Gdk::GC Class Reference

All drawing operations in GDK take a graphics context (GC) argument. More...

Collaboration diagram for Gdk::GC:

Public Member Functions
virtual	~GC ()
GdkGC*	gobj ()
	Provides access to the underlying C GObject.
const GdkGC*	gobj () const
	Provides access to the underlying C GObject.
GdkGC*	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
void	set_foreground (const Color& color)
	Sets the foreground color for a graphics context.
void	set_background (const Color& color)
	Sets the background color for a graphics context.
void	set_function (Function function)
	Determines how the current pixel values and the pixel values being drawn are combined to produce the final pixel values.
void	set_fill (Fill fill)
	Set the fill mode for a graphics context.
void	set_tile (const Glib::RefPtr< Pixmap >& tile)
	Set a tile pixmap for a graphics context.
void	set_stipple (const Glib::RefPtr< Pixmap >& stipple)
	Set the stipple bitmap for a graphics context.
void	set_ts_origin (int x, int y)
	Set the origin when using tiles or stipples with the GC.
void	set_clip_origin (int x, int y)
	Sets the origin of the clip mask.
void	set_clip_mask (const Glib::RefPtr< Bitmap >& mask)
	Sets the clip mask for a graphics context from a bitmap.
void	set_clip_rectangle (Rectangle& rectangle)
void	set_clip_rectangle (const Rectangle& rectangle)
	Sets the clip mask for a graphics context from a rectangle.
void	set_clip_region (const Region& region)
	Sets the clip mask for a graphics context from a region structure.
void	set_subwindow (SubwindowMode mode)
	Sets how drawing with this GC on a window will affect child windows of that window.
void	set_exposures (bool exposures)
	Sets whether copying non-visible portions of a drawable using this graphics context generate exposure events for the corresponding regions of the destination drawable.
void	set_line_attributes (int line_width, LineStyle line_style, CapStyle cap_style, JoinStyle join_style)
	Sets various attributes of how lines are drawn.
void	set_dashes (int dash_offset, gint8* dash_list, int n)
	Sets the way dashed-lines are drawn.
void	offset (int x_offset, int y_offset)
	Offset attributes such as the clip and tile-stipple origins of the GC so that drawing at x - x_offset, y - y_offset with the offset GC has the same effect as drawing at x, y with the original GC.
void	set_colormap (const Glib::RefPtr< Colormap >& colormap)
	Sets the colormap for the GC to the given colormap.
Glib::RefPtr< Colormap >	get_colormap ()
	Retrieves the colormap for a given GC, if it exists.
void	set_rgb_fg_color (const Color& color)
	Set the foreground color of a GC using an unallocated color.
void	set_rgb_bg_color (const Color& color)
	Set the background color of a GC using an unallocated color.
Glib::RefPtr< Screen >	get_screen ()
	Gets the Gdk::Screen for which gc was created.
Glib::RefPtr< const Screen >	get_screen () const
	Gets the Gdk::Screen for which gc was created.
Static Public Member Functions
static Glib::RefPtr< GC >	create ()
static Glib::RefPtr< GC >	create (const Glib::RefPtr< Drawable >& drawable)
Protected Member Functions
	GC ()
	GC (const Glib::RefPtr< Drawable >& drawable)
Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gdk::GC >	wrap (GdkGC* object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

All drawing operations in GDK take a graphics context (GC) argument.

A graphics context encapsulates information about the way things are drawn, such as the foreground color or line width. By using graphics contexts, the number of arguments to each drawing call is greatly reduced, and communication overhead is minimized, since identical arguments do not need to be passed repeatedly.

Constructor & Destructor Documentation

virtual Gdk::GC::~GC ( ) [virtual]

Gdk::GC::GC ( ) [protected]

Gdk::GC::GC ( const Glib::RefPtr< Drawable >& drawable ) [explicit, protected]

Member Function Documentation

static Glib::RefPtr<GC> Gdk::GC::create ( const Glib::RefPtr< Drawable >& drawable ) [static]

static Glib::RefPtr<GC> Gdk::GC::create ( ) [static]

Glib::RefPtr<Colormap> Gdk::GC::get_colormap ( )

Retrieves the colormap for a given GC, if it exists.

A GC will have a colormap if the drawable for which it was created has a colormap, or if a colormap was set explicitely with gdk_gc_set_colormap.

Returns:: The colormap of gc, or 0 if gc doesn't have one.

Glib::RefPtr<const Screen> Gdk::GC::get_screen ( ) const

Gets the Gdk::Screen for which gc was created.

Since gtkmm 2.2:

Returns:: The Gdk::Screen for gc.

Glib::RefPtr<Screen> Gdk::GC::get_screen ( )

Gets the Gdk::Screen for which gc was created.

Since gtkmm 2.2:

Returns:: The Gdk::Screen for gc.

const GdkGC* Gdk::GC::gobj ( ) const [inline]

Provides access to the underlying C GObject.

Reimplemented from Glib::ObjectBase.

GdkGC* Gdk::GC::gobj ( ) [inline]

Provides access to the underlying C GObject.

Reimplemented from Glib::ObjectBase.

GdkGC* Gdk::GC::gobj_copy ( )

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

void Gdk::GC::offset	(	int	x_offset,
		int	y_offset
	)

Offset attributes such as the clip and tile-stipple origins of the GC so that drawing at x - x_offset, y - y_offset with the offset GC has the same effect as drawing at x, y with the original GC.

Parameters:

	x_offset	Amount by which to offset the GC in the X direction.
	y_offset	Amount by which to offset the GC in the Y direction.

void Gdk::GC::set_background ( const Color& color )

Sets the background color for a graphics context.

Note that this function uses color->pixel, use set_rgb_bg_color() to specify the background color as red, green, blue components.

Parameters:

color

The new background color.

void Gdk::GC::set_clip_mask ( const Glib::RefPtr< Bitmap >& mask )

Sets the clip mask for a graphics context from a bitmap.

The clip mask is interpreted relative to the clip origin. (See set_clip_origin()).

Parameters:

mask

A bitmap.

void Gdk::GC::set_clip_origin	(	int	x,
		int	y
	)

Sets the origin of the clip mask.

The coordinates are interpreted relative to the upper-left corner of the destination drawable of the current operation.

Parameters:

	x	The x-coordinate of the origin.
	y	The y-coordinate of the origin.

void Gdk::GC::set_clip_rectangle ( const Rectangle& rectangle )

Sets the clip mask for a graphics context from a rectangle.

The clip mask is interpreted relative to the clip origin. (See set_clip_origin()).

Parameters:

rectangle

The rectangle to clip to.

void Gdk::GC::set_clip_rectangle ( Rectangle& rectangle )

Deprecated:: Use set_clip_rectangle(const Rectangle& rectangle) instead.

void Gdk::GC::set_clip_region ( const Region& region )

Sets the clip mask for a graphics context from a region structure.

The clip mask is interpreted relative to the clip origin. (See set_clip_origin()).

Parameters:

region

The Gdk::Region.

void Gdk::GC::set_colormap ( const Glib::RefPtr< Colormap >& colormap )

Sets the colormap for the GC to the given colormap.

The depth of the colormap's visual must match the depth of the drawable for which the GC was created.

Parameters:

colormap

A Gdk::Colormap.

void Gdk::GC::set_dashes	(	int	dash_offset,
		gint8 *	dash_list,
		int	n
	)

Sets the way dashed-lines are drawn.

Lines will be drawn with alternating on and off segments of the lengths specified in dash_list. The manner in which the on and off segments are drawn is determined by the line_style value of the GC. (This can be changed with set_line_attributes().)

The dash_offset defines the phase of the pattern, specifying how many pixels into the dash-list the pattern should actually begin.

Parameters:

	dash_offset	The phase of the dash pattern.
	dash_list	An array of dash lengths.
	n	The number of elements in dash_list.

void Gdk::GC::set_exposures ( bool exposures )

Sets whether copying non-visible portions of a drawable using this graphics context generate exposure events for the corresponding regions of the destination drawable.

(See gdk_draw_drawable()).

Parameters:

exposures If true, exposure events will be generated.

void Gdk::GC::set_fill ( Fill fill )

Set the fill mode for a graphics context.

Parameters:

fill

The new fill mode.

void Gdk::GC::set_foreground ( const Color& color )

Sets the foreground color for a graphics context.

Note that this function uses color->pixel, use set_rgb_fg_color() to specify the foreground color as red, green, blue components.

Parameters:

color

The new foreground color.

void Gdk::GC::set_function ( Function function )

Determines how the current pixel values and the pixel values being drawn are combined to produce the final pixel values.

Parameters:

function

The Gdk::Function to use.

void Gdk::GC::set_line_attributes	(	int	line_width,
		LineStyle	line_style,
		CapStyle	cap_style,
		JoinStyle	join_style
	)

Sets various attributes of how lines are drawn.

See the corresponding members of Gdk::GCValues for full explanations of the arguments.

Parameters:

	line_width	The width of lines.
	line_style	The dash-style for lines.
	cap_style	The manner in which the ends of lines are drawn.
	join_style	The in which lines are joined together.

void Gdk::GC::set_rgb_bg_color ( const Color& color )

Set the background color of a GC using an unallocated color.

The pixel value for the color will be determined using GdkRGB. If the colormap for the GC has not previously been initialized for GdkRGB, then for pseudo-color colormaps (colormaps with a small modifiable number of colors), a colorcube will be allocated in the colormap.

Calling this function for a GC without a colormap is an error.

Parameters:

color

An unallocated Gdk::Color.

void Gdk::GC::set_rgb_fg_color ( const Color& color )

Set the foreground color of a GC using an unallocated color.

The pixel value for the color will be determined using GdkRGB. If the colormap for the GC has not previously been initialized for GdkRGB, then for pseudo-color colormaps (colormaps with a small modifiable number of colors), a colorcube will be allocated in the colormap.

Calling this function for a GC without a colormap is an error.

Parameters:

color

An unallocated Gdk::Color.

void Gdk::GC::set_stipple ( const Glib::RefPtr< Pixmap >& stipple )

Set the stipple bitmap for a graphics context.

The stipple will only be used if the fill mode is Gdk::STIPPLED or Gdk::OPAQUE_STIPPLED.

Parameters:

stipple

The new stipple bitmap.

void Gdk::GC::set_subwindow ( SubwindowMode mode )

Sets how drawing with this GC on a window will affect child windows of that window.

Parameters:

mode

The subwindow mode.

void Gdk::GC::set_tile ( const Glib::RefPtr< Pixmap >& tile )

Set a tile pixmap for a graphics context.

This will only be used if the fill mode is Gdk::TILED.

Parameters:

tile

The new tile pixmap.

void Gdk::GC::set_ts_origin	(	int	x,
		int	y
	)

Set the origin when using tiles or stipples with the GC.

The tile or stipple will be aligned such that the upper left corner of the tile or stipple will coincide with this point.

Parameters:

	x	The x-coordinate of the origin.
	y	The y-coordinate of the origin.

Friends And Related Function Documentation

Glib::RefPtr< Gdk::GC > wrap	(	GdkGC *	object,
		bool	take_copy = `false`
	)			`[related]`

A Glib::wrap() method for this object.

Parameters:

	object	The C instance.
	take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns:: A C++ instance that wraps this C instance.

The documentation for this class was generated from the following file:

gdkmm/gc.h

Gdk::GC Class Reference

Public Member Functions

Static Public Member Functions

Protected Member Functions

Related Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation