ui/views/corewm/tooltip_aura.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/views/corewm/tooltip_aura.h"
   6
   7 #include "base/strings/string_split.h"
   8 #include "ui/aura/window.h"
   9 #include "ui/aura/window_tree_host.h"
  10 #include "ui/gfx/screen.h"
  11 #include "ui/gfx/text_elider.h"
  12 #include "ui/gfx/text_utils.h"
  13 #include "ui/native_theme/native_theme.h"
  14 #include "ui/views/background.h"
  15 #include "ui/views/border.h"
  16 #include "ui/views/widget/widget.h"
  17
  18 namespace {
  19
  20 const int kTooltipHorizontalPadding = 3;
  21
  22 // Max visual tooltip width. If a tooltip is greater than this width, it will
  23 // be wrapped.
  24 const int kTooltipMaxWidthPixels = 400;
  25
  26 const size_t kMaxLines = 10;
  27
  28 // TODO(derat): This padding is needed on Chrome OS devices but seems excessive
  29 // when running the same binary on a Linux workstation; presumably there's a
  30 // difference in font metrics.  Rationalize this.
  31 const int kTooltipVerticalPadding = 2;
  32
  33 // FIXME: get cursor offset from actual cursor size.
  34 const int kCursorOffsetX = 10;
  35 const int kCursorOffsetY = 15;
  36
  37 // Creates a widget of type TYPE_TOOLTIP
  38 views::Widget* CreateTooltipWidget(aura::Window* tooltip_window) {
  39   views::Widget* widget = new views::Widget;
  40   views::Widget::InitParams params;
  41   // For aura, since we set the type to TYPE_TOOLTIP, the widget will get
  42   // auto-parented to the right container.
  43   params.type = views::Widget::InitParams::TYPE_TOOLTIP;
  44   params.context = tooltip_window;
  45   DCHECK(params.context);
  46   params.keep_on_top = true;
  47   params.accept_events = false;
  48   widget->Init(params);
  49   return widget;
  50 }
  51
  52 }  // namespace
  53
  54 namespace views {
  55 namespace corewm {
  56
  57 TooltipAura::TooltipAura(gfx::ScreenType screen_type)
  58     : screen_type_(screen_type),
  59       widget_(NULL),
  60       tooltip_window_(NULL) {
  61   label_.set_owned_by_client();
  62   label_.SetMultiLine(true);
  63 }
  64
  65 TooltipAura::~TooltipAura() {
  66   DestroyWidget();
  67 }
  68
  69 // static
  70 void TooltipAura::TrimTooltipToFit(const gfx::FontList& font_list,
  71                                    int max_width,
  72                                    base::string16* text,
  73                                    int* width,
  74                                    int* line_count) {
  75   *width = 0;
  76   *line_count = 0;
  77
  78   // Determine the available width for the tooltip.
  79   int available_width = std::min(kTooltipMaxWidthPixels, max_width);
  80
  81   std::vector<base::string16> lines;
  82   base::SplitString(*text, '\n', &lines);
  83   std::vector<base::string16> result_lines;
  84
  85   // Format each line to fit.
  86   for (std::vector<base::string16>::iterator l = lines.begin();
  87        l != lines.end(); ++l) {
  88     // We break the line at word boundaries, then stuff as many words as we can
  89     // in the available width to the current line, and move the remaining words
  90     // to a new line.
  91     std::vector<base::string16> words;
  92     base::SplitStringDontTrim(*l, ' ', &words);
  93     int current_width = 0;
  94     base::string16 line;
  95     for (std::vector<base::string16>::iterator w = words.begin();
  96          w != words.end(); ++w) {
  97       base::string16 word = *w;
  98       if (w + 1 != words.end())
  99         word.push_back(' ');
 100       int word_width = gfx::GetStringWidth(word, font_list);
 101       if (current_width + word_width > available_width) {
 102         // Current width will exceed the available width. Must start a new line.
 103         if (!line.empty())
 104           result_lines.push_back(line);
 105         current_width = 0;
 106         line.clear();
 107       }
 108       current_width += word_width;
 109       line.append(word);
 110     }
 111     result_lines.push_back(line);
 112   }
 113
 114   // Clamp number of lines to |kMaxLines|.
 115   if (result_lines.size() > kMaxLines) {
 116     result_lines.resize(kMaxLines);
 117     // Add ellipses character to last line.
 118     result_lines[kMaxLines - 1] = gfx::TruncateString(
 119         result_lines.back(), result_lines.back().length() - 1, gfx::WORD_BREAK);
 120   }
 121   *line_count = result_lines.size();
 122
 123   // Flatten the result.
 124   base::string16 result;
 125   for (std::vector<base::string16>::iterator l = result_lines.begin();
 126       l != result_lines.end(); ++l) {
 127     if (!result.empty())
 128       result.push_back('\n');
 129     int line_width = gfx::GetStringWidth(*l, font_list);
 130     // Since we only break at word boundaries, it could happen that due to some
 131     // very long word, line_width is greater than the available_width. In such
 132     // case, we simply truncate at available_width and add ellipses at the end.
 133     if (line_width > available_width) {
 134       *width = available_width;
 135       result.append(gfx::ElideText(*l, font_list, available_width,
 136                                    gfx::ELIDE_TAIL));
 137     } else {
 138       *width = std::max(*width, line_width);
 139       result.append(*l);
 140     }
 141   }
 142   *text = result;
 143 }
 144
 145 int TooltipAura::GetMaxWidth(const gfx::Point& location) const {
 146   // TODO(varunjain): implementation duplicated in tooltip_manager_aura. Figure
 147   // out a way to merge.
 148   gfx::Screen* screen = gfx::Screen::GetScreenByType(screen_type_);
 149   gfx::Rect display_bounds(screen->GetDisplayNearestPoint(location).bounds());
 150   return (display_bounds.width() + 1) / 2;
 151 }
 152
 153 void TooltipAura::SetTooltipBounds(const gfx::Point& mouse_pos,
 154                                    int tooltip_width,
 155                                    int tooltip_height) {
 156   gfx::Rect tooltip_rect(mouse_pos.x(), mouse_pos.y(), tooltip_width,
 157                          tooltip_height);
 158
 159   tooltip_rect.Offset(kCursorOffsetX, kCursorOffsetY);
 160   gfx::Screen* screen = gfx::Screen::GetScreenByType(screen_type_);
 161   gfx::Rect display_bounds(screen->GetDisplayNearestPoint(mouse_pos).bounds());
 162
 163   // If tooltip is out of bounds on the x axis, we simply shift it
 164   // horizontally by the offset.
 165   if (tooltip_rect.right() > display_bounds.right()) {
 166     int h_offset = tooltip_rect.right() - display_bounds.right();
 167     tooltip_rect.Offset(-h_offset, 0);
 168   }
 169
 170   // If tooltip is out of bounds on the y axis, we flip it to appear above the
 171   // mouse cursor instead of below.
 172   if (tooltip_rect.bottom() > display_bounds.bottom())
 173     tooltip_rect.set_y(mouse_pos.y() - tooltip_height);
 174
 175   tooltip_rect.AdjustToFit(display_bounds);
 176   widget_->SetBounds(tooltip_rect);
 177 }
 178
 179 void TooltipAura::DestroyWidget() {
 180   if (widget_) {
 181     widget_->RemoveObserver(this);
 182     widget_->Close();
 183     widget_ = NULL;
 184   }
 185 }
 186
 187 void TooltipAura::SetText(aura::Window* window,
 188                           const base::string16& tooltip_text,
 189                           const gfx::Point& location) {
 190   tooltip_window_ = window;
 191   int max_width, line_count;
 192   base::string16 trimmed_text(tooltip_text);
 193   TrimTooltipToFit(label_.font_list(), GetMaxWidth(location), &trimmed_text,
 194                    &max_width, &line_count);
 195   label_.SetText(trimmed_text);
 196
 197   int width = max_width + 2 * kTooltipHorizontalPadding;
 198   int height = label_.GetHeightForWidth(max_width) +
 199       2 * kTooltipVerticalPadding;
 200
 201   if (!widget_) {
 202     widget_ = CreateTooltipWidget(tooltip_window_);
 203     widget_->SetContentsView(&label_);
 204     widget_->AddObserver(this);
 205   }
 206
 207   SetTooltipBounds(location, width, height);
 208
 209   ui::NativeTheme* native_theme = widget_->GetNativeTheme();
 210   label_.set_background(
 211       views::Background::CreateSolidBackground(
 212           native_theme->GetSystemColor(
 213               ui::NativeTheme::kColorId_TooltipBackground)));
 214
 215   label_.SetAutoColorReadabilityEnabled(false);
 216   label_.SetEnabledColor(native_theme->GetSystemColor(
 217       ui::NativeTheme::kColorId_TooltipText));
 218 }
 219
 220 void TooltipAura::Show() {
 221   if (widget_) {
 222     widget_->Show();
 223     widget_->StackAtTop();
 224   }
 225 }
 226
 227 void TooltipAura::Hide() {
 228   tooltip_window_ = NULL;
 229   if (widget_)
 230     widget_->Hide();
 231 }
 232
 233 bool TooltipAura::IsVisible() {
 234   return widget_ && widget_->IsVisible();
 235 }
 236
 237 void TooltipAura::OnWidgetDestroying(views::Widget* widget) {
 238   DCHECK_EQ(widget_, widget);
 239   widget_ = NULL;
 240   tooltip_window_ = NULL;
 241 }
 242
 243 }  // namespace corewm
 244 }  // namespace views