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         sigc::connection release_connection;
  40         sigc::connection position_changed_connection;
  41
  42         Record() : parent(NULL) {}
  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
  61                 while ( first != last ) {
  62                     Siblings::const_iterator mid = first + ( last - first + 1 ) / 2;
  63                     int pos = sp_object_compare_position(*mid, obj);
  64                     if ( pos < 0 ) {
  65                         first = mid;
  66                     } else if ( pos > 0 ) {
  67                         if ( last == mid ) {
  68                             last = mid - 1; // already at the top limit
  69                         } else {
  70                             last = mid;
  71                         }
  72                     } else {
  73                         g_assert_not_reached();
  74                     }
  75                 }
  76
  77                 if ( first == last ) {
  78                     // compare to the single possiblity left
  79                     int pos = sp_object_compare_position(*last, obj);
  80                     if ( pos < 0 ) {
  81                         last++;
  82                     }
  83                 }
  84
  85                 return last - children.begin();
  86             }
  87         }
  88
  89         void addChild(SPObject *obj) {
  90             unsigned index=findInsertIndex(obj);
  91             children.insert(children.begin()+index, obj);
  92         }
  93
  94         template <typename OutputIterator>
  95         void extractDescendants(OutputIterator descendants,
  96                                 SPObject *obj)
  97         {
  98             Siblings new_children;
  99             bool found_one=false;
 100             for ( Siblings::iterator iter=children.begin()
 101                 ; iter != children.end() ; iter++ )
 102             {
 103                 if (obj->isAncestorOf(*iter)) {
 104                     if (!found_one) {
 105                         found_one = true;
 106                         new_children.insert(new_children.end(),
 107                                             children.begin(), iter);
 108                     }
 109                     *descendants++ = *iter;
 110                 } else if (found_one) {
 111                     new_children.push_back(*iter);
 112                 }
 113             }
 114             if (found_one) {
 115                 children.swap(new_children);
 116             }
 117         }
 118
 119         unsigned removeChild(SPObject *obj) {
 120             Siblings::iterator found;
 121             found = std::find(children.begin(), children.end(), obj);
 122             unsigned index = found - children.begin();
 123             if ( found != children.end() ) {
 124                 children.erase(found);
 125             }
 126             return index;
 127         }
 128     };
 129
 130     typedef std::map<SPObject *, Record> Map;
 131     Map records;
 132
 133     sigc::signal<void> changed_signal;
 134     sigc::signal<void, SPObject *> added_signal;
 135     sigc::signal<void, SPObject *> removed_signal;
 136
 137     Relations() { records[NULL]; }
 138
 139     ~Relations() {
 140         for ( Map::iterator iter=records.begin()
 141             ; iter != records.end() ; ++iter )
 142         {
 143             if ((*iter).first) {
 144                 sp_object_unref((*iter).first);
 145                 Record &record=(*iter).second;
 146                 record.release_connection.disconnect();
 147                 record.position_changed_connection.disconnect();
 148             }
 149         }
 150     }
 151
 152     Record *get(SPObject *obj) {
 153         Map::iterator found=records.find(obj);
 154         if ( found != records.end() ) {
 155             return &(*found).second;
 156         } else {
 157             return NULL;
 158         }
 159     }
 160
 161     void addOne(SPObject *obj);
 162     void remove(SPObject *obj, bool subtree);
 163     void reorder(SPObject *obj);
 164     void clear();
 165
 166 private:
 167     Record &_doAdd(SPObject *obj) {
 168         sp_object_ref(obj);
 169         Record &record=records[obj];
 170         record.release_connection
 171           = obj->connectRelease(
 172               sigc::mem_fun(this, &Relations::_release_object)
 173             );
 174         record.position_changed_connection
 175           = obj->connectPositionChanged(
 176               sigc::mem_fun(this, &Relations::reorder)
 177             );
 178         return record;
 179     }
 180
 181     void _notifyAdded(SPObject *obj) {
 182         added_signal.emit(obj);
 183     }
 184
 185     void _doRemove(SPObject *obj) {
 186         Record &record=records[obj];
 187
 188         if ( record.parent == NULL ) {
 189             Record &root = records[NULL];
 190             for ( Siblings::iterator it = root.children.begin(); it != root.children.end(); ++it ) {
 191                 if ( *it == obj ) {
 192                     root.children.erase( it );
 193                     break;
 194                 }
 195             }
 196         }
 197
 198         record.release_connection.disconnect();
 199         record.position_changed_connection.disconnect();
 200         records.erase(obj);
 201         removed_signal.emit(obj);
 202         sp_object_unref(obj);
 203     }
 204
 205     void _doRemoveSubtree(SPObject *obj) {
 206         Record *record=get(obj);
 207         if (record) {
 208             Siblings &children=record->children;
 209             for ( Siblings::iterator iter=children.begin()
 210                 ; iter != children.end() ; ++iter )
 211             {
 212                 _doRemoveSubtree(*iter);
 213             }
 214             _doRemove(obj);
 215         }
 216     }
 217
 218     void _release_object(SPObject *obj) {
 219         if (get(obj)) {
 220             remove(obj, true);
 221         }
 222     }
 223 };
 224
 225 DocumentSubset::DocumentSubset()
 226 : _relations(new DocumentSubset::Relations())
 227 {
 228 }
 229
 230 void DocumentSubset::Relations::addOne(SPObject *obj) {
 231     g_return_if_fail( obj != NULL );
 232     g_return_if_fail( get(obj) == NULL );
 233
 234     Record &record=_doAdd(obj);
 235
 236     /* find the nearest ancestor in the subset */
 237     Record *parent_record=NULL;
 238     for ( SPObject::ParentIterator parent_iter=obj->parent
 239         ; !parent_record && parent_iter ; ++parent_iter )
 240     {
 241         parent_record = get(parent_iter);
 242         if (parent_record) {
 243             record.parent = parent_iter;
 244         }
 245     }
 246     if (!parent_record) {
 247         parent_record = get(NULL);
 248         g_assert( parent_record != NULL );
 249     }
 250
 251     Siblings &children=record.children;
 252
 253     /* reparent descendants of obj to obj */
 254     parent_record->extractDescendants(
 255         std::back_insert_iterator<Siblings>(children),
 256         obj
 257     );
 258     for ( Siblings::iterator iter=children.begin()
 259         ; iter != children.end() ; ++iter )
 260     {
 261         Record *child_record=get(*iter);
 262         g_assert( child_record != NULL );
 263         child_record->parent = obj;
 264     }
 265
 266     /* add obj to the child list */
 267     parent_record->addChild(obj);
 268
 269     _notifyAdded(obj);
 270     changed_signal.emit();
 271 }
 272
 273 void DocumentSubset::Relations::remove(SPObject *obj, bool subtree) {
 274     g_return_if_fail( obj != NULL );
 275
 276     Record *record=get(obj);
 277     g_return_if_fail( record != NULL );
 278
 279     Record *parent_record=get(record->parent);
 280     g_assert( parent_record != NULL );
 281
 282     unsigned index=parent_record->removeChild(obj);
 283
 284     if (subtree) {
 285         _doRemoveSubtree(obj);
 286     } else {
 287         /* reparent obj's orphaned children to their grandparent */
 288         Siblings &siblings=parent_record->children;
 289         Siblings &children=record->children;
 290         siblings.insert(siblings.begin()+index,
 291                         children.begin(), children.end());
 292
 293         for ( Siblings::iterator iter=children.begin()
 294             ; iter != children.end() ; iter++ )
 295         {
 296             Record *child_record=get(*iter);
 297             g_assert( child_record != NULL );
 298             child_record->parent = record->parent;
 299         }
 300
 301         /* remove obj's record */
 302         _doRemove(obj);
 303     }
 304
 305     changed_signal.emit();
 306 }
 307
 308 void DocumentSubset::Relations::clear() {
 309     Record &root=records[NULL];
 310
 311     while (!root.children.empty()) {
 312         _doRemoveSubtree(root.children.front());
 313     }
 314
 315     changed_signal.emit();
 316 }
 317
 318 void DocumentSubset::Relations::reorder(SPObject *obj) {
 319     SPObject::ParentIterator parent=obj;
 320
 321     /* find nearest ancestor in the subset */
 322     Record *parent_record=NULL;
 323     while (!parent_record) {
 324         parent_record = get(++parent);
 325     }
 326
 327     if (get(obj)) {
 328         /* move the object if it's in the subset */
 329         parent_record->removeChild(obj);
 330         parent_record->addChild(obj);
 331         changed_signal.emit();
 332     } else {
 333         /* otherwise, move any top-level descendants */
 334         Siblings descendants;
 335         parent_record->extractDescendants(
 336             std::back_insert_iterator<Siblings>(descendants),
 337             obj
 338         );
 339         if (!descendants.empty()) {
 340             unsigned index=parent_record->findInsertIndex(obj);
 341             Siblings &family=parent_record->children;
 342             family.insert(family.begin()+index,
 343                           descendants.begin(), descendants.end());
 344             changed_signal.emit();
 345         }
 346     }
 347 }
 348
 349 void DocumentSubset::_addOne(SPObject *obj) {
 350     _relations->addOne(obj);
 351 }
 352
 353 void DocumentSubset::_remove(SPObject *obj, bool subtree) {
 354     _relations->remove(obj, subtree);
 355 }
 356
 357 void DocumentSubset::_clear() {
 358     _relations->clear();
 359 }
 360
 361 bool DocumentSubset::includes(SPObject *obj) const {
 362     return _relations->get(obj);
 363 }
 364
 365 SPObject *DocumentSubset::parentOf(SPObject *obj) const {
 366     Relations::Record *record=_relations->get(obj);
 367     return ( record ? record->parent : NULL );
 368 }
 369
 370 unsigned DocumentSubset::childCount(SPObject *obj) const {
 371     Relations::Record *record=_relations->get(obj);
 372     return ( record ? record->children.size() : 0 );
 373 }
 374
 375 unsigned DocumentSubset::indexOf(SPObject *obj) const {
 376     SPObject *parent=parentOf(obj);
 377     Relations::Record *record=_relations->get(parent);
 378     return ( record ? record->childIndex(obj) : 0 );
 379 }
 380
 381 SPObject *DocumentSubset::nthChildOf(SPObject *obj, unsigned n) const {
 382     Relations::Record *record=_relations->get(obj);
 383     return ( record ? record->children[n] : NULL );
 384 }
 385
 386 sigc::connection DocumentSubset::connectChanged(sigc::slot<void> slot) const {
 387     return _relations->changed_signal.connect(slot);
 388 }
 389
 390 sigc::connection
 391 DocumentSubset::connectAdded(sigc::slot<void, SPObject *> slot) const {
 392     return _relations->added_signal.connect(slot);
 393 }
 394
 395 sigc::connection
 396 DocumentSubset::connectRemoved(sigc::slot<void, SPObject *> slot) const {
 397     return _relations->removed_signal.connect(slot);
 398 }
 399
 400 }
 401
 402 /*
 403   Local Variables:
 404   mode:c++
 405   c-file-style:"stroustrup"
 406   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 407   indent-tabs-mode:nil
 408   fill-column:99
 409   End:
 410 */
 411 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :