Make views::Label and views::Link auto-color themselves to be readable over their background colo...

views/controls/label.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef VIEWS_CONTROLS_LABEL_H_
 #define VIEWS_CONTROLS_LABEL_H_
 #pragma once
 
 #include <string>
 
@@ skipping 57 matching lines @@
 
   // Return the label text.
   const string16 GetText() const;
 
   // Set URL Value - text_ is set to spec().
   void SetURL(const GURL& url);
 
   // Return the label URL.
   const GURL GetURL() const;
 
-  // Set the color
-  virtual void SetColor(const SkColor& color);
+  // Enables or disables auto-color-readability (enabled by default).  If this
+  // is enabled, then calls to set any foreground or background color will
+  // trigger an automatic mapper that uses color_utils::GetReadableColor() to
+  // ensure that the foreground colors are readable over the background color.
+  void SetAutoColorReadabilityEnabled(bool enabled);
 
-  // Return a reference to the currently used color.
-  virtual SkColor GetColor() const;
+  // Set the color.  This will automatically force the color to be readable
+  // over the current background color.
+  virtual void SetEnabledColor(const SkColor& color);
+  void SetDisabledColor(const SkColor& color);
 
-  // If you'll be displaying the label over some non-system background color,
-  // call this with the relevant color and the label will auto-set its color to
-  // be readable.
-  virtual void MakeReadableOverBackgroundColor(const SkColor& background_color);
+  SkColor enabled_color() const { return actual_enabled_color_; }
+
+  // Set the background color.  This won't be explicitly drawn, but the label
+  // will force the text color to be readable over it.
+  void SetBackgroundColor(const SkColor& color);
 
   // Set horizontal alignment. If the locale is RTL, and the RTL alignment
   // setting is set as USE_UI_ALIGNMENT, the alignment is flipped around.
   //
   // Caveat: for labels originating from a web page, the RTL alignment mode
   // should be reset to AUTO_DETECT_ALIGNMENT before the horizontal alignment
   // is set. Otherwise, the label's alignment specified as a parameter will be
   // flipped in RTL locales. Please see the comments in SetRTLAlignmentMode for
   // more information.
   void SetHorizontalAlignment(Alignment alignment);
@@ skipping 63 matching lines @@
 
   // Overridden from View:
   virtual gfx::Insets GetInsets() const;
   virtual int GetBaseline() const OVERRIDE;
   // Overridden to compute the size required to display this label.
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   // Return the height necessary to display this label with the provided width.
   // This method is used to layout multi-line labels. It is equivalent to
   // GetPreferredSize().height() if the receiver is not multi-line.
   virtual int GetHeightForWidth(int w);
-  // Sets the enabled state. Setting the enabled state resets the color.
-  virtual void OnEnabledChanged() OVERRIDE;
   virtual std::string GetClassName() const OVERRIDE;
   virtual bool HitTest(const gfx::Point& l) const OVERRIDE;
   // Mouse enter/exit are overridden to render mouse over background color.
   // These invoke SetContainsMouse as necessary.
   virtual void OnMouseMoved(const MouseEvent& event) OVERRIDE;
   virtual void OnMouseEntered(const MouseEvent& event) OVERRIDE;
   virtual void OnMouseExited(const MouseEvent& event) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
   // Gets the tooltip text for labels that are wider than their bounds, except
   // when the label is multiline, in which case it just returns false (no
   // tooltip).  If a custom tooltip has been specified with SetTooltipText()
   // it is returned instead.
   virtual bool GetTooltipText(const gfx::Point& p, string16* tooltip) OVERRIDE;
 
  protected:
   // Called by Paint to paint the text.  Override this to change how
   // text is painted.
   virtual void PaintText(gfx::Canvas* canvas,
                          const string16& text,
                          const gfx::Rect& text_bounds,
                          int flags);
 
   void invalidate_text_size() { text_size_valid_ = false; }
 
   virtual gfx::Size GetTextSize() const;
 
+  SkColor disabled_color() const { return actual_disabled_color_; }
+
   // Overridden from View:
   // Overridden to dirty our text bounds if we're multi-line.
   virtual void OnBoundsChanged(const gfx::Rect& previous_bounds) OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
   // If the mouse is over the label, and a mouse over background has been
   // specified, its used. Otherwise super's implementation is invoked.
   virtual void OnPaintBackground(gfx::Canvas* canvas) OVERRIDE;
 
  private:
   // These tests call CalculateDrawStringParams in order to verify the
   // calculations done for drawing text.
   FRIEND_TEST_ALL_PREFIXES(LabelTest, DrawSingleLineString);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, DrawMultiLineString);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, DrawSingleLineStringInRTL);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, DrawMultiLineStringInRTL);
 
   static gfx::Font GetDefaultFont();
 
   void Init(const string16& text, const gfx::Font& font);
 
+  void RecalculateColors();
+
   // If the mouse is over the text, SetContainsMouse(true) is invoked, otherwise
   // SetContainsMouse(false) is invoked.
   void UpdateContainsMouse(const MouseEvent& event);
 
   // Updates whether the mouse is contained in the Label. If the new value
   // differs from the current value, and a mouse over background is specified,
   // SchedulePaint is invoked.
   void SetContainsMouse(bool contains_mouse);
 
   // Returns where the text is drawn, in the receivers coordinate system.
   gfx::Rect GetTextBounds() const;
 
   int ComputeMultiLineFlags() const;
 
   gfx::Rect GetAvailableRect() const;
 
   // Returns parameters to be used for the DrawString call.
   void CalculateDrawStringParams(string16* paint_text,
                                  gfx::Rect* text_bounds,
                                  int* flags) const;
 
   string16 text_;
   GURL url_;
   gfx::Font font_;
-  SkColor color_;
+  SkColor requested_enabled_color_;
+  SkColor actual_enabled_color_;
+  SkColor requested_disabled_color_;
+  SkColor actual_disabled_color_;
+  SkColor background_color_;
+  bool auto_color_readability_;
   mutable gfx::Size text_size_;
   mutable bool text_size_valid_;
   bool is_multi_line_;
   bool allow_character_break_;
   bool elide_in_middle_;
   bool url_set_;
   Alignment horiz_alignment_;
   string16 tooltip_text_;
   // Whether the mouse is over this label.
   bool contains_mouse_;
@@ skipping 11 matching lines @@
   // allows this view to reserve space for a focus border that it otherwise
   // might not have because it is not itself focusable.
   bool has_focus_border_;
 
   DISALLOW_COPY_AND_ASSIGN(Label);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_LABEL_H_