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 #ifndef UI_VIEWS_CONTROLS_STYLED_LABEL_H_ 6 #define UI_VIEWS_CONTROLS_STYLED_LABEL_H_ 7 8 #include <list> 9 #include <map> 10 11 #include "base/basictypes.h" 12 #include "base/strings/string16.h" 13 #include "third_party/skia/include/core/SkColor.h" 14 #include "ui/gfx/font_list.h" 15 #include "ui/gfx/range/range.h" 16 #include "ui/gfx/size.h" 17 #include "ui/views/controls/link_listener.h" 18 #include "ui/views/view.h" 19 20 namespace views { 21 22 class Link; 23 class StyledLabelListener; 24 25 // A class which can apply mixed styles to a block of text. Currently, text is 26 // always multiline. Trailing whitespace in the styled label text is not 27 // supported and will be trimmed on StyledLabel construction. Leading 28 // whitespace is respected, provided not only whitespace fits in the first line. 29 // In this case, leading whitespace is ignored. 30 class VIEWS_EXPORT StyledLabel : public View, public LinkListener { 31 public: 32 // Parameters that define label style for a styled label's text range. 33 struct VIEWS_EXPORT RangeStyleInfo { 34 RangeStyleInfo(); 35 ~RangeStyleInfo(); 36 37 // Creates a range style info with default values for link. 38 static RangeStyleInfo CreateForLink(); 39 40 // The font style that will be applied to the range. Should be a bitmask of 41 // values defined in gfx::Font::FontStyle (BOLD, ITALIC, UNDERLINE). 42 int font_style; 43 44 // The text color for the range. 45 SkColor color; 46 47 // Tooltip for the range. 48 base::string16 tooltip; 49 50 // If set, the whole range will be put on a single line. 51 bool disable_line_wrapping; 52 53 // If set, the range will be created as a link. 54 bool is_link; 55 }; 56 57 // Note that any trailing whitespace in |text| will be trimmed. 58 StyledLabel(const base::string16& text, StyledLabelListener* listener); 59 virtual ~StyledLabel(); 60 61 // Sets the text to be displayed, and clears any previous styling. 62 void SetText(const base::string16& text); 63 64 // Sets the fonts used by all labels. Can be augemented by styling set by 65 // AddStyleRange and SetDefaultStyle. 66 void SetBaseFontList(const gfx::FontList& font_list); 67 68 // Marks the given range within |text_| with style defined by |style_info|. 69 // |range| must be contained in |text_|. 70 void AddStyleRange(const gfx::Range& range, const RangeStyleInfo& style_info); 71 72 // Sets the default style to use for any part of the text that isn't within 73 // a range set by AddStyleRange. 74 void SetDefaultStyle(const RangeStyleInfo& style_info); 75 76 // Sets the color of the background on which the label is drawn. This won't 77 // be explicitly drawn, but the label will force the text color to be 78 // readable over it. 79 void SetDisplayedOnBackgroundColor(SkColor color); displayed_on_background_color()80 SkColor displayed_on_background_color() const { 81 return displayed_on_background_color_; 82 } 83 set_auto_color_readability_enabled(bool auto_color_readability)84 void set_auto_color_readability_enabled(bool auto_color_readability) { 85 auto_color_readability_enabled_ = auto_color_readability; 86 } 87 88 // View implementation: 89 virtual gfx::Insets GetInsets() const OVERRIDE; 90 virtual int GetHeightForWidth(int w) const OVERRIDE; 91 virtual void Layout() OVERRIDE; 92 virtual void PreferredSizeChanged() OVERRIDE; 93 94 // LinkListener implementation: 95 virtual void LinkClicked(Link* source, int event_flags) OVERRIDE; 96 97 private: 98 struct StyleRange { StyleRangeStyleRange99 StyleRange(const gfx::Range& range, 100 const RangeStyleInfo& style_info) 101 : range(range), 102 style_info(style_info) { 103 } ~StyleRangeStyleRange104 ~StyleRange() {} 105 106 bool operator<(const StyleRange& other) const; 107 108 gfx::Range range; 109 RangeStyleInfo style_info; 110 }; 111 typedef std::list<StyleRange> StyleRanges; 112 113 // Calculates how to layout child views, creates them and sets their size 114 // and position. |width| is the horizontal space, in pixels, that the view 115 // has to work with. If |dry_run| is true, the view hierarchy is not touched. 116 // The return value is the necessary size. 117 gfx::Size CalculateAndDoLayout(int width, bool dry_run); 118 119 // The text to display. 120 base::string16 text_; 121 122 // Fonts used to display text. Can be augmented by RangeStyleInfo. 123 gfx::FontList font_list_; 124 125 // The default style to use for any part of the text that isn't within 126 // a range in |style_ranges_|. 127 RangeStyleInfo default_style_info_; 128 129 // The listener that will be informed of link clicks. 130 StyledLabelListener* listener_; 131 132 // The ranges that should be linkified, sorted by start position. 133 StyleRanges style_ranges_; 134 135 // A mapping from a view to the range it corresponds to in |text_|. Only views 136 // that correspond to ranges with is_link style set will be added to the map. 137 std::map<View*, gfx::Range> link_targets_; 138 139 // This variable saves the result of the last GetHeightForWidth call in order 140 // to avoid repeated calculation. 141 mutable gfx::Size calculated_size_; 142 143 // Background color on which the label is drawn, for auto color readability. 144 SkColor displayed_on_background_color_; 145 bool displayed_on_background_color_set_; 146 147 // Controls whether the text is automatically re-colored to be readable on the 148 // background. 149 bool auto_color_readability_enabled_; 150 151 DISALLOW_COPY_AND_ASSIGN(StyledLabel); 152 }; 153 154 } // namespace views 155 156 #endif // UI_VIEWS_CONTROLS_STYLED_LABEL_H_ 157