src/graphlayout.cpp

   1 /** @file
   2  * @brief Interface between Inkscape code (SPItem) and graphlayout functions.
   3  */
   4 /*
   5  * Authors:
   6  *   Tim Dwyer <Tim.Dwyer@infotech.monash.edu.au>
   7  *
   8  * Copyright (C) 2005 Authors
   9  *
  10  * Released under GNU GPL.  Read the file 'COPYING' for more information.
  11  */
  12
  13 #include <iostream>
  14 #include <config.h>
  15 #include <map>
  16 #include <vector>
  17 #include <algorithm>
  18 #include <cstring>
  19 #include <cstdlib>
  20 #include <float.h>
  21
  22 #include "desktop.h"
  23 #include "inkscape.h"
  24 #include "sp-namedview.h"
  25 #include "util/glib-list-iterators.h"
  26 #include "graphlayout.h"
  27 #include "sp-path.h"
  28 #include "sp-item.h"
  29 #include "sp-item-transform.h"
  30 #include "sp-conn-end-pair.h"
  31 #include "style.h"
  32 #include "conn-avoid-ref.h"
  33 #include "libavoid/connector.h"
  34 #include "libavoid/router.h"
  35 #include "libavoid/geomtypes.h"
  36 #include "libcola/cola.h"
  37 #include "libvpsc/generate-constraints.h"
  38 #include "preferences.h"
  39
  40 using namespace std;
  41 using namespace cola;
  42 using namespace vpsc;
  43 /**
  44  * Returns true if item is a connector
  45  */
  46 bool isConnector(SPItem const *const i) {
  47     SPPath *path = NULL;
  48     if(SP_IS_PATH(i)) {
  49         path = SP_PATH(i);
  50     }
  51     return path && path->connEndPair.isAutoRoutingConn();
  52 }
  53
  54 struct CheckProgress : TestConvergence {
  55     CheckProgress(double d,unsigned i,list<SPItem *>&
  56                   selected,vector<Rectangle*>& rs,map<string,unsigned>& nodelookup) :
  57         TestConvergence(d,i), selected(selected), rs(rs), nodelookup(nodelookup) {}
  58     bool operator()(double new_stress, double* X, double* Y) {
  59         /* This is where, if we wanted to animate the layout, we would need to update
  60          * the positions of all objects and redraw the canvas and maybe sleep a bit
  61          cout << "stress="<<new_stress<<endl;
  62         cout << "x[0]="<<rs[0]->getMinX()<<endl;
  63         for (list<SPItem *>::iterator it(selected.begin());
  64             it != selected.end();
  65             ++it)
  66         {
  67             SPItem *u=*it;
  68             if(!isConnector(u)) {
  69                 Rectangle* r=rs[nodelookup[u->id]];
  70                 Geom::Rect const item_box(sp_item_bbox_desktop(u));
  71                 Geom::Point const curr(item_box.midpoint());
  72                 Geom::Point const dest(r->getCentreX(),r->getCentreY());
  73                 sp_item_move_rel(u, Geom::Translate(dest - curr));
  74             }
  75         }
  76         */
  77         return TestConvergence::operator()(new_stress,X,Y);
  78     }
  79     list<SPItem *>& selected;
  80     vector<Rectangle*>& rs;
  81     map<string,unsigned>& nodelookup;
  82 };
  83
  84 /**
  85  * Scans the items list and places those items that are
  86  * not connectors in filtered
  87  */
  88 void filterConnectors(GSList const *const items, list<SPItem *> &filtered) {
  89     for(GSList *i=(GSList *)items; i!=NULL; i=i->next) {
  90         SPItem *item=SP_ITEM(i->data);
  91         if(!isConnector(item)) {
  92             filtered.push_back(item);
  93         }
  94     }
  95 }
  96 /**
  97 * Takes a list of inkscape items, extracts the graph defined by
  98 * connectors between them, and uses graph layout techniques to find
  99 * a nice layout
 100 */
 101 void graphlayout(GSList const *const items) {
 102     if(!items) {
 103         return;
 104     }
 105
 106     using Inkscape::Util::GSListConstIterator;
 107     list<SPItem *> selected;
 108     filterConnectors(items,selected);
 109     if (selected.empty()) return;
 110
 111     const unsigned n=selected.size();
 112     //Check 2 or more selected objects
 113     if (n < 2) return;
 114
 115     // add the connector spacing to the size of node bounding boxes
 116     // so that connectors can always be routed between shapes
 117     SPDesktop* desktop = inkscape_active_desktop();
 118     double spacing = 0;
 119     if(desktop) spacing = desktop->namedview->connector_spacing+0.1;
 120
 121     map<string,unsigned> nodelookup;
 122     vector<Rectangle*> rs;
 123     vector<Edge> es;
 124     for (list<SPItem *>::iterator i(selected.begin());
 125          i != selected.end();
 126          ++i)
 127     {
 128         SPItem *u=*i;
 129         Geom::OptRect const item_box(sp_item_bbox_desktop(u));
 130         if(item_box) {
 131             Geom::Point ll(item_box->min());
 132             Geom::Point ur(item_box->max());
 133             nodelookup[u->getId()]=rs.size();
 134             rs.push_back(new Rectangle(ll[0]-spacing,ur[0]+spacing,
 135                         ll[1]-spacing,ur[1]+spacing));
 136         } else {
 137             // I'm not actually sure if it's possible for something with a
 138             // NULL item-box to be attached to a connector in which case we
 139             // should never get to here... but if such a null box can occur it's
 140             // probably pretty safe to simply ignore
 141             //fprintf(stderr,"NULL item_box found in graphlayout, ignoring!\n");
 142         }
 143     }
 144
 145     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 146     SimpleConstraints scx,scy;
 147     double ideal_connector_length = prefs->getDouble("/tools/connector/length", 100.0);
 148     double directed_edge_height_modifier = 1.0;
 149
 150     bool directed =       prefs->getBool("/tools/connector/directedlayout");
 151     bool avoid_overlaps = prefs->getBool("/tools/connector/avoidoverlaplayout");
 152
 153     for (list<SPItem *>::iterator i(selected.begin());
 154          i != selected.end();
 155          ++i)
 156     {
 157         SPItem *iu=*i;
 158         map<string,unsigned>::iterator i=nodelookup.find(iu->getId());
 159         if(i==nodelookup.end()) {
 160             continue;
 161         }
 162         unsigned u=i->second;
 163         GSList *nlist=iu->avoidRef->getAttachedConnectors(Avoid::runningFrom);
 164         list<SPItem *> connectors;
 165
 166         connectors.insert<GSListConstIterator<SPItem *> >(connectors.end(),nlist,NULL);
 167         for (list<SPItem *>::iterator j(connectors.begin());
 168                 j != connectors.end();
 169                 ++j) {
 170             SPItem *conn=*j;
 171             SPItem *iv;
 172             SPItem *items[2];
 173             assert(isConnector(conn));
 174             SP_PATH(conn)->connEndPair.getAttachedItems(items);
 175             if(items[0]==iu) {
 176                 iv=items[1];
 177             } else {
 178                 iv=items[0];
 179             }
 180
 181             if (iv == NULL) {
 182                 // The connector is not attached to anything at the
 183                 // other end so we should just ignore it.
 184                 continue;
 185             }
 186
 187             // If iv not in nodelookup we again treat the connector
 188             // as disconnected and continue
 189             map<string,unsigned>::iterator v_pair=nodelookup.find(iv->getId());
 190             if(v_pair!=nodelookup.end()) {
 191                 unsigned v=v_pair->second;
 192                 //cout << "Edge: (" << u <<","<<v<<")"<<endl;
 193                 es.push_back(make_pair(u,v));
 194                 if(conn->style->marker[SP_MARKER_LOC_END].set) {
 195                     if(directed && strcmp(conn->style->marker[SP_MARKER_LOC_END].value,"none")) {
 196                         scy.push_back(new SimpleConstraint(v, u,
 197                                     (ideal_connector_length * directed_edge_height_modifier)));
 198                     }
 199                 }
 200             }
 201         }
 202         if(nlist) {
 203             g_slist_free(nlist);
 204         }
 205     }
 206     const unsigned E = es.size();
 207     double eweights[E];
 208     fill(eweights,eweights+E,1);
 209     vector<Component*> cs;
 210     connectedComponents(rs,es,scx,scy,cs);
 211     for(unsigned i=0;i<cs.size();i++) {
 212         Component* c=cs[i];
 213         if(c->edges.size()<2) continue;
 214         CheckProgress test(0.0001,100,selected,rs,nodelookup);
 215         ConstrainedMajorizationLayout alg(c->rects,c->edges,eweights,ideal_connector_length,test);
 216         alg.setupConstraints(NULL,NULL,avoid_overlaps,
 217                 NULL,NULL,&c->scx,&c->scy,NULL,NULL);
 218         alg.run();
 219     }
 220     separateComponents(cs);
 221
 222     for (list<SPItem *>::iterator it(selected.begin());
 223          it != selected.end();
 224          ++it)
 225     {
 226         SPItem *u=*it;
 227         if(!isConnector(u)) {
 228             map<string,unsigned>::iterator i=nodelookup.find(u->getId());
 229             if(i!=nodelookup.end()) {
 230                 Rectangle* r=rs[i->second];
 231                 Geom::OptRect item_box(sp_item_bbox_desktop(u));
 232                 if(item_box) {
 233                     Geom::Point const curr(item_box->midpoint());
 234                     Geom::Point const dest(r->getCentreX(),r->getCentreY());
 235                     sp_item_move_rel(u, Geom::Translate(dest - curr));
 236                 }
 237             }
 238         }
 239     }
 240     for(unsigned i=0;i<scx.size();i++) {
 241         delete scx[i];
 242     }
 243     for(unsigned i=0;i<scy.size();i++) {
 244         delete scy[i];
 245     }
 246     for(unsigned i=0;i<rs.size();i++) {
 247         delete rs[i];
 248     }
 249 }
 250 // vim: set cindent
 251 // vim: ts=4 sw=4 et tw=0 wm=0
 252
 253 /*
 254   Local Variables:
 255   mode:c++
 256   c-file-style:"stroustrup"
 257   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 258   indent-tabs-mode:nil
 259   fill-column:99
 260   End:
 261 */
 262 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :