ui/message_center/views/bounded_label.cc

   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/message_center/views/bounded_label.h"
   6
   7 #include <limits>
   8
   9 #include "base/strings/string_util.h"
  10 #include "base/strings/utf_string_conversions.h"
  11 #include "ui/gfx/canvas.h"
  12 #include "ui/gfx/text_elider.h"
  13 #include "ui/gfx/text_utils.h"
  14 #include "ui/views/controls/label.h"
  15
  16 namespace {
  17
  18 const size_t kPreferredLinesCacheSize = 10;
  19
  20 }  // namespace
  21
  22 namespace message_center {
  23
  24 // InnerBoundedLabel ///////////////////////////////////////////////////////////
  25
  26 // InnerBoundedLabel is a views::Label subclass that does all of the work for
  27 // BoundedLabel. It is kept private to prevent outside code from calling a
  28 // number of views::Label methods like SetFontList() that break BoundedLabel's
  29 // caching but can't be overridden.
  30 //
  31 // TODO(dharcourt): Move the line limiting functionality to views::Label to make
  32 // this unnecessary.
  33
  34 class InnerBoundedLabel : public views::Label {
  35  public:
  36   InnerBoundedLabel(const BoundedLabel& owner);
  37   ~InnerBoundedLabel() override;
  38
  39   void SetNativeTheme(const ui::NativeTheme* theme);
  40
  41   // Pass in a -1 width to use the preferred width, a -1 limit to skip limits.
  42   int GetLinesForWidthAndLimit(int width, int limit);
  43   gfx::Size GetSizeForWidthAndLines(int width, int lines);
  44   std::vector<base::string16> GetWrappedText(int width, int lines);
  45
  46   // Overridden from views::Label.
  47   void SetText(const base::string16& new_text) override;
  48   void OnPaint(gfx::Canvas* canvas) override;
  49
  50  protected:
  51   // Overridden from views::Label.
  52   void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
  53
  54  private:
  55   int GetTextFlags();
  56
  57   void ClearCaches();
  58   int GetCachedLines(int width);
  59   void SetCachedLines(int width, int lines);
  60   gfx::Size GetCachedSize(const std::pair<int, int>& width_and_lines);
  61   void SetCachedSize(std::pair<int, int> width_and_lines, gfx::Size size);
  62
  63   const BoundedLabel* owner_;  // Weak reference.
  64   base::string16 wrapped_text_;
  65   int wrapped_text_width_;
  66   int wrapped_text_lines_;
  67   std::map<int, int> lines_cache_;
  68   std::list<int> lines_widths_;  // Most recently used in front.
  69   std::map<std::pair<int, int>, gfx::Size> size_cache_;
  70   std::list<std::pair<int, int> > size_widths_and_lines_;  // Recent in front.
  71
  72   DISALLOW_COPY_AND_ASSIGN(InnerBoundedLabel);
  73 };
  74
  75 InnerBoundedLabel::InnerBoundedLabel(const BoundedLabel& owner)
  76     : owner_(&owner),
  77       wrapped_text_width_(0),
  78       wrapped_text_lines_(0) {
  79   SetMultiLine(true);
  80   SetAllowCharacterBreak(true);
  81   SetHorizontalAlignment(gfx::ALIGN_LEFT);
  82   set_collapse_when_hidden(true);
  83 }
  84
  85 InnerBoundedLabel::~InnerBoundedLabel() {
  86 }
  87
  88 void InnerBoundedLabel::SetNativeTheme(const ui::NativeTheme* theme) {
  89   ClearCaches();
  90   OnNativeThemeChanged(theme);
  91 }
  92
  93 int InnerBoundedLabel::GetLinesForWidthAndLimit(int width, int limit) {
  94   if (width == 0 || limit == 0)
  95     return 0;
  96   int lines = GetCachedLines(width);
  97   if (lines == std::numeric_limits<int>::max()) {
  98     int text_width = std::max(width - owner_->GetInsets().width(), 0);
  99     lines = GetWrappedText(text_width, lines).size();
 100     SetCachedLines(width, lines);
 101   }
 102   return (limit < 0 || lines <= limit) ? lines : limit;
 103 }
 104
 105 gfx::Size InnerBoundedLabel::GetSizeForWidthAndLines(int width, int lines) {
 106   if (width == 0 || lines == 0)
 107     return gfx::Size();
 108   std::pair<int, int> key(width, lines);
 109   gfx::Size size = GetCachedSize(key);
 110   if (size.height() == std::numeric_limits<int>::max()) {
 111     gfx::Insets insets = owner_->GetInsets();
 112     int text_width = (width < 0) ? std::numeric_limits<int>::max() :
 113                                    std::max(width - insets.width(), 0);
 114     int text_height = std::numeric_limits<int>::max();
 115     std::vector<base::string16> wrapped = GetWrappedText(text_width, lines);
 116     gfx::Canvas::SizeStringInt(
 117         base::JoinString(wrapped, base::ASCIIToUTF16("\n")),
 118         font_list(), &text_width, &text_height, owner_->GetLineHeight(),
 119         GetTextFlags());
 120     size.set_width(text_width + insets.width());
 121     size.set_height(text_height + insets.height());
 122     SetCachedSize(key, size);
 123   }
 124   return size;
 125 }
 126
 127 std::vector<base::string16> InnerBoundedLabel::GetWrappedText(int width,
 128                                                               int lines) {
 129   // Short circuit simple case.
 130   if (width == 0 || lines == 0)
 131     return std::vector<base::string16>();
 132
 133   // Restrict line limit to ensure (lines + 1) * line_height <= INT_MAX and
 134   // use it to calculate a reasonable text height.
 135   int height = std::numeric_limits<int>::max();
 136   if (lines > 0) {
 137     int line_height = std::max(font_list().GetHeight(),
 138                                2);  // At least 2 pixels.
 139     int max_lines = std::numeric_limits<int>::max() / line_height - 1;
 140     lines = std::min(lines, max_lines);
 141     height = (lines + 1) * line_height;
 142   }
 143
 144   // Wrap, using INT_MAX for -1 widths that indicate no wrapping.
 145   std::vector<base::string16> wrapped;
 146   gfx::ElideRectangleText(text(), font_list(),
 147                           (width < 0) ? std::numeric_limits<int>::max() : width,
 148                           height, gfx::WRAP_LONG_WORDS, &wrapped);
 149
 150   // Elide if necessary.
 151   if (lines > 0 && wrapped.size() > static_cast<unsigned int>(lines)) {
 152     // Add an ellipsis to the last line. If this ellipsis makes the last line
 153     // too wide, that line will be further elided by the gfx::ElideText below,
 154     // so for example "ABC" could become "ABC..." and then "AB...".
 155     base::string16 last =
 156         wrapped[lines - 1] + base::UTF8ToUTF16(gfx::kEllipsis);
 157     if (width > 0 && gfx::GetStringWidth(last, font_list()) > width)
 158       last = gfx::ElideText(last, font_list(), width, gfx::ELIDE_TAIL);
 159     wrapped.resize(lines - 1);
 160     wrapped.push_back(last);
 161   }
 162
 163   return wrapped;
 164 }
 165
 166 void InnerBoundedLabel::OnBoundsChanged(const gfx::Rect& previous_bounds) {
 167   ClearCaches();
 168   views::Label::OnBoundsChanged(previous_bounds);
 169 }
 170
 171 void InnerBoundedLabel::OnPaint(gfx::Canvas* canvas) {
 172   views::Label::OnPaintBackground(canvas);
 173   views::Label::OnPaintBorder(canvas);
 174   int lines = owner_->GetLineLimit();
 175   int height = GetSizeForWidthAndLines(width(), lines).height();
 176   if (height > 0) {
 177     gfx::Rect bounds(width(), height);
 178     bounds.Inset(owner_->GetInsets());
 179     if (bounds.width() != wrapped_text_width_ || lines != wrapped_text_lines_) {
 180       wrapped_text_ = base::JoinString(GetWrappedText(bounds.width(), lines),
 181                                        base::ASCIIToUTF16("\n"));
 182       wrapped_text_width_ = bounds.width();
 183       wrapped_text_lines_ = lines;
 184     }
 185     bounds.set_x(GetMirroredXForRect(bounds));
 186     canvas->DrawStringRectWithFlags(
 187         wrapped_text_, font_list(), enabled_color(), bounds, GetTextFlags());
 188   }
 189 }
 190
 191 void InnerBoundedLabel::SetText(const base::string16& new_text) {
 192   if (text() == new_text)
 193     return;
 194   views::Label::SetText(new_text);
 195   ClearCaches();
 196 }
 197
 198 int InnerBoundedLabel::GetTextFlags() {
 199   int flags = gfx::Canvas::MULTI_LINE | gfx::Canvas::CHARACTER_BREAK;
 200
 201   // We can't use subpixel rendering if the background is non-opaque.
 202   if (SkColorGetA(background_color()) != 0xFF)
 203     flags |= gfx::Canvas::NO_SUBPIXEL_RENDERING;
 204
 205   return flags | gfx::Canvas::TEXT_ALIGN_TO_HEAD;
 206 }
 207
 208 void InnerBoundedLabel::ClearCaches() {
 209   wrapped_text_width_ = 0;
 210   wrapped_text_lines_ = 0;
 211   lines_cache_.clear();
 212   lines_widths_.clear();
 213   size_cache_.clear();
 214   size_widths_and_lines_.clear();
 215 }
 216
 217 int InnerBoundedLabel::GetCachedLines(int width) {
 218   int lines = std::numeric_limits<int>::max();
 219   std::map<int, int>::const_iterator found;
 220   if ((found = lines_cache_.find(width)) != lines_cache_.end()) {
 221     lines = found->second;
 222     lines_widths_.remove(width);
 223     lines_widths_.push_front(width);
 224   }
 225   return lines;
 226 }
 227
 228 void InnerBoundedLabel::SetCachedLines(int width, int lines) {
 229   if (lines_cache_.size() >= kPreferredLinesCacheSize) {
 230     lines_cache_.erase(lines_widths_.back());
 231     lines_widths_.pop_back();
 232   }
 233   lines_cache_[width] = lines;
 234   lines_widths_.push_front(width);
 235 }
 236
 237 gfx::Size InnerBoundedLabel::GetCachedSize(
 238     const std::pair<int, int>& width_and_lines) {
 239   gfx::Size size(width_and_lines.first, std::numeric_limits<int>::max());
 240   std::map<std::pair<int, int>, gfx::Size>::const_iterator found;
 241   if ((found = size_cache_.find(width_and_lines)) != size_cache_.end()) {
 242     size = found->second;
 243     size_widths_and_lines_.remove(width_and_lines);
 244     size_widths_and_lines_.push_front(width_and_lines);
 245   }
 246   return size;
 247 }
 248
 249 void InnerBoundedLabel::SetCachedSize(std::pair<int, int> width_and_lines,
 250                                       gfx::Size size) {
 251   if (size_cache_.size() >= kPreferredLinesCacheSize) {
 252     size_cache_.erase(size_widths_and_lines_.back());
 253     size_widths_and_lines_.pop_back();
 254   }
 255   size_cache_[width_and_lines] = size;
 256   size_widths_and_lines_.push_front(width_and_lines);
 257 }
 258
 259 // BoundedLabel ///////////////////////////////////////////////////////////
 260
 261 BoundedLabel::BoundedLabel(const base::string16& text,
 262                            const gfx::FontList& font_list)
 263     : line_limit_(-1) {
 264   label_.reset(new InnerBoundedLabel(*this));
 265   label_->SetFontList(font_list);
 266   label_->SetText(text);
 267 }
 268
 269 BoundedLabel::BoundedLabel(const base::string16& text)
 270     : line_limit_(-1) {
 271   label_.reset(new InnerBoundedLabel(*this));
 272   label_->SetText(text);
 273 }
 274
 275 BoundedLabel::~BoundedLabel() {
 276 }
 277
 278 void BoundedLabel::SetColors(SkColor textColor, SkColor backgroundColor) {
 279   label_->SetEnabledColor(textColor);
 280   label_->SetBackgroundColor(backgroundColor);
 281 }
 282
 283 void BoundedLabel::SetLineHeight(int height) {
 284   label_->SetLineHeight(height);
 285 }
 286
 287 void BoundedLabel::SetLineLimit(int lines) {
 288   line_limit_ = std::max(lines, -1);
 289 }
 290
 291 void BoundedLabel::SetText(const base::string16& text) {
 292   label_->SetText(text);
 293 }
 294
 295 int BoundedLabel::GetLineHeight() const {
 296   return label_->line_height();
 297 }
 298
 299 int BoundedLabel::GetLineLimit() const {
 300   return line_limit_;
 301 }
 302
 303 int BoundedLabel::GetLinesForWidthAndLimit(int width, int limit) {
 304   return visible() ? label_->GetLinesForWidthAndLimit(width, limit) : 0;
 305 }
 306
 307 gfx::Size BoundedLabel::GetSizeForWidthAndLines(int width, int lines) {
 308   return visible() ?
 309          label_->GetSizeForWidthAndLines(width, lines) : gfx::Size();
 310 }
 311
 312 int BoundedLabel::GetBaseline() const {
 313   return label_->GetBaseline();
 314 }
 315
 316 gfx::Size BoundedLabel::GetPreferredSize() const {
 317   return visible() ? label_->GetSizeForWidthAndLines(-1, -1) : gfx::Size();
 318 }
 319
 320 int BoundedLabel::GetHeightForWidth(int width) const {
 321   return visible() ?
 322          label_->GetSizeForWidthAndLines(width, line_limit_).height() : 0;
 323 }
 324
 325 void BoundedLabel::OnPaint(gfx::Canvas* canvas) {
 326   label_->OnPaint(canvas);
 327 }
 328
 329 bool BoundedLabel::CanProcessEventsWithinSubtree() const {
 330   return label_->CanProcessEventsWithinSubtree();
 331 }
 332
 333 void BoundedLabel::GetAccessibleState(ui::AXViewState* state) {
 334   label_->GetAccessibleState(state);
 335 }
 336
 337 void BoundedLabel::OnBoundsChanged(const gfx::Rect& previous_bounds) {
 338   label_->SetBoundsRect(bounds());
 339   views::View::OnBoundsChanged(previous_bounds);
 340 }
 341
 342 void BoundedLabel::OnNativeThemeChanged(const ui::NativeTheme* theme) {
 343   label_->SetNativeTheme(theme);
 344 }
 345
 346 base::string16 BoundedLabel::GetWrappedTextForTest(int width, int lines) {
 347   return base::JoinString(label_->GetWrappedText(width, lines),
 348                           base::ASCIIToUTF16("\n"));
 349 }
 350
 351 }  // namespace message_center