taxeditor-store/src/main/java/eu/etaxonomy/taxeditor/store/model/TaxonTransfer.java

   1 package eu.etaxonomy.taxeditor.store.model;
   2
   3 import org.eclipse.swt.dnd.ByteArrayTransfer;
   4 import org.eclipse.swt.dnd.TransferData;
   5
   6 import eu.etaxonomy.cdm.model.taxon.TaxonBase;
   7
   8 /**
   9  * For drag and drop - a drag widget with this transfer type can only be dropped onto
  10  *  a drop widget with the same type.
  11  *
  12  * @author p.ciardelli
  13  *
  14  */
  15 public class TaxonTransfer extends ByteArrayTransfer {
  16
  17         private static final String TAXONTYPENAME = "taxon_type";
  18         private static final int TAXONTYPEID = registerType (TAXONTYPENAME);
  19         private static final TaxonTransfer INSTANCE = new TaxonTransfer();
  20
  21         /*
  22          * The object associated with this transfer event
  23          */
  24         private TaxonBase<?> taxonBase;
  25
  26         /*
  27          * Returns the singleton
  28          */
  29         public static TaxonTransfer getInstance() {
  30                 return INSTANCE;
  31         }
  32         /*
  33          * Set transfer data for local use
  34          */
  35         public void setTaxon(TaxonBase<?> taxon) {
  36                 this.taxonBase = taxon;
  37         }
  38         /*
  39          * Returns the local transfer data
  40          */
  41         public TaxonBase<?> getTaxon() {
  42                 return taxonBase;
  43         }
  44
  45         /*
  46          * The type ID is used to identify this transfer
  47          */
  48         @Override
  49         protected int[] getTypeIds() {
  50                 return new int[] { TAXONTYPEID };
  51         }
  52
  53         @Override
  54         protected String[] getTypeNames() {
  55                 return new String[] { TAXONTYPENAME } ;
  56         }
  57
  58         @Override
  59         protected void javaToNative(Object object, TransferData transferData) {
  60                 // No encoding needed since this is a hardcoded string read and written
  61                 // in the same process.
  62                 // See nativeToJava below
  63                 byte[] check = TAXONTYPENAME.getBytes();
  64                 super.javaToNative(check, transferData);
  65         }
  66
  67         @Override
  68         protected Object nativeToJava(TransferData transferData) {
  69                 Object result = super.nativeToJava(transferData);
  70                 if (isInvalidNativeType(result)) {
  71                         throw new RuntimeException(); //$NON-NLS-1$
  72                 }
  73                 return taxonBase;
  74         }
  75
  76         private boolean isInvalidNativeType(Object result) {
  77                 // No encoding needed since this is a hardcoded string read and written
  78                 // in the same process.
  79                 // See javaToNative above
  80                 return !(result instanceof byte[])
  81                                 || !TAXONTYPENAME.equals(new String((byte[]) result));
  82         }
  83 }