src/document-subset.cpp

   1 /*
   2  * Inkscape::DocumentSubset - view of a document including only a subset
   3  *                            of nodes
   4  *
   5  * Copyright 2006  MenTaLguY  <mental@rydia.net>
   6  *
   7  * Released under GNU GPL, read the file 'COPYING' for more information
   8  */
   9
  10 #include "gc-finalized.h"
  11 #include "document-subset.h"
  12 #include "document.h"
  13 #include "sp-object.h"
  14
  15 #include <glib/gmessages.h>
  16
  17 #include <sigc++/signal.h>
  18 #include <sigc++/functors/mem_fun.h>
  19
  20 #include "util/list.h"
  21 #include "util/reverse-list.h"
  22
  23 #include <vector>
  24 #include <map>
  25 #include <algorithm>
  26 #include <iterator>
  27
  28 namespace Inkscape {
  29
  30 struct DocumentSubset::Relations : public GC::Managed<GC::ATOMIC>,
  31                                    public GC::Finalized
  32 {
  33     typedef std::vector<SPObject *> Siblings;
  34
  35     struct Record {
  36         SPObject *parent;
  37         Siblings children;
  38
  39         gulong release_connection;
  40         sigc::connection position_changed_connection;
  41
  42         Record() : parent(NULL), release_connection(0) {}
  43
  44         unsigned childIndex(SPObject *obj) {
  45             Siblings::iterator found;
  46             found = std::find(children.begin(), children.end(), obj);
  47             if ( found != children.end() ) {
  48                 return found - children.begin();
  49             } else {
  50                 return 0;
  51             }
  52         }
  53
  54         unsigned findInsertIndex(SPObject *obj) const {
  55             if (children.empty()) {
  56                 return 0;
  57             } else {
  58                 Siblings::const_iterator first=children.begin();
  59                 Siblings::const_iterator last=children.end() - 1;
  60                 while ( first != last ) {
  61                     Siblings::const_iterator mid=first + ( last - first + 1 ) / 2;
  62                     int pos=sp_object_compare_position(*mid, obj);
  63                     if ( pos < 0 ) {
  64                         first = mid;
  65                     } else if ( pos > 0 ) {
  66                         last = mid;
  67                     } else {
  68                         g_assert_not_reached();
  69                     }
  70                 }
  71                 return last - children.begin();
  72             }
  73         }
  74
  75         void addChild(SPObject *obj) {
  76             unsigned index=findInsertIndex(obj);
  77             children.insert(children.begin()+index, obj);
  78         }
  79
  80         template <typename OutputIterator>
  81         void extractDescendants(OutputIterator descendants,
  82                                 SPObject *obj)
  83         {
  84             Siblings new_children;
  85             bool found_one=false;
  86             for ( Siblings::iterator iter=children.begin()
  87                 ; iter != children.end() ; iter++ )
  88             {
  89                 if (obj->isAncestorOf(*iter)) {
  90                     if (!found_one) {
  91                         found_one = true;
  92                         new_children.insert(new_children.end(),
  93                                             children.begin(), iter);
  94                     }
  95                     *descendants++ = *iter;
  96                 } else if (found_one) {
  97                     new_children.push_back(*iter);
  98                 }
  99             }
 100             if (found_one) {
 101                 children.swap(new_children);
 102             }
 103         }
 104
 105         unsigned removeChild(SPObject *obj) {
 106             Siblings::iterator found;
 107             found = std::find(children.begin(), children.end(), obj);
 108             unsigned index = found - children.begin();
 109             if ( found != children.end() ) {
 110                 children.erase(found);
 111             }
 112             return index;
 113         }
 114     };
 115
 116     typedef std::map<SPObject *, Record> Map;
 117     Map records;
 118
 119     sigc::signal<void> changed_signal;
 120     sigc::signal<void, SPObject *> added_signal;
 121     sigc::signal<void, SPObject *> removed_signal;
 122
 123     Relations() { records[NULL]; }
 124
 125     ~Relations() {
 126         for ( Map::iterator iter=records.begin()
 127             ; iter != records.end() ; ++iter )
 128         {
 129             sp_object_unref((*iter).first);
 130         }
 131     }
 132
 133     Record *get(SPObject *obj) {
 134         Map::iterator found=records.find(obj);
 135         if ( found != records.end() ) {
 136             return &(*found).second;
 137         } else {
 138             return NULL;
 139         }
 140     }
 141
 142     void addOne(SPObject *obj);
 143     void remove(SPObject *obj, bool subtree);
 144     void reorder(SPObject *obj);
 145
 146 private:
 147     Record &_doAdd(SPObject *obj) {
 148         sp_object_ref(obj);
 149         Record &record=records[obj];
 150         record.release_connection
 151           = g_signal_connect(obj, "release",
 152                              (GCallback)&Relations::_release_object, this);
 153         record.position_changed_connection
 154           = obj->connectPositionChanged(
 155               sigc::mem_fun(this, &Relations::reorder)
 156             );
 157         return record;
 158     }
 159
 160     void _notifyAdded(SPObject *obj) {
 161         added_signal.emit(obj);
 162     }
 163
 164     void _doRemove(SPObject *obj) {
 165         Record &record=records[obj];
 166         if (record.release_connection) {
 167             g_signal_handler_disconnect(obj, record.release_connection);
 168             record.release_connection = 0;
 169         }
 170         record.position_changed_connection.disconnect();
 171         records.erase(obj);
 172         removed_signal.emit(obj);
 173         sp_object_unref(obj);
 174     }
 175
 176     void _doRemoveSubtree(SPObject *obj) {
 177         Record *record=get(obj);
 178         if (record) {
 179             Siblings &children=record->children;
 180             for ( Siblings::iterator iter=children.begin()
 181                 ; iter != children.end() ; ++iter )
 182             {
 183                 _doRemoveSubtree(*iter);
 184             }
 185             _doRemove(obj);
 186         }
 187     }
 188
 189     static void _release_object(SPObject *obj, void *relations_p) {
 190         Relations &relations=*static_cast<Relations *>(relations_p);
 191         if (relations.get(obj)) {
 192             relations.remove(obj, true);
 193         }
 194     }
 195 };
 196
 197 DocumentSubset::DocumentSubset(SPDocument *document)
 198 : _document(document), _relations(new DocumentSubset::Relations())
 199 {
 200 }
 201
 202 void DocumentSubset::Relations::addOne(SPObject *obj) {
 203     g_return_if_fail( obj != NULL );
 204     g_return_if_fail( get(obj) != NULL );
 205
 206     Record &record=_doAdd(obj);
 207
 208     /* find the nearest ancestor in the subset */
 209     Record *parent_record=NULL;
 210     for ( SPObject::ParentIterator parent_iter=obj->parent
 211         ; !parent_record && parent_iter ; ++parent_iter )
 212     {
 213         parent_record = get(parent_iter);
 214         if (parent_record) {
 215             record.parent = parent_iter;
 216         }
 217     }
 218     if (!parent_record) {
 219         parent_record = get(NULL);
 220         g_assert( parent_record != NULL );
 221     }
 222
 223     Siblings &children=record.children;
 224
 225     /* reparent descendants of obj to obj */
 226     parent_record->extractDescendants(
 227         std::back_insert_iterator<Siblings>(children),
 228         obj
 229     );
 230     for ( Siblings::iterator iter=children.begin()
 231         ; iter != children.end() ; ++iter )
 232     {
 233         Record *child_record=get(*iter);
 234         g_assert( child_record != NULL );
 235         child_record->parent = obj;
 236     }
 237
 238     /* add obj to the child list */
 239     parent_record->addChild(obj);
 240
 241     _notifyAdded(obj);
 242     changed_signal.emit();
 243 }
 244
 245 void DocumentSubset::Relations::remove(SPObject *obj, bool subtree) {
 246     g_return_if_fail( obj != NULL );
 247
 248     Record *record=get(obj);
 249     g_return_if_fail( record != NULL );
 250
 251     Record *parent_record=get(record->parent);
 252     g_assert( parent_record != NULL );
 253
 254     unsigned index=parent_record->removeChild(obj);
 255
 256     if (subtree) {
 257         _doRemoveSubtree(obj);
 258     } else {
 259         /* reparent obj's orphaned children to their grandparent */
 260         Siblings &siblings=parent_record->children;
 261         Siblings &children=record->children;
 262         siblings.insert(siblings.begin()+index,
 263                         children.begin(), children.end());
 264
 265         for ( Siblings::iterator iter=children.begin()
 266             ; iter != children.end() ; iter++ )
 267         {
 268             Record *child_record=get(*iter);
 269             g_assert( child_record != NULL );
 270             child_record->parent = record->parent;
 271         }
 272
 273         /* remove obj's record */
 274         _doRemove(obj);
 275     }
 276
 277     changed_signal.emit();
 278 }
 279
 280 void DocumentSubset::Relations::reorder(SPObject *obj) {
 281     SPObject::ParentIterator parent=obj;
 282
 283     /* find nearest ancestor in the subset */
 284     Record *parent_record=NULL;
 285     while (!parent_record) {
 286         parent_record = get(++parent);
 287     }
 288
 289     if (get(obj)) {
 290         /* move the object if it's in the subset */
 291         parent_record->removeChild(obj);
 292         parent_record->addChild(obj);
 293         changed_signal.emit();
 294     } else {
 295         /* otherwise, move any top-level descendants */
 296         Siblings descendants;
 297         parent_record->extractDescendants(
 298             std::back_insert_iterator<Siblings>(descendants),
 299             obj
 300         );
 301         if (!descendants.empty()) {
 302             unsigned index=parent_record->findInsertIndex(obj);
 303             Siblings &family=parent_record->children;
 304             family.insert(family.begin()+index,
 305                           descendants.begin(), descendants.end());
 306             changed_signal.emit();
 307         }
 308     }
 309 }
 310
 311 void DocumentSubset::_addOne(SPObject *obj) {
 312     _relations->addOne(obj);
 313 }
 314
 315 void DocumentSubset::_remove(SPObject *obj, bool subtree) {
 316     _relations->remove(obj, subtree);
 317 }
 318
 319 bool DocumentSubset::includes(SPObject *obj) const {
 320     return _relations->get(obj);
 321 }
 322
 323 SPObject *DocumentSubset::parentOf(SPObject *obj) const {
 324     Relations::Record *record=_relations->get(obj);
 325     return ( record ? record->parent : NULL );
 326 }
 327
 328 unsigned DocumentSubset::childCount(SPObject *obj) const {
 329     Relations::Record *record=_relations->get(obj);
 330     return ( record ? record->children.size() : 0 );
 331 }
 332
 333 unsigned DocumentSubset::indexOf(SPObject *obj) const {
 334     SPObject *parent=parentOf(obj);
 335     Relations::Record *record=_relations->get(parent);
 336     return ( record ? record->childIndex(obj) : 0 );
 337 }
 338
 339 SPObject *DocumentSubset::nthChildOf(SPObject *obj, unsigned n) const {
 340     Relations::Record *record=_relations->get(obj);
 341     return ( record ? record->children[n] : NULL );
 342 }
 343
 344 sigc::connection DocumentSubset::connectChanged(sigc::slot<void> slot) const {
 345     return _relations->changed_signal.connect(slot);
 346 }
 347
 348 sigc::connection
 349 DocumentSubset::connectAdded(sigc::slot<void, SPObject *> slot) const {
 350     return _relations->added_signal.connect(slot);
 351 }
 352
 353 sigc::connection
 354 DocumentSubset::connectRemoved(sigc::slot<void, SPObject *> slot) const {
 355     return _relations->removed_signal.connect(slot);
 356 }
 357
 358 }
 359
 360 /*
 361   Local Variables:
 362   mode:c++
 363   c-file-style:"stroustrup"
 364   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 365   indent-tabs-mode:nil
 366   fill-column:99
 367   End:
 368 */
 369 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :