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+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * @file
+ * Interface between Inkscape code (SPItem) and graphlayout functions.
+ */
+/*
+ * Authors:
+ * Tim Dwyer <Tim.Dwyer@infotech.monash.edu.au>
+ * Abhishek Sharma
+ *
+ * Copyright (C) 2005 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <algorithm>
+#include <cstring>
+#include <iostream>
+#include <list>
+#include <map>
+#include <string>
+#include <valarray>
+#include <vector>
+
+#include <2geom/transforms.h>
+
+#include "conn-avoid-ref.h"
+#include "desktop.h"
+#include "graphlayout.h"
+#include "inkscape.h"
+
+#include "3rdparty/adaptagrams/libavoid/router.h"
+
+#include "3rdparty/adaptagrams/libcola/cola.h"
+#include "3rdparty/adaptagrams/libcola/connected_components.h"
+
+#include "object/sp-item-transform.h"
+#include "object/sp-namedview.h"
+#include "object/sp-path.h"
+#include "style.h"
+
+using namespace cola;
+using namespace vpsc;
+
+/**
+ * Returns true if item is a connector
+ */
+bool isConnector(SPItem const * const item) {
+ SPPath * path = nullptr;
+ if (SP_IS_PATH(item)) {
+ path = SP_PATH(item);
+ }
+ return path && path->connEndPair.isAutoRoutingConn();
+}
+
+struct CheckProgress: TestConvergence {
+ CheckProgress(double d, unsigned i, std::list<SPItem*> & selected, Rectangles & rs,
+ std::map<std::string, unsigned> & nodelookup)
+ : TestConvergence(d, i)
+ , selected(selected)
+ , rs(rs)
+ , nodelookup(nodelookup)
+ {}
+ bool operator()(const double new_stress, std::valarray<double> & X, std::valarray<double> & Y) override {
+ /* This is where, if we wanted to animate the layout, we would need to update
+ * the positions of all objects and redraw the canvas and maybe sleep a bit
+ cout << "stress="<<new_stress<<endl;
+ cout << "x[0]="<<rs[0]->getMinX()<<endl;
+ for (std::list<SPItem *>::iterator it(selected.begin());
+ it != selected.end();
+ ++it)
+ {
+ SPItem *u=*it;
+ if(!isConnector(u)) {
+ Rectangle* r=rs[nodelookup[u->id]];
+ Geom::Rect const item_box(sp_item_bbox_desktop(u));
+ Geom::Point const curr(item_box.midpoint());
+ Geom::Point const dest(r->getCentreX(),r->getCentreY());
+ u->move_rel(Geom::Translate(dest - curr));
+ }
+ }
+ */
+ return TestConvergence::operator()(new_stress, X, Y);
+ }
+ std::list<SPItem*> & selected;
+ Rectangles & rs;
+ std::map<std::string, unsigned> & nodelookup;
+};
+
+/**
+ * Scans the items list and places those items that are
+ * not connectors in filtered
+ */
+void filterConnectors(std::vector<SPItem*> const & items, std::list<SPItem*> & filtered) {
+ for (SPItem * item: items) {
+ if (!isConnector(item)) {
+ filtered.push_back(item);
+ }
+ }
+}
+
+/**
+ * Takes a list of inkscape items, extracts the graph defined by
+ * connectors between them, and uses graph layout techniques to find
+ * a nice layout
+ */
+void graphlayout(std::vector<SPItem*> const & items) {
+ if (items.empty()) return;
+
+ std::list<SPItem*> selected;
+ filterConnectors(items, selected);
+
+ if (selected.size() < 2) return;
+
+ // add the connector spacing to the size of node bounding boxes
+ // so that connectors can always be routed between shapes
+ SPDesktop * desktop = SP_ACTIVE_DESKTOP;
+ double spacing = 0;
+ if (desktop) spacing = desktop->namedview->connector_spacing + 0.1;
+
+ std::map<std::string, unsigned> nodelookup;
+ Rectangles rs;
+ std::vector<Edge> es;
+ for (SPItem * item: selected) {
+ Geom::OptRect const item_box = item->desktopVisualBounds();
+ if (item_box) {
+ Geom::Point ll(item_box->min());
+ Geom::Point ur(item_box->max());
+ nodelookup[item->getId()] = rs.size();
+ rs.push_back(new Rectangle(ll[0] - spacing, ur[0] + spacing,
+ ll[1] - spacing, ur[1] + spacing));
+ } else {
+ // I'm not actually sure if it's possible for something with a
+ // NULL item-box to be attached to a connector in which case we
+ // should never get to here... but if such a null box can occur it's
+ // probably pretty safe to simply ignore
+ //fprintf(stderr, "NULL item_box found in graphlayout, ignoring!\n");
+ }
+ }
+
+ Inkscape::Preferences * prefs = Inkscape::Preferences::get();
+ CompoundConstraints constraints;
+ double ideal_connector_length = prefs->getDouble("/tools/connector/length", 100.0);
+ double directed_edge_height_modifier = 1.0;
+
+ bool directed = prefs->getBool("/tools/connector/directedlayout");
+ bool avoid_overlaps = prefs->getBool("/tools/connector/avoidoverlaplayout");
+
+ for (SPItem * item: selected) {
+ std::map<std::string, unsigned>::iterator i_iter=nodelookup.find(item->getId());
+ if (i_iter == nodelookup.end()) continue;
+ unsigned u = i_iter->second;
+ std::vector<SPItem*> nlist = item->getAvoidRef().getAttachedConnectors(Avoid::runningFrom);
+ std::list<SPItem*> connectors;
+
+ connectors.insert(connectors.end(), nlist.begin(), nlist.end());
+
+ for (SPItem * conn: connectors) {
+ SPItem * iv;
+ SPItem * items[2];
+ assert(isConnector(conn));
+ SP_PATH(conn)->connEndPair.getAttachedItems(items);
+ if (items[0] == item) {
+ iv = items[1];
+ } else {
+ iv = items[0];
+ }
+
+ if (iv == nullptr) {
+ // The connector is not attached to anything at the
+ // other end so we should just ignore it.
+ continue;
+ }
+
+ // If iv not in nodelookup we again treat the connector
+ // as disconnected and continue
+ std::map<std::string, unsigned>::iterator v_pair = nodelookup.find(iv->getId());
+ if (v_pair != nodelookup.end()) {
+ unsigned v = v_pair->second;
+ //cout << "Edge: (" << u <<","<<v<<")"<<endl;
+ es.emplace_back(u, v);
+ if (conn->style->marker_end.set) {
+ if (directed && strcmp(conn->style->marker_end.value(), "none")) {
+ constraints.push_back(new SeparationConstraint(YDIM, v, u,
+ ideal_connector_length * directed_edge_height_modifier));
+ }
+ }
+ }
+ }
+ }
+ EdgeLengths elengths(es.size(), 1);
+ std::vector<Component*> cs;
+ connectedComponents(rs, es, cs);
+ for (Component * c: cs) {
+ if (c->edges.size() < 2) continue;
+ CheckProgress test(0.0001, 100, selected, rs, nodelookup);
+ ConstrainedMajorizationLayout alg(c->rects, c->edges, nullptr, ideal_connector_length, elengths, &test);
+ if (avoid_overlaps) alg.setAvoidOverlaps();
+ alg.setConstraints(&constraints);
+ alg.run();
+ }
+ separateComponents(cs);
+
+ for (SPItem * item: selected) {
+ if (!isConnector(item)) {
+ std::map<std::string, unsigned>::iterator i = nodelookup.find(item->getId());
+ if (i != nodelookup.end()) {
+ Rectangle * r = rs[i->second];
+ Geom::OptRect item_box = item->desktopVisualBounds();
+ if (item_box) {
+ Geom::Point const curr(item_box->midpoint());
+ Geom::Point const dest(r->getCentreX(),r->getCentreY());
+ item->move_rel(Geom::Translate(dest - curr));
+ }
+ }
+ }
+ }
+ for (CompoundConstraint * c: constraints) {
+ delete c;
+ }
+ for (Rectangle * r: rs) {
+ delete r;
+ }
+}
+// vim: set cindent
+// vim: ts=4 sw=4 et tw=0 wm=0
+
+/*
+ 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:fileencoding=utf-8:textwidth=99 :