# wxColour Class Reference
[Graphics Device Interface (GDI)]

`#include </home/work/projects/wx/2.9/wx/interface/wx/colour.h>`

Inheritance diagram for wxColour:
[legend]

## Detailed Description

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: Graphics Device Interface (GDI)

Predefined objects/pointers:

- wxNullColour - An empty, invalid colour.
- wxTransparentColour - Valid but fully transparent colour (new in 2.9.1).
- wxBLACK
- wxBLUE
- wxCYAN
- wxGREEN
- wxYELLOW
- wxLIGHT_GREY
- wxRED
- wxWHITE

See also:
  wxColourDatabase, wxPen, wxBrush, wxColourDialog, wxSystemSettings

## Public Member Functions

| wxColour ()
| Default constructor.
| wxColour (unsigned char red, unsigned char green, unsigned char blue, unsigned char alpha=wxALPHA_OPAQUE)
| wxColour (const wxString &colourName)
| wxColour (unsigned long colRGB)
| wxColour (const wxColour &colour)
| Copy constructor.
virtual unsigned char | Alpha () const
| Returns the alpha value, on platforms where alpha is not yet supported, this always returns wxALPHA_OPAQUE.
virtual unsigned char | Blue () const
| Returns the blue intensity.
virtual wxString | GetAsString (long flags=wxC2S_NAME|wxC2S_CSS_SYNTAX) const
| Converts this colour to a wxString using the given flags.
wxIntPtr | GetPixel () const
| Returns a pixel value which is platform-dependent.
virtual unsigned char | Green () const
| Returns the green intensity.
virtual bool | IsOk () const
| Returns true if the colour object is valid (the colour has been initialised with RGB values).
virtual unsigned char | Red () const
| Returns the red intensity.
bool | operator!= (const wxColour &colour) const
| Tests the inequality of two colours by comparing individual red, green, blue colours and alpha values.
wxColour & | operator= (const wxColour &colour)
| Assignment operator, using a colour name to be found in the colour database.
bool | operator== (const wxColour &colour) const
| Tests the equality of two colours by comparing individual red, green, blue colours and alpha values.
wxColour | ChangeLightness (int ialpha) const
| wxColour wrapper for ChangeLightness(r,g,b,ialpha).
void | SetRGB (wxUint32 colRGB)
| Sets the RGB or RGBA colour values from a single 32 bit value.
void | SetRGBA (wxUint32 colRGBA)
| Sets the RGB or RGBA colour values from a single 32 bit value.
wxUint32 | GetRGB () const
| Gets the RGB or RGBA colour values as a single 32 bit value.
wxUint32 | GetRGBA () const
| Gets the RGB or RGBA colour values as a single 32 bit value.
void | Set (unsigned char red, unsigned char green, unsigned char blue, unsigned char alpha=wxALPHA_OPAQUE)
| Sets the RGB intensity values using the given values (first overload), extracting them from the packed long (second overload), using the given string (third overload).
void | Set (unsigned long RGB)
| Sets the RGB intensity values using the given values (first overload), extracting them from the packed long (second overload), using the given string (third overload).
bool | Set (const wxString &str)
| Sets the RGB intensity values using the given values (first overload), extracting them from the packed long (second overload), using the given string (third overload).

## Static Public Member Functions

static void | MakeMono (unsigned char *r, unsigned char *g, unsigned char *b, bool on)
| Assign 0 or 255 to rgb out parameters.
static void | MakeDisabled (unsigned char *r, unsigned char *g, unsigned char *b, unsigned char brightness=255)
| Create a disabled (dimmed) colour from (in/out) rgb parameters.
static void | MakeGrey (unsigned char *r, unsigned char *g, unsigned char *b)
| Create a grey colour from (in/out) rgb parameters using integer arithmetic.
static void | MakeGrey (unsigned char *r, unsigned char *g, unsigned char *b, double weight_r, double weight_g, double weight_b)
| Create a grey colour from (in/out) rgb parameters using floating point arithmetic.
static unsigned char | AlphaBlend (unsigned char fg, unsigned char bg, double alpha)
| Blend colour, taking alpha into account.
static void | ChangeLightness (unsigned char *r, unsigned char *g, unsigned char *b, int ialpha)
| ChangeLightness() is a utility function that simply darkens or lightens a color, based on the specified percentage ialpha of 0 would be completely black, 200 completely white an ialpha of 100 returns the same colour.

List of all members.

## Constructor & Destructor Documentation

wxColour::wxColour | ( |  | ) |

Default constructor.

wxColour::wxColour | ( | unsigned char | red,
|  | unsigned char | green,
|  | unsigned char | blue,
|  | unsigned char | alpha = `wxALPHA_OPAQUE` |
| ) |  |  |

Parameters:

  | red | The red value.
  | green | The green value.
  | blue | The blue value.
  | alpha | The alpha value. Alpha values range from 0 (wxALPHA_TRANSPARENT) to 255 (wxALPHA_OPAQUE).

wxColour::wxColour | ( | const wxString & | colourName | ) |

Parameters:

  | colourName | The colour name.

wxColour::wxColour | ( | unsigned long | colRGB | ) |

Parameters:

  | colRGB | A packed RGB value.

wxColour::wxColour | ( | const wxColour & | colour | ) |

Copy constructor.

## Member Function Documentation

virtual unsigned char wxColour::Alpha | ( |  | ) | const`[virtual]`

Returns the alpha value, on platforms where alpha is not yet supported, this always returns wxALPHA_OPAQUE.

static unsigned char wxColour::AlphaBlend | ( | unsigned char | fg,
|  | unsigned char | bg,
|  | double | alpha |
| ) |  |  | `[static]`

Blend colour, taking alpha into account.

Since:
  2.9.0

virtual unsigned char wxColour::Blue | ( |  | ) | const`[virtual]`

Returns the blue intensity.

static void wxColour::ChangeLightness | ( | unsigned char * | r,
|  | unsigned char * | g,
|  | unsigned char * | b,
|  | int | ialpha |
| ) |  |  | `[static]`

ChangeLightness() is a utility function that simply darkens or lightens a color, based on the specified percentage ialpha of 0 would be completely black, 200 completely white an ialpha of 100 returns the same colour.

Since:
  2.9.0

wxColour wxColour::ChangeLightness | ( | int | ialpha | ) | const

wxColour wrapper for ChangeLightness(r,g,b,ialpha).

Since:
  2.9.0

virtual wxString wxColour::GetAsString | ( | long | flags = `wxC2S_NAME|wxC2S_CSS_SYNTAX` | ) | const`[virtual]`

Converts this colour to a wxString using the given flags.

The supported flags are `wxC2S_NAME`, to obtain the colour name (e.g. wxColour(255,0,0) == "red"), `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` (which is the only one supporting alpha) is not specified in flags.

Since:
  2.7.0

wxIntPtr wxColour::GetPixel | ( |  | ) | const

Returns a pixel value which is platform-dependent.

On Windows, a COLORREF is returned. On X, an allocated pixel value is returned. If the pixel is invalid (on X, unallocated), `-1` is returned.

wxUint32 wxColour::GetRGB | ( |  | ) | const

Gets the RGB or RGBA colour values as a single 32 bit value.

The returned value is of the same form as expected by SetRGB() and SetRGBA().

Notice that GetRGB() returns the value with 0 as its highest byte independently of the value actually returned by Alpha(). So for a fully opaque colour, the return value of GetRGBA() is `0xFFBBGGRR` while that of GetRGB() is `0x00BBGGRR`.

Since:
  2.9.1

wxUint32 wxColour::GetRGBA | ( |  | ) | const

Gets the RGB or RGBA colour values as a single 32 bit value.

The returned value is of the same form as expected by SetRGB() and SetRGBA().

Notice that GetRGB() returns the value with 0 as its highest byte independently of the value actually returned by Alpha(). So for a fully opaque colour, the return value of GetRGBA() is `0xFFBBGGRR` while that of GetRGB() is `0x00BBGGRR`.

Since:
  2.9.1

virtual unsigned char wxColour::Green | ( |  | ) | const`[virtual]`

Returns the green intensity.

virtual bool wxColour::IsOk | ( |  | ) | const`[virtual]`

Returns true if the colour object is valid (the colour has been initialised with RGB values).

static void wxColour::MakeDisabled | ( | unsigned char * | r,
|  | unsigned char * | g,
|  | unsigned char * | b,
|  | unsigned char | brightness = `255` |
| ) |  |  | `[static]`

Create a disabled (dimmed) colour from (in/out) rgb parameters.

Since:
  2.9.0

static void wxColour::MakeGrey | ( | unsigned char * | r,
|  | unsigned char * | g,
|  | unsigned char * | b |
| ) |  |  | `[static]`

Create a grey colour from (in/out) rgb parameters using integer arithmetic.

Since:
  2.9.0

static void wxColour::MakeGrey | ( | unsigned char * | r,
|  | unsigned char * | g,
|  | unsigned char * | b,
|  | double | weight_r,
|  | double | weight_g,
|  | double | weight_b |
| ) |  |  | `[static]`

Create a grey colour from (in/out) rgb parameters using floating point arithmetic.

Defaults to using the standard ITU-T BT.601 when converting to YUV, where every pixel equals (R * weight_r) + (G * weight_g) + (B * weight_b).

Since:
  2.9.0

static void wxColour::MakeMono | ( | unsigned char * | r,
|  | unsigned char * | g,
|  | unsigned char * | b,
|  | bool | on |
| ) |  |  | `[static]`

Assign 0 or 255 to rgb out parameters.

Since:
  2.9.0

bool wxColour::operator!= | ( | const wxColour & | colour | ) | const

Tests the inequality of two colours by comparing individual red, green, blue colours and alpha values.

wxColour& wxColour::operator= | ( | const wxColour & | colour | ) |

Assignment operator, using a colour name to be found in the colour database.

See also:
  wxColourDatabase

bool wxColour::operator== | ( | const wxColour & | colour | ) | const

Tests the equality of two colours by comparing individual red, green, blue colours and alpha values.

virtual unsigned char wxColour::Red | ( |  | ) | const`[virtual]`

Returns the red intensity.

bool wxColour::Set | ( | const wxString & | str | ) |

Sets the RGB intensity values using the given values (first overload), extracting them from the packed long (second overload), using the given string (third overload).

When using third form, Set() accepts: colour names (those listed in wxColourDatabase), the CSS-like `"rgb(r,g,b)"` or `"rgba(r,g,b,a)"` syntax (case insensitive) and the HTML-like syntax: `"#"` followed by 6 hexadecimal digits for red, green, blue components.

Returns true if the conversion was successful, false otherwise.

Since:
  2.7.0

void wxColour::Set | ( | unsigned char | red,
|  | unsigned char | green,
|  | unsigned char | blue,
|  | unsigned char | alpha = `wxALPHA_OPAQUE` |
| ) |  |  |

Sets the RGB intensity values using the given values (first overload), extracting them from the packed long (second overload), using the given string (third overload).

When using third form, Set() accepts: colour names (those listed in wxColourDatabase), the CSS-like `"rgb(r,g,b)"` or `"rgba(r,g,b,a)"` syntax (case insensitive) and the HTML-like syntax: `"#"` followed by 6 hexadecimal digits for red, green, blue components.

Returns true if the conversion was successful, false otherwise.

Since:
  2.7.0

void wxColour::Set | ( | unsigned long | RGB | ) |

Sets the RGB intensity values using the given values (first overload), extracting them from the packed long (second overload), using the given string (third overload).

When using third form, Set() accepts: colour names (those listed in wxColourDatabase), the CSS-like `"rgb(r,g,b)"` or `"rgba(r,g,b,a)"` syntax (case insensitive) and the HTML-like syntax: `"#"` followed by 6 hexadecimal digits for red, green, blue components.

Returns true if the conversion was successful, false otherwise.

Since:
  2.7.0

void wxColour::SetRGB | ( | wxUint32 | colRGB | ) |

Sets the RGB or RGBA colour values from a single 32 bit value.

The arguments colRGB and colRGBA should be of the form 0x00BBGGRR and 0xAABBGGRR respectively where `0xRR`, `0xGG`, `0xBB` and `0xAA` are the values of the red, blue, green and alpha components.

Notice the right-to-left order of components!

See also:
  GetRGB(), GetRGBA()

Since:
  2.9.1

void wxColour::SetRGBA | ( | wxUint32 | colRGBA | ) |

Sets the RGB or RGBA colour values from a single 32 bit value.

The arguments colRGB and colRGBA should be of the form 0x00BBGGRR and 0xAABBGGRR respectively where `0xRR`, `0xGG`, `0xBB` and `0xAA` are the values of the red, blue, green and alpha components.

Notice the right-to-left order of components!

See also:
  GetRGB(), GetRGBA()

Since:
  2.9.1

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