1    package gui.tree; 
2     
3    import javax.swing.*; 
4    import javax.swing.tree.DefaultMutableTreeNode; 
5    import javax.swing.tree.DefaultTreeModel; 
6    import javax.swing.tree.TreePath; 
7    import java.awt.*; 
8    import java.awt.datatransfer.Transferable; 
9    import java.awt.dnd.*; 
10   import java.awt.event.ActionEvent; 
11   import java.awt.event.ActionListener; 
12   import java.io.File; 
13    
14   public class FileTreeDragSource implements DragGestureListener, 
15           DragSourceListener { 
16       public FileTreeDragSource(FileTree tree) { 
17           this.tree = tree; 
18    
19           // Use the default DragSource 
20           DragSource dragSource = DragSource.getDefaultDragSource(); 
21    
22           // Create a DragGestureRecognizer and 
23           // register as the listener 
24           dragSource.createDefaultDragGestureRecognizer( 
25                   tree, DnDConstants.ACTION_COPY_OR_MOVE, 
26                   this); 
27       } 
28    
29       // Implementation of DragGestureListener interface. 
30       public void dragGestureRecognized(DragGestureEvent dge) { 
31           // Get the gui.mouse.m2.mouse location and convert it to 
32           // a location within the gui.tree. 
33           Point location = dge.getDragOrigin(); 
34           TreePath dragPath = tree.getPathForLocation(location.x, location.y); 
35           if (dragPath != null && tree.isPathSelected(dragPath)) { 
36               // Get the list of selected files and create a Transferable 
37               // The list of files and the is saved for use when 
38               // the drop completes. 
39               paths = tree.getSelectionPaths(); 
40               if (paths != null && paths.length > 0) { 
41                   dragFiles = new File[paths.length]; 
42                   for (int i = 0; i < paths.length; i++) { 
43                       String pathName = tree.getPathName(paths[i]); 
44                       dragFiles[i] = new File(pathName); 
45                   } 
46    
47                   Transferable transferable = 
48                           new FileListTransferable(dragFiles); 
49                   dge.startDrag(null, transferable, this); 
50               } 
51           } 
52       } 
53    
54       // Implementation of DragSourceListener interface 
55       public void dragEnter(DragSourceDragEvent dsde) { 
56           DnDUtils.debugPrintln("Drag Source: dragEnter, drop action = " 
57                   + DnDUtils.showActions(dsde.getDropAction())); 
58       } 
59    
60       public void dragOver(DragSourceDragEvent dsde) { 
61           DnDUtils.debugPrintln("Drag Source: dragOver, drop action = " 
62                   + DnDUtils.showActions(dsde.getDropAction())); 
63       } 
64    
65       public void dragExit(DragSourceEvent dse) { 
66           DnDUtils.debugPrintln("Drag Source: dragExit"); 
67       } 
68    
69       public void dropActionChanged(DragSourceDragEvent dsde) { 
70           DnDUtils.debugPrintln("Drag Source: dropActionChanged, drop action = " 
71                   + DnDUtils.showActions(dsde.getDropAction())); 
72       } 
73    
74       public void dragDropEnd(DragSourceDropEvent dsde) { 
75           DnDUtils.debugPrintln("Drag Source: drop completed, drop action = " 
76                   + DnDUtils.showActions(dsde.getDropAction()) 
77                   + ", success: " + dsde.getDropSuccess()); 
78           // If the drop action was ACTION_MOVE, 
79           // the gui.tree might need to be updated. 
80           if (dsde.getDropAction() == DnDConstants.ACTION_MOVE) { 
81               final File[] draggedFiles = dragFiles; 
82               final TreePath[] draggedPaths = paths; 
83    
84    
85               Timer tm = new Timer(200, new ActionListener() { 
86                   public void actionPerformed(ActionEvent evt) { 
87                       // Check whether each of the dragged files exists. 
88                       // If it does not, we need to remove the node 
89                       // that represents it from the gui.tree. 
90                       for (int i = 0; i < draggedFiles.length; i++) { 
91                           if (draggedFiles[i].exists() == false) { 
92                               // Remove this node 
93                               DefaultMutableTreeNode node = 
94                                       (DefaultMutableTreeNode) draggedPaths[i]. 
95                                       getLastPathComponent(); 
96                               ((DefaultTreeModel) tree.getModel()). 
97                                       removeNodeFromParent(node); 
98                           } 
99                       } 
100                  } 
101              }); 
102              tm.setRepeats(false); 
103              tm.start(); 
104          } 
105      } 
106   
107      public static void main(String[] args) { 
108          JFrame f = new JFrame("Draggable File Tree"); 
109          try { 
110              FileTree tree = new FileTree(args[0]); 
111              f.getContentPane().add(new JScrollPane(tree)); 
112   
113              // Attach the drag source 
114              FileTreeDragSource dragSource = new FileTreeDragSource(tree); 
115          } catch (Exception e) { 
116          } 
117          f.pack(); 
118          f.setVisible(true); 
119      } 
120   
121      protected FileTree tree;            // The associated gui.tree 
122      protected File[] dragFiles;         // Dragged files 
123      protected TreePath[] paths;         // Dragged paths 
124  } 
125   
126