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 <map> 9 #include <queue> 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/range/range.h" 15 #include "ui/gfx/size.h" 16 #include "ui/views/controls/link_listener.h" 17 #include "ui/views/view.h" 18 19 namespace views { 20 21 class Link; 22 class StyledLabelListener; 23 24 // A class which can apply mixed styles to a block of text. Currently, text is 25 // always multiline. Trailing whitespace in the styled label text is not 26 // supported and will be trimmed on StyledLabel construction. Leading 27 // whitespace is respected, provided not only whitespace fits in the first line. 28 // In this case, leading whitespace is ignored. 29 class VIEWS_EXPORT StyledLabel : public View, public LinkListener { 30 public: 31 // Parameters that define label style for a styled label's text range. 32 struct VIEWS_EXPORT RangeStyleInfo { 33 RangeStyleInfo(); 34 ~RangeStyleInfo(); 35 36 // Creates a range style info with default values for link. 37 static RangeStyleInfo CreateForLink(); 38 39 // The font style that will be applied to the range. Should be a bitmask of 40 // values defined in gfx::Font::FontStyle (BOLD, ITALIC, UNDERLINE). 41 int font_style; 42 43 // The text color for the range. 44 SkColor color; 45 46 // Tooltip for the range. 47 string16 tooltip; 48 49 // If set, the whole range will be put on a single line. 50 bool disable_line_wrapping; 51 52 // If set, the range will be created as a link. 53 bool is_link; 54 }; 55 56 // Note that any trailing whitespace in |text| will be trimmed. 57 StyledLabel(const string16& text, StyledLabelListener* listener); 58 virtual ~StyledLabel(); 59 60 // Sets the text to be displayed, and clears any previous styling. 61 void SetText(const string16& text); 62 63 // Marks the given range within |text_| with style defined by |style_info|. 64 // |range| must be contained in |text_|. 65 void AddStyleRange(const gfx::Range& range, const RangeStyleInfo& style_info); 66 67 // Sets the default style to use for any part of the text that isn't within 68 // a range set by AddStyleRange. 69 void SetDefaultStyle(const RangeStyleInfo& style_info); 70 71 // Sets the color of the background on which the label is drawn. This won't 72 // be explicitly drawn, but the label will force the text color to be 73 // readable over it. 74 void SetDisplayedOnBackgroundColor(SkColor color); displayed_on_background_color()75 SkColor displayed_on_background_color() const { 76 return displayed_on_background_color_; 77 } 78 set_auto_color_readability_enabled(bool auto_color_readability)79 void set_auto_color_readability_enabled(bool auto_color_readability) { 80 auto_color_readability_enabled_ = auto_color_readability; 81 } 82 83 // View implementation: 84 virtual gfx::Insets GetInsets() const OVERRIDE; 85 virtual int GetHeightForWidth(int w) OVERRIDE; 86 virtual void Layout() OVERRIDE; 87 virtual void PreferredSizeChanged() OVERRIDE; 88 89 // LinkListener implementation: 90 virtual void LinkClicked(Link* source, int event_flags) OVERRIDE; 91 92 private: 93 struct StyleRange { StyleRangeStyleRange94 StyleRange(const gfx::Range& range, 95 const RangeStyleInfo& style_info) 96 : range(range), 97 style_info(style_info) { 98 } ~StyleRangeStyleRange99 ~StyleRange() {} 100 101 bool operator<(const StyleRange& other) const; 102 103 gfx::Range range; 104 RangeStyleInfo style_info; 105 }; 106 107 // Calculates how to layout child views, creates them and sets their size 108 // and position. |width| is the horizontal space, in pixels, that the view 109 // has to work with. If |dry_run| is true, the view hierarchy is not touched. 110 // The return value is the height in pixels. 111 int CalculateAndDoLayout(int width, bool dry_run); 112 113 // The text to display. 114 string16 text_; 115 116 // The default style to use for any part of the text that isn't within 117 // a range in |style_ranges_|. 118 RangeStyleInfo default_style_info_; 119 120 // The listener that will be informed of link clicks. 121 StyledLabelListener* listener_; 122 123 // The ranges that should be linkified, sorted by start position. 124 std::priority_queue<StyleRange> style_ranges_; 125 126 // A mapping from a view to the range it corresponds to in |text_|. Only views 127 // that correspond to ranges with is_link style set will be added to the map. 128 std::map<View*, gfx::Range> link_targets_; 129 130 // This variable saves the result of the last GetHeightForWidth call in order 131 // to avoid repeated calculation. 132 gfx::Size calculated_size_; 133 134 // Background color on which the label is drawn, for auto color readability. 135 SkColor displayed_on_background_color_; 136 bool displayed_on_background_color_set_; 137 138 // Controls whether the text is automatically re-colored to be readable on the 139 // background. 140 bool auto_color_readability_enabled_; 141 142 DISALLOW_COPY_AND_ASSIGN(StyledLabel); 143 }; 144 145 } // namespace views 146 147 #endif // UI_VIEWS_CONTROLS_STYLED_LABEL_H_ 148