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/base/text/text_elider.h"
  12 #include "ui/gfx/canvas.h"
  13 #include "ui/views/controls/label.h"
  14
  15 namespace {
  16
  17 const size_t kPreferredLinesCacheSize = 10;
  18 const size_t kPreferredSizeCacheSize = 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 setFont() 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   virtual ~InnerBoundedLabel();
  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<string16> GetWrappedText(int width, int lines);
  45
  46  protected:
  47   // Overridden from views::Label.
  48   virtual void OnBoundsChanged(const gfx::Rect& previous_bounds) OVERRIDE;
  49   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
  50
  51  private:
  52   int GetTextFlags();
  53
  54   void ClearCaches();
  55   int GetCachedLines(int width);
  56   void SetCachedLines(int width, int lines);
  57   gfx::Size GetCachedSize(const std::pair<int, int>& width_and_lines);
  58   void SetCachedSize(std::pair<int, int> width_and_lines, gfx::Size size);
  59
  60   const BoundedLabel* owner_;  // Weak reference.
  61   string16 wrapped_text_;
  62   int wrapped_text_width_;
  63   int wrapped_text_lines_;
  64   std::map<int, int> lines_cache_;
  65   std::list<int> lines_widths_;  // Most recently used in front.
  66   std::map<std::pair<int, int>, gfx::Size> size_cache_;
  67   std::list<std::pair<int, int> > size_widths_and_lines_;  // Recent in front.
  68
  69   DISALLOW_COPY_AND_ASSIGN(InnerBoundedLabel);
  70 };
  71
  72 InnerBoundedLabel::InnerBoundedLabel(const BoundedLabel& owner)
  73     : owner_(&owner),
  74       wrapped_text_width_(0),
  75       wrapped_text_lines_(0) {
  76   SetMultiLine(true);
  77   SetAllowCharacterBreak(true);
  78   SetHorizontalAlignment(gfx::ALIGN_LEFT);
  79   set_collapse_when_hidden(true);
  80 }
  81
  82 InnerBoundedLabel::~InnerBoundedLabel() {
  83 }
  84
  85 void InnerBoundedLabel::SetNativeTheme(const ui::NativeTheme* theme) {
  86   ClearCaches();
  87   OnNativeThemeChanged(theme);
  88 }
  89
  90 int InnerBoundedLabel::GetLinesForWidthAndLimit(int width, int limit) {
  91   if (width == 0 || limit == 0)
  92     return 0;
  93   int lines = GetCachedLines(width);
  94   if (lines == std::numeric_limits<int>::max()) {
  95     int text_width = std::max(width - owner_->GetInsets().width(), 0);
  96     lines = GetWrappedText(text_width, lines).size();
  97     SetCachedLines(width, lines);
  98   }
  99   return (limit < 0 || lines <= limit) ? lines : limit;
 100 }
 101
 102 gfx::Size InnerBoundedLabel::GetSizeForWidthAndLines(int width, int lines) {
 103   if (width == 0 || lines == 0)
 104     return gfx::Size();
 105   std::pair<int, int> key(width, lines);
 106   gfx::Size size = GetCachedSize(key);
 107   if (size.height() == std::numeric_limits<int>::max()) {
 108     gfx::Insets insets = owner_->GetInsets();
 109     int text_width = (width < 0) ? std::numeric_limits<int>::max() :
 110                                    std::max(width - insets.width(), 0);
 111     int text_height = std::numeric_limits<int>::max();
 112     std::vector<string16> wrapped = GetWrappedText(text_width, lines);
 113     gfx::Canvas::SizeStringInt(JoinString(wrapped, '\n'), font(),
 114                                &text_width, &text_height,
 115                                owner_->GetLineHeight(),
 116                                GetTextFlags());
 117     size.set_width(text_width + insets.width());
 118     size.set_height(text_height + insets.height());
 119     SetCachedSize(key, size);
 120   }
 121   return size;
 122 }
 123
 124 std::vector<string16> InnerBoundedLabel::GetWrappedText(int width, int lines) {
 125   // Short circuit simple case.
 126   if (width == 0 || lines == 0)
 127     return std::vector<string16>();
 128
 129   // Restrict line limit to ensure (lines + 1) * line_height <= INT_MAX and
 130   // use it to calculate a reasonable text height.
 131   int height = std::numeric_limits<int>::max();
 132   if (lines > 0) {
 133     int line_height = std::max(font().GetHeight(), 2);  // At least 2 pixels.
 134     int max_lines = std::numeric_limits<int>::max() / line_height - 1;
 135     lines = std::min(lines, max_lines);
 136     height = (lines + 1) * line_height;
 137   }
 138
 139   // Try to ensure that the width is no smaller than the width of the text's
 140   // characters to avoid the http://crbug.com/237700 infinite loop.
 141   // TODO(dharcourt): Remove when http://crbug.com/237700 is fixed.
 142   width = std::max(width, 2 * font().GetStringWidth(UTF8ToUTF16("W")));
 143
 144   // Wrap, using INT_MAX for -1 widths that indicate no wrapping.
 145   std::vector<string16> wrapped;
 146   ui::ElideRectangleText(text(), font(),
 147                          (width < 0) ? std::numeric_limits<int>::max() : width,
 148                          height, ui::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 ui::ElideText below,
 154     // so for example "ABC" could become "ABC..." and then "AB...".
 155     string16 last = wrapped[lines - 1] + UTF8ToUTF16(ui::kEllipsis);
 156     if (width > 0 && font().GetStringWidth(last) > width)
 157       last = ui::ElideText(last, font(), width, ui::ELIDE_AT_END);
 158     wrapped.resize(lines - 1);
 159     wrapped.push_back(last);
 160   }
 161
 162   return wrapped;
 163 }
 164
 165 void InnerBoundedLabel::OnBoundsChanged(const gfx::Rect& previous_bounds) {
 166   ClearCaches();
 167   views::Label::OnBoundsChanged(previous_bounds);
 168 }
 169
 170 void InnerBoundedLabel::OnPaint(gfx::Canvas* canvas) {
 171   views::Label::OnPaintBackground(canvas);
 172   views::Label::OnPaintFocusBorder(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_ = JoinString(GetWrappedText(bounds.width(), lines), '\n');
 181       wrapped_text_width_ = bounds.width();
 182       wrapped_text_lines_ = lines;
 183     }
 184     bounds.set_x(GetMirroredXForRect(bounds));
 185     PaintText(canvas, wrapped_text_, bounds, GetTextFlags());
 186   }
 187 }
 188
 189 int InnerBoundedLabel::GetTextFlags() {
 190   int flags = gfx::Canvas::MULTI_LINE | gfx::Canvas::CHARACTER_BREAK;
 191
 192   // We can't use subpixel rendering if the background is non-opaque.
 193   if (SkColorGetA(background_color()) != 0xFF)
 194     flags |= gfx::Canvas::NO_SUBPIXEL_RENDERING;
 195
 196   if (directionality_mode() ==
 197       views::Label::AUTO_DETECT_DIRECTIONALITY) {
 198     base::i18n::TextDirection direction =
 199         base::i18n::GetFirstStrongCharacterDirection(text());
 200     if (direction == base::i18n::RIGHT_TO_LEFT)
 201       flags |= gfx::Canvas::FORCE_RTL_DIRECTIONALITY;
 202     else
 203       flags |= gfx::Canvas::FORCE_LTR_DIRECTIONALITY;
 204   }
 205
 206   return flags;
 207 }
 208
 209 void InnerBoundedLabel::ClearCaches() {
 210   wrapped_text_width_ = 0;
 211   wrapped_text_lines_ = 0;
 212   lines_cache_.clear();
 213   lines_widths_.clear();
 214   size_cache_.clear();
 215   size_widths_and_lines_.clear();
 216 }
 217
 218 int InnerBoundedLabel::GetCachedLines(int width) {
 219   int lines = std::numeric_limits<int>::max();
 220   std::map<int, int>::const_iterator found;
 221   if ((found = lines_cache_.find(width)) != lines_cache_.end()) {
 222     lines = found->second;
 223     lines_widths_.remove(width);
 224     lines_widths_.push_front(width);
 225   }
 226   return lines;
 227 }
 228
 229 void InnerBoundedLabel::SetCachedLines(int width, int lines) {
 230   if (lines_cache_.size() >= kPreferredLinesCacheSize) {
 231     lines_cache_.erase(lines_widths_.back());
 232     lines_widths_.pop_back();
 233   }
 234   lines_cache_[width] = lines;
 235   lines_widths_.push_front(width);
 236 }
 237
 238 gfx::Size InnerBoundedLabel::GetCachedSize(
 239     const std::pair<int, int>& width_and_lines) {
 240   gfx::Size size(width_and_lines.first, std::numeric_limits<int>::max());
 241   std::map<std::pair<int, int>, gfx::Size>::const_iterator found;
 242   if ((found = size_cache_.find(width_and_lines)) != size_cache_.end()) {
 243     size = found->second;
 244     size_widths_and_lines_.remove(width_and_lines);
 245     size_widths_and_lines_.push_front(width_and_lines);
 246   }
 247   return size;
 248 }
 249
 250 void InnerBoundedLabel::SetCachedSize(std::pair<int, int> width_and_lines,
 251                                       gfx::Size size) {
 252   if (size_cache_.size() >= kPreferredLinesCacheSize) {
 253     size_cache_.erase(size_widths_and_lines_.back());
 254     size_widths_and_lines_.pop_back();
 255   }
 256   size_cache_[width_and_lines] = size;
 257   size_widths_and_lines_.push_front(width_and_lines);
 258 }
 259
 260 // BoundedLabel ///////////////////////////////////////////////////////////
 261
 262 BoundedLabel::BoundedLabel(const string16& text, gfx::Font font)
 263     : line_limit_(-1) {
 264   label_.reset(new InnerBoundedLabel(*this));
 265   label_->SetFont(font);
 266   label_->SetText(text);
 267 }
 268
 269 BoundedLabel::BoundedLabel(const 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 int BoundedLabel::GetLineHeight() const {
 292   return label_->line_height();
 293 }
 294
 295 int BoundedLabel::GetLineLimit() const {
 296   return line_limit_;
 297 }
 298
 299 int BoundedLabel::GetLinesForWidthAndLimit(int width, int limit) {
 300   return visible() ? label_->GetLinesForWidthAndLimit(width, limit) : 0;
 301 }
 302
 303 gfx::Size BoundedLabel::GetSizeForWidthAndLines(int width, int lines) {
 304   return visible() ?
 305          label_->GetSizeForWidthAndLines(width, lines) : gfx::Size();
 306 }
 307
 308 int BoundedLabel::GetBaseline() const {
 309   return label_->GetBaseline();
 310 }
 311
 312 gfx::Size BoundedLabel::GetPreferredSize() {
 313   return visible() ? label_->GetSizeForWidthAndLines(-1, -1) : gfx::Size();
 314 }
 315
 316 int BoundedLabel::GetHeightForWidth(int width) {
 317   return visible() ?
 318          label_->GetSizeForWidthAndLines(width, line_limit_).height() : 0;
 319 }
 320
 321 void BoundedLabel::Paint(gfx::Canvas* canvas) {
 322   if (visible())
 323     label_->Paint(canvas);
 324 }
 325
 326 bool BoundedLabel::HitTestRect(const gfx::Rect& rect) const {
 327   return label_->HitTestRect(rect);
 328 }
 329
 330 void BoundedLabel::GetAccessibleState(ui::AccessibleViewState* state) {
 331   label_->GetAccessibleState(state);
 332 }
 333
 334 void BoundedLabel::OnBoundsChanged(const gfx::Rect& previous_bounds) {
 335   label_->SetBoundsRect(bounds());
 336   views::View::OnBoundsChanged(previous_bounds);
 337 }
 338
 339 void BoundedLabel::OnNativeThemeChanged(const ui::NativeTheme* theme) {
 340   label_->SetNativeTheme(theme);
 341 }
 342
 343 string16 BoundedLabel::GetWrappedTextForTest(int width, int lines) {
 344   return JoinString(label_->GetWrappedText(width, lines), '\n');
 345 }
 346
 347 }  // namespace message_center