Methods Index

CPen

Heritage

Description

The CPen class encapsulates XVT pens. Objects of this type describe a color pen for drawing lines, but not for filling in shapes with an interior (use a CBrush for that). Each window has its own current CPen. The CPen object describes the color, the pattern, the style, and the width of the pen.

The color is indicated by RGB values. XVT uses a 24-bit number to specify a color. The 24 bits are divided into three 8-bit values for the red, green, and blue components.

For your convenience, XVT provides symbols for the colors in Table 11. You can use other colors if you wish. However, if your target platform doesn't flexibly support color, XVT recommends that you use one of the predefined colors.

The pattern indicates the pen pattern, which has the allowable values shown in Table 12. The style indicates the style used by the pen, which has the predefined values shown in Table 13. The width is the width of the pen stroke in pixels.

Table 11. Predefined XVT Portability Toolkit Color Variables
Color Symbol Color
#define COLOR_INVALID

Error return

#define COLOR_RED

Red

#define COLOR_GREEN

Green

#define COLOR_BLUE

Blue

#define COLOR_CYAN

Cyan

#define COLOR_MAGENTA

Magenta

#define COLOR_YELLOW

Yellow

#define COLOR_BLACK

Black

#define COLOR_DKGRAY

Dark Gray

#define COLOR_GRAY

Gray

#define COLOR_LTGRAY

Light Gray

#define COLOR_WHITE

White

*Table 11. Predefined XVT Portability Toolkit Color Variables*
Color Symbol	Color
#define COLOR_INVALID	Error return
#define COLOR_RED	Red
#define COLOR_GREEN	Green
#define COLOR_BLUE	Blue
#define COLOR_CYAN	Cyan
#define COLOR_MAGENTA	Magenta
#define COLOR_YELLOW	Yellow
#define COLOR_BLACK	Black
#define COLOR_DKGRAY	Dark Gray
#define COLOR_GRAY	Gray
#define COLOR_LTGRAY	Light Gray
#define COLOR_WHITE	White

Table 12. Predefined XVT Portability Toolkit Pen Patterns
Pattern Symbol Description
PAT_SOLID
A normal pen that draws a solid line in the specified width with the specified color.
PAT_HOLLOW
No pen at all; shapes with a brush do not have a border around them, and shapes with only a pen are not seen.
PAT_RUBBER
Used for rubberbanding; a grayish or dotted line that allows a user to stretch a rectangle or other shape by moving the mouse. Drawing is always done with a mode of M_XOR.

*Table 12. Predefined XVT Portability Toolkit Pen Patterns*
Pattern Symbol	Description
PAT_SOLID	A normal pen that draws a solid line in the specified width with the specified color.
PAT_HOLLOW	No pen at all; shapes with a brush do not have a border around them, and shapes with only a pen are not seen.
PAT_RUBBER	Used for rubberbanding; a grayish or dotted line that allows a user to stretch a rectangle or other shape by moving the mouse. Drawing is always done with a mode of M_XOR.

Table 13. Predefined XVT Portability Toolkit Pen Styles
Style Symbol Description
P_SOLID
Solid line
P_DOT
Dotted line
P_DASH
Dashed line

*Table 13. Predefined XVT Portability Toolkit Pen Styles*
Style Symbol	Description
P_SOLID	Solid line
P_DOT	Dotted line
P_DASH	Dashed line

See Also: For information on filling closed shapes, see CBrush. For information on drawing modes and other "environmental" attributes, see CEnvironment.

Usage

CPen aPen(COLOR_RED, PAT_SOLID, P_SOLID, 1);
 
CPEN anXVTPen = aPen;
xvt_dwin_set_cpen(itsXVTWindow, &anXVTPen);
 
xvt_dwin_set_back_color(itsXVTWindow, aPen.GetColor());

Protected Data Members

CPen Attributes

`CPEN` `itsPen;` The pen


`CPEN`	`itsPen;`	The pen

Public Methods

Constructor, Destructor, and Initializer Methods

CPen();

An empty constructor that initializes a default pen.

CPen(COLOR theColor,
	PAT_STYLE thePattern,
	PEN_STYLE theStyle	= P_SOLID,
	short theWidth	= 1);

A constructor that creates a pen with a specified color, pattern, style, and width.

CPen(CPEN thePen);

A constructor that copies a pen object from an existing XVT Portability Toolkit CPEN object.

CPen(const CPen &theImage);

A copy constructor, which duplicates the CPen object associated with the specified image.

CPen & operator= (const CPen &thePen);

An assignment operator, which copies the attributes of the CPen specified by thePen.

~CPen();

A destructor, which deletes the pen.

Helper Operators

operator CPEN () const;

A conversion operator, which returns a reference to an XVT Portability Toolkit CPEN. Since this method returns a direct reference into internal information, use this method carefully. Specifically, do not use this method in cases in which the calling method might destroy or alter the handle.

CPen & operator= (CPEN thePen);

An assignment operator, which consumes an XVT Portability Toolkit CPEN.

State Methods

void IPen(COLOR theColor,
	PAT_STYLE thePattern,
	PEN_STYLE theStyle = P_SOLID,
	short theWidth = 1);

The initializer. With this method you can simultaneously initialize a pen's color (theColor), pattern (thePattern), style (theStyle), and width (theWidth).

void SetColor(COLOR theColor);

Sets the color of the pen's ink.

void SetPattern(PAT_STYLE thePattern);

Sets the pattern of the pen's line.

void SetStyle(PEN_STYLE theStyle);

Sets the style of the pen's line.

void SetWidth(short theWidth);

Sets the width of the pen's line in pixels.

COLOR GetColor(void) const;

Returns the color of the pen's ink.

PAT_STYLE GetPattern(void) const;

Returns the pattern of the pen's line.

PEN_STYLE GetStyle(void) const;

Returns the style of the pen's line.

short GetWidth(void) const;

Returns the width of the pen's line in pixels.

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CPen

CPen

Heritage

Description

Error return

Red

Green

Blue

Cyan

Magenta

Yellow

Black

Dark Gray

Gray

Light Gray

White

Usage

Protected Data Members

CPen Attributes CPEN itsPen; The pen

Public Methods

Constructor, Destructor, and Initializer Methods

Helper Operators

State Methods

CPen Attributes

`CPEN` `itsPen;` The pen