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Diffstat (limited to 'src/object/sp-polygon.cpp')
| -rw-r--r-- | src/object/sp-polygon.cpp | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/object/sp-polygon.cpp b/src/object/sp-polygon.cpp new file mode 100644 index 0000000..b92dfcb --- /dev/null +++ b/src/object/sp-polygon.cpp @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SVG <polygon> implementation + * + * Authors: + * Lauris Kaplinski <lauris@kaplinski.com> + * Abhishek Sharma + * + * Copyright (C) 1999-2002 Lauris Kaplinski + * Copyright (C) 2000-2001 Ximian, Inc. + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include "attributes.h" +#include "sp-polygon.h" +#include "display/curve.h" +#include <glibmm/i18n.h> +#include <2geom/curves.h> +#include "helper/geom-curves.h" +#include "svg/stringstream.h" +#include "xml/repr.h" +#include "document.h" + +SPPolygon::SPPolygon() : SPShape() { +} + +SPPolygon::~SPPolygon() = default; + +void SPPolygon::build(SPDocument *document, Inkscape::XML::Node *repr) { + SPPolygon* object = this; + + SPShape::build(document, repr); + + object->readAttr(SPAttr::POINTS); +} + +/* + * sp_svg_write_polygon: Write points attribute for polygon tag. + * pathv may only contain paths with only straight line segments + * Return value: points attribute string. + */ +static gchar *sp_svg_write_polygon(Geom::PathVector const & pathv) +{ + Inkscape::SVGOStringStream os; + + for (const auto & pit : pathv) { + for (Geom::Path::const_iterator cit = pit.begin(); cit != pit.end_default(); ++cit) { + if ( is_straight_curve(*cit) ) + { + os << cit->finalPoint()[0] << "," << cit->finalPoint()[1] << " "; + } else { + g_error("sp_svg_write_polygon: polygon path contains non-straight line segments"); + } + } + } + + return g_strdup(os.str().c_str()); +} + +Inkscape::XML::Node* SPPolygon::write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags) { + // Tolerable workaround: we need to update the object's curve before we set points= + // because it's out of sync when e.g. some extension attrs of the polygon or star are changed in XML editor + this->set_shape(); + + if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) { + repr = xml_doc->createElement("svg:polygon"); + } + + /* We can safely write points here, because all subclasses require it too (Lauris) */ + /* While saving polygon element without points attribute _curve is NULL (see bug 1202753) */ + if (this->_curve != nullptr) { + gchar *str = sp_svg_write_polygon(this->_curve->get_pathvector()); + repr->setAttribute("points", str); + g_free(str); + } + + SPShape::write(xml_doc, repr, flags); + + return repr; +} + + +static gboolean polygon_get_value(gchar const **p, gdouble *v) +{ + while (**p != '\0' && (**p == ',' || **p == '\x20' || **p == '\x9' || **p == '\xD' || **p == '\xA')) { + (*p)++; + } + + if (**p == '\0') { + return false; + } + + gchar *e = nullptr; + *v = g_ascii_strtod(*p, &e); + + if (e == *p) { + return false; + } + + *p = e; + + return true; +} + +void SPPolygon::set(SPAttr key, const gchar* value) { + switch (key) { + case SPAttr::POINTS: { + if (!value) { + /* fixme: The points attribute is required. We should handle its absence as per + * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing. */ + break; + } + + auto curve = std::make_unique<SPCurve>(); + gboolean hascpt = FALSE; + + gchar const *cptr = value; + bool has_error = false; + + while (TRUE) { + gdouble x; + + if (!polygon_get_value(&cptr, &x)) { + break; + } + + gdouble y; + + if (!polygon_get_value(&cptr, &y)) { + /* fixme: It is an error for an odd number of points to be specified. We + * should display the points up to now (as we currently do, though perhaps + * without the closepath: the spec isn't quite clear on whether to do a + * closepath or not, though I'd guess it's best not to do a closepath), but + * then flag the document as in error, as per + * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing. + * + * (Ref: http://www.w3.org/TR/SVG11/shapes.html#PolygonElement.) */ + has_error = true; + break; + } + + if (hascpt) { + curve->lineto(x, y); + } else { + curve->moveto(x, y); + hascpt = TRUE; + } + } + + if (has_error || *cptr != '\0') { + /* TODO: Flag the document as in error, as per + * http://www.w3.org/TR/SVG11/implnote.html#ErrorProcessing. */ + } else if (hascpt) { + /* We might have done a moveto but no lineto. I'm not sure how we're supposed to represent + * a single-point polygon in SPCurve. TODO: add a testcase with only one coordinate pair */ + curve->closepath(); + } + + setCurve(std::move(curve)); + break; + } + default: + SPShape::set(key, value); + break; + } +} + +const char* SPPolygon::typeName() const { + return "path"; +} + +gchar* SPPolygon::description() const { + return g_strdup(_("<b>Polygon</b>")); +} + +/* + 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: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 : |