wxPen Class Reference

#include </home/zeitlin/src/wx/github/interface/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.

注:

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:

• wxNullPen
• wxBLACK_DASHED_PEN
• wxBLACK_PEN
• wxBLUE_PEN
• wxCYAN_PEN
• wxGREEN_PEN
• wxYELLOW_PEN
• wxGREY_PEN
• wxLIGHT_GREY_PEN
• wxMEDIUM_GREY_PEN
• wxRED_PEN
• wxTRANSPARENT_PEN
• wxWHITE_PEN

参照:

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 wxBitmap *	GetStipple () 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.
wxPen &	operator= (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.

List of all members.

---

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:

colour	A colour object.
width	Pen 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.
style	The style may be one of the wxPenStyle values.

注意:

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.

参照:

SetStyle(), SetColour(), SetWidth()

wxPen::wxPen	(	const wxBitmap &	stipple,
		int	width
	)

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

Parameters:

width	Pen 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.
stipple	A stipple bitmap.

Availability:  only available for the wxMSW, wxOSX ports.

参照:

SetWidth(), SetStipple()

wxPen::wxPen

(

const wxPen &

pen

)

Copy constructor, uses Reference Counting.

Parameters:

pen	A pointer or reference to a pen to copy.

virtual wxPen::~wxPen

(

)

[virtual]

Destructor.

参照:

reference-counted object destruction

注意:

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.

参照:

SetCap()

virtual wxColour wxPen::GetColour

(

)

const [virtual]

Returns a reference to the pen colour.

参照:

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.

参照:

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.

参照:

SetJoin()

virtual wxBitmap* wxPen::GetStipple

(

)

const [virtual]

Gets a pointer to the stipple bitmap.

参照:

SetStipple()

virtual wxPenStyle wxPen::GetStyle

(

)

const [virtual]

Returns the pen style.

参照:

wxPen(), SetStyle()

virtual int wxPen::GetWidth

(

)

const [virtual]

Returns the pen width.

参照:

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.

参照:

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.

参照:

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.

参照:

GetCap()

virtual void wxPen::SetColour	(	unsigned char	red,
		unsigned char	green,
		unsigned char	blue
	)		[virtual]

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

参照:

GetColour()

virtual void wxPen::SetColour

(

wxColour &

colour

)

[virtual]

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

参照:

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.

参照:

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.

参照:

GetJoin()

virtual void wxPen::SetStipple

(

const wxBitmap &

stipple

)

[virtual]

Sets the bitmap for stippling.

参照:

GetStipple()

virtual void wxPen::SetStyle

(

wxPenStyle

style

)

[virtual]

Set the pen style.

参照:

wxPen()

virtual void wxPen::SetWidth

(

int

width

)

[virtual]

Sets the pen width.

参照:

GetWidth()