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Gdk::Drawable Class Reference

Drawing Primitives. More...

Inheritance diagram for Gdk::Drawable:

Inheritance graph
[legend]
List of all members.

Public Methods

virtual ~Drawable ()
GdkDrawable* gobj ()
const GdkDrawable* gobj () const
GdkDrawable* gobj_copy ()
void get_size (int& width, int& height)
 Fills * width and * height with the size of drawable .

int get_depth () const
 Obtains the bit depth of the drawable, that is, the number of bits that make up a pixel in the drawable's visual.

void set_colormap (const Glib::RefPtr<Colormap>& colormap)
 Sets the colormap associated with drawable .

Glib::RefPtr<Colormap> get_colormap ()
 Gets the colormap for drawable , if one is set; returns 0 otherwise.

Glib::RefPtr<Visual> get_visual ()
 Gets the Gdk::Visual describing the pixel format of drawable .

void draw_point (const Glib::RefPtr<const GC>& gc, int x, int y)
 Draws a point, using the foreground color and other attributes of the Gdk::GC.

void draw_points (const Glib::RefPtr<const GC>& gc, const Glib::ArrayHandle<Point>& points)
void draw_line (const Glib::RefPtr<const GC>& gc, int x1, int y1, int x2, int y2)
 Draws a line, using the foreground color and other attributes of the Gdk::GC.

void draw_lines (const Glib::RefPtr<const GC>& gc, const Glib::ArrayHandle<Point>& points)
void draw_rectangle (const Glib::RefPtr<const GC>& gc, bool filled, int x, int y, int width, int height)
 Draws a rectangular outline or filled rectangle, using the foreground color and other attributes of the Gdk::GC.

void draw_arc (const Glib::RefPtr<const GC>& gc, bool filled, int x, int y, int width, int height, int angle1, int angle2)
 Draws an arc or a filled 'pie slice'.

void draw_polygon (const Glib::RefPtr<const GC>& gc, bool filled, const Glib::ArrayHandle<Point>& points)
void draw_drawable (const Glib::RefPtr<const GC>& gc, const Glib::RefPtr<const Drawable>& src, int xsrc, int ysrc, int xdest, int ydest, int width=-1, int height=-1)
 Copies the width x height region of src at coordinates ( xsrc , ysrc ) to coordinates ( xdest , ydest ) in drawable .

void draw_image (const Glib::RefPtr<const GC>& gc, const Glib::RefPtr<const Image>& image, int xsrc, int ysrc, int xdest, int ydest, int width=-1, int height=-1)
 Draws a Gdk::Image onto a drawable.

void draw_segments (const Glib::RefPtr<const GC>& gc, GdkSegment* segs, int nsegs)
 Draws a number of unconnected lines.

void draw_glyphs (const Glib::RefPtr<const GC>& gc, const Glib::RefPtr<const Pango::Font>& font, int x, int y, PangoGlyphString* glyphs)
 This is a low-level function; 99% of text rendering should be done using gdk_draw_layout() instead.

void draw_layout_line (const Glib::RefPtr<const GC>& gc, int x, int y, const Glib::RefPtr<const Pango::LayoutLine>& line)
 Render a Pango::LayoutLine onto an GDK drawable.

void draw_layout_line (const Glib::RefPtr<const GC>& gc, int x, int y, const Glib::RefPtr<const Pango::LayoutLine>& line, const Color& foreground, const Color& background)
 Render a Pango::LayoutLine onto a Gdk::Drawable, overriding the layout's normal colors with foreground and/or background .

void draw_layout (const Glib::RefPtr<const GC>& gc, int x, int y, const Glib::RefPtr<const Pango::Layout>& layout)
 Render a Pango::Layout onto a GDK drawable.

void draw_layout (const Glib::RefPtr<const GC>& gc, int x, int y, const Glib::RefPtr<const Pango::Layout>& layout, const Color& foreground, const Color& background)
 Render a Pango::Layout onto a Gdk::Drawable, overriding the layout's normal colors with foreground and/or background .

void draw_pixbuf (const Glib::RefPtr<const GC>& gc, const Glib::RefPtr<Pixbuf>& pixbuf, int src_x, int src_y, int dest_x, int dest_y, int width, int height, RgbDither dither, int x_dither, int y_dither)
 Renders a rectangular portion of a pixbuf to a drawable.

Glib::RefPtr<Image> get_image (int x, int y, int width, int height) const
 A Gdk::Image stores client-side image data (pixels).

Region get_clip_region () const
 Computes the region of a drawable that potentially can be written to by drawing primitives.

Region get_visible_region () const
 Computes the region of a drawable that is potentially visible.

void draw_rgb_image (const Glib::RefPtr<const GC>& gc, int x, int y, int width, int height, RgbDither dith, const guchar* rgb_buf, int rowstride)
void draw_rgb_image_dithalign (const Glib::RefPtr<const GC>& gc, int x, int y, int width, int height, RgbDither dith, const guchar* rgb_buf, int rowstride, int xdith, int ydith)
void draw_rgb_32_image (const Glib::RefPtr<const GC>& gc, int x, int y, int width, int height, RgbDither dith, const guchar* rgb_buf, int rowstride)
void draw_rgb_32_image_dithalign (const Glib::RefPtr<const GC>& gc, int x, int y, int width, int height, RgbDither dith, const guchar* rgb_buf, int rowstride, int xdith, int ydith)
 Like gdk_draw_rgb_32_image(), but allows you to specify the dither offsets.

void draw_gray_image (const Glib::RefPtr<const GC>& gc, int x, int y, int width, int height, RgbDither dith, const guchar* rgb_buf, int rowstride)
void draw_indexed_image (const Glib::RefPtr<const GC>& gc, int x, int y, int width, int height, RgbDither dith, const guchar* rgb_buf, int rowstride, const RgbCmap& cmap)
Glib::RefPtr<Screen> get_screen ()
 Gets the Gdk::Screen associated with a Gdk::Drawable.

Glib::RefPtr<const Screen> get_screen () const
 Gets the Gdk::Screen associated with a Gdk::Drawable.

Glib::RefPtr<Display> get_display ()
 Gets the Gdk::Display associated with a Gdk::Drawable.

Glib::RefPtr<const Display> get_display () const
 Gets the Gdk::Display associated with a Gdk::Drawable.


Static Public Methods

Glib::RefPtr<Drawable> create ()

Protected Methods

 Drawable ()

Related Functions

(Note that these are not member functions.)

Glib::RefPtr<Gdk::Drawable> wrap (GdkDrawable* object, bool take_copy=false)

Detailed Description

Drawing Primitives.

Gdk::Drawable is the base class for all of the objects that accept drawing commands. The available drawables include pixmaps, windows, and bitmaps. Drawable is abstract as there is no such type on the server side.

To use a drawable, create a concrete Drawable of the type you wish to use and a Gdk::GC (graphics context) for that Drawable. With the GC you can draw lines, text, arcs and such.

Constructor & Destructor Documentation

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

Gdk::Drawable::Drawable (   )  [protected]
 

Member Function Documentation

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

Reimplemented in Gdk::Pixmap.

void Gdk::Drawable::draw_arc ( const Glib::RefPtr<const GC>&    gc,
bool    filled,
int    x,
int    y,
int    width,
int    height,
int    angle1,
int    angle2
) 
 

Draws an arc or a filled 'pie slice'.

The arc is defined by the bounding rectangle of the entire ellipse, and the start and end angles of the part of the ellipse to be drawn.

Parameters:
drawable A Gdk::Drawable (a Gdk::Window or a Gdk::Pixmap).
gc A Gdk::GC.
filled true if the arc should be filled, producing a 'pie slice'.
x The x coordinate of the left edge of the bounding rectangle.
y The y coordinate of the top edge of the bounding rectangle.
width The width of the bounding rectangle.
height The height of the bounding rectangle.
angle1 The start angle of the arc, relative to the 3 o'clock position, counter-clockwise, in 1/64ths of a degree.
angle2 The end angle of the arc, relative to , in 1/64ths of a degree.

void Gdk::Drawable::draw_drawable ( const Glib::RefPtr<const GC>&    gc,
const Glib::RefPtr<const Drawable>&    src,
int    xsrc,
int    ysrc,
int    xdest,
int    ydest,
int    width = -1,
int    height = -1
) 
 

Copies the width x height region of src at coordinates ( xsrc , ysrc ) to coordinates ( xdest , ydest ) in drawable .

width and/or height may be given as -1, in which case the entire src drawable will be copied.

Most fields in gc are not used for this operation, but notably the clip mask or clip region will be honored.

The source and destination drawables must have the same visual and colormap, or errors will result. (On X11, failure to match visual/colormap results in a BadMatch error from the X server.) A common cause of this problem is an attempt to draw a bitmap to a color drawable. The way to draw a bitmap is to set the bitmap as a clip mask on your Gdk::GC, then use gdk_draw_rectangle() to draw a rectangle clipped to the bitmap.

Parameters:
drawable A Gdk::Drawable.
gc A Gdk::GC sharing the drawable's visual and colormap.
src Another Gdk::Drawable.
xsrc X position in src of rectangle to draw.
ysrc Y position in src of rectangle to draw.
xdest X position in drawable where the rectangle should be drawn.
ydest Y position in drawable where the rectangle should be drawn.
width Width of rectangle to draw, or -1 for entire src width.
height Height of rectangle to draw, or -1 for entire src height.

void Gdk::Drawable::draw_glyphs ( const Glib::RefPtr<const GC>&    gc,
const Glib::RefPtr<const Pango::Font>&    font,
int    x,
int    y,
PangoGlyphString*    glyphs
) 
 

This is a low-level function; 99% of text rendering should be done using gdk_draw_layout() instead.

A glyph is a character in a font. This function draws a sequence of glyphs. To obtain a sequence of glyphs you have to understand a lot about internationalized text handling, which you don't want to understand; thus, use gdk_draw_layout() instead of this function, gdk_draw_layout() handles the details.

Parameters:
drawable A Gdk::Drawable.
gc A Gdk::GC.
font Font to be used.
x X coordinate of baseline origin.
y Y coordinate of baseline origin.
glyphs Glyphs to render.

void Gdk::Drawable::draw_gray_image ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
int    width,
int    height,
RgbDither    dith,
const guchar*    rgb_buf,
int    rowstride
) 
 

void Gdk::Drawable::draw_image ( const Glib::RefPtr<const GC>&    gc,
const Glib::RefPtr<const Image>&    image,
int    xsrc,
int    ysrc,
int    xdest,
int    ydest,
int    width = -1,
int    height = -1
) 
 

Draws a Gdk::Image onto a drawable.

The depth of the Gdk::Image must match the depth of the Gdk::Drawable.

Parameters:
drawable A Gdk::Drawable (a Gdk::Window or a Gdk::Pixmap).
gc A Gdk::GC.
image The Gdk::Image to draw.
xsrc The left edge of the source rectangle within image .
ysrc The top of the source rectangle within image .
xdest The x coordinate of the destination within drawable .
ydest The y coordinate of the destination within drawable .
width The width of the area to be copied, or -1 to make the area extend to the right edge of image .
height The height of the area to be copied, or -1 to make the area extend to the bottom edge of image .

void Gdk::Drawable::draw_indexed_image ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
int    width,
int    height,
RgbDither    dith,
const guchar*    rgb_buf,
int    rowstride,
const RgbCmap&    cmap
) 
 

void Gdk::Drawable::draw_layout ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
const Glib::RefPtr<const Pango::Layout>&    layout,
const Color&    foreground,
const Color&    background
) 
 

Render a Pango::Layout onto a Gdk::Drawable, overriding the layout's normal colors with foreground and/or background .

foreground and background need not be allocated.

Parameters:
drawable The drawable on which to draw string.
gc Base graphics context to use.
x The X position of the left of the layout (in pixels).
y The Y position of the top of the layout (in pixels).
layout A Pango::Layout.
foreground Foreground override color, or 0 for none.
background Background override color, or 0 for none.

void Gdk::Drawable::draw_layout ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
const Glib::RefPtr<const Pango::Layout>&    layout
) 
 

Render a Pango::Layout onto a GDK drawable.

Parameters:
drawable The drawable on which to draw string.
gc Base graphics context to use.
x The X position of the left of the layout (in pixels).
y The Y position of the top of the layout (in pixels).
layout A Pango::Layout.

void Gdk::Drawable::draw_layout_line ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
const Glib::RefPtr<const Pango::LayoutLine>&    line,
const Color&    foreground,
const Color&    background
) 
 

Render a Pango::LayoutLine onto a Gdk::Drawable, overriding the layout's normal colors with foreground and/or background .

foreground and background need not be allocated.

Parameters:
drawable The drawable on which to draw the line.
gc Base graphics to use.
x The x position of start of string (in pixels).
y The y position of baseline (in pixels).
line A Pango::LayoutLine.
foreground Foreground override color, or 0 for none.
background Background override color, or 0 for none.

void Gdk::Drawable::draw_layout_line ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
const Glib::RefPtr<const Pango::LayoutLine>&    line
) 
 

Render a Pango::LayoutLine onto an GDK drawable.

Parameters:
drawable The drawable on which to draw the line.
gc Base graphics to use.
x The x position of start of string (in pixels).
y The y position of baseline (in pixels).
line A Pango::LayoutLine.

void Gdk::Drawable::draw_line ( const Glib::RefPtr<const GC>&    gc,
int    x1,
int    y1,
int    x2,
int    y2
) 
 

Draws a line, using the foreground color and other attributes of the Gdk::GC.

Parameters:
drawable A Gdk::Drawable (a Gdk::Window or a Gdk::Pixmap).
gc A Gdk::GC.
x1_ The x coordinate of the start point.
y1_ The y coordinate of the start point.
x2_ The x coordinate of the end point.
y2_ The y coordinate of the end point.

void Gdk::Drawable::draw_lines ( const Glib::RefPtr<const GC>&    gc,
const Glib::ArrayHandle<Point>&    points
) 
 

void Gdk::Drawable::draw_pixbuf ( const Glib::RefPtr<const GC>&    gc,
const Glib::RefPtr<Pixbuf>&    pixbuf,
int    src_x,
int    src_y,
int    dest_x,
int    dest_y,
int    width,
int    height,
RgbDither    dither,
int    x_dither,
int    y_dither
) 
 

Renders a rectangular portion of a pixbuf to a drawable.

The destination drawable must have a colormap. All windows have a colormap, however, pixmaps only have colormap by default if they were created with a non-0 window argument. Otherwise a colormap must be set on them with Gdk::Drawable::set_colormap().

On older X servers, rendering pixbufs with an alpha channel involves round trips to the X server, and may be somewhat slow.

Since: 2.2

Parameters:
drawable Destination drawable.
gc A Gdk::GC, used for clipping, or 0.
pixbuf A Gdk::Pixbuf.
src_x Source X coordinate within pixbuf.
src_y Source Y coordinates within pixbuf.
dest_x Destination X coordinate within drawable.
dest_y Destination Y coordinate within drawable.
width Width of region to render, in pixels, or -1 to use pixbuf width.
height Height of region to render, in pixels, or -1 to use pixbuf height.
dither Dithering mode for Gdk::RGB.
x_dither X offset for dither.
y_dither Y offset for dither.

void Gdk::Drawable::draw_point ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y
) 
 

Draws a point, using the foreground color and other attributes of the Gdk::GC.

Parameters:
drawable A Gdk::Drawable (a Gdk::Window or a Gdk::Pixmap).
gc A Gdk::GC.
x The x coordinate of the point.
y The y coordinate of the point.

void Gdk::Drawable::draw_points ( const Glib::RefPtr<const GC>&    gc,
const Glib::ArrayHandle<Point>&    points
) 
 

void Gdk::Drawable::draw_polygon ( const Glib::RefPtr<const GC>&    gc,
bool    filled,
const Glib::ArrayHandle<Point>&    points
) 
 

void Gdk::Drawable::draw_rectangle ( const Glib::RefPtr<const GC>&    gc,
bool    filled,
int    x,
int    y,
int    width,
int    height
) 
 

Draws a rectangular outline or filled rectangle, using the foreground color and other attributes of the Gdk::GC.

A rectangle drawn filled is 1 pixel smaller in both dimensions than a rectangle outlined. Calling gdk_draw_rectangle (window, gc, true, 0, 0, 20, 20) results in a filled rectangle 20 pixels wide and 20 pixels high. Calling gdk_draw_rectangle (window, gc, false, 0, 0, 20, 20) results in an outlined rectangle with corners at (0, 0), (0, 20), (20, 20), and (20, 0), which makes it 21 pixels wide and 21 pixels high.

Parameters:
drawable A Gdk::Drawable (a Gdk::Window or a Gdk::Pixmap).
gc A Gdk::GC.
filled true if the rectangle should be filled.
x The x coordinate of the left edge of the rectangle.
y The y coordinate of the top edge of the rectangle.
width The width of the rectangle.
height The height of the rectangle.

void Gdk::Drawable::draw_rgb_32_image ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
int    width,
int    height,
RgbDither    dith,
const guchar*    rgb_buf,
int    rowstride
) 
 

void Gdk::Drawable::draw_rgb_32_image_dithalign ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
int    width,
int    height,
RgbDither    dith,
const guchar*    rgb_buf,
int    rowstride,
int    xdith,
int    ydith
) 
 

Like gdk_draw_rgb_32_image(), but allows you to specify the dither offsets.

See gdk_draw_rgb_image_dithalign() for more details.

Parameters:
drawable A Gdk::Drawable.
gc A Gdk::GC.
x X coordinate on drawable where image should go.
y Y coordinate on drawable where image should go.
width Width of area of image to draw.
height Height of area of image to draw.
dith Dithering mode.
buf RGB image data.
rowstride Rowstride of RGB image data.
xdith X dither offset.
ydith Y dither offset.

void Gdk::Drawable::draw_rgb_image ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
int    width,
int    height,
RgbDither    dith,
const guchar*    rgb_buf,
int    rowstride
) 
 

void Gdk::Drawable::draw_rgb_image_dithalign ( const Glib::RefPtr<const GC>&    gc,
int    x,
int    y,
int    width,
int    height,
RgbDither    dith,
const guchar*    rgb_buf,
int    rowstride,
int    xdith,
int    ydith
) 
 

void Gdk::Drawable::draw_segments ( const Glib::RefPtr<const GC>&    gc,
GdkSegment*    segs,
int    nsegs
) 
 

Draws a number of unconnected lines.

Parameters:
drawable A Gdk::Drawable (a Gdk::Window or a Gdk::Pixmap).
gc A Gdk::GC.
segs An array of Gdk::Segment structures specifying the start and end points of the lines to be drawn.
nsegs The number of line segments to draw, i.e. the size of the segs array.

Region Gdk::Drawable::get_clip_region (   )  const
 

Computes the region of a drawable that potentially can be written to by drawing primitives.

This region will not take into account the clip region for the GC, and may also not take into account other factors such as if the window is obscured by other windows, but no area outside of this region will be affected by drawing primitives.

Returns:
A Gdk::Region. This must be freed with gdk_region_destroy() when you are done.

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

Gets the colormap for drawable , if one is set; returns 0 otherwise.

Returns:
The colormap, or 0.

int Gdk::Drawable::get_depth (   )  const
 

Obtains the bit depth of the drawable, that is, the number of bits that make up a pixel in the drawable's visual.

Examples are 8 bits per pixel, 24 bits per pixel, etc.

Returns:
Number of bits per pixel.

Glib::RefPtr<const Display> Gdk::Drawable::get_display (   )  const
 

Gets the Gdk::Display associated with a Gdk::Drawable.

Returns:
The Gdk::Display associated with drawable
Since: 2.2.

Glib::RefPtr<Display> Gdk::Drawable::get_display (   ) 
 

Gets the Gdk::Display associated with a Gdk::Drawable.

Returns:
The Gdk::Display associated with drawable
Since: 2.2.

Glib::RefPtr<Image> Gdk::Drawable::get_image ( int    x,
int    y,
int    width,
int    height
)  const
 

A Gdk::Image stores client-side image data (pixels).

In contrast, Gdk::Pixmap and Gdk::Window are server-side objects. get_image() obtains the pixels from a server-side drawable as a client-side Gdk::Image. The format of a Gdk::Image depends on the Gdk::Visual of the current display, which makes manipulating Gdk::Image extremely difficult; therefore, in most cases you should use Gdk::Pixbuf::get_from_drawable() instead of this lower-level function. A Gdk::Pixbuf contains image data in a canonicalized RGB format, rather than a display-dependent format. Of course, there's a convenience vs. speed tradeoff here, so you'll want to think about what makes sense for your application.

x , y , width , and height define the region of drawable to obtain as an image.

You would usually copy image data to the client side if you intend to examine the values of individual pixels, for example to darken an image or add a red tint. It would be prohibitively slow to make a round-trip request to the windowing system for each pixel, so instead you get all of them at once, modify them, then copy them all back at once.

If the X server or other windowing system backend is on the local machine, this function may use shared memory to avoid copying the image data.

If the source drawable is a Gdk::Window and partially offscreen or obscured, then the obscured portions of the returned image will contain undefined data.

Parameters:
x X coordinate on drawable .
y Y coordinate on drawable .
width Width of region to get.
height Height or region to get.
Returns:
A Gdk::Image containing the contents of drawable .

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

Gets the Gdk::Screen associated with a Gdk::Drawable.

Returns:
The Gdk::Screen associated with drawable
Since: 2.2.

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

Gets the Gdk::Screen associated with a Gdk::Drawable.

Returns:
The Gdk::Screen associated with drawable
Since: 2.2.

void Gdk::Drawable::get_size ( int&    width,
int&    height
) 
 

Fills * width and * height with the size of drawable .

width or height can be 0 if you only want the other one.

On the X11 platform, if drawable is a Gdk::Window, the returned size is the size reported in the most-recently-processed configure event, rather than the current size on the X server.

Parameters:
width Location to store drawable's width, or 0.
height Location to store drawable's height, or 0.

Region Gdk::Drawable::get_visible_region (   )  const
 

Computes the region of a drawable that is potentially visible.

This does not necessarily take into account if the window is obscured by other windows, but no area outside of this region is visible.

Returns:
A Gdk::Region. This must be freed with gdk_region_destroy() when you are done.

Glib::RefPtr<Visual> Gdk::Drawable::get_visual (   ) 
 

Gets the Gdk::Visual describing the pixel format of drawable .

Returns:
A Gdk::Visual.

const GdkDrawable* Gdk::Drawable::gobj (   )  const [inline]
 

Reimplemented from Glib::ObjectBase.

Reimplemented in Gdk::Pixmap, and Gdk::Window.

GdkDrawable* Gdk::Drawable::gobj (   )  [inline]
 

Reimplemented from Glib::ObjectBase.

Reimplemented in Gdk::Pixmap, and Gdk::Window.

GdkDrawable* Gdk::Drawable::gobj_copy (   ) 
 

Reimplemented in Gdk::Pixmap, and Gdk::Window.

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

Sets the colormap associated with drawable .

Normally this will happen automatically when the drawable is created; you only need to use this function if the drawable-creating function did not have a way to determine the colormap, and you then use drawable operations that require a colormap. The colormap for all drawables and graphics contexts you intend to use together should match. i.e. when using a Gdk::GC to draw to a drawable, or copying one drawable to another, the colormaps should match.

Parameters:
colormap A Gdk::Colormap.

Friends And Related Function Documentation

Glib::RefPtr<Gdk::Drawable> wrap ( GdkDrawable*    object,
bool    take_copy = false
)  [related]
 

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