/* -*- Mode: C; tab-width: 8; indent-tabs-mode: 8; c-basic-offset: 8 -*- */
/*
* Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation
* All rights reserved.
*
* This file is part of the Gnome Library.
*
* The Gnome Library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* The Gnome 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with the Gnome Library; see the file COPYING.LIB. If not,
* write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/*
@NOTATION@
*/
/* GnomeCanvas widget - Tk-like canvas widget for Gnome
*
* GnomeCanvas is basically a port of the Tk toolkit's most excellent canvas
* widget. Tk is copyrighted by the Regents of the University of California,
* Sun Microsystems, and other parties.
*
*
* Authors: Federico Mena <federico@nuclecu.unam.mx>
* Raph Levien <raph@gimp.org>
*/
#ifndef GNOME_CANVAS_H
#define GNOME_CANVAS_H
#include <gtk/gtk.h>
#include <stdarg.h>
#include <libart_lgpl/art_misc.h>
#include <libart_lgpl/art_rect.h>
#include <libart_lgpl/art_svp.h>
#include <libart_lgpl/art_uta.h>
#include <libart_lgpl/art_affine.h>
G_BEGIN_DECLS
/* "Small" value used by canvas stuff */
#define GNOME_CANVAS_EPSILON 1e-10
/* Macros for building colors that fit in a 32-bit integer. The values are in
* [0, 255].
*/
#define GNOME_CANVAS_COLOR(r, g, b) ((((unsigned int) (r) & 0xff) << 24) \
| (((unsigned int) (g) & 0xff) << 16) \
| (((unsigned int) (b) & 0xff) << 8) \
| 0xff)
#define GNOME_CANVAS_COLOR_A(r, g, b, a) ((((unsigned int) (r) & 0xff) << 24) \
| (((unsigned int) (g) & 0xff) << 16) \
| (((unsigned int) (b) & 0xff) << 8) \
| ((guint) (a) & 0xff))
typedef struct _GnomeCanvas GnomeCanvas;
typedef struct _GnomeCanvasClass GnomeCanvasClass;
typedef struct _GnomeCanvasItem GnomeCanvasItem;
typedef struct _GnomeCanvasItemClass GnomeCanvasItemClass;
typedef struct _GnomeCanvasGroup GnomeCanvasGroup;
typedef struct _GnomeCanvasGroupClass GnomeCanvasGroupClass;
/* GnomeCanvasItem - base item class for canvas items
*
* All canvas items are derived from GnomeCanvasItem. The only information a
* GnomeCanvasItem contains is its parent canvas, its parent canvas item group,
* its bounding box in world coordinates, and its current affine transformation.
*
* Items inside a canvas are organized in a tree of GnomeCanvasItemGroup nodes
* and GnomeCanvasItem leaves. Each canvas has a single root group, which can
* be obtained with the gnome_canvas_get_root() function.
*
* The abstract GnomeCanvasItem class does not have any configurable or
* queryable attributes.
*/
/* Object flags for items */
typedef enum {
GNOME_CANVAS_ITEM_REALIZED = 1 << 0,
GNOME_CANVAS_ITEM_MAPPED = 1 << 1,
GNOME_CANVAS_ITEM_ALWAYS_REDRAW = 1 << 2,
GNOME_CANVAS_ITEM_VISIBLE = 1 << 3,
GNOME_CANVAS_ITEM_NEED_UPDATE = 1 << 4,
GNOME_CANVAS_ITEM_NEED_AFFINE = 1 << 5,
GNOME_CANVAS_ITEM_NEED_CLIP = 1 << 6,
GNOME_CANVAS_ITEM_NEED_VIS = 1 << 7,
GNOME_CANVAS_ITEM_AFFINE_FULL = 1 << 8
} GnomeCanvasItemFlags;
/* Update flags for items */
enum {
GNOME_CANVAS_UPDATE_REQUESTED = 1 << 0,
GNOME_CANVAS_UPDATE_AFFINE = 1 << 1,
GNOME_CANVAS_UPDATE_CLIP = 1 << 2,
GNOME_CANVAS_UPDATE_VISIBILITY = 1 << 3,
GNOME_CANVAS_UPDATE_IS_VISIBLE = 1 << 4 /* Deprecated. FIXME: remove this */
};
/* Data for rendering in antialiased mode */
typedef struct {
/* 24-bit RGB buffer for rendering */
guchar *buf;
/* Rectangle describing the rendering area */
ArtIRect rect;
/* Rowstride for the buffer */
gint buf_rowstride;
/* Background color, given as 0xrrggbb */
guint32 bg_color;
/* Invariant: at least one of the following flags is true. */
/* Set when the render rectangle area is the solid color bg_color */
guint is_bg : 1;
/* Set when the render rectangle area is represented by the buf */
guint is_buf : 1;
} GnomeCanvasBuf;
#define GNOME_TYPE_CANVAS_ITEM (gnome_canvas_item_get_type ())
#define GNOME_CANVAS_ITEM(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GNOME_TYPE_CANVAS_ITEM, GnomeCanvasItem))
#define GNOME_CANVAS_ITEM_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GNOME_TYPE_CANVAS_ITEM, GnomeCanvasItemClass))
#define GNOME_IS_CANVAS_ITEM(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GNOME_TYPE_CANVAS_ITEM))
#define GNOME_IS_CANVAS_ITEM_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GNOME_TYPE_CANVAS_ITEM))
#define GNOME_CANVAS_ITEM_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GNOME_TYPE_CANVAS_ITEM, GnomeCanvasItemClass))
struct _GnomeCanvasItem {
GtkObject object;
/* Parent canvas for this item */
GnomeCanvas *canvas;
/* Parent canvas group for this item (a GnomeCanvasGroup) */
GnomeCanvasItem *parent;
/* If NULL, assumed to be the identity tranform. If flags does not have
* AFFINE_FULL, then a two-element array containing a translation. If
* flags contains AFFINE_FULL, a six-element array containing an affine
* transformation.
*/
gdouble *xform;
/* Bounding box for this item (in canvas coordinates) */
gdouble x1, y1, x2, y2;
/* XXX GtkObject flags are sealed now, so we have to provide
* our own. This breaks ABI compatibility with upstream. */
GnomeCanvasItemFlags flags;
};
struct _GnomeCanvasItemClass {
GtkObjectClass parent_class;
/* Tell the item to update itself. The flags are from the update flags
* defined above. The item should update its internal state from its
* queued state, and recompute and request its repaint area. The
* affine, if used, is a pointer to a 6-element array of doubles. The
* update method also recomputes the bounding box of the item.
*/
void (* update) (GnomeCanvasItem *item, gdouble *affine, ArtSVP *clip_path, gint flags);
/* Realize an item -- create GCs, etc. */
void (* realize) (GnomeCanvasItem *item);
/* Unrealize an item */
void (* unrealize) (GnomeCanvasItem *item);
/* Map an item - normally only need by items with their own GdkWindows */
void (* map) (GnomeCanvasItem *item);
/* Unmap an item */
void (* unmap) (GnomeCanvasItem *item);
/* Return the microtile coverage of the item */
ArtUta *(* coverage) (GnomeCanvasItem *item);
/* Draw an item of this type. (x, y) are the upper-left canvas pixel
* coordinates of the drawable, a temporary pixmap, where things get
* drawn. (width, height) are the dimensions of the drawable.
*/
void (* draw) (GnomeCanvasItem *item, GdkDrawable *drawable,
gint x, gint y, gint width, gint height);
/* Render the item over the buffer given. The buf data structure
* contains both a pointer to a packed 24-bit RGB array, and the
* coordinates. This method is only used for antialiased canvases.
*
* TODO: figure out where clip paths fit into the rendering framework.
*/
void (* render) (GnomeCanvasItem *item, GnomeCanvasBuf *buf);
/* Calculate the distance from an item to the specified point. It also
* returns a canvas item which is the item itself in the case of the
* object being an actual leaf item, or a child in case of the object
* being a canvas group. (cx, cy) are the canvas pixel coordinates that
* correspond to the item-relative coordinates (x, y).
*/
gdouble (* point) (GnomeCanvasItem *item, gdouble x, gdouble y, gint cx, gint cy,
GnomeCanvasItem **actual_item);
/* Fetch the item's bounding box (need not be exactly tight). This
* should be in item-relative coordinates.
*/
void (* bounds) (GnomeCanvasItem *item, gdouble *x1, gdouble *y1, gdouble *x2, gdouble *y2);
/* Signal: an event occurred for an item of this type. The (x, y)
* coordinates are in the canvas world coordinate system.
*/
gboolean (* event) (GnomeCanvasItem *item, GdkEvent *event);
/* Reserved for future expansion */
gpointer spare_vmethods [4];
};
GType gnome_canvas_item_get_type (void) G_GNUC_CONST;
/* Create a canvas item using the standard Gtk argument mechanism. The item is
* automatically inserted at the top of the specified canvas group. The last
* argument must be a NULL pointer.
*/
GnomeCanvasItem *gnome_canvas_item_new (GnomeCanvasGroup *parent, GType type,
const gchar *first_arg_name, ...);
/* Constructors for use in derived classes and language wrappers */
void gnome_canvas_item_construct (GnomeCanvasItem *item, GnomeCanvasGroup *parent,
const gchar *first_arg_name, va_list args);
/* Configure an item using the standard Gtk argument mechanism. The last
* argument must be a NULL pointer.
*/
void gnome_canvas_item_set (GnomeCanvasItem *item, const gchar *first_arg_name, ...);
/* Used only for language wrappers and the like */
void gnome_canvas_item_set_valist (GnomeCanvasItem *item,
const gchar *first_arg_name, va_list args);
/* Move an item by the specified amount */
void gnome_canvas_item_move (GnomeCanvasItem *item, gdouble dx, gdouble dy);
/* Apply a relative affine transformation to the item. */
void gnome_canvas_item_affine_relative (GnomeCanvasItem *item, const gdouble affine[6]);
/* Apply an absolute affine transformation to the item. */
void gnome_canvas_item_affine_absolute (GnomeCanvasItem *item, const gdouble affine[6]);
/* Raise an item in the z-order of its parent group by the specified number of
* positions.
*/
void gnome_canvas_item_raise (GnomeCanvasItem *item, gint positions);
/* Lower an item in the z-order of its parent group by the specified number of
* positions.
*/
void gnome_canvas_item_lower (GnomeCanvasItem *item, gint positions);
/* Raise an item to the top of its parent group's z-order. */
void gnome_canvas_item_raise_to_top (GnomeCanvasItem *item);
/* Lower an item to the bottom of its parent group's z-order */
void gnome_canvas_item_lower_to_bottom (GnomeCanvasItem *item);
/* Show an item (make it visible). If the item is already shown, it has no
* effect.
*/
void gnome_canvas_item_show (GnomeCanvasItem *item);
/* Hide an item (make it invisible). If the item is already invisible, it has
* no effect.
*/
void gnome_canvas_item_hide (GnomeCanvasItem *item);
/* Grab the mouse for the specified item. Only the events in event_mask will be
* reported. If cursor is non-NULL, it will be used during the duration of the
* grab. Time is a proper X event time parameter. Returns the same values as
* XGrabPointer().
*/
gint gnome_canvas_item_grab (GnomeCanvasItem *item, guint event_mask,
GdkCursor *cursor, guint32 etime);
/* Ungrabs the mouse -- the specified item must be the same that was passed to
* gnome_canvas_item_grab(). Time is a proper X event time parameter.
*/
void gnome_canvas_item_ungrab (GnomeCanvasItem *item, guint32 etime);
/* These functions convert from a coordinate system to another. "w" is world
* coordinates and "i" is item coordinates.
*/
void gnome_canvas_item_w2i (GnomeCanvasItem *item, gdouble *x, gdouble *y);
void gnome_canvas_item_i2w (GnomeCanvasItem *item, gdouble *x, gdouble *y);
/* Gets the affine transform that converts from item-relative coordinates to
* world coordinates.
*/
void gnome_canvas_item_i2w_affine (GnomeCanvasItem *item, gdouble affine[6]);
/* Gets the affine transform that converts from item-relative coordinates to
* canvas pixel coordinates.
*/
void gnome_canvas_item_i2c_affine (GnomeCanvasItem *item, gdouble affine[6]);
/* Remove the item from its parent group and make the new group its parent. The
* item will be put on top of all the items in the new group. The item's
* coordinates relative to its new parent to *not* change -- this means that the
* item could potentially move on the screen.
*
* The item and the group must be in the same canvas. An item cannot be
* reparented to a group that is the item itself or that is an inferior of the
* item.
*/
void gnome_canvas_item_reparent (GnomeCanvasItem *item, GnomeCanvasGroup *new_group);
/* Used to send all of the keystroke events to a specific item as well as
* GDK_FOCUS_CHANGE events.
*/
void gnome_canvas_item_grab_focus (GnomeCanvasItem *item);
/* Fetch the bounding box of the item. The bounding box may not be exactly
* tight, but the canvas items will do the best they can. The returned bounding
* box is in the coordinate system of the item's parent.
*/
void gnome_canvas_item_get_bounds (GnomeCanvasItem *item,
gdouble *x1, gdouble *y1, gdouble *x2, gdouble *y2);
/* Request that the update method eventually get called. This should be used
* only by item implementations.
*/
void gnome_canvas_item_request_update (GnomeCanvasItem *item);
/* GnomeCanvasGroup - a group of canvas items
*
* A group is a node in the hierarchical tree of groups/items inside a canvas.
* Groups serve to give a logical structure to the items.
*
* Consider a circuit editor application that uses the canvas for its schematic
* display. Hierarchically, there would be canvas groups that contain all the
* components needed for an "adder", for example -- this includes some logic
* gates as well as wires. You can move stuff around in a convenient way by
* doing a gnome_canvas_item_move() of the hierarchical groups -- to move an
* adder, simply move the group that represents the adder.
*
* The following arguments are available:
*
* name type read/write description
* --------------------------------------------------------------------------------
* x gdouble RW X coordinate of group's origin
* y gdouble RW Y coordinate of group's origin
*/
#define GNOME_TYPE_CANVAS_GROUP (gnome_canvas_group_get_type ())
#define GNOME_CANVAS_GROUP(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GNOME_TYPE_CANVAS_GROUP, GnomeCanvasGroup))
#define GNOME_CANVAS_GROUP_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GNOME_TYPE_CANVAS_GROUP, GnomeCanvasGroupClass))
#define GNOME_IS_CANVAS_GROUP(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GNOME_TYPE_CANVAS_GROUP))
#define GNOME_IS_CANVAS_GROUP_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GNOME_TYPE_CANVAS_GROUP))
#define GNOME_CANVAS_GROUP_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GNOME_TYPE_CANVAS_GROUP, GnomeCanvasGroupClass))
struct _GnomeCanvasGroup {
GnomeCanvasItem item;
/* Children of the group */
GList *item_list;
GList *item_list_end;
};
struct _GnomeCanvasGroupClass {
GnomeCanvasItemClass parent_class;
};
GType gnome_canvas_group_get_type (void) G_GNUC_CONST;
/*** GnomeCanvas ***/
#define GNOME_TYPE_CANVAS (gnome_canvas_get_type ())
#define GNOME_CANVAS(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GNOME_TYPE_CANVAS, GnomeCanvas))
#define GNOME_CANVAS_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GNOME_TYPE_CANVAS, GnomeCanvasClass))
#define GNOME_IS_CANVAS(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GNOME_TYPE_CANVAS))
#define GNOME_IS_CANVAS_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GNOME_TYPE_CANVAS))
#define GNOME_CANVAS_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GNOME_TYPE_CANVAS, GnomeCanvasClass))
struct _GnomeCanvas {
GtkLayout layout;
/* Root canvas group */
GnomeCanvasItem *root;
/* Area that needs redrawing, stored as a microtile array */
ArtUta *redraw_area;
/* The item containing the mouse pointer, or NULL if none */
GnomeCanvasItem *current_item;
/* Item that is about to become current (used to track deletions and such) */
GnomeCanvasItem *new_current_item;
/* Item that holds a pointer grab, or NULL if none */
GnomeCanvasItem *grabbed_item;
/* If non-NULL, the currently focused item */
GnomeCanvasItem *focused_item;
/* GC for temporary draw pixmap */
GdkGC *pixmap_gc;
/* Event on which selection of current item is based */
GdkEvent pick_event;
/* Scrolling region */
gdouble scroll_x1, scroll_y1;
gdouble scroll_x2, scroll_y2;
/* Scaling factor to be used for display */
gdouble pixels_per_unit;
/* Idle handler ID */
guint idle_id;
/* Signal handler ID for destruction of the root item */
guint root_destroy_id;
/* Area that is being redrawn. Contains (x1, y1) but not (x2, y2).
* Specified in canvas pixel coordinates.
*/
gint redraw_x1, redraw_y1;
gint redraw_x2, redraw_y2;
/* Offsets of the temprary drawing pixmap */
gint draw_xofs, draw_yofs;
/* Internal pixel offsets when zoomed out */
gint zoom_xofs, zoom_yofs;
/* Last known modifier state, for deferred repick when a button is down */
gint state;
/* Event mask specified when grabbing an item */
guint grabbed_event_mask;
/* Tolerance distance for picking items */
gint close_enough;
/* Whether the canvas should center the scroll region in the middle of
* the window if the scroll region is smaller than the window.
*/
guint center_scroll_region : 1;
/* Whether items need update at next idle loop iteration */
guint need_update : 1;
/* Whether the canvas needs redrawing at the next idle loop iteration */
guint need_redraw : 1;
/* Whether current item will be repicked at next idle loop iteration */
guint need_repick : 1;
/* For use by internal pick_current_item() function */
guint left_grabbed_item : 1;
/* For use by internal pick_current_item() function */
guint in_repick : 1;
/* Whether the canvas is in antialiased mode or not */
guint aa : 1;
/* Which dither mode to use for antialiased mode drawing */
GdkRgbDither dither;
};
struct _GnomeCanvasClass {
GtkLayoutClass parent_class;
/* Draw the background for the area given. This method is only used
* for non-antialiased canvases.
*/
void (* draw_background) (GnomeCanvas *canvas, GdkDrawable *drawable,
gint x, gint y, gint width, gint height);
/* Render the background for the buffer given. The buf data structure
* contains both a pointer to a packed 24-bit RGB array, and the
* coordinates. This method is only used for antialiased canvases.
*/
void (* render_background) (GnomeCanvas *canvas, GnomeCanvasBuf *buf);
/* Private Virtual methods for groping the canvas inside bonobo */
void (* request_update) (GnomeCanvas *canvas);
/* Reserved for future expansion */
gpointer spare_vmethods [4];
};
GType gnome_canvas_get_type (void) G_GNUC_CONST;
/* Creates a new canvas. You should check that the canvas is created with the
* proper visual and colormap. Any visual will do unless you intend to insert
* gdk_imlib images into it, in which case you should use the gdk_imlib visual.
*
* You should call gnome_canvas_set_scroll_region() soon after calling this
* function to set the desired scrolling limits for the canvas.
*/
GtkWidget *gnome_canvas_new (void);
/* Creates a new antialiased empty canvas. You should push the GdkRgb colormap
* and visual for this.
*/
#ifndef GNOME_EXCLUDE_EXPERIMENTAL
GtkWidget *gnome_canvas_new_aa (void);
#endif
/* Returns the root canvas item group of the canvas */
GnomeCanvasGroup *gnome_canvas_root (GnomeCanvas *canvas);
/* Sets the limits of the scrolling region, in world coordinates */
void gnome_canvas_set_scroll_region (GnomeCanvas *canvas,
gdouble x1, gdouble y1, gdouble x2, gdouble y2);
/* Gets the limits of the scrolling region, in world coordinates */
void gnome_canvas_get_scroll_region (GnomeCanvas *canvas,
gdouble *x1, gdouble *y1, gdouble *x2, gdouble *y2);
/* Whether the canvas centers the scroll region if it is smaller than the window */
void gnome_canvas_set_center_scroll_region (GnomeCanvas *canvas, gboolean center_scroll_region);
/* Returns whether the canvas is set to center the scroll region if it is smaller than the window */
gboolean gnome_canvas_get_center_scroll_region (GnomeCanvas *canvas);
/* Sets the number of pixels that correspond to one unit in world coordinates */
void gnome_canvas_set_pixels_per_unit (GnomeCanvas *canvas, gdouble n);
/* Scrolls the canvas to the specified offsets, given in canvas pixel coordinates */
void gnome_canvas_scroll_to (GnomeCanvas *canvas, gint cx, gint cy);
/* Returns the scroll offsets of the canvas in canvas pixel coordinates. You
* can specify NULL for any of the values, in which case that value will not be
* queried.
*/
void gnome_canvas_get_scroll_offsets (GnomeCanvas *canvas, gint *cx, gint *cy);
/* Requests that the canvas be repainted immediately instead of in the idle
* loop.
*/
void gnome_canvas_update_now (GnomeCanvas *canvas);
/* Returns the item that is at the specified position in world coordinates, or
* NULL if no item is there.
*/
GnomeCanvasItem *gnome_canvas_get_item_at (GnomeCanvas *canvas, gdouble x, gdouble y);
/* For use only by item type implementations. Request that the canvas eventually
* redraw the specified region. The region is specified as a microtile
* array. This function takes over responsibility for freeing the uta argument.
*/
void gnome_canvas_request_redraw_uta (GnomeCanvas *canvas, ArtUta *uta);
/* For use only by item type implementations. Request that the canvas
* eventually redraw the specified region, specified in canvas pixel
* coordinates. The region contains (x1, y1) but not (x2, y2).
*/
void gnome_canvas_request_redraw (GnomeCanvas *canvas, gint x1, gint y1, gint x2, gint y2);
/* Gets the affine transform that converts world coordinates into canvas pixel
* coordinates.
*/
void gnome_canvas_w2c_affine (GnomeCanvas *canvas, gdouble affine[6]);
/* These functions convert from a coordinate system to another. "w" is world
* coordinates, "c" is canvas pixel coordinates (pixel coordinates that are
* (0,0) for the upper-left scrolling limit and something else for the
* lower-left scrolling limit).
*/
void gnome_canvas_w2c (GnomeCanvas *canvas, gdouble wx, gdouble wy, gint *cx, gint *cy);
void gnome_canvas_w2c_d (GnomeCanvas *canvas, gdouble wx, gdouble wy, gdouble *cx, gdouble *cy);
void gnome_canvas_c2w (GnomeCanvas *canvas, gint cx, gint cy, gdouble *wx, gdouble *wy);
/* This function takes in coordinates relative to the GTK_LAYOUT
* (canvas)->bin_window and converts them to world coordinates.
*/
void gnome_canvas_window_to_world (GnomeCanvas *canvas,
gdouble winx, gdouble winy, gdouble *worldx, gdouble *worldy);
/* This is the inverse of gnome_canvas_window_to_world() */
void gnome_canvas_world_to_window (GnomeCanvas *canvas,
gdouble worldx, gdouble worldy, gdouble *winx, gdouble *winy);
/* Takes a string specification for a color and allocates it into the specified
* GdkColor. If the string is null, then it returns FALSE. Otherwise, it
* returns TRUE.
*/
gint gnome_canvas_get_color (GnomeCanvas *canvas, const gchar *spec, GdkColor *color);
/* Allocates a color from the RGB value passed into this function. */
gulong gnome_canvas_get_color_pixel (GnomeCanvas *canvas,
guint rgba);
/* Sets the stipple origin of the specified gc so that it will be aligned with
* all the stipples used in the specified canvas. This is intended for use only
* by canvas item implementations.
*/
void gnome_canvas_set_stipple_origin (GnomeCanvas *canvas, GdkGC *gc);
/* Controls the dithering used when the canvas renders.
* Only applicable to antialiased canvases - ignored by non-antialiased canvases.
*/
void gnome_canvas_set_dither (GnomeCanvas *canvas, GdkRgbDither dither);
/* Returns the dither mode of an antialiased canvas.
* Only applicable to antialiased canvases - ignored by non-antialiased canvases.
*/
GdkRgbDither gnome_canvas_get_dither (GnomeCanvas *canvas);
G_END_DECLS
#endif
