interface/wx/colour.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        colour.h
   3 // Purpose:     interface of wxColour
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9
  10
  11 /**
  12     Flags for wxColour -> wxString conversion (see wxColour::GetAsString).
  13
  14     @{
  15 */
  16 #define wxC2S_NAME              1   //!< Return colour name, when possible.
  17 #define wxC2S_CSS_SYNTAX        2   //!< Return colour in "rgb(r,g,b)" syntax.
  18 #define wxC2S_HTML_SYNTAX       4   //!< Return colour in "#rrggbb" syntax.
  19
  20 //@}
  21
  22
  23 /**
  24     @class wxColour
  25
  26     A colour is an object representing a combination of Red, Green, and Blue
  27     (RGB) intensity values, and is used to determine drawing colours. See the
  28     entry for wxColourDatabase for how a pointer to a predefined, named colour
  29     may be returned instead of creating a new colour.
  30
  31     Valid RGB values are in the range 0 to 255.
  32
  33     You can retrieve the current system colour settings with wxSystemSettings.
  34
  35     @library{wxcore}
  36     @category{gdi}
  37
  38     @stdobjects
  39     - ::wxNullColour - An empty, invalid colour.
  40     - ::wxTransparentColour - Valid but fully transparent colour (new in 2.9.1).
  41     - ::wxBLACK
  42     - ::wxBLUE
  43     - ::wxCYAN
  44     - ::wxGREEN
  45     - ::wxYELLOW
  46     - ::wxLIGHT_GREY
  47     - ::wxRED
  48     - ::wxWHITE
  49
  50     @see wxColourDatabase, wxPen, wxBrush, wxColourDialog, wxSystemSettings
  51 */
  52 class wxColour : public wxObject
  53 {
  54 public:
  55
  56     /**
  57         Default constructor.
  58     */
  59     wxColour();
  60
  61     /**
  62         @param red
  63             The red value.
  64         @param green
  65             The green value.
  66         @param blue
  67             The blue value.
  68         @param alpha
  69             The alpha value. Alpha values range from 0 (wxALPHA_TRANSPARENT) to
  70             255 (wxALPHA_OPAQUE).
  71     */
  72     wxColour(unsigned char red, unsigned char green, unsigned char blue,
  73              unsigned char alpha = wxALPHA_OPAQUE);
  74
  75     /**
  76         @param colourName
  77             The colour name.
  78     */
  79     wxColour(const wxString& colourName);
  80
  81     /**
  82         Copy constructor.
  83     */
  84     wxColour(const wxColour& colour);
  85
  86     /**
  87         Returns the alpha value, on platforms where alpha is not yet supported, this
  88         always returns wxALPHA_OPAQUE.
  89     */
  90     virtual unsigned char Alpha() const;
  91
  92     /**
  93         Returns the blue intensity.
  94     */
  95     virtual unsigned char Blue() const;
  96
  97     /**
  98         Converts this colour to a wxString using the given flags.
  99
 100         The supported flags are @c wxC2S_NAME, to obtain the colour name
 101         (e.g. wxColour(255,0,0) == "red"), @c wxC2S_CSS_SYNTAX, to obtain
 102         the colour in the "rgb(r,g,b)" or "rgba(r,g,b,a)" syntax
 103         (e.g. wxColour(255,0,0,85) == "rgba(255,0,0,0.333)"), and
 104         @c wxC2S_HTML_SYNTAX, to obtain the colour as "#" followed by 6
 105         hexadecimal digits (e.g. wxColour(255,0,0) == "#FF0000").
 106
 107         This function never fails and always returns a non-empty string but
 108         asserts if the colour has alpha channel (i.e. is non opaque) but
 109         @c wxC2S_CSS_SYNTAX (which is the only one supporting alpha) is not
 110         specified in flags.
 111
 112         @since 2.7.0
 113     */
 114     virtual wxString GetAsString(long flags = wxC2S_NAME | wxC2S_CSS_SYNTAX) const;
 115
 116     //@{
 117     /**
 118         Sets the RGB or RGBA colour values from a single 32 bit value.
 119
 120         The arguments @a colRGB and @a colRGBA should be of the form 0x00BBGGRR
 121         and 0xAABBGGRR respectively where @c 0xRR, @c 0xGG, @c 0xBB and @c 0xAA
 122         are the values of the red, blue, green and alpha components.
 123
 124         Notice the right-to-left order of components!
 125
 126         @see GetRGB(), GetRGBA()
 127
 128         @since 2.9.1
 129     */
 130     void SetRGB(wxUint32 colRGB);
 131     void SetRGBA(wxUint32 colRGBA);
 132     //@}
 133
 134     //@{
 135     /**
 136         Gets the RGB or RGBA colour values as a single 32 bit value.
 137
 138         The returned value is of the same form as expected by SetRGB() and
 139         SetRGBA().
 140
 141         Notice that GetRGB() returns the value with 0 as its highest byte
 142         independently of the value actually returned by Alpha(). So for a fully
 143         opaque colour, the return value of GetRGBA() is @c 0xFFBBGGRR while
 144         that of GetRGB() is @c 0x00BBGGRR.
 145
 146         @since 2.9.1
 147     */
 148     wxUint32 GetRGB() const;
 149     wxUint32 GetRGBA() const;
 150     //@}
 151
 152     /**
 153         Returns a pixel value which is platform-dependent.
 154         On Windows, a COLORREF is returned.
 155         On X, an allocated pixel value is returned.
 156         If the pixel is invalid (on X, unallocated), @c -1 is returned.
 157     */
 158     int GetPixel() const;
 159
 160     /**
 161         Returns the green intensity.
 162     */
 163     virtual unsigned char Green() const;
 164
 165     /**
 166         Returns @true if the colour object is valid (the colour has been initialised
 167         with RGB values).
 168     */
 169     virtual bool IsOk() const;
 170
 171     /**
 172         Returns the red intensity.
 173     */
 174     virtual unsigned char Red() const;
 175
 176     //@{
 177     /**
 178         Sets the RGB intensity values using the given values (first overload),
 179         extracting them from the packed long (second overload), using the given
 180         string (third overloard).
 181
 182         When using third form, Set() accepts: colour names (those listed in
 183         wxColourDatabase), the CSS-like @c "rgb(r,g,b)" or @c "rgba(r,g,b,a)" syntax
 184         (case insensitive) and the HTML-like syntax: @c "#" followed by 6 hexadecimal
 185         digits for red, green, blue components.
 186
 187         Returns @true if the conversion was successful, @false otherwise.
 188
 189         @since 2.7.0
 190     */
 191     void Set(unsigned char red, unsigned char green,
 192              unsigned char blue,
 193              unsigned char alpha = wxALPHA_OPAQUE);
 194     void Set(unsigned long RGB);
 195     bool Set(const wxString& str);
 196     //@}
 197
 198     /**
 199         Tests the inequality of two colours by comparing individual red, green, blue
 200         colours and alpha values.
 201     */
 202     bool operator !=(const wxColour& colour) const;
 203
 204     /**
 205         Assignment operator, using a colour name to be found in the colour database.
 206
 207         @see wxColourDatabase
 208     */
 209     wxColour& operator=(const wxColour& colour);
 210
 211     /**
 212         Tests the equality of two colours by comparing individual red, green, blue
 213         colours and alpha values.
 214     */
 215     bool operator ==(const wxColour& colour) const;
 216
 217     /**
 218         Assign 0 or 255 to rgb out parameters.
 219         @since 2.9.0
 220     */
 221     static void MakeMono(unsigned char* r, unsigned char* g, unsigned char* b, bool on);
 222
 223     /**
 224         Create a disabled (dimmed) colour from (in/out) rgb parameters.
 225         @since 2.9.0
 226     */
 227     static void MakeDisabled(unsigned char* r, unsigned char* g, unsigned char* b, unsigned char brightness = 255);
 228
 229     /**
 230         Create a grey colour from (in/out) rgb parameters using integer arithmetic.
 231         @since 2.9.0
 232     */
 233     static void MakeGrey(unsigned char* r, unsigned char* g, unsigned char* b);
 234
 235     /**
 236         Create a grey colour from (in/out) rgb parameters using floating point arithmetic.
 237         Defaults to using the standard ITU-T BT.601 when converting to YUV, where every pixel equals
 238         (R * @a weight_r) + (G * @a weight_g) + (B * @a weight_b).
 239         @since 2.9.0
 240     */
 241     static void MakeGrey(unsigned char* r, unsigned char* g, unsigned char* b,
 242                          double weight_r, double weight_g, double weight_b);
 243
 244     /**
 245         Blend colour, taking alpha into account.
 246         @since 2.9.0
 247     */
 248     static unsigned char AlphaBlend(unsigned char fg, unsigned char bg, double alpha);
 249
 250     /**
 251         ChangeLightness() is a utility function that simply darkens
 252         or lightens a color, based on the specified percentage
 253         ialpha of 0 would be completely black, 200 completely white
 254         an ialpha of 100 returns the same colour
 255         @since 2.9.0
 256     */
 257     static void ChangeLightness(unsigned char* r, unsigned char* g, unsigned char* b, int ialpha);
 258
 259     /**
 260         wxColour wrapper for ChangeLightness(r,g,b,ialpha).
 261         @since 2.9.0
 262     */
 263     wxColour ChangeLightness(int ialpha) const;
 264 };
 265
 266
 267 /** @name Predefined colors. */
 268 //@{
 269 wxColour wxNullColour;
 270 wxColour wxTransparentColour;
 271 wxColour* wxBLACK;
 272 wxColour* wxBLUE;
 273 wxColour* wxCYAN;
 274 wxColour* wxGREEN;
 275 wxColour* wxYELLOW;
 276 wxColour* wxLIGHT_GREY;
 277 wxColour* wxRED;
 278 wxColour* wxWHITE;
 279 //@}
 280
 281
 282
 283 // ============================================================================
 284 // Global functions/macros
 285 // ============================================================================
 286
 287 /** @addtogroup group_funcmacro_misc */
 288 //@{
 289
 290 /**
 291     Converts string to a wxColour best represented by the given string. Returns
 292     @true on success.
 293
 294     @see wxToString(const wxColour&)
 295
 296     @header{wx/colour.h}
 297 */
 298 bool wxFromString(const wxString& string, wxColour* colour);
 299
 300 /**
 301     Converts the given wxColour into a string.
 302
 303     @see wxFromString(const wxString&, wxColour*)
 304
 305     @header{wx/colour.h}
 306 */
 307 wxString wxToString(const wxColour& colour);
 308
 309 //@}
 310