test.java

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import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.util.EventObject;

public class Test extends JFrame {
	public Test() {
		JTree tree = new JTree(createTreeModel());
		JScrollPane scrollPane = new JScrollPane(tree);

		FileNodeRenderer renderer = new FileNodeRenderer();
		FileNodeEditor editor = new FileNodeEditor();
								  
		tree.setEditable(true);
		tree.setCellRenderer(renderer);
		tree.setCellEditor(new ImmediateEditor(tree, 
											   renderer, editor));

		getContentPane().add(scrollPane, BorderLayout.CENTER);

		tree.addTreeExpansionListener(new TreeExpansionListener(){
			public void treeCollapsed(TreeExpansionEvent e) {
			}
			public void treeExpanded(TreeExpansionEvent e) {
				TreePath path = e.getPath();
				FileNode node = (FileNode)
								   path.getLastPathComponent();

				if( ! node.isExplored())
					node.explore();
			}
		});
		tree.getCellEditor().addCellEditorListener(
						new CellEditorListener() {
			public void editingCanceled(ChangeEvent e) {
				CellEditor cellEditor = (CellEditor)e.getSource();
				SelectableFile sf = 
						(SelectableFile)
						cellEditor.getCellEditorValue();

				System.out.println("editing canceled: " + 
									sf.toString());
			}
			public void editingStopped(ChangeEvent e) {
				CellEditor cellEditor = (CellEditor)e.getSource();
				SelectableFile sf = 
						(SelectableFile)
						cellEditor.getCellEditorValue();

				System.out.println("editing stopped: " + 
									sf.toString());
			}
		});
	}
	private DefaultTreeModel createTreeModel() {
		File root = new File("E:/");
		FileNode rootNode = new FileNode(root), node;

		rootNode.explore();
		return new DefaultTreeModel(rootNode);
	}
	public static void main(String args[]) {
		GJApp.launch(new Test(),"JTree File Explorer",
								 300,300,450,400);
	}
}
class SelectableFile {
	private File file;
	private boolean selected = false;

	public SelectableFile(File file) {
		this.file = file;
	}
	public String toString() {
		return file.toString() + " selected: " + selected;
	}
	public void setSelected(boolean s) { selected = s; }
	public boolean isSelected()		   { return selected; }
	public File getFile() 			   { return file; }
}
class FileNode extends DefaultMutableTreeNode {
	private boolean explored = false;

	public FileNode(File file) 	{ 
		setUserObject(new SelectableFile(file)); 
	}
	public boolean getAllowsChildren() { return isDirectory(); }
	public boolean isLeaf() 	{ return !isDirectory(); }

	public File getFile() { 
		SelectableFile sf = (SelectableFile)getUserObject(); 
		return sf.getFile();
	}
	public boolean isSelected() {
		SelectableFile sf = (SelectableFile)getUserObject(); 
		return sf.isSelected();
	}
	public void setSelected(boolean b) {
		SelectableFile sf = (SelectableFile)getUserObject(); 
		sf.setSelected(b);
	}
	public boolean isDirectory() {
		File file = getFile();
		return file.isDirectory();
	}
	public String toString() {
		File file = getFile();
		String filename = file.toString();
		int index = filename.lastIndexOf("\\");

		return (index != -1 && index != filename.length()-1) ? 
									filename.substring(index+1) : 
									filename;
	}
	public void explore() 		{ explore(false); }
	public boolean isExplored() { return explored; }

	public void explore(boolean force) {
		if(!isExplored() || force) {
			File file = getFile();
			File[] children = file.listFiles();

			for(int i=0; i < children.length; ++i) 
				add(new FileNode(children[i]));

			explored = true;
		}
	}
}
class FileNodeRenderer extends DefaultTreeCellRenderer {
	protected JCheckBox checkBox = new JCheckBox("backup");
	private Component strut = Box.createHorizontalStrut(5);
	private JPanel panel = new JPanel();

	public FileNodeRenderer() {
		panel.setBackground(
					UIManager.getColor("Tree.textBackground"));
					
		setOpaque(false);
		checkBox.setOpaque(false);
		panel.setOpaque(false);

		panel.setLayout(new FlowLayout(FlowLayout.CENTER,0,0));
		panel.add(this);
		panel.add(strut);
		panel.add(checkBox);

	}	
	public Component getTreeCellRendererComponent(
						JTree tree, Object value, 
						boolean selected, boolean expanded,
						boolean leaf, int row, 
						boolean hasFocus) {
		FileNode node = (FileNode)value;

		super.getTreeCellRendererComponent(
								tree, value, selected, expanded,
								leaf, row, hasFocus);

		checkBox.setVisible(node.isDirectory());
		checkBox.setSelected(node.isSelected());

		return panel;
	}
	public Dimension getCheckBoxOffset() {
		Graphics g = panel.getGraphics();
		int xoffset = 0;

		if(g != null) {
			try {
				FontMetrics fm = g.getFontMetrics();
				xoffset = fm.stringWidth(getText()) + 
						  strut.getPreferredSize().width;
			}
			finally  {
				g.dispose();
			}
		}
		return new Dimension(xoffset, 0);
	}
}
class FileNodeEditorRenderer extends FileNodeRenderer {
	public Component getTreeCellRendererComponent(
						JTree tree, Object value, 
						boolean selected, boolean expanded,
						boolean leaf, int row, 
						boolean hasFocus) {
		Component c = super.getTreeCellRendererComponent(tree, 
							value, selected, expanded, 
							leaf, row, hasFocus);
		setIcon(null);
		return c;
	}
	public JCheckBox getCheckBox() {
		return checkBox;
	}
}
class FileNodeEditor extends AbstractCellEditor {
	FileNodeEditorRenderer renderer;
	FileNode lastEditedNode;
	JCheckBox checkBox;

	public FileNodeEditor() {
		renderer = new FileNodeEditorRenderer();
		checkBox = renderer.getCheckBox();

		checkBox.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				lastEditedNode.setSelected(checkBox.isSelected());
				stopCellEditing();
			}
		});
	}
	public Component getTreeCellEditorComponent(
						JTree tree, Object value, 
						boolean selected, boolean expanded,
						boolean leaf, int row) {
		lastEditedNode = (FileNode)value;

		return renderer.getTreeCellRendererComponent(tree,
							value, selected, expanded,
							leaf, row, true); // hasFocus ignored
	}
	public Object getCellEditorValue() {
		return lastEditedNode.getUserObject();
	}
}
class ImmediateEditor extends DefaultTreeCellEditor {
	private FileNodeRenderer renderer;

	public ImmediateEditor(JTree tree, 
							FileNodeRenderer renderer, 
							FileNodeEditor editor) {
		super(tree, renderer, editor);
		this.renderer = renderer;
	}
	protected boolean canEditImmediately(EventObject e) {
		boolean rv = false;  // rv = return value

		if(e instanceof MouseEvent) {
			MouseEvent me = (MouseEvent)e;
			rv = inCheckBoxHitRegion(me);
		}
		return rv;
	}
	public boolean shouldSelectCell(EventObject e) {
		boolean rv = false;  // only mouse events

		if(e instanceof MouseEvent) {
			MouseEvent me = (MouseEvent)e;
			TreePath path = tree.getPathForLocation(me.getX(), 
												    me.getY());
			FileNode node = (FileNode)
							   path.getLastPathComponent();
					   
			rv = node.isLeaf() || !inCheckBoxHitRegion(me);
		}
		return rv;
	}
	public boolean inCheckBoxHitRegion(MouseEvent e) {
		TreePath path = tree.getPathForLocation(e.getX(), 
											    e.getY());
		FileNode node = (FileNode)path.getLastPathComponent();
		boolean rv = false;

		if(node.isDirectory()) {
			// offset and lastRow DefaultTreeCellEditor 
			// protected members

			Rectangle bounds = tree.getRowBounds(lastRow);
			Dimension checkBoxOffset = 
									 renderer.getCheckBoxOffset();

			bounds.translate(offset + checkBoxOffset.width, 
							 checkBoxOffset.height);

			rv = bounds.contains(e.getPoint());
		}
		return rv;
	}
}
class GJApp extends WindowAdapter {
	static private JPanel statusArea = new JPanel();
	static private JLabel status = new JLabel(" ");

	public static void launch(final JFrame f, String title,
							  final int x, final int y, 
							  final int w, int h) {
		f.setTitle(title);
		f.setBounds(x,y,w,h);
		f.setVisible(true);

		statusArea.setBorder(BorderFactory.createEtchedBorder());
		statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));
		statusArea.add(status);
		status.setHorizontalAlignment(JLabel.LEFT);

		f.setDefaultCloseOperation(
							WindowConstants.DISPOSE_ON_CLOSE);

		f.addWindowListener(new WindowAdapter() {
			public void windowClosed(WindowEvent e) {
				System.exit(0);
			}
		});
	}
	static public JPanel getStatusArea() {
		return statusArea;
	}
	static public void updateStatus(String s) {
		status.setText(s);
	}
}