gtk/gdk/gdkdraw.c
2010-08-10 21:02:27 +02:00

936 lines
27 KiB
C

/* GDK - The GIMP Drawing Kit
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include "config.h"
#include <math.h>
#include <pango/pangocairo.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include "gdkcairo.h"
#include "gdkdrawable.h"
#include "gdkinternals.h"
#include "gdkwindow.h"
#include "gdkscreen.h"
#include "gdkpixbuf.h"
static GdkDrawable* gdk_drawable_real_get_composite_drawable (GdkDrawable *drawable,
gint x,
gint y,
gint width,
gint height,
gint *composite_x_offset,
gint *composite_y_offset);
static cairo_region_t * gdk_drawable_real_get_visible_region (GdkDrawable *drawable);
static void gdk_drawable_real_draw_drawable (GdkDrawable *drawable,
GdkGC *gc,
GdkDrawable *src,
gint xsrc,
gint ysrc,
gint xdest,
gint ydest,
gint width,
gint height);
G_DEFINE_ABSTRACT_TYPE (GdkDrawable, gdk_drawable, G_TYPE_OBJECT)
static void
gdk_drawable_class_init (GdkDrawableClass *klass)
{
klass->get_composite_drawable = gdk_drawable_real_get_composite_drawable;
/* Default implementation for clip and visible region is the same */
klass->get_clip_region = gdk_drawable_real_get_visible_region;
klass->get_visible_region = gdk_drawable_real_get_visible_region;
klass->draw_drawable = gdk_drawable_real_draw_drawable;
}
static void
gdk_drawable_init (GdkDrawable *drawable)
{
}
/* Manipulation of drawables
*/
/**
* gdk_drawable_get_size:
* @drawable: a #GdkDrawable
* @width: (out) (allow-none): location to store drawable's width, or %NULL
* @height: (out) (allow-none): location to store drawable's height, or %NULL
*
* Fills *@width and *@height with the size of @drawable.
* @width or @height can be %NULL if you only want the other one.
*
* On the X11 platform, if @drawable is a #GdkWindow, the returned
* size is the size reported in the most-recently-processed configure
* event, rather than the current size on the X server.
*
**/
void
gdk_drawable_get_size (GdkDrawable *drawable,
gint *width,
gint *height)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
GDK_DRAWABLE_GET_CLASS (drawable)->get_size (drawable, width, height);
}
/**
* gdk_drawable_get_visual:
* @drawable: a #GdkDrawable
*
* Gets the #GdkVisual describing the pixel format of @drawable.
*
* Return value: a #GdkVisual
**/
GdkVisual*
gdk_drawable_get_visual (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_visual (drawable);
}
/**
* gdk_drawable_get_depth:
* @drawable: a #GdkDrawable
*
* 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.
*
* Return value: number of bits per pixel
**/
gint
gdk_drawable_get_depth (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), 0);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_depth (drawable);
}
/**
* gdk_drawable_get_screen:
* @drawable: a #GdkDrawable
*
* Gets the #GdkScreen associated with a #GdkDrawable.
*
* Return value: the #GdkScreen associated with @drawable
*
* Since: 2.2
**/
GdkScreen*
gdk_drawable_get_screen(GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_screen (drawable);
}
/**
* gdk_drawable_get_display:
* @drawable: a #GdkDrawable
*
* Gets the #GdkDisplay associated with a #GdkDrawable.
*
* Return value: the #GdkDisplay associated with @drawable
*
* Since: 2.2
**/
GdkDisplay*
gdk_drawable_get_display (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return gdk_screen_get_display (gdk_drawable_get_screen (drawable));
}
/**
* gdk_drawable_set_colormap:
* @drawable: a #GdkDrawable
* @colormap: a #GdkColormap
*
* 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 #GdkGC to draw to a drawable, or copying one drawable
* to another, the colormaps should match.
*
**/
void
gdk_drawable_set_colormap (GdkDrawable *drawable,
GdkColormap *cmap)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (cmap == NULL || gdk_drawable_get_depth (drawable)
== cmap->visual->depth);
GDK_DRAWABLE_GET_CLASS (drawable)->set_colormap (drawable, cmap);
}
/**
* gdk_drawable_get_colormap:
* @drawable: a #GdkDrawable
*
* Gets the colormap for @drawable, if one is set; returns
* %NULL otherwise.
*
* Return value: the colormap, or %NULL
**/
GdkColormap*
gdk_drawable_get_colormap (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_colormap (drawable);
}
/* Drawing
*/
/**
* gdk_draw_point:
* @drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
* @gc: a #GdkGC.
* @x: the x coordinate of the point.
* @y: the y coordinate of the point.
*
* Draws a point, using the foreground color and other attributes of
* the #GdkGC.
**/
void
gdk_draw_point (GdkDrawable *drawable,
GdkGC *gc,
gint x,
gint y)
{
GdkPoint point;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
point.x = x;
point.y = y;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_points (drawable, gc, &point, 1);
}
/**
* gdk_draw_line:
* @drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
* @gc: a #GdkGC.
* @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.
*
* Draws a line, using the foreground color and other attributes of
* the #GdkGC.
**/
void
gdk_draw_line (GdkDrawable *drawable,
GdkGC *gc,
gint x1,
gint y1,
gint x2,
gint y2)
{
GdkSegment segment;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
segment.x1 = x1;
segment.y1 = y1;
segment.x2 = x2;
segment.y2 = y2;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_segments (drawable, gc, &segment, 1);
}
/**
* gdk_draw_rectangle:
* @drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
* @gc: a #GdkGC.
* @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.
*
* Draws a rectangular outline or filled rectangle, using the foreground color
* and other attributes of the #GdkGC.
*
* A rectangle drawn filled is 1 pixel smaller in both dimensions than a
* rectangle outlined. Calling
* <literal>gdk_draw_rectangle (window, gc, TRUE, 0, 0, 20, 20)</literal>
* results in a filled rectangle 20 pixels wide and 20 pixels high. Calling
* <literal>gdk_draw_rectangle (window, gc, FALSE, 0, 0, 20, 20)</literal>
* 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.
**/
void
gdk_draw_rectangle (GdkDrawable *drawable,
GdkGC *gc,
gboolean filled,
gint x,
gint y,
gint width,
gint height)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
if (width < 0 || height < 0)
{
gint real_width;
gint real_height;
gdk_drawable_get_size (drawable, &real_width, &real_height);
if (width < 0)
width = real_width;
if (height < 0)
height = real_height;
}
GDK_DRAWABLE_GET_CLASS (drawable)->draw_rectangle (drawable, gc, filled, x, y,
width, height);
}
/**
* gdk_draw_polygon:
* @drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
* @gc: a #GdkGC.
* @filled: %TRUE if the polygon should be filled. The polygon is closed
* automatically, connecting the last point to the first point if
* necessary.
* @points: an array of #GdkPoint structures specifying the points making
* up the polygon.
* @n_points: the number of points.
*
* Draws an outlined or filled polygon.
**/
void
gdk_draw_polygon (GdkDrawable *drawable,
GdkGC *gc,
gboolean filled,
const GdkPoint *points,
gint n_points)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
GDK_DRAWABLE_GET_CLASS (drawable)->draw_polygon (drawable, gc, filled,
(GdkPoint *) points,
n_points);
}
/**
* gdk_draw_drawable:
* @drawable: a #GdkDrawable
* @gc: a #GdkGC sharing the drawable's visual and colormap
* @src: the source #GdkDrawable, which may be the same as @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
*
* 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
* the stipple on the #GdkGC, set the fill mode to %GDK_STIPPLED, and
* then draw the rectangle.
**/
void
gdk_draw_drawable (GdkDrawable *drawable,
GdkGC *gc,
GdkDrawable *src,
gint xsrc,
gint ysrc,
gint xdest,
gint ydest,
gint width,
gint height)
{
GdkDrawable *composite;
gint composite_x_offset = 0;
gint composite_y_offset = 0;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_DRAWABLE (src));
g_return_if_fail (GDK_IS_GC (gc));
if (width < 0 || height < 0)
{
gint real_width;
gint real_height;
gdk_drawable_get_size (src, &real_width, &real_height);
if (width < 0)
width = real_width;
if (height < 0)
height = real_height;
}
composite =
GDK_DRAWABLE_GET_CLASS (src)->get_composite_drawable (src,
xsrc, ysrc,
width, height,
&composite_x_offset,
&composite_y_offset);
/* TODO: For non-native windows this may copy stuff from other overlapping
windows. We should clip that and (for windows with bg != None) clear that
area in the destination instead. */
if (GDK_DRAWABLE_GET_CLASS (drawable)->draw_drawable_with_src)
GDK_DRAWABLE_GET_CLASS (drawable)->draw_drawable_with_src (drawable, gc,
composite,
xsrc - composite_x_offset,
ysrc - composite_y_offset,
xdest, ydest,
width, height,
src);
else /* backwards compat for old out-of-tree implementations of GdkDrawable (are there any?) */
GDK_DRAWABLE_GET_CLASS (drawable)->draw_drawable (drawable, gc,
composite,
xsrc - composite_x_offset,
ysrc - composite_y_offset,
xdest, ydest,
width, height);
g_object_unref (composite);
}
/**
* gdk_draw_points:
* @drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
* @gc: a #GdkGC.
* @points: an array of #GdkPoint structures.
* @n_points: the number of points to be drawn.
*
* Draws a number of points, using the foreground color and other
* attributes of the #GdkGC.
**/
void
gdk_draw_points (GdkDrawable *drawable,
GdkGC *gc,
const GdkPoint *points,
gint n_points)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail ((points != NULL) && (n_points > 0));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (n_points >= 0);
if (n_points == 0)
return;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_points (drawable, gc,
(GdkPoint *) points, n_points);
}
/**
* gdk_draw_segments:
* @drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
* @gc: a #GdkGC.
* @segs: an array of #GdkSegment structures specifying the start and
* end points of the lines to be drawn.
* @n_segs: the number of line segments to draw, i.e. the size of the
* @segs array.
*
* Draws a number of unconnected lines.
**/
void
gdk_draw_segments (GdkDrawable *drawable,
GdkGC *gc,
const GdkSegment *segs,
gint n_segs)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
if (n_segs == 0)
return;
g_return_if_fail (segs != NULL);
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (n_segs >= 0);
GDK_DRAWABLE_GET_CLASS (drawable)->draw_segments (drawable, gc,
(GdkSegment *) segs, n_segs);
}
/**
* gdk_draw_lines:
* @drawable: a #GdkDrawable (a #GdkWindow or a #GdkPixmap).
* @gc: a #GdkGC.
* @points: an array of #GdkPoint structures specifying the endpoints of the
* @n_points: the size of the @points array.
*
* Draws a series of lines connecting the given points.
* The way in which joins between lines are draw is determined by the
* #GdkCapStyle value in the #GdkGC. This can be set with
* gdk_gc_set_line_attributes().
**/
void
gdk_draw_lines (GdkDrawable *drawable,
GdkGC *gc,
const GdkPoint *points,
gint n_points)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (points != NULL);
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (n_points >= 0);
if (n_points == 0)
return;
GDK_DRAWABLE_GET_CLASS (drawable)->draw_lines (drawable, gc,
(GdkPoint *) points, n_points);
}
static void
real_draw_glyphs (GdkDrawable *drawable,
GdkGC *gc,
const PangoMatrix *matrix,
PangoFont *font,
gdouble x,
gdouble y,
PangoGlyphString *glyphs)
{
cairo_t *cr;
cr = gdk_cairo_create (drawable);
_gdk_gc_update_context (gc, cr, NULL, NULL, TRUE, drawable);
if (matrix)
{
cairo_matrix_t cairo_matrix;
cairo_matrix.xx = matrix->xx;
cairo_matrix.yx = matrix->yx;
cairo_matrix.xy = matrix->xy;
cairo_matrix.yy = matrix->yy;
cairo_matrix.x0 = matrix->x0;
cairo_matrix.y0 = matrix->y0;
cairo_set_matrix (cr, &cairo_matrix);
}
cairo_move_to (cr, x, y);
pango_cairo_show_glyph_string (cr, font, glyphs);
cairo_destroy (cr);
}
/**
* gdk_draw_glyphs:
* @drawable: a #GdkDrawable
* @gc: a #GdkGC
* @font: font to be used
* @x: X coordinate of baseline origin
* @y: Y coordinate of baseline origin
* @glyphs: the glyph string to draw
*
* This is a low-level function; 99% of text rendering should be done
* using gdk_draw_layout() instead.
*
* A glyph is a single image 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.
*
**/
void
gdk_draw_glyphs (GdkDrawable *drawable,
GdkGC *gc,
PangoFont *font,
gint x,
gint y,
PangoGlyphString *glyphs)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
real_draw_glyphs (drawable, gc, NULL, font,
x, y, glyphs);
}
/**
* gdk_draw_glyphs_transformed:
* @drawable: a #GdkDrawable
* @gc: a #GdkGC
* @matrix: (allow-none): a #PangoMatrix, or %NULL to use an identity transformation
* @font: the font in which to draw the string
* @x: the x position of the start of the string (in Pango
* units in user space coordinates)
* @y: the y position of the baseline (in Pango units
* in user space coordinates)
* @glyphs: the glyph string to draw
*
* Renders a #PangoGlyphString onto a drawable, possibly
* transforming the layed-out coordinates through a transformation
* matrix. Note that the transformation matrix for @font is not
* changed, so to produce correct rendering results, the @font
* must have been loaded using a #PangoContext with an identical
* transformation matrix to that passed in to this function.
*
* See also gdk_draw_glyphs(), gdk_draw_layout().
*
* Since: 2.6
**/
void
gdk_draw_glyphs_transformed (GdkDrawable *drawable,
GdkGC *gc,
const PangoMatrix *matrix,
PangoFont *font,
gint x,
gint y,
PangoGlyphString *glyphs)
{
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
real_draw_glyphs (drawable, gc, matrix, font,
x / PANGO_SCALE, y / PANGO_SCALE, glyphs);
}
/**
* gdk_draw_trapezoids:
* @drawable: a #GdkDrawable
* @gc: a #GdkGC
* @trapezoids: an array of #GdkTrapezoid structures
* @n_trapezoids: the number of trapezoids to draw
*
* Draws a set of anti-aliased trapezoids. The trapezoids are
* combined using saturation addition, then drawn over the background
* as a set. This is low level functionality used internally to implement
* rotated underlines and backgrouds when rendering a PangoLayout and is
* likely not useful for applications.
*
* Since: 2.6
**/
void
gdk_draw_trapezoids (GdkDrawable *drawable,
GdkGC *gc,
const GdkTrapezoid *trapezoids,
gint n_trapezoids)
{
cairo_t *cr;
int i;
g_return_if_fail (GDK_IS_DRAWABLE (drawable));
g_return_if_fail (GDK_IS_GC (gc));
g_return_if_fail (n_trapezoids == 0 || trapezoids != NULL);
cr = gdk_cairo_create (drawable);
_gdk_gc_update_context (gc, cr, NULL, NULL, TRUE, drawable);
for (i = 0; i < n_trapezoids; i++)
{
cairo_move_to (cr, trapezoids[i].x11, trapezoids[i].y1);
cairo_line_to (cr, trapezoids[i].x21, trapezoids[i].y1);
cairo_line_to (cr, trapezoids[i].x22, trapezoids[i].y2);
cairo_line_to (cr, trapezoids[i].x12, trapezoids[i].y2);
cairo_close_path (cr);
}
cairo_fill (cr);
cairo_destroy (cr);
}
static GdkDrawable *
gdk_drawable_real_get_composite_drawable (GdkDrawable *drawable,
gint x,
gint y,
gint width,
gint height,
gint *composite_x_offset,
gint *composite_y_offset)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
*composite_x_offset = 0;
*composite_y_offset = 0;
return g_object_ref (drawable);
}
/**
* gdk_drawable_get_clip_region:
* @drawable: a #GdkDrawable
*
* 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 #cairo_region_t. This must be freed with cairo_region_destroy()
* when you are done.
**/
cairo_region_t *
gdk_drawable_get_clip_region (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_clip_region (drawable);
}
/**
* gdk_drawable_get_visible_region:
* @drawable: a #GdkDrawable
*
* 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 #cairo_region_t. This must be freed with cairo_region_destroy()
* when you are done.
**/
cairo_region_t *
gdk_drawable_get_visible_region (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->get_visible_region (drawable);
}
static cairo_region_t *
gdk_drawable_real_get_visible_region (GdkDrawable *drawable)
{
GdkRectangle rect;
rect.x = 0;
rect.y = 0;
gdk_drawable_get_size (drawable, &rect.width, &rect.height);
return cairo_region_create_rectangle (&rect);
}
/**
* _gdk_drawable_ref_cairo_surface:
* @drawable: a #GdkDrawable
*
* Obtains a #cairo_surface_t for the given drawable. If a
* #cairo_surface_t for the drawable already exists, it will be
* referenced, otherwise a new surface will be created.
*
* Return value: a newly referenced #cairo_surface_t that points
* to @drawable. Unref with cairo_surface_destroy()
**/
cairo_surface_t *
_gdk_drawable_ref_cairo_surface (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
return GDK_DRAWABLE_GET_CLASS (drawable)->ref_cairo_surface (drawable);
}
/* Implementation of the old vfunc in terms of the new one
in case someone calls it directly (which they shouldn't!) */
static void
gdk_drawable_real_draw_drawable (GdkDrawable *drawable,
GdkGC *gc,
GdkDrawable *src,
gint xsrc,
gint ysrc,
gint xdest,
gint ydest,
gint width,
gint height)
{
GDK_DRAWABLE_GET_CLASS (drawable)->draw_drawable_with_src (drawable,
gc,
src,
xsrc,
ysrc,
xdest,
ydest,
width,
height,
src);
}
/************************************************************************/
/**
* _gdk_drawable_get_scratch_gc:
* @drawable: A #GdkDrawable
* @graphics_exposures: Whether the returned #GdkGC should generate graphics exposures
*
* Returns a #GdkGC suitable for drawing on @drawable. The #GdkGC has
* the standard values for @drawable, except for the graphics_exposures
* field which is determined by the @graphics_exposures parameter.
*
* The foreground color of the returned #GdkGC is undefined. The #GdkGC
* must not be altered in any way, except to change its foreground color.
*
* Return value: A #GdkGC suitable for drawing on @drawable
*
* Since: 2.4
**/
GdkGC *
_gdk_drawable_get_scratch_gc (GdkDrawable *drawable,
gboolean graphics_exposures)
{
GdkScreen *screen;
gint depth;
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
screen = gdk_drawable_get_screen (drawable);
g_return_val_if_fail (!screen->closed, NULL);
depth = gdk_drawable_get_depth (drawable) - 1;
if (graphics_exposures)
{
if (!screen->exposure_gcs[depth])
{
GdkGCValues values;
GdkGCValuesMask mask;
values.graphics_exposures = TRUE;
mask = GDK_GC_EXPOSURES;
screen->exposure_gcs[depth] =
gdk_gc_new_with_values (drawable, &values, mask);
}
return screen->exposure_gcs[depth];
}
else
{
if (!screen->normal_gcs[depth])
{
screen->normal_gcs[depth] =
gdk_gc_new (drawable);
}
return screen->normal_gcs[depth];
}
}
/**
* _gdk_drawable_get_subwindow_scratch_gc:
* @drawable: A #GdkDrawable
*
* Returns a #GdkGC suitable for drawing on @drawable. The #GdkGC has
* the standard values for @drawable, except for the graphics_exposures
* field which is %TRUE and the subwindow mode which is %GDK_INCLUDE_INFERIORS.
*
* The foreground color of the returned #GdkGC is undefined. The #GdkGC
* must not be altered in any way, except to change its foreground color.
*
* Return value: A #GdkGC suitable for drawing on @drawable
*
* Since: 2.18
**/
GdkGC *
_gdk_drawable_get_subwindow_scratch_gc (GdkDrawable *drawable)
{
GdkScreen *screen;
gint depth;
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
screen = gdk_drawable_get_screen (drawable);
g_return_val_if_fail (!screen->closed, NULL);
depth = gdk_drawable_get_depth (drawable) - 1;
if (!screen->subwindow_gcs[depth])
{
GdkGCValues values;
GdkGCValuesMask mask;
values.graphics_exposures = TRUE;
values.subwindow_mode = GDK_INCLUDE_INFERIORS;
mask = GDK_GC_EXPOSURES | GDK_GC_SUBWINDOW;
screen->subwindow_gcs[depth] =
gdk_gc_new_with_values (drawable, &values, mask);
}
return screen->subwindow_gcs[depth];
}
/*
* _gdk_drawable_get_source_drawable:
* @drawable: a #GdkDrawable
*
* Returns a drawable for the passed @drawable that is guaranteed to be
* usable to create a pixmap (e.g.: not an offscreen window).
*
* Since: 2.16
*/
GdkDrawable *
_gdk_drawable_get_source_drawable (GdkDrawable *drawable)
{
g_return_val_if_fail (GDK_IS_DRAWABLE (drawable), NULL);
if (GDK_DRAWABLE_GET_CLASS (drawable)->get_source_drawable)
return GDK_DRAWABLE_GET_CLASS (drawable)->get_source_drawable (drawable);
return drawable;
}
cairo_surface_t *
_gdk_drawable_create_cairo_surface (GdkDrawable *drawable,
int width,
int height)
{
return GDK_DRAWABLE_GET_CLASS (drawable)->create_cairo_surface (drawable,
width, height);
}