sp-offset.h revision 003725d316171849211106435e09bb28c59cd30c
#ifndef __SP_OFFSET_H__
#define __SP_OFFSET_H__
/** \file
* SPOffset class.
*
* Authors:
* Mitsuru Oka <oka326@parkcity.ne.jp>
* Lauris Kaplinski <lauris@kaplinski.com>
* (of the sp-spiral.h upon which this file was created)
* Copyright (C) 1999-2002 Lauris Kaplinski
* Copyright (C) 2000-2001 Ximian, Inc.
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "sp-shape.h"
#include <sigc++/sigc++.h>
#define SP_TYPE_OFFSET (sp_offset_get_type ())
#define SP_OFFSET(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), SP_TYPE_OFFSET, SPOffset))
#define SP_OFFSET_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), SP_TYPE_OFFSET, SPOffsetClass))
#define SP_IS_OFFSET(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), SP_TYPE_OFFSET))
#define SP_IS_OFFSET_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), SP_TYPE_OFFSET))
class SPOffset;
class SPOffsetClass;
class SPUseReference;
/**
* SPOffset class.
*
* An offset is defined by curve and radius. The original curve is kept as
* a path in a sodipodi:original attribute. It's not possible to change
* the original curve.
*
* SPOffset is a derivative of SPShape, much like the SPSpiral or SPRect.
* The goal is to have a source shape (= originalPath), an offset (= radius)
* and compute the offset of the source by the radius. To get it to work,
* one needs to know what the source is and what the radius is, and how it's
* stored in the xml representation. The object itself is a "path" element,
* to get lots of shape functionality for free. The source is the easy part:
* it's stored in a "inkscape:original" attribute in the path. In case of
* "linked" offset, as they've been dubbed, there is an additional
* "inkscape:href" that contains the id of an element of the svg.
* When built, the object will attach a listener vector to that object and
* rebuild the "inkscape:original" whenever the href'd object changes. This
* is of course grossly inefficient, and also does not react to changes
* to the href'd during context stuff (like changing the shape of a star by
* dragging control points) unless the path of that object is changed during
* the context (seems to be the case for SPEllipse). The computation of the
* offset is done in sp_offset_set_shape(), a function that is called whenever
* a change occurs to the offset (change of source or change of radius).
* just like the sp-star and other, this path derivative can make control
* points, or more precisely one control point, that's enough to define the
* radius (look in object-edit).
*/
struct SPOffset : public SPShape {
void *originalPath; ///< will be a livarot Path, just don't declare it here to please the gcc linker
char *original; ///< SVG description of the source path
float rad; ///< offset radius
/// for interactive setting of the radius
bool knotSet;
Geom::Point knot;
bool sourceDirty;
bool isUpdating;
gchar *sourceHref;
SPUseReference *sourceRef;
Inkscape::XML::Node *sourceRepr; ///< the repr associated with that id
SPObject *sourceObject;
sigc::connection _modified_connection;
sigc::connection _delete_connection;
sigc::connection _changed_connection;
sigc::connection _transformed_connection;
};
/// The SPOffset vtable.
struct SPOffsetClass
{
SPShapeClass parent_class;
};
/* Standard Gtk function */
GType sp_offset_get_type (void);
double sp_offset_distance_to_original (SPOffset * offset, Geom::Point px);
void sp_offset_top_point (SPOffset * offset, Geom::Point *px);
SPItem *sp_offset_get_source (SPOffset *offset);
#endif
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
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