eclipseprojects/eu.etaxonomy.taxeditor.prototype2/src/eu/etaxonomy/taxeditor/prototype2/model/NameTreeContentProvider.java

   1 package eu.etaxonomy.taxeditor.prototype2.model;
   2
   3 import java.util.Set;
   4
   5 import org.eclipse.core.databinding.observable.Realm;
   6 import org.eclipse.core.databinding.observable.list.IListChangeListener;
   7 import org.eclipse.core.databinding.observable.list.IObservableList;
   8 import org.eclipse.core.databinding.observable.list.ListChangeEvent;
   9 import org.eclipse.core.databinding.observable.list.ListDiffEntry;
  10 import org.eclipse.core.databinding.observable.list.WritableList;
  11 import org.eclipse.core.databinding.observable.set.IObservableSet;
  12 import org.eclipse.core.databinding.observable.set.WritableSet;
  13 import org.eclipse.core.runtime.Assert;
  14 import org.eclipse.jface.databinding.swt.SWTObservables;
  15 import org.eclipse.jface.databinding.viewers.ObservableListContentProvider;
  16 import org.eclipse.jface.viewers.ITreeContentProvider;
  17 import org.eclipse.jface.viewers.Viewer;
  18 import org.eclipse.swt.widgets.Display;
  19
  20 import eu.etaxonomy.cdm.model.taxon.Taxon;
  21 import eu.etaxonomy.taxeditor.prototype2.view.TaxonomicTreeViewer;
  22
  23 public class NameTreeContentProvider extends ObservableListContentProvider
  24                 implements ITreeContentProvider {
  25
  26         public Object[] getChildren(Object parentElement) {
  27                 Set<Taxon> children = ((Taxon) parentElement).getTaxonomicChildren();
  28                 observableList.addAll(children);
  29                 return children == null ? new Object[0] : children.toArray();
  30         }
  31
  32         public Object getParent(Object element) {
  33                 return ((Taxon) element).getTaxonomicParent();
  34         }
  35
  36         public boolean hasChildren(Object element) {
  37                 return ((Taxon) element).hasTaxonomicChildren();
  38         }
  39
  40         private IObservableList observableList;
  41
  42         private Viewer viewer;
  43
  44         private IListChangeListener listener = new IListChangeListener() {
  45                 public void handleListChange(ListChangeEvent event) {
  46                         if (viewer.getControl().isDisposed()) {
  47                                 return;
  48                         }
  49                         ListDiffEntry[] differences = event.diff.getDifferences();
  50                         for (int i = 0; i < differences.length; i++) {
  51                                 ListDiffEntry entry = differences[i];
  52
  53                                 if (entry.isAddition()) {
  54
  55                                         knownElements.add(entry.getElement());
  56
  57                                         ((TaxonomicTreeViewer) viewer).add(
  58                                                         ((Taxon) entry.getElement()).getTaxonomicParent(),
  59                                                         entry.getElement());
  60                                 } else {
  61
  62                                         knownElements.remove(entry.getElement());
  63
  64                                         ((TaxonomicTreeViewer) viewer).remove(entry.getElement());
  65                                 }
  66                         }
  67                 }
  68         };
  69
  70         private IObservableSet knownElements;
  71
  72         /**
  73          *
  74          */
  75         public NameTreeContentProvider() {
  76
  77                 Assert.isNotNull(Realm.getDefault());
  78
  79                 observableList = new WritableList(SWTObservables.getRealm(Display.getDefault()));
  80                 knownElements = new WritableSet(SWTObservables.getRealm(Display.getDefault()));
  81         }
  82
  83         public Object[] getElements(Object inputElement) {
  84                 return observableList.toArray();
  85         }
  86
  87         public void dispose() {
  88                 observableList.removeListChangeListener(listener);
  89         }
  90
  91         public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
  92                 this.viewer = viewer;
  93
  94                 if (newInput != null && !(newInput instanceof IObservableList)) {
  95                         throw new IllegalArgumentException(
  96                                         "This content provider only works with input of type IObservableList"); //$NON-NLS-1$
  97                 }
  98
  99                 setInput((IObservableList) newInput);
 100         }
 101
 102         /**
 103          * @param list
 104          */
 105         private void setInput(IObservableList list) {
 106
 107                 if (list == null) {
 108                         list = new WritableList(SWTObservables.getRealm(Display.getDefault()));
 109                 }
 110
 111                 if (observableList != null) {
 112                         observableList.removeListChangeListener(listener);
 113                 }
 114
 115                 knownElements.clear();
 116
 117                 observableList = list;
 118
 119                 knownElements.addAll(list);
 120
 121
 122                 observableList.addListChangeListener(listener);
 123         }
 124
 125         /**
 126          * @return the set of elements known to this content provider. Label providers may track
 127          * this set if they need to be notified about additions before the viewer sees the added
 128          * element, and notified about removals after the element was removed from the viewer.
 129          */
 130         public IObservableSet getKnownElements() {
 131                 return knownElements;
 132         }
 133 }