wxWidgets/interface/colour.h

/////////////////////////////////////////////////////////////////////////////
// Name:        colour.h
// Purpose:     documentation for wxColour class
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxColour
    @wxheader{colour.h}
    
    A colour is an object representing a combination of Red, Green, and Blue (RGB)
    intensity values,
    and is used to determine drawing colours. See the
    entry for wxColourDatabase for how a pointer to a predefined,
    named colour may be returned instead of creating a new colour.
    
    Valid RGB values are in the range 0 to 255.
    
    You can retrieve the current system colour settings with wxSystemSettings.
    
    @library{wxcore}
    @category{gdi}
    
    @stdobjects
    Objects:
    wxNullColour
    Pointers:
    wxBLACK
    
    wxWHITE
    
    wxRED
    
    wxBLUE
    
    wxGREEN
    
    wxCYAN
    
    wxLIGHT_GREY
    
    @seealso
    wxColourDatabase, wxPen, wxBrush, wxColourDialog, wxSystemSettings
*/
class wxColour : public wxObject
{
public:
    //@{
    /**
        Copy constructor.
        
        @param red 
        The red value.
        
        @param green 
        The green value.
        
        @param blue 
        The blue value.
        
        @param alpha 
        The alpha value. Alpha values range from 0 (wxALPHA_TRANSPARENT) to 255
        (wxALPHA_OPAQUE).
        
        @param colourName 
        The colour name.
        
        @param colour 
        The colour to copy.
        
        @sa wxColourDatabase
    */
    wxColour();
        wxColour(unsigned char red, unsigned char green,
                 unsigned char blue,
                 unsigned char alpha=wxALPHA_OPAQUE);
        wxColour(const wxString& colourNname);
        wxColour(const wxColour& colour);
    //@}

    /**
        Returns the alpha value, on platforms where alpha is not yet supported, this
        always returns wxALPHA_OPAQUE.
    */
    unsigned char Alpha();

    /**
        Returns the blue intensity.
    */
    unsigned char Blue();

    //@{
    /**
        is not
        specified in flags.
        
        This function is new since wxWidgets version 2.7.0
    */
    wxString GetAsString(long flags);
        wxC2S_NAME wxC2S_CSS_SYNTAX, to obtain
the colour in the "rgb(r,g,b)" or "rgba(r,g,b,a)" syntax
(e.g. wxColour(255,0,0,85) - "rgba(255,0,0,0.333)"), and 
wxC2S_HTML_SYNTAX, to obtain the colour as  "#" followed
by 6 hexadecimal digits (e.g. wxColour(255,0,0) - "#FF0000").
This function never fails and always returns a non-empty string but asserts if
the colour has alpha channel (i.e. is non opaque) but
wxC2S_CSS_SYNTAX();
    //@}

    /**
        Returns a pixel value which is platform-dependent. On Windows, a COLORREF is
        returned.
        On X, an allocated pixel value is returned.
        
        -1 is returned if the pixel is invalid (on X, unallocated).
    */
    long GetPixel();

    /**
        Returns the green intensity.
    */
    unsigned char Green();

    /**
        Returns @true if the colour object is valid (the colour has been initialised
        with RGB values).
    */
#define bool IsOk()     /* implementation is private */

    /**
        Returns the red intensity.
    */
#define unsigned char Red()     /* implementation is private */

    //@{
    /**
        Sets the RGB intensity values using the given values (first overload),
        extracting them from the packed long (second overload), using the given string (third overloard).
        
        When using third form, Set() accepts: colour names (those listed in 
        wxTheColourDatabase), the CSS-like 
        @c "rgb(r,g,b)" or @c "rgba(r,g,b,a)" syntax (case insensitive) 
        and the HTML-like syntax (i.e. @c "#" followed by 6 hexadecimal digits 
        for red, green, blue components).
        
        Returns @true if the conversion was successful, @false otherwise.
        
        This function is new since wxWidgets version 2.7.0
    */
    void Set(unsigned char red, unsigned char green,
             unsigned char blue,
             unsigned char alpha=wxALPHA_OPAQUE);
        void Set(unsigned long RGB);
        bool Set(const wxString & str);
    //@}

    /**
        Tests the inequality of two colours by comparing individual red, green, blue
        colours and alpha values.
    */
    bool operator !=(const wxColour& colour);

    //@{
    /**
        Assignment operator, using a colour name to be found in the colour database.
        
        @sa wxColourDatabase
    */
    wxColour operator =(const wxColour& colour);
        wxColour operator =(const wxString& colourName);
    //@}

    /**
        Tests the equality of two colours by comparing individual red, green, blue
        colours and alpha values.
    */
    bool operator ==(const wxColour& colour);
};