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