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             sp_object_unref((*iter).first);
 144         }
 145     }
 146
 147     Record *get(SPObject *obj) {
 148         Map::iterator found=records.find(obj);
 149         if ( found != records.end() ) {
 150             return &(*found).second;
 151         } else {
 152             return NULL;
 153         }
 154     }
 155
 156     void addOne(SPObject *obj);
 157     void remove(SPObject *obj, bool subtree);
 158     void reorder(SPObject *obj);
 159     void clear();
 160
 161 private:
 162     Record &_doAdd(SPObject *obj) {
 163         sp_object_ref(obj);
 164         Record &record=records[obj];
 165         record.release_connection
 166           = obj->connectRelease(
 167               sigc::mem_fun(this, &Relations::_release_object)
 168             );
 169         record.position_changed_connection
 170           = obj->connectPositionChanged(
 171               sigc::mem_fun(this, &Relations::reorder)
 172             );
 173         return record;
 174     }
 175
 176     void _notifyAdded(SPObject *obj) {
 177         added_signal.emit(obj);
 178     }
 179
 180     void _doRemove(SPObject *obj) {
 181         Record &record=records[obj];
 182         record.release_connection.disconnect();
 183         record.position_changed_connection.disconnect();
 184         records.erase(obj);
 185
 186         if ( record.parent == NULL ) {
 187             Record &root = records[NULL];
 188             for ( Siblings::iterator it = root.children.begin(); it != root.children.end(); ++it ) {
 189                 if ( *it == obj ) {
 190                     root.children.erase( it );
 191                     break;
 192                 }
 193             }
 194         }
 195
 196         removed_signal.emit(obj);
 197         sp_object_unref(obj);
 198     }
 199
 200     void _doRemoveSubtree(SPObject *obj) {
 201         Record *record=get(obj);
 202         if (record) {
 203             Siblings &children=record->children;
 204             for ( Siblings::iterator iter=children.begin()
 205                 ; iter != children.end() ; ++iter )
 206             {
 207                 _doRemoveSubtree(*iter);
 208             }
 209             _doRemove(obj);
 210         }
 211     }
 212
 213     void _release_object(SPObject *obj) {
 214         if (get(obj)) {
 215             remove(obj, true);
 216         }
 217     }
 218 };
 219
 220 DocumentSubset::DocumentSubset()
 221 : _relations(new DocumentSubset::Relations())
 222 {
 223 }
 224
 225 void DocumentSubset::Relations::addOne(SPObject *obj) {
 226     g_return_if_fail( obj != NULL );
 227     g_return_if_fail( get(obj) == NULL );
 228
 229     Record &record=_doAdd(obj);
 230
 231     /* find the nearest ancestor in the subset */
 232     Record *parent_record=NULL;
 233     for ( SPObject::ParentIterator parent_iter=obj->parent
 234         ; !parent_record && parent_iter ; ++parent_iter )
 235     {
 236         parent_record = get(parent_iter);
 237         if (parent_record) {
 238             record.parent = parent_iter;
 239         }
 240     }
 241     if (!parent_record) {
 242         parent_record = get(NULL);
 243         g_assert( parent_record != NULL );
 244     }
 245
 246     Siblings &children=record.children;
 247
 248     /* reparent descendants of obj to obj */
 249     parent_record->extractDescendants(
 250         std::back_insert_iterator<Siblings>(children),
 251         obj
 252     );
 253     for ( Siblings::iterator iter=children.begin()
 254         ; iter != children.end() ; ++iter )
 255     {
 256         Record *child_record=get(*iter);
 257         g_assert( child_record != NULL );
 258         child_record->parent = obj;
 259     }
 260
 261     /* add obj to the child list */
 262     parent_record->addChild(obj);
 263
 264     _notifyAdded(obj);
 265     changed_signal.emit();
 266 }
 267
 268 void DocumentSubset::Relations::remove(SPObject *obj, bool subtree) {
 269     g_return_if_fail( obj != NULL );
 270
 271     Record *record=get(obj);
 272     g_return_if_fail( record != NULL );
 273
 274     Record *parent_record=get(record->parent);
 275     g_assert( parent_record != NULL );
 276
 277     unsigned index=parent_record->removeChild(obj);
 278
 279     if (subtree) {
 280         _doRemoveSubtree(obj);
 281     } else {
 282         /* reparent obj's orphaned children to their grandparent */
 283         Siblings &siblings=parent_record->children;
 284         Siblings &children=record->children;
 285         siblings.insert(siblings.begin()+index,
 286                         children.begin(), children.end());
 287
 288         for ( Siblings::iterator iter=children.begin()
 289             ; iter != children.end() ; iter++ )
 290         {
 291             Record *child_record=get(*iter);
 292             g_assert( child_record != NULL );
 293             child_record->parent = record->parent;
 294         }
 295
 296         /* remove obj's record */
 297         _doRemove(obj);
 298     }
 299
 300     changed_signal.emit();
 301 }
 302
 303 void DocumentSubset::Relations::clear() {
 304     Record &root=records[NULL];
 305
 306     while (!root.children.empty()) {
 307         _doRemoveSubtree(root.children.front());
 308     }
 309
 310     changed_signal.emit();
 311 }
 312
 313 void DocumentSubset::Relations::reorder(SPObject *obj) {
 314     SPObject::ParentIterator parent=obj;
 315
 316     /* find nearest ancestor in the subset */
 317     Record *parent_record=NULL;
 318     while (!parent_record) {
 319         parent_record = get(++parent);
 320     }
 321
 322     if (get(obj)) {
 323         /* move the object if it's in the subset */
 324         parent_record->removeChild(obj);
 325         parent_record->addChild(obj);
 326         changed_signal.emit();
 327     } else {
 328         /* otherwise, move any top-level descendants */
 329         Siblings descendants;
 330         parent_record->extractDescendants(
 331             std::back_insert_iterator<Siblings>(descendants),
 332             obj
 333         );
 334         if (!descendants.empty()) {
 335             unsigned index=parent_record->findInsertIndex(obj);
 336             Siblings &family=parent_record->children;
 337             family.insert(family.begin()+index,
 338                           descendants.begin(), descendants.end());
 339             changed_signal.emit();
 340         }
 341     }
 342 }
 343
 344 void DocumentSubset::_addOne(SPObject *obj) {
 345     _relations->addOne(obj);
 346 }
 347
 348 void DocumentSubset::_remove(SPObject *obj, bool subtree) {
 349     _relations->remove(obj, subtree);
 350 }
 351
 352 void DocumentSubset::_clear() {
 353     _relations->clear();
 354 }
 355
 356 bool DocumentSubset::includes(SPObject *obj) const {
 357     return _relations->get(obj);
 358 }
 359
 360 SPObject *DocumentSubset::parentOf(SPObject *obj) const {
 361     Relations::Record *record=_relations->get(obj);
 362     return ( record ? record->parent : NULL );
 363 }
 364
 365 unsigned DocumentSubset::childCount(SPObject *obj) const {
 366     Relations::Record *record=_relations->get(obj);
 367     return ( record ? record->children.size() : 0 );
 368 }
 369
 370 unsigned DocumentSubset::indexOf(SPObject *obj) const {
 371     SPObject *parent=parentOf(obj);
 372     Relations::Record *record=_relations->get(parent);
 373     return ( record ? record->childIndex(obj) : 0 );
 374 }
 375
 376 SPObject *DocumentSubset::nthChildOf(SPObject *obj, unsigned n) const {
 377     Relations::Record *record=_relations->get(obj);
 378     return ( record ? record->children[n] : NULL );
 379 }
 380
 381 sigc::connection DocumentSubset::connectChanged(sigc::slot<void> slot) const {
 382     return _relations->changed_signal.connect(slot);
 383 }
 384
 385 sigc::connection
 386 DocumentSubset::connectAdded(sigc::slot<void, SPObject *> slot) const {
 387     return _relations->added_signal.connect(slot);
 388 }
 389
 390 sigc::connection
 391 DocumentSubset::connectRemoved(sigc::slot<void, SPObject *> slot) const {
 392     return _relations->removed_signal.connect(slot);
 393 }
 394
 395 }
 396
 397 /*
 398   Local Variables:
 399   mode:c++
 400   c-file-style:"stroustrup"
 401   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 402   indent-tabs-mode:nil
 403   fill-column:99
 404   End:
 405 */
 406 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :