Version: 3.1.1

#include <wx/bitmap.h>

+ Inheritance diagram for wxBitmap:

Detailed Description

This class encapsulates the concept of a platform-dependent bitmap, either monochrome or colour or colour with alpha channel support.

If you need direct access the bitmap data instead going through drawing to it using wxMemoryDC you need to use the wxPixelData class (either wxNativePixelData for RGB bitmaps or wxAlphaPixelData for bitmaps with an additionally alpha channel).

Note that many wxBitmap functions take a type parameter, which is a value of the wxBitmapType enumeration. The validity of those values depends however on the platform where your program is running and from the wxWidgets configuration. If all possible wxWidgets settings are used:

  • wxMSW supports BMP and ICO files, BMP and ICO resources;
  • wxGTK supports any file supported by gdk-pixbuf;
  • wxMac supports PICT resources;
  • wxX11 supports XPM files, XPM data, XBM data;

In addition, wxBitmap can load and save all formats that wxImage can; see wxImage for more info. Of course, you must have loaded the wxImage handlers (see wxInitAllImageHandlers() and wxImage::AddHandler). Note that all available wxBitmapHandlers for a given wxWidgets port are automatically loaded at startup so you won't need to use wxBitmap::AddHandler.

More on the difference between wxImage and wxBitmap: wxImage is just a buffer of RGB bytes with an optional buffer for the alpha bytes. It is all generic, platform independent and image file format independent code. It includes generic code for scaling, resizing, clipping, and other manipulations of the image data. OTOH, wxBitmap is intended to be a wrapper of whatever is the native image format that is quickest/easiest to draw to a DC or to be the target of the drawing operations performed on a wxMemoryDC. By splitting the responsibilities between wxImage/wxBitmap like this then it's easier to use generic code shared by all platforms and image types for generic operations and platform specific code where performance or compatibility is needed.

Library:  wxCore
Category:  Graphics Device Interface (GDI)

Predefined objects/pointers: wxNullBitmap

See also
Bitmaps and Icons, Supported Bitmap File Formats, wxDC::Blit, wxIcon, wxCursor, wxMemoryDC, wxImage, wxPixelData

Public Member Functions

 wxBitmap ()
 Default constructor. More...
 
 wxBitmap (const wxBitmap &bitmap)
 Copy constructor, uses reference counting. More...
 
 wxBitmap (const char bits[], int width, int height, int depth=1)
 Creates a bitmap from the given array bits. More...
 
 wxBitmap (int width, int height, int depth=wxBITMAP_SCREEN_DEPTH)
 Creates a new bitmap. More...
 
 wxBitmap (const wxSize &sz, int depth=wxBITMAP_SCREEN_DEPTH)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
 wxBitmap (const char *const *bits)
 Creates a bitmap from XPM data. More...
 
 wxBitmap (const wxString &name, wxBitmapType type=wxBITMAP_DEFAULT_TYPE)
 Loads a bitmap from a file or resource. More...
 
 wxBitmap (const wxImage &img, int depth=wxBITMAP_SCREEN_DEPTH)
 Creates this bitmap object from the given image. More...
 
 wxBitmap (const wxCursor &cursor)
 Creates bitmap corresponding to the given cursor. More...
 
virtual ~wxBitmap ()
 Destructor. More...
 
virtual wxImage ConvertToImage () const
 Creates an image from a platform-dependent bitmap. More...
 
virtual bool CopyFromIcon (const wxIcon &icon)
 Creates the bitmap from an icon. More...
 
virtual bool Create (int width, int height, int depth=wxBITMAP_SCREEN_DEPTH)
 Creates a fresh bitmap. More...
 
virtual bool Create (const wxSize &sz, int depth=wxBITMAP_SCREEN_DEPTH)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
bool Create (int width, int height, const wxDC &dc)
 Create a bitmap compatible with the given DC, inheriting its magnification factor. More...
 
bool CreateScaled (int logwidth, int logheight, int depth, double logicalScale)
 Create a bitmap with a scale factor, width and height are multiplied with that factor. More...
 
virtual int GetDepth () const
 Gets the colour depth of the bitmap. More...
 
virtual int GetHeight () const
 Gets the height of the bitmap in pixels. More...
 
virtual wxMaskGetMask () const
 Gets the associated mask (if any) which may have been loaded from a file or set for the bitmap. More...
 
virtual wxPaletteGetPalette () const
 Gets the associated palette (if any) which may have been loaded from a file or set for the bitmap. More...
 
virtual wxBitmap GetSubBitmap (const wxRect &rect) const
 Returns a sub bitmap of the current one as long as the rect belongs entirely to the bitmap. More...
 
wxSize GetSize () const
 Returns the size of the bitmap in pixels. More...
 
wxBitmap ConvertToDisabled (unsigned char brightness=255) const
 Returns disabled (dimmed) version of the bitmap. More...
 
virtual int GetWidth () const
 Gets the width of the bitmap in pixels. More...
 
virtual bool IsOk () const
 Returns true if bitmap data is present. More...
 
virtual bool LoadFile (const wxString &name, wxBitmapType type=wxBITMAP_DEFAULT_TYPE)
 Loads a bitmap from a file or resource. More...
 
virtual bool SaveFile (const wxString &name, wxBitmapType type, const wxPalette *palette=NULL) const
 Saves a bitmap in the named file. More...
 
virtual void SetDepth (int depth)
 Sets the depth member (does not affect the bitmap data). More...
 
virtual void SetHeight (int height)
 Sets the height member (does not affect the bitmap data). More...
 
virtual void SetMask (wxMask *mask)
 Sets the mask for this bitmap. More...
 
virtual void SetPalette (const wxPalette &palette)
 Sets the associated palette. More...
 
virtual void SetWidth (int width)
 Sets the width member (does not affect the bitmap data). More...
 
- Public Member Functions inherited from wxGDIObject
 wxGDIObject ()
 Default constructor. More...
 
- Public Member Functions inherited from wxObject
 wxObject ()
 Default ctor; initializes to NULL 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=NULL, 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 AddHandler (wxBitmapHandler *handler)
 Adds a handler to the end of the static list of format handlers. More...
 
static void CleanUpHandlers ()
 Deletes all bitmap handlers. More...
 
static wxBitmapHandlerFindHandler (const wxString &name)
 Finds the handler with the given name. More...
 
static wxBitmapHandlerFindHandler (const wxString &extension, wxBitmapType bitmapType)
 Finds the handler associated with the given extension and type. More...
 
static wxBitmapHandlerFindHandler (wxBitmapType bitmapType)
 Finds the handler associated with the given bitmap type. More...
 
static wxList & GetHandlers ()
 Returns the static list of bitmap format handlers. More...
 
static void InitStandardHandlers ()
 Adds the standard bitmap format handlers, which, depending on wxWidgets configuration, can be handlers for Windows bitmap, Windows bitmap resource, and XPM. More...
 
static void InsertHandler (wxBitmapHandler *handler)
 Adds a handler at the start of the static list of format handlers. More...
 
static wxBitmap NewFromPNGData (const void *data, size_t size)
 Loads a bitmap from the memory containing image data in PNG format. More...
 
static bool RemoveHandler (const wxString &name)
 Finds the handler with the given name, and removes it. 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

wxBitmap::wxBitmap ( )

Default constructor.

Constructs a bitmap object with no data; an assignment or another member function such as Create() or LoadFile() must be called subsequently.

wxBitmap::wxBitmap ( const wxBitmap bitmap)

Copy constructor, uses reference counting.

To make a real copy, you can use:

wxBitmap newBitmap = oldBitmap.GetSubBitmap(
wxRect(0, 0, oldBitmap.GetWidth(), oldBitmap.GetHeight()));
wxBitmap::wxBitmap ( const char  bits[],
int  width,
int  height,
int  depth = 1 
)

Creates a bitmap from the given array bits.

You should only use this function for monochrome bitmaps (depth 1) in portable programs: in this case the bits parameter should contain an XBM image.

For other bit depths, the behaviour is platform dependent: under Windows, the data is passed without any changes to the underlying CreateBitmap() API. Under other platforms, only monochrome bitmaps may be created using this constructor and wxImage should be used for creating colour bitmaps from static data.

Parameters
bitsSpecifies an array of pixel values.
widthSpecifies the width of the bitmap.
heightSpecifies the height of the bitmap.
depthSpecifies the depth of the bitmap. If this is omitted, then a value of 1 (monochrome bitmap) is used.

wxPerl Note: In wxPerl use Wx::Bitmap->newFromBits(bits, width, height, depth).

wxBitmap::wxBitmap ( int  width,
int  height,
int  depth = wxBITMAP_SCREEN_DEPTH 
)

Creates a new bitmap.

A depth of wxBITMAP_SCREEN_DEPTH indicates the depth of the current screen or visual.

Some platforms only support 1 for monochrome and wxBITMAP_SCREEN_DEPTH for the current colour setting.

A depth of 32 including an alpha channel is supported under MSW, Mac and GTK+.

Parameters
widthThe width of the bitmap in pixels, must be strictly positive.
heightThe height of the bitmap in pixels, must be strictly positive.
depthThe number of bits used to represent each bitmap pixel.
wxBitmap::wxBitmap ( const wxSize sz,
int  depth = wxBITMAP_SCREEN_DEPTH 
)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

wxBitmap::wxBitmap ( const char *const *  bits)

Creates a bitmap from XPM data.

wxPerl Note: In wxPerl use Wx::Bitmap->newFromXPM(data).

wxBitmap::wxBitmap ( const wxString name,
wxBitmapType  type = wxBITMAP_DEFAULT_TYPE 
)

Loads a bitmap from a file or resource.

Parameters
nameThis can refer to a resource name or a filename under MS Windows and X. Its meaning is determined by the type parameter.
typeMay be one of the wxBitmapType values and indicates which type of bitmap should be loaded. See the note in the class detailed description. Note that the wxBITMAP_DEFAULT_TYPE constant has different value under different wxWidgets ports. See the bitmap.h header for the value it takes for a specific port.
See also
LoadFile()
wxBitmap::wxBitmap ( const wxImage img,
int  depth = wxBITMAP_SCREEN_DEPTH 
)

Creates this bitmap object from the given image.

This has to be done to actually display an image as you cannot draw an image directly on a window.

The resulting bitmap will use the provided colour depth (or that of the current system if depth is wxBITMAP_SCREEN_DEPTH) which entails that a colour reduction may take place.

On Windows, if there is a palette present (set with SetPalette), it will be used when creating the wxBitmap (most useful in 8-bit display mode). On other platforms, the palette is currently ignored.

Parameters
imgPlatform-independent wxImage object.
depthSpecifies the depth of the bitmap. If this is omitted, the display depth of the screen is used.
wxBitmap::wxBitmap ( const wxCursor cursor)
explicit

Creates bitmap corresponding to the given cursor.

This can be useful to display a cursor as it cannot be drawn directly on a window.

This constructor only exists in wxMSW and wxGTK (where it is implemented for GTK+ 2.8 or later) only.

Parameters
cursorA valid wxCursor.
Since
3.1.0
virtual wxBitmap::~wxBitmap ( )
virtual

Destructor.

See Object Destruction for more info.

If the application omits to delete the bitmap explicitly, the bitmap will be destroyed automatically by wxWidgets when the application exits.

Warning
Do not delete a bitmap that is selected into a memory device context.

Member Function Documentation

static void wxBitmap::AddHandler ( wxBitmapHandler handler)
static

Adds a handler to the end of the static list of format handlers.

Parameters
handlerA new bitmap format handler object. There is usually only one instance of a given handler class in an application session.

Note that unlike wxImage::AddHandler, there's no documented list of the wxBitmapHandlers available in wxWidgets. This is because they are platform-specific and most important, they are all automatically loaded at startup.

If you want to be sure that wxBitmap can load a certain type of image, you'd better use wxImage::AddHandler.

See also
wxBitmapHandler
static void wxBitmap::CleanUpHandlers ( )
static

Deletes all bitmap handlers.

This function is called by wxWidgets on exit.

wxBitmap wxBitmap::ConvertToDisabled ( unsigned char  brightness = 255) const

Returns disabled (dimmed) version of the bitmap.

This method is not available when wxUSE_IMAGE == 0.

Since
2.9.0
virtual wxImage wxBitmap::ConvertToImage ( ) const
virtual

Creates an image from a platform-dependent bitmap.

This preserves mask information so that bitmaps and images can be converted back and forth without loss in that respect.

virtual bool wxBitmap::CopyFromIcon ( const wxIcon icon)
virtual

Creates the bitmap from an icon.

virtual bool wxBitmap::Create ( int  width,
int  height,
int  depth = wxBITMAP_SCREEN_DEPTH 
)
virtual

Creates a fresh bitmap.

If the final argument is omitted, the display depth of the screen is used.

Parameters
widthThe width of the bitmap in pixels, must be strictly positive.
heightThe height of the bitmap in pixels, must be strictly positive.
depthThe number of bits used to represent each bitmap pixel.
Returns
true if the creation was successful.
virtual bool wxBitmap::Create ( const wxSize sz,
int  depth = wxBITMAP_SCREEN_DEPTH 
)
virtual

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

bool wxBitmap::Create ( int  width,
int  height,
const wxDC dc 
)

Create a bitmap compatible with the given DC, inheriting its magnification factor.

Parameters
widthThe width of the bitmap in pixels, must be strictly positive.
heightThe height of the bitmap in pixels, must be strictly positive.
dcDC from wich the scaling factor is inherited
Returns
true if the creation was successful.
Since
3.1.0
bool wxBitmap::CreateScaled ( int  logwidth,
int  logheight,
int  depth,
double  logicalScale 
)

Create a bitmap with a scale factor, width and height are multiplied with that factor.

Parameters
widthThe width of the bitmap in pixels, must be strictly positive.
heightThe height of the bitmap in pixels, must be strictly positive.
depthThe number of bits used to represent each bitmap pixel.
logicalScaleScale factor used by the bitmap
Returns
true if the creation was successful.
Since
3.1.0
static wxBitmapHandler* wxBitmap::FindHandler ( const wxString name)
static

Finds the handler with the given name.

Returns
A pointer to the handler if found, NULL otherwise.
static wxBitmapHandler* wxBitmap::FindHandler ( const wxString extension,
wxBitmapType  bitmapType 
)
static

Finds the handler associated with the given extension and type.

Parameters
extensionThe file extension, such as "bmp" (without the dot).
bitmapTypeThe bitmap type managed by the handler, see wxBitmapType.
Returns
A pointer to the handler if found, NULL otherwise.
static wxBitmapHandler* wxBitmap::FindHandler ( wxBitmapType  bitmapType)
static

Finds the handler associated with the given bitmap type.

Parameters
bitmapTypeThe bitmap type managed by the handler, see wxBitmapType.
Returns
A pointer to the handler if found, NULL otherwise.
See also
wxBitmapHandler
virtual int wxBitmap::GetDepth ( ) const
virtual

Gets the colour depth of the bitmap.

A value of 1 indicates a monochrome bitmap.

static wxList& wxBitmap::GetHandlers ( )
static

Returns the static list of bitmap format handlers.

See also
wxBitmapHandler
virtual int wxBitmap::GetHeight ( ) const
virtual

Gets the height of the bitmap in pixels.

See also
GetWidth(), GetSize()
virtual wxMask* wxBitmap::GetMask ( ) const
virtual

Gets the associated mask (if any) which may have been loaded from a file or set for the bitmap.

See also
SetMask(), wxMask
virtual wxPalette* wxBitmap::GetPalette ( ) const
virtual

Gets the associated palette (if any) which may have been loaded from a file or set for the bitmap.

See also
wxPalette
wxSize wxBitmap::GetSize ( ) const

Returns the size of the bitmap in pixels.

Since
2.9.0
See also
GetHeight(), GetWidth()
virtual wxBitmap wxBitmap::GetSubBitmap ( const wxRect rect) const
virtual

Returns a sub bitmap of the current one as long as the rect belongs entirely to the bitmap.

This function preserves bit depth and mask information.

virtual int wxBitmap::GetWidth ( ) const
virtual

Gets the width of the bitmap in pixels.

See also
GetHeight(), GetSize()
static void wxBitmap::InitStandardHandlers ( )
static

Adds the standard bitmap format handlers, which, depending on wxWidgets configuration, can be handlers for Windows bitmap, Windows bitmap resource, and XPM.

This function is called by wxWidgets on startup.

See also
wxBitmapHandler
static void wxBitmap::InsertHandler ( wxBitmapHandler handler)
static

Adds a handler at the start of the static list of format handlers.

Parameters
handlerA new bitmap format handler object. There is usually only one instance of a given handler class in an application session.
See also
wxBitmapHandler
virtual bool wxBitmap::IsOk ( ) const
virtual

Returns true if bitmap data is present.

virtual bool wxBitmap::LoadFile ( const wxString name,
wxBitmapType  type = wxBITMAP_DEFAULT_TYPE 
)
virtual

Loads a bitmap from a file or resource.

Parameters
nameEither a filename or a Windows resource name. The meaning of name is determined by the type parameter.
typeOne of the wxBitmapType values; see the note in the class detailed description. Note that the wxBITMAP_DEFAULT_TYPE constant has different value under different wxWidgets ports. See the bitmap.h header for the value it takes for a specific port.
Returns
true if the operation succeeded, false otherwise.
Remarks
A palette may be associated with the bitmap if one exists (especially for colour Windows bitmaps), and if the code supports it. You can check if one has been created by using the GetPalette() member.
See also
SaveFile()
static wxBitmap wxBitmap::NewFromPNGData ( const void *  data,
size_t  size 
)
static

Loads a bitmap from the memory containing image data in PNG format.

This helper function provides the simplest way to create a wxBitmap from PNG image data. On most platforms, it's simply a wrapper around wxImage loading functions and so requires the PNG image handler to be registered by either calling wxInitAllImageHandlers() which also registers all the other image formats or including the necessary header:

#include <wx/imagpng.h>

and calling

wxImage::AddHandler(new wxPNGHandler);

in your application startup code.

However under OS X this function uses native image loading and so doesn't require wxWidgets PNG support.

Since
2.9.5
static bool wxBitmap::RemoveHandler ( const wxString name)
static

Finds the handler with the given name, and removes it.

The handler is not deleted.

Parameters
nameThe handler name.
Returns
true if the handler was found and removed, false otherwise.
See also
wxBitmapHandler
virtual bool wxBitmap::SaveFile ( const wxString name,
wxBitmapType  type,
const wxPalette palette = NULL 
) const
virtual

Saves a bitmap in the named file.

Parameters
nameA filename. The meaning of name is determined by the type parameter.
typeOne of the wxBitmapType values; see the note in the class detailed description.
paletteAn optional palette used for saving the bitmap.
Returns
true if the operation succeeded, false otherwise.
Remarks
Depending on how wxWidgets has been configured, not all formats may be available.
See also
LoadFile()
virtual void wxBitmap::SetDepth ( int  depth)
virtual

Sets the depth member (does not affect the bitmap data).

Todo:
since these functions do not affect the bitmap data, why they exist??
Parameters
depthBitmap depth.
virtual void wxBitmap::SetHeight ( int  height)
virtual

Sets the height member (does not affect the bitmap data).

Parameters
heightBitmap height in pixels.
virtual void wxBitmap::SetMask ( wxMask mask)
virtual

Sets the mask for this bitmap.

Remarks
The bitmap object owns the mask once this has been called.
See also
GetMask(), wxMask
virtual void wxBitmap::SetPalette ( const wxPalette palette)
virtual

Sets the associated palette.

(Not implemented under GTK+).

Parameters
paletteThe palette to set.
See also
wxPalette
virtual void wxBitmap::SetWidth ( int  width)
virtual

Sets the width member (does not affect the bitmap data).

Parameters
widthBitmap width in pixels.