path: root/chrome/views/label.h

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#ifndef CHROME_VIEWS_LABEL_H__
#define CHROME_VIEWS_LABEL_H__

#include "chrome/common/gfx/chrome_font.h"
#include "chrome/views/view.h"
#include "googleurl/src/gurl.h"
#include "SkColor.h"

namespace ChromeViews {

/////////////////////////////////////////////////////////////////////////////
//
// Label class
//
// A label is a view subclass that can display a string.
//
/////////////////////////////////////////////////////////////////////////////
class Label : public View {
 public:
  enum Alignment { ALIGN_LEFT = 0,
                   ALIGN_CENTER,
                   ALIGN_RIGHT };

  // The view class name.
  static const char kViewClassName[];

  // Create a new label with a default font and empty value
  Label();

  // Create a new label with a default font
  explicit Label(const std::wstring& text);

  Label(const std::wstring& text, const ChromeFont& font);

  virtual ~Label();

  // Overridden to compute the size required to display this label
  virtual void GetPreferredSize(CSize* out);

  // 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().cy if the receiver is not multi-line
  virtual int GetHeightForWidth(int w);

  // Returns chrome/views/Label.
  virtual std::string GetClassName() const;

  // Overridden to paint
  virtual void Paint(ChromeCanvas* canvas);

  // 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 PaintBackground(ChromeCanvas* canvas);

  // Set the font.
  void SetFont(const ChromeFont& font);

  // Return the font used by this label
  ChromeFont GetFont() const;

  // Set the label text.
  void SetText(const std::wstring& text);

  // Return the label text.
  const std::wstring 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);

  // Return a reference to the currently used color
  virtual const SkColor GetColor() const;

  // Alignment
  void SetHorizontalAlignment(Alignment a);
  Alignment GetHorizontalAlignment() const;

  // Set whether the label text can wrap on multiple lines.
  // Default is false
  void SetMultiLine(bool f);

  // Return whether the label text can wrap on multiple lines
  bool IsMultiLine();

  // Sets the tooltip text.  Default behavior for a label (single-line) is to
  // show the full text if it is wider than its bounds.  Calling this overrides
  // the default behavior and lets you set a custom tooltip.  To revert to
  // default behavior, call this with an empty string.
  void SetTooltipText(const std::wstring& tooltip_text);

  // 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(int x, int y, std::wstring* tooltip);

  // Mouse enter/exit are overridden to render mouse over background color. These
  // invoke SetContainsMouse as necessary.
  virtual void OnMouseMoved(const MouseEvent& e);
  virtual void OnMouseEntered(const MouseEvent& event);
  virtual void OnMouseExited(const MouseEvent& event);

  // The background color to use when the mouse is over the label. Label
  // takes ownership of the Background.
  void SetMouseOverBackground(Background* background);
  const Background* GetMouseOverBackground() const;

  // Sets the enabled state. Setting the enabled state resets the color.
  virtual void SetEnabled(bool enabled);

  // Resizes the label so its width is set to the width of the longest line and
  // its height deduced accordingly.
  // This is only intended for multi-line labels and is useful when the label's
  // text contains several lines separated with \n.
  // |max_width| is the maximum width that will be used (longer lines will be
  // wrapped).  If 0, no maximum width is enforced.
  void SizeToFit(int max_width);

  // Returns the MSAA role of the current view. The role is what assistive
  // technologies (ATs) use to determine what behavior to expect from a given
  // control.
  bool GetAccessibleRole(VARIANT* role);

  // Returns a brief, identifying string, containing a unique, readable name.
  bool GetAccessibleName(std::wstring* name);

  // Returns the MSAA state of the current view. Sets the input VARIANT
  // appropriately, and returns true if a change was performed successfully.
  // Overriden from View.
  virtual bool GetAccessibleState(VARIANT* state);

 private:
  static ChromeFont GetDefaultFont();

  // If the mouse is over the text, SetContainsMouse(true) is invoked, otherwise
  // SetContainsMouse(false) is invoked.
  void Label::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();

  int ComputeMultiLineFlags();
  void GetTextSize(CSize* out);
  void Init(const std::wstring& text, const ChromeFont& font);
  std::wstring text_;
  GURL url_;
  ChromeFont font_;
  SkColor color_;
  CSize text_size_;
  bool text_size_valid_;
  bool is_multi_line_;
  bool url_set_;
  Alignment horiz_alignment_;
  std::wstring tooltip_text_;
  // Whether the mouse is over this label.
  bool contains_mouse_;
  scoped_ptr<Background> mouse_over_background_;
};

}
#endif  // CHROME_VIEWS_VIEW_H__