Version: 3.3.0

#include <wx/colour.h>

+ Inheritance diagram for wxColour:

Detailed Description

A colour is an object representing a combination of Red, Green, and Blue (RGB) intensity values and an Alpha value, 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.

Channel Accessor Functions

Note that this class provides pairs of functions for each of the colour channels, i.e. red, green, blue and alpha values. The one word functions Red(), Green(), Blue() and Alpha() return the values of type unsigned char, while GetRed(), GetGreen(), GetBlue() and GetAlpha() returns the same value as unsigned int. According to the C++ integer promotion rules, the result of any arithmetic expression involving the former will be (signed) int, while that of the latter will be unsigned, which is what would be commonly expected, so the latter family of functions should be typically preferred (but they are only available since wxWidgets 3.1.6).

Library:  wxCore
Category:  Graphics Device Interface (GDI)

Predefined objects/pointers:

See also
wxColourDatabase, wxPen, wxBrush, wxColourDialog, wxSystemSettings

Public Member Functions

 wxColour ()
 Default constructor. More...
 
 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. More...
 
virtual unsigned char Alpha () const
 Returns the alpha value, on platforms where alpha is not yet supported, this always returns wxALPHA_OPAQUE. More...
 
virtual unsigned char Blue () const
 Returns the blue intensity. More...
 
unsigned int GetAlpha () const
 Returns the alpha value, on platforms where alpha is not yet supported, this always returns wxALPHA_OPAQUE. More...
 
unsigned int GetBlue () const
 Returns the blue intensity as unsigned int. More...
 
unsigned int GetGreen () const
 Returns the green intensity as unsigned int. More...
 
unsigned int GetRed () const
 Returns the red intensity as unsigned int. More...
 
virtual wxString GetAsString (long flags=wxC2S_NAME|wxC2S_CSS_SYNTAX) const
 Converts this colour to a wxString using the given flags. More...
 
double GetLuminance () const
 Return the perceived brightness of the colour. More...
 
wxIntPtr GetPixel () const
 Returns a pixel value which is platform-dependent. More...
 
virtual unsigned char Green () const
 Returns the green intensity. More...
 
virtual bool IsOk () const
 Returns true if the colour object is valid (the colour has been initialised with RGB values). More...
 
virtual unsigned char Red () const
 Returns the red intensity. More...
 
virtual bool IsSolid () const
 Returns true if the color can be described using RGB values, i.e. More...
 
bool operator!= (const wxColour &colour) const
 Tests the inequality of two colours by comparing individual red, green, blue intensities and alpha values. More...
 
wxColouroperator= (const wxColour &colour)
 Assignment operator. More...
 
bool operator== (const wxColour &colour) const
 Tests the equality of two colours by comparing individual red, green, blue intensities and alpha values. More...
 
wxColourMakeDisabled (unsigned char brightness=255)
 Make a disabled version of this colour. More...
 
wxColour ChangeLightness (int ialpha) const
 wxColour wrapper for ChangeLightness(r,g,b,ialpha). More...
 
void SetRGB (wxUint32 colRGB)
 Sets the RGB or RGBA colour values from a single 32 bit value. More...
 
void SetRGBA (wxUint32 colRGBA)
 Sets the RGB or RGBA colour values from a single 32 bit value. More...
 
wxUint32 GetRGB () const
 Gets the RGB or RGBA colour values as a single 32 bit value. More...
 
wxUint32 GetRGBA () const
 Gets the RGB or RGBA colour values as a single 32 bit value. More...
 
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). More...
 
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). More...
 
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). More...
 
- Public Member Functions inherited from wxObject
 wxObject ()
 Default ctor; initializes to nullptr the internal reference data. More...
 
 wxObject (const wxObject &other)
 Copy ctor. More...
 
virtual ~wxObject ()
 Destructor. More...
 
virtual wxClassInfoGetClassInfo () const
 This virtual function is redefined for every class that requires run-time type information, when using the wxDECLARE_CLASS macro (or similar). More...
 
wxObjectRefDataGetRefData () const
 Returns the wxObject::m_refData pointer, i.e. the data referenced by this object. More...
 
bool IsKindOf (const wxClassInfo *info) const
 Determines whether this class is a subclass of (or the same class as) the given class. More...
 
bool IsSameAs (const wxObject &obj) const
 Returns true if this object has the same data pointer as obj. More...
 
void Ref (const wxObject &clone)
 Makes this object refer to the data in clone. More...
 
void SetRefData (wxObjectRefData *data)
 Sets the wxObject::m_refData pointer. More...
 
void UnRef ()
 Decrements the reference count in the associated data, and if it is zero, deletes the data. More...
 
void UnShare ()
 This is the same of AllocExclusive() but this method is public. More...
 
void operator delete (void *buf)
 The delete operator is defined for debugging versions of the library only, when the identifier __WXDEBUG__ is defined. More...
 
void * operator new (size_t size, const wxString &filename=nullptr, int lineNum=0)
 The new operator is defined for debugging versions of the library only, when the identifier __WXDEBUG__ is defined. More...
 

Static Public Member Functions

static void MakeMono (unsigned char *r, unsigned char *g, unsigned char *b, bool on)
 Assigns the same value to r, g, b: 0 if on is false, 255 otherwise. More...
 
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. More...
 
static void MakeGrey (unsigned char *r, unsigned char *g, unsigned char *b)
 Create a grey colour from (in/out) rgb parameters using integer arithmetic. More...
 
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. More...
 
static unsigned char AlphaBlend (unsigned char fg, unsigned char bg, double alpha)
 Blend colour, taking alpha into account. More...
 
static void ChangeLightness (unsigned char *r, unsigned char *g, unsigned char *b, int ialpha)
 Utility function that simply darkens or lightens a color, based on the specified percentage ialpha. More...
 

Additional Inherited Members

- Protected Member Functions inherited from wxObject
void AllocExclusive ()
 Ensure that this object's data is not shared with any other object. More...
 
virtual wxObjectRefDataCreateRefData () const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it. More...
 
virtual wxObjectRefDataCloneRefData (const wxObjectRefData *data) const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and initializes it copying data. More...
 
- Protected Attributes inherited from wxObject
wxObjectRefDatam_refData
 Pointer to an object which is the object's reference-counted data. More...
 

Constructor & Destructor Documentation

◆ wxColour() [1/5]

wxColour::wxColour ( )

Default constructor.

◆ wxColour() [2/5]

wxColour::wxColour ( unsigned char  red,
unsigned char  green,
unsigned char  blue,
unsigned char  alpha = wxALPHA_OPAQUE 
)
Parameters
redThe red value.
greenThe green value.
blueThe blue value.
alphaThe alpha value. Alpha values range from 0 (wxALPHA_TRANSPARENT) to 255 (wxALPHA_OPAQUE).

◆ wxColour() [3/5]

wxColour::wxColour ( const wxString colourName)
Parameters
colourNameThe colour name.

◆ wxColour() [4/5]

wxColour::wxColour ( unsigned long  colRGB)
Parameters
colRGBA packed RGB value.

◆ wxColour() [5/5]

wxColour::wxColour ( const wxColour colour)

Copy constructor.

Member Function Documentation

◆ Alpha()

virtual unsigned char wxColour::Alpha ( ) const
virtual

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

See also
GetAlpha()

◆ AlphaBlend()

static unsigned char wxColour::AlphaBlend ( unsigned char  fg,
unsigned char  bg,
double  alpha 
)
static

Blend colour, taking alpha into account.

Since
2.9.0

◆ Blue()

virtual unsigned char wxColour::Blue ( ) const
virtual

Returns the blue intensity.

See also
GetBlue()

◆ ChangeLightness() [1/2]

wxColour wxColour::ChangeLightness ( int  ialpha) const

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

Since
2.9.0

◆ ChangeLightness() [2/2]

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

Utility function that simply darkens or lightens a color, based on the specified percentage ialpha.

ialpha of 0 would be make the color completely black, 200 completely white and 100 would not change the color.

Since
2.9.0

◆ GetAlpha()

unsigned int wxColour::GetAlpha ( ) const

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

Since
3.1.6

◆ GetAsString()

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 returns empty string if the colour is not initialized (see IsOk()). Otherwise, the returned string is always non-empty, but the function 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.

Note
For non-solid (i.e. non-RGB) colour this function returns "rgb(??, ?? ??)" or "#??????".
Since
2.7.0

◆ GetBlue()

unsigned int wxColour::GetBlue ( ) const

Returns the blue intensity as unsigned int.

Since
3.1.6

◆ GetGreen()

unsigned int wxColour::GetGreen ( ) const

Returns the green intensity as unsigned int.

Since
3.1.6

◆ GetLuminance()

double wxColour::GetLuminance ( ) const

Return the perceived brightness of the colour.

This value is computed using the simple

0.299*R + 0.587*G + 0.114*B

formula with the coefficients taken from the RGB to YIQ conversion formula and R, G and B being the values of the corresponding colour channels normalized to 0..1 range, so that the return value is 0 for black and 1 for white.

Since
3.1.3

◆ GetPixel()

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.

◆ GetRed()

unsigned int wxColour::GetRed ( ) const

Returns the red intensity as unsigned int.

Since
3.1.6

◆ GetRGB()

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

◆ GetRGBA()

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

◆ Green()

virtual unsigned char wxColour::Green ( ) const
virtual

Returns the green intensity.

See also
GetGreen()

◆ IsOk()

virtual bool wxColour::IsOk ( ) const
virtual

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

◆ IsSolid()

virtual bool wxColour::IsSolid ( ) const
virtual

Returns true if the color can be described using RGB values, i.e.

is solid, false if it is a pattern (currently only possible on macOS)

Since
3.1.2

◆ MakeDisabled() [1/2]

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

◆ MakeDisabled() [2/2]

wxColour& wxColour::MakeDisabled ( unsigned char  brightness = 255)

Make a disabled version of this colour.

This method modifies the object in place and returns the object itself.

Since
2.9.5

◆ MakeGrey() [1/2]

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

◆ MakeGrey() [2/2]

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

◆ MakeMono()

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

Assigns the same value to r, g, b: 0 if on is false, 255 otherwise.

Since
2.9.0

◆ operator!=()

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

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

◆ operator=()

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

Assignment operator.

See also
wxColourDatabase

◆ operator==()

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

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

◆ Red()

virtual unsigned char wxColour::Red ( ) const
virtual

Returns the red intensity.

See also
GetRed()

◆ Set() [1/3]

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

◆ Set() [2/3]

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

◆ Set() [3/3]

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

◆ SetRGB()

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, green, blue and alpha components.

Notice the right-to-left order of components!

See also
GetRGB(), GetRGBA()
Since
2.9.1

◆ SetRGBA()

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, green, blue and alpha components.

Notice the right-to-left order of components!

See also
GetRGB(), GetRGBA()
Since
2.9.1