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graphlayout.cpp

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/** \file
 * Interface between Inkscape code (SPItem) and graphlayout functions.
 */
/*
* Authors:
*   Tim Dwyer <Tim.Dwyer@infotech.monash.edu.au>
*
* Copyright (C) 2005 Authors
*
* Released under GNU GPL.  Read the file 'COPYING' for more information.
*/
#include <iostream>
#include <config.h>
#include <map>
#include <vector>
#include <algorithm>
#include <float.h>

#include "desktop.h"
#include "inkscape.h"
#include "sp-namedview.h"
#include "util/glib-list-iterators.h"
#include "graphlayout/graphlayout.h"
#include "sp-path.h"
#include "sp-item.h"
#include "sp-item-transform.h"
#include "sp-conn-end-pair.h"
#include "style.h"
#include "conn-avoid-ref.h"
#include "libavoid/connector.h"
#include "libavoid/geomtypes.h"
#include "libcola/cola.h"
#include "libvpsc/generate-constraints.h"
#include "prefs-utils.h"

using namespace std;
using namespace cola;
using namespace vpsc;

/**
 * Returns true if item is a connector
 */
00043 bool isConnector(SPItem const *const i) {
      SPPath *path = NULL;
      if(SP_IS_PATH(i)) {
            path = SP_PATH(i);
      }
      return path && path->connEndPair.isAutoRoutingConn();
}

/**
 * Scans the items list and places those items that are 
 * not connectors in filtered
 */
00055 void filterConnectors(GSList const *const items, list<SPItem *> &filtered) {
      for(GSList *i=(GSList *)items; i!=NULL; i=i->next) {
            SPItem *item=SP_ITEM(i->data);
            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
*/
00068 void graphlayout(GSList const *const items) {
      if(!items) {
            return;
      }

      using Inkscape::Util::GSListConstIterator;
      list<SPItem *> selected;
      filterConnectors(items,selected);
      if (selected.empty()) return;

      const unsigned n=selected.size();
      //Check 2 or more selected objects
      if (n < 2) return;

    // add the connector spacing to the size of node bounding boxes
    // so that connectors can always be routed between shapes
    SPDesktop* desktop = inkscape_active_desktop();
    double spacing = 0;
    if(desktop) spacing = desktop->namedview->connector_spacing+0.1;

      map<string,unsigned> nodelookup;
      vector<Rectangle*> rs;
      vector<Edge> es;
      for (list<SPItem *>::iterator i(selected.begin());
            i != selected.end();
            ++i)
      {
            SPItem *u=*i;
            NR::Rect const item_box(sp_item_bbox_desktop(u));
            NR::Point ll(item_box.min());
            NR::Point ur(item_box.max());
            nodelookup[u->id]=rs.size();
            rs.push_back(new Rectangle(ll[0]-spacing,ur[0]+spacing,
                    ll[1]-spacing,ur[1]+spacing));
      }

      SimpleConstraints scx,scy;
      double ideal_connector_length = prefs_get_double_attribute("tools.connector","length",100);
      double directed_edge_height_modifier = 1.0;
      gchar const *directed_str = NULL, *overlaps_str = NULL;
      directed_str = prefs_get_string_attribute("tools.connector",
                        "directedlayout");
      overlaps_str = prefs_get_string_attribute("tools.connector",
                        "avoidoverlaplayout");
      bool avoid_overlaps = false;
      bool directed = false;
    if (directed_str && !strcmp(directed_str, "true")) {
          directed = true;
      }
    if (overlaps_str && !strcmp(overlaps_str, "true")) {
          avoid_overlaps = true;
      }

      for (list<SPItem *>::iterator i(selected.begin());
            i != selected.end();
            ++i)
      {
            SPItem *iu=*i;
            unsigned u=nodelookup[iu->id];
            GSList *nlist=iu->avoidRef->getAttachedConnectors(Avoid::runningFrom);
            list<SPItem *> connectors;
            
            connectors.insert<GSListConstIterator<SPItem *> >(connectors.end(),nlist,NULL);
            for (list<SPItem *>::iterator j(connectors.begin());
                        j != connectors.end();
                        ++j) {
                  SPItem *conn=*j;
                  SPItem *iv;
                  SPItem *items[2];
                  assert(isConnector(conn));
                  SP_PATH(conn)->connEndPair.getAttachedItems(items);
                  if(items[0]==iu) {
                        iv=items[1];
                  } else {
                        iv=items[0];
                  }
      
            if (iv == NULL) {
                // The connector is not attached to anything at the 
                // other end so we should just ignore it.
                continue;
            }

                  // What do we do if iv not in nodelookup?!?!
                  map<string,unsigned>::iterator v_pair=nodelookup.find(iv->id);
                  if(v_pair!=nodelookup.end()) {
                        unsigned v=v_pair->second;
                        //cout << "Edge: (" << u <<","<<v<<")"<<endl;
                        es.push_back(make_pair(u,v));
                        if(conn->style->marker[SP_MARKER_LOC_END].set) {
                              if(directed && strcmp(conn->style->marker[SP_MARKER_LOC_END].value,"none")) {
                                    scy.push_back(new SimpleConstraint(v, u, 
                                    (ideal_connector_length * directed_edge_height_modifier)));
                              }
                        }
                  }
            }
            if(nlist) {
                  g_slist_free(nlist);
            }
      }
      const unsigned E = es.size();
      double eweights[E];
      fill(eweights,eweights+E,1);
    vector<Component*> cs;
    connectedComponents(rs,es,scx,scy,cs);
    for(unsigned i=0;i<cs.size();i++) {
        Component* c=cs[i];
        if(c->edges.size()<2) continue;
        ConstrainedMajorizationLayout alg(c->rects,c->edges,eweights,ideal_connector_length);
        alg.setupConstraints(NULL,NULL,avoid_overlaps,
                NULL,NULL,&c->scx,&c->scy,NULL,NULL);
        alg.run();
    }
    separateComponents(cs);
      
      for (list<SPItem *>::iterator it(selected.begin());
            it != selected.end();
            ++it)
      {
            SPItem *u=*it;
            if(!isConnector(u)) {
                  Rectangle* r=rs[nodelookup[u->id]];
                  NR::Rect const item_box(sp_item_bbox_desktop(u));
                  NR::Point const curr(item_box.midpoint());
                  NR::Point const dest(r->getCentreX(),r->getCentreY());
                  sp_item_move_rel(u, NR::translate(dest - curr));
            }
      }
    for(unsigned i=0;i<scx.size();i++) {
        delete scx[i];
    }
    for(unsigned i=0;i<scy.size();i++) {
        delete scy[i];
    }
    for(unsigned i=0;i<rs.size();i++) {
        delete rs[i];
    }
}
// vim: set cindent 
// vim: ts=4 sw=4 et tw=0 wm=0

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