Version: 3.0.2
wxPen Class Reference

#include <wx/pen.h>

+ Inheritance diagram for wxPen:

Detailed Description

A pen is a drawing tool for drawing outlines.

It is used for drawing lines and painting the outline of rectangles, ellipses, etc. It has a colour, a width and a style.

Note
On a monochrome display, wxWidgets shows all non-white pens as black.

Do not initialize objects on the stack before the program commences, since other required structures may not have been set up yet. Instead, define global pointers to objects and create them in wxApp::OnInit() or when required.

An application may wish to dynamically create pens with different characteristics, and there is the consequent danger that a large number of duplicate pens will be created. Therefore an application may wish to get a pointer to a pen by using the global list of pens wxThePenList, and calling the member function wxPenList::FindOrCreatePen(). See wxPenList for more info.

This class uses reference counting and copy-on-write internally so that assignments between two instances of this class are very cheap. You can therefore use actual objects instead of pointers without efficiency problems. If an instance of this class is changed it will create its own data internally so that other instances, which previously shared the data using the reference counting, are not affected.

Library:  wxCore
Category:  Graphics Device Interface (GDI)

Predefined objects/pointers:

See Also
wxPenList, wxDC, wxDC::SetPen()

Public Member Functions

 wxPen ()
 Default constructor.
 
 wxPen (const wxColour &colour, int width=1, wxPenStyle style=wxPENSTYLE_SOLID)
 Constructs a pen from a colour object, pen width and style.
 
 wxPen (const wxBitmap &stipple, int width)
 Constructs a stippled pen from a stipple bitmap and a width.
 
 wxPen (const wxPen &pen)
 Copy constructor, uses Reference Counting.
 
virtual ~wxPen ()
 Destructor.
 
virtual wxPenCap GetCap () const
 Returns the pen cap style, which may be one of wxCAP_ROUND, wxCAP_PROJECTING and wxCAP_BUTT.
 
virtual wxColour GetColour () const
 Returns a reference to the pen colour.
 
virtual int GetDashes (wxDash **dashes) const
 Gets an array of dashes (defined as char in X, DWORD under Windows).
 
virtual wxPenJoin GetJoin () const
 Returns the pen join style, which may be one of wxJOIN_BEVEL, wxJOIN_ROUND and wxJOIN_MITER.
 
virtual wxBitmapGetStipple () const
 Gets a pointer to the stipple bitmap.
 
virtual wxPenStyle GetStyle () const
 Returns the pen style.
 
virtual int GetWidth () const
 Returns the pen width.
 
virtual bool IsOk () const
 Returns true if the pen is initialised.
 
bool IsNonTransparent () const
 Returns true if the pen is a valid non-transparent pen.
 
bool IsTransparent () const
 Returns true if the pen is transparent.
 
virtual void SetCap (wxPenCap capStyle)
 Sets the pen cap style, which may be one of wxCAP_ROUND, wxCAP_PROJECTING and wxCAP_BUTT.
 
virtual void SetDashes (int n, const wxDash *dash)
 Associates an array of dash values (defined as char in X, DWORD under Windows) with the pen.
 
virtual void SetJoin (wxPenJoin join_style)
 Sets the pen join style, which may be one of wxJOIN_BEVEL, wxJOIN_ROUND and wxJOIN_MITER.
 
virtual void SetStipple (const wxBitmap &stipple)
 Sets the bitmap for stippling.
 
virtual void SetStyle (wxPenStyle style)
 Set the pen style.
 
virtual void SetWidth (int width)
 Sets the pen width.
 
bool operator!= (const wxPen &pen) const
 Inequality operator.
 
wxPenoperator= (const wxPen &pen)
 Assignment operator, using Reference Counting.
 
bool operator== (const wxPen &pen) const
 Equality operator.
 
virtual void SetColour (wxColour &colour)
 The pen's colour is changed to the given colour.
 
virtual void SetColour (unsigned char red, unsigned char green, unsigned char blue)
 The pen's colour is changed to the given colour.
 
- Public Member Functions inherited from wxGDIObject
 wxGDIObject ()
 Default constructor.
 
- Public Member Functions inherited from wxObject
 wxObject ()
 Default ctor; initializes to NULL the internal reference data.
 
 wxObject (const wxObject &other)
 Copy ctor.
 
virtual ~wxObject ()
 Destructor.
 
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).
 
wxObjectRefDataGetRefData () const
 Returns the wxObject::m_refData pointer, i.e. the data referenced by this object.
 
bool IsKindOf (const wxClassInfo *info) const
 Determines whether this class is a subclass of (or the same class as) the given class.
 
bool IsSameAs (const wxObject &obj) const
 Returns true if this object has the same data pointer as obj.
 
void Ref (const wxObject &clone)
 Makes this object refer to the data in clone.
 
void SetRefData (wxObjectRefData *data)
 Sets the wxObject::m_refData pointer.
 
void UnRef ()
 Decrements the reference count in the associated data, and if it is zero, deletes the data.
 
void UnShare ()
 This is the same of AllocExclusive() but this method is public.
 
void operator delete (void *buf)
 The delete operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined.
 
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.
 

Additional Inherited Members

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

Constructor & Destructor Documentation

wxPen::wxPen ( )

Default constructor.

The pen will be uninitialised, and IsOk() will return false.

wxPen::wxPen ( const wxColour colour,
int  width = 1,
wxPenStyle  style = wxPENSTYLE_SOLID 
)

Constructs a pen from a colour object, pen width and style.

Parameters
colourA colour object.
widthPen width. Under Windows, the pen width cannot be greater than 1 if the style is wxPENSTYLE_DOT, wxPENSTYLE_LONG_DASH, wxPENSTYLE_SHORT_DASH, wxPENSTYLE_DOT_DASH, or wxPENSTYLE_USER_DASH.
styleThe style may be one of the wxPenStyle values.
Remarks
Different versions of Windows and different versions of other platforms support very different subsets of the styles above
  • there is no similarity even between Windows95 and Windows98 - so handle with care.
See Also
SetStyle(), SetColour(), SetWidth()
wxPen::wxPen ( const wxBitmap stipple,
int  width 
)

Constructs a stippled pen from a stipple bitmap and a width.

Parameters
widthPen width. Under Windows, the pen width cannot be greater than 1 if the style is wxPENSTYLE_DOT, wxPENSTYLE_LONG_DASH, wxPENSTYLE_SHORT_DASH, wxPENSTYLE_DOT_DASH, or wxPENSTYLE_USER_DASH.
stippleA stipple bitmap.
Availability:  only available for the wxMSW, wxOSX ports.
See Also
SetWidth(), SetStipple()
wxPen::wxPen ( const wxPen pen)

Copy constructor, uses Reference Counting.

Parameters
penA pointer or reference to a pen to copy.
virtual wxPen::~wxPen ( )
virtual

Destructor.

See Also
reference-counted object destruction
Remarks
Although all remaining pens are deleted when the application exits, the application should try to clean up all pens itself. This is because wxWidgets cannot know if a pointer to the pen object is stored in an application data structure, and there is a risk of double deletion.

Member Function Documentation

virtual wxPenCap wxPen::GetCap ( ) const
virtual

Returns the pen cap style, which may be one of wxCAP_ROUND, wxCAP_PROJECTING and wxCAP_BUTT.

The default is wxCAP_ROUND.

See Also
SetCap()
virtual wxColour wxPen::GetColour ( ) const
virtual

Returns a reference to the pen colour.

See Also
SetColour()
virtual int wxPen::GetDashes ( wxDash **  dashes) const
virtual

Gets an array of dashes (defined as char in X, DWORD under Windows).

dashes is a pointer to the internal array. Do not deallocate or store this pointer.

Returns
The number of dashes associated with this pen.
See Also
SetDashes()
virtual wxPenJoin wxPen::GetJoin ( ) const
virtual

Returns the pen join style, which may be one of wxJOIN_BEVEL, wxJOIN_ROUND and wxJOIN_MITER.

The default is wxJOIN_ROUND.

See Also
SetJoin()
virtual wxBitmap* wxPen::GetStipple ( ) const
virtual

Gets a pointer to the stipple bitmap.

See Also
SetStipple()
virtual wxPenStyle wxPen::GetStyle ( ) const
virtual

Returns the pen style.

See Also
wxPen(), SetStyle()
virtual int wxPen::GetWidth ( ) const
virtual

Returns the pen width.

See Also
SetWidth()
bool wxPen::IsNonTransparent ( ) const

Returns true if the pen is a valid non-transparent pen.

This method returns true if the pen object is initialized and has a non-transparent style. Notice that this should be used instead of simply testing whether GetStyle() returns a style different from wxPENSTYLE_TRANSPARENT if the pen may be invalid as GetStyle() would assert in this case.

See Also
IsTransparent()
Since
2.9.2.
virtual bool wxPen::IsOk ( ) const
virtual

Returns true if the pen is initialised.

Notice that an uninitialized pen object can't be queried for any pen properties and all calls to the accessor methods on it will result in an assert failure.

bool wxPen::IsTransparent ( ) const

Returns true if the pen is transparent.

A transparent pen is simply a pen with wxPENSTYLE_TRANSPARENT style.

Notice that this function works even for non-initialized pens (for which it returns false) unlike tests of the form GetStyle() == wxPENSTYLE_TRANSPARENT which would assert if the pen is invalid.

See Also
IsNonTransparent()
Since
2.9.2.
bool wxPen::operator!= ( const wxPen pen) const

Inequality operator.

See reference-counted object comparison for more info.

wxPen& wxPen::operator= ( const wxPen pen)

Assignment operator, using Reference Counting.

bool wxPen::operator== ( const wxPen pen) const

Equality operator.

See reference-counted object comparison for more info.

virtual void wxPen::SetCap ( wxPenCap  capStyle)
virtual

Sets the pen cap style, which may be one of wxCAP_ROUND, wxCAP_PROJECTING and wxCAP_BUTT.

The default is wxCAP_ROUND.

See Also
GetCap()
virtual void wxPen::SetColour ( wxColour colour)
virtual

The pen's colour is changed to the given colour.

See Also
GetColour()
virtual void wxPen::SetColour ( unsigned char  red,
unsigned char  green,
unsigned char  blue 
)
virtual

The pen's colour is changed to the given colour.

See Also
GetColour()
virtual void wxPen::SetDashes ( int  n,
const wxDash *  dash 
)
virtual

Associates an array of dash values (defined as char in X, DWORD under Windows) with the pen.

The array is not deallocated by wxPen, but neither must it be deallocated by the calling application until the pen is deleted or this function is called with a NULL array.

See Also
GetDashes()
virtual void wxPen::SetJoin ( wxPenJoin  join_style)
virtual

Sets the pen join style, which may be one of wxJOIN_BEVEL, wxJOIN_ROUND and wxJOIN_MITER.

The default is wxJOIN_ROUND.

See Also
GetJoin()
virtual void wxPen::SetStipple ( const wxBitmap stipple)
virtual

Sets the bitmap for stippling.

See Also
GetStipple()
virtual void wxPen::SetStyle ( wxPenStyle  style)
virtual

Set the pen style.

See Also
wxPen()
virtual void wxPen::SetWidth ( int  width)
virtual

Sets the pen width.

See Also
GetWidth()