliding text.
188 if (position >= range.start()) {
189 text_font_list = text_font_list.DeriveFontListWithSizeDeltaAndStyle(
190 0, style_ranges.top().style_info.font_style);
191 }
192 gfx::ElideRectangleText(remaining_string,
193 text_font_list,
194 chunk_bounds.width(),
195 chunk_bounds.height(),
196 gfx::IGNORE_LONG_WORDS,
197 &substrings);
198
199 DCHECK(!substrings.empty());
200 string16 chunk = substrings[0];
201 if (chunk.empty()) {
202 // Nothing fits on this line. Start a new line.
203 // If x is 0, first line may have leading whitespace that doesn't fit in a
204 // single line, so try trimming those. Otherwise there is no room for
205 // anything; abort.
206 if (x == 0) {
207 if (line == 0) {
208 TrimWhitespace(remaining_string, TRIM_LEADING, &remaining_string);
209 continue;
210 }
211 break;
212 }
213
214 x = 0;
215 line++;
216 continue;
217 }
218
219 scoped_ptr<Label> label;
220 if (position >= range.start()) {
221 const RangeStyleInfo& style_info = style_ranges.top().style_info;
222
223 if (style_info.disable_line_wrapping && chunk.size() < range.length() &&
224 position == range.start() && x != 0) {
225 // If the chunk should not be wrapped, try to fit it entirely on the
226 // next line.
227 x = 0;
228 line++;
229 continue;
230 }
231
232 chunk = chunk.substr(0, std::min(chunk.size(), range.end() - position));
233
234 label = CreateLabelRange(chunk, style_info, this);
235
236 if (style_info.is_link && !dry_run)
237 link_targets_[label.get()] = range;
238
239 if (position + chunk.size() >= range.end())
240 style_ranges.pop();
241 } else {
242 // This chunk is normal text.
243 if (position + chunk.size() > range.start())
244 chunk = chunk.substr(0, range.start() - position);
245 label = CreateLabelRange(chunk, default_style_info_, this);
246 }
247
248 if (displayed_on_background_color_set_)
249 label->SetBackgroundColor(displayed_on_background_color_);
250 label->SetAutoColorReadabilityEnabled(auto_color_readability_enabled_);
251
252 // Lay out the views to overlap by 1 pixel to compensate for their border
253 // spacing. Otherwise, "<a>link</a>," will render as "link ,".
254 const int overlap = 1;
255 const gfx::Size view_size = label->GetPreferredSize();
256 DCHECK_EQ(line_height, view_size.height() - 2 * overlap);
257 if (!dry_run) {
258 label->SetBoundsRect(gfx::Rect(
259 gfx::Point(GetInsets().left() + x - overlap,
260 GetInsets().top() + line * line_height - overlap),
261 view_size));
262 AddChildView(label.release());
263 }
264 x += view_size.width() - 2 * overlap;
265
266 remaining_string = remaining_string.substr(chunk.size());
267 }
268
269 return (line + 1) * line_height + GetInsets().height();
270 }
271
272 } // namespace views
273