net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/dnd/BasicSelectionTransferDragAdapter.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.ui.dnd;
  12
  13 //incastrix
  14 //import org.eclipse.jface.text.Assert;
  15 import org.eclipse.core.runtime.Assert;
  16 import org.eclipse.jface.viewers.ISelection;
  17 import org.eclipse.jface.viewers.ISelectionProvider;
  18 import org.eclipse.swt.dnd.DND;
  19 import org.eclipse.swt.dnd.DragSourceAdapter;
  20 import org.eclipse.swt.dnd.DragSourceEvent;
  21 import org.eclipse.swt.dnd.Transfer;
  22
  23 public class BasicSelectionTransferDragAdapter extends DragSourceAdapter
  24                 implements TransferDragSourceListener {
  25
  26         private ISelectionProvider fProvider;
  27
  28         public BasicSelectionTransferDragAdapter(ISelectionProvider provider) {
  29                 Assert.isNotNull(provider);
  30                 fProvider = provider;
  31         }
  32
  33         /**
  34          * @see TransferDragSourceListener#getTransfer
  35          */
  36         public Transfer getTransfer() {
  37                 return LocalSelectionTransfer.getInstance();
  38         }
  39
  40         /*
  41          * non Java-doc
  42          *
  43          * @see org.eclipse.swt.dnd.DragSourceListener#dragStart
  44          */
  45         public void dragStart(DragSourceEvent event) {
  46                 ISelection selection = fProvider.getSelection();
  47                 LocalSelectionTransfer.getInstance().setSelection(selection);
  48                 LocalSelectionTransfer.getInstance().setSelectionSetTime(event.time);
  49                 event.doit = isDragable(selection);
  50         }
  51
  52         /**
  53          * Checks if the elements contained in the given selection can be dragged.
  54          * <p>
  55          * Subclasses may override.
  56          *
  57          * @param selection
  58          *            containing the elements to be dragged
  59          */
  60         protected boolean isDragable(ISelection selection) {
  61                 return true;
  62         }
  63
  64         /*
  65          * non Java-doc
  66          *
  67          * @see org.eclipse.swt.dnd.DragSourceListener#dragSetData
  68          */
  69         public void dragSetData(DragSourceEvent event) {
  70                 // For consistency set the data to the selection even though
  71                 // the selection is provided by the LocalSelectionTransfer
  72                 // to the drop target adapter.
  73                 event.data = LocalSelectionTransfer.getInstance().getSelection();
  74         }
  75
  76         /*
  77          * non Java-doc
  78          *
  79          * @see org.eclipse.swt.dnd.DragSourceListener#dragFinished
  80          */
  81         public void dragFinished(DragSourceEvent event) {
  82                 // We assume that the drop target listener has done all
  83                 // the work.
  84                 Assert.isTrue(event.detail == DND.DROP_NONE);
  85                 LocalSelectionTransfer.getInstance().setSelection(null);
  86                 LocalSelectionTransfer.getInstance().setSelectionSetTime(0);
  87         }
  88 }