diff --git a/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeCellRenderer.java b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeCellRenderer.java
new file mode 100644
index 0000000..9e11063
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeCellRenderer.java
@@ -0,0 +1,91 @@
+package net.vhati.modmanager.ui.tree;
+
+import java.awt.BorderLayout;
+import java.awt.Component;
+import javax.swing.JPanel;
+import javax.swing.JTree;
+import javax.swing.tree.TreeCellRenderer;
+import javax.swing.tree.TreePath;
+
+import net.vhati.modmanager.ui.tree.ChecklistTreePathFilter;
+import net.vhati.modmanager.ui.tree.ChecklistTreeSelectionModel;
+import net.vhati.modmanager.ui.tree.TristateCheckBox;
+import net.vhati.modmanager.ui.tree.TristateButtonModel.TristateState;
+
+
+/**
+ * A cell renderer that augments an existing renderer with a checkbox.
+ */
+public class ChecklistTreeCellRenderer extends JPanel implements TreeCellRenderer {
+
+	protected ChecklistTreeSelectionModel selectionModel;
+	protected ChecklistTreePathFilter checklistFilter;
+	protected TreeCellRenderer delegate;
+	protected TristateCheckBox checkbox = new TristateCheckBox();
+	protected int checkMaxX = 0;
+
+
+	/**
+	 * Constructor.
+	 *
+	 * @param delegate  a traditional TreeCellRenderer
+	 * @param selectionModel  a model to query for checkbox states
+	 * @param checklistFilter  a TreePath filter, or null to always show a checkbox
+	 */
+	public ChecklistTreeCellRenderer( TreeCellRenderer delegate, ChecklistTreeSelectionModel selectionModel, ChecklistTreePathFilter checklistFilter ) {
+		super();
+		this.delegate = delegate;
+		this.selectionModel = selectionModel;
+		this.checklistFilter = checklistFilter;
+
+		this.setLayout( new BorderLayout() );
+		this.setOpaque( false );
+		checkbox.setOpaque( false );
+
+		checkMaxX = checkbox.getPreferredSize().width;
+	}
+
+
+	@Override
+	public Component getTreeCellRendererComponent( JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus ) {
+		this.removeAll();
+		checkbox.setState( TristateState.DESELECTED );
+
+		Component delegateComp = delegate.getTreeCellRendererComponent( tree, value, sel, expanded, leaf, row, hasFocus );
+
+		TreePath path = tree.getPathForRow( row );
+		if ( path != null ) {
+			if ( selectionModel.isPathSelected( path, selectionModel.isDigged() ) ) {
+				checkbox.setState( TristateState.SELECTED );
+			} else {
+				checkbox.setState( ( selectionModel.isDigged() && selectionModel.isPartiallySelected( path ) ) ? TristateState.INDETERMINATE : TristateState.DESELECTED );
+			}
+		}
+		checkbox.setVisible( path == null || checklistFilter == null || checklistFilter.isSelectable( path ) );
+		checkbox.setEnabled( tree.isEnabled() );
+
+		this.add( checkbox, BorderLayout.WEST );
+		this.add( delegateComp, BorderLayout.CENTER );
+		return this;
+	}
+
+
+	public void setDelegate( TreeCellRenderer delegate ) {
+		this.delegate = delegate;
+	}
+
+	public TreeCellRenderer getDelegate() {
+		return delegate;
+	}
+
+
+	/**
+	 * Returns the checkbox's right edge (in the renderer component's coordinate space).
+	 *
+	 * Values less than that can be interpreted as within the checkbox's bounds.
+	 * X=0 is the renderer component's left edge.
+	 */
+	public int getCheckboxMaxX() {
+		return checkMaxX;
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeManager.java b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeManager.java
new file mode 100644
index 0000000..84f83f6
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeManager.java
@@ -0,0 +1,129 @@
+/**
+ * Based on CheckTreeManager (rev 120, 2007-07-20)
+ * By Santhosh Kumar T
+ * https://java.net/projects/myswing
+ *
+ * https://java.net/projects/myswing/sources/svn/content/trunk/src/skt/swing/tree/check/CheckTreeManager.java?rev=120
+ */
+
+/**
+ * MySwing: Advanced Swing Utilites
+ * Copyright (C) 2005  Santhosh Kumar T
+ * <p/>
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * <p/>
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ */
+
+package net.vhati.modmanager.ui.tree;
+
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import javax.swing.JTree;
+import javax.swing.event.TreeSelectionEvent;
+import javax.swing.event.TreeSelectionListener;
+import javax.swing.tree.TreePath;
+
+import net.vhati.modmanager.ui.tree.ChecklistTreePathFilter;
+import net.vhati.modmanager.ui.tree.ChecklistTreeSelectionModel;
+
+
+public class ChecklistTreeManager extends MouseAdapter implements TreeSelectionListener {
+
+	private ChecklistTreeSelectionModel selectionModel;
+	private ChecklistTreePathFilter checklistFilter;
+	protected JTree tree = new JTree();
+	protected int checkMaxX = 0;
+
+
+	/**
+	 * Constructor.
+	 *
+	 * Modifies a given tree to add checkboxes.
+	 * - The tree's existing cell renderer will be wrapped with a ChecklistTreeCellRenderer.
+	 * - A MouseListener will be added to the tree to detect clicks, which will toggle checkboxes.
+	 *
+	 * A secondary ChecklistTreeSelectionModel will track checkboxes' states (independent of row
+	 * highlighting).
+	 *
+	 * @param tree  a tree to modify
+	 * @param dig  true show that a node is partially selected by scanning its descendents, false otherwise
+	 * @checklistFilter  a filter to decide which TreePaths need checkboxes, or null
+	 */
+	public ChecklistTreeManager( JTree tree, boolean dig, ChecklistTreePathFilter checklistFilter ) {
+		this.tree = tree;
+		this.checklistFilter = checklistFilter;
+
+		// Note: If largemodel is not set then treenodes are getting truncated.
+		// Need to debug further to find the problem.
+		if ( checklistFilter != null ) tree.setLargeModel( true );
+
+		selectionModel = new ChecklistTreeSelectionModel( tree.getModel(), dig );
+
+		ChecklistTreeCellRenderer checklistRenderer = new ChecklistTreeCellRenderer( tree.getCellRenderer(), selectionModel, checklistFilter );
+		setCheckboxMaxX( checklistRenderer.getCheckboxMaxX() );
+		tree.setCellRenderer( checklistRenderer );
+
+		selectionModel.addTreeSelectionListener( this );
+		tree.addMouseListener( this );
+	}
+
+
+	/**
+	 * Sets the checkbox's right edge (in the TreeCellRenderer component's coordinate space).
+	 *
+	 * Values less than that will be interpreted as within the checkbox's bounds.
+	 * X=0 is the renderer component's left edge.
+	 */
+	public void setCheckboxMaxX( int x ) {
+		checkMaxX = x;
+	}
+
+
+	public ChecklistTreePathFilter getChecklistFilter() {
+		return checklistFilter;
+	}
+
+
+	public ChecklistTreeSelectionModel getSelectionModel() {
+		return selectionModel;
+	}
+
+
+	@Override
+	public void mouseClicked( MouseEvent e ) {
+		TreePath path = tree.getPathForLocation( e.getX(), e.getY() );
+		if ( path == null ) return;
+
+		if ( e.getX() > tree.getPathBounds(path).x + checkMaxX ) return;
+
+		if ( checklistFilter != null && !checklistFilter.isSelectable(path) ) return;
+
+		boolean selected = selectionModel.isPathSelected( path, selectionModel.isDigged() );
+		selectionModel.removeTreeSelectionListener( this );
+
+		try {
+			if ( selected ) {
+				selectionModel.removeSelectionPath( path );
+			} else {
+				selectionModel.addSelectionPath( path );
+			}
+		}
+		finally {
+			selectionModel.addTreeSelectionListener( this );
+			tree.treeDidChange();
+		}
+	}
+
+
+	@Override
+	public void valueChanged( TreeSelectionEvent e ) {
+		tree.treeDidChange();
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreePanel.java b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreePanel.java
new file mode 100644
index 0000000..37ec53a
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreePanel.java
@@ -0,0 +1,196 @@
+package net.vhati.modmanager.ui.tree;
+
+import java.awt.BorderLayout;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+import javax.swing.DropMode;
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+import javax.swing.JScrollPane;
+import javax.swing.JTree;
+import javax.swing.SwingUtilities;
+import javax.swing.tree.DefaultMutableTreeNode;
+import javax.swing.tree.DefaultTreeModel;
+import javax.swing.tree.TreePath;
+import javax.swing.tree.TreeSelectionModel;
+
+import net.vhati.modmanager.ui.tree.ChecklistTreeManager;
+import net.vhati.modmanager.ui.tree.ChecklistTreeSelectionModel;
+import net.vhati.modmanager.ui.tree.GroupTreeCellRenderer;
+import net.vhati.modmanager.ui.tree.TreeTransferHandler;
+
+
+public class ChecklistTreePanel extends JPanel {
+
+	private DefaultTreeModel treeModel = null;
+	private JTree tree = null;
+	private ChecklistTreeManager checklistManager = null;
+
+
+	public ChecklistTreePanel() {
+		super( new BorderLayout() );
+
+		DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode( "Root" );
+		treeModel = new DefaultTreeModel( rootNode );
+		tree = new JTree( treeModel );
+		tree.setCellRenderer( new GroupTreeCellRenderer() );
+		tree.setRootVisible( false );
+		tree.getSelectionModel().setSelectionMode( TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION );
+		checklistManager = new ChecklistTreeManager( tree, true, null );
+
+		JScrollPane scrollPane = new JScrollPane( tree, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED );
+		this.add( scrollPane, BorderLayout.CENTER );
+
+		tree.setTransferHandler( new TreeTransferHandler( tree ) );
+		tree.setDropMode( DropMode.ON_OR_INSERT );  // Drop between rows, or onto groups.
+		tree.setDragEnabled( true );
+	}
+
+
+	/**
+	 * Returns all userObjects of nodes with ticked checkboxes (except root itself).
+	 */
+	public List<Object> getSelectedUserObjects() {
+		ChecklistTreeSelectionModel checklistSelectionModel = checklistManager.getSelectionModel();
+		List<Object> results = new ArrayList<Object>();
+
+		for ( Enumeration enumer = checklistSelectionModel.getAllSelectedPaths(); enumer.hasMoreElements(); ) {
+			DefaultMutableTreeNode childNode = (DefaultMutableTreeNode)enumer.nextElement();
+			if ( !childNode.isRoot() && childNode.getUserObject() != null ) {
+				results.add( childNode.getUserObject() );
+			}
+		}
+
+		return results;
+	}
+
+	/**
+	 * Returns all userObjects of all nodes (except root itself).
+	 */
+	public List<Object> getAllUserObjects() {
+		List<Object> results = new ArrayList<Object>();
+
+		DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode)treeModel.getRoot();
+		getAllUserObjects( rootNode, results );
+
+		return results;
+	}
+
+	private void getAllUserObjects( DefaultMutableTreeNode currentNode, List<Object> results ) {
+		if ( !currentNode.isRoot() && currentNode.getUserObject() != null ) {
+			results.add( currentNode.getUserObject() );
+		}
+
+		for ( Enumeration enumer = currentNode.children(); enumer.hasMoreElements(); ) {
+			DefaultMutableTreeNode childNode = (DefaultMutableTreeNode)enumer.nextElement();
+			getAllUserObjects( currentNode, results );
+		}
+	}
+
+
+	public void clear() {
+		DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode)treeModel.getRoot();
+		rootNode.removeAllChildren();
+		treeModel.reload();
+	}
+
+
+	/**
+	 * Adds a group to consolidate mods.
+	 *
+	 * TODO: Trigger a rename.
+	 */
+	public void addGroup() {
+		DefaultMutableTreeNode rootNode = (DefaultMutableTreeNode)treeModel.getRoot();
+		GroupAwareTreeNode groupNode = new GroupAwareTreeNode( "New Group", true );
+		rootNode.add( groupNode );
+		treeModel.nodesWereInserted( rootNode, new int[]{rootNode.getIndex( groupNode )} );
+	}
+
+	/**
+	 * Disband selected groups.
+	 *
+	 * TODO
+	 */
+	public void removeSelectedGroups() {
+	}
+
+	/**
+	 * Rename last selected group.
+	 *
+	 * TODO
+	 */
+	public void  renameSelectedGroup() {
+	}
+
+
+	/**
+	 * Cycles through ticking all checkboxes and clearing them.
+	 */
+	public void toggleAllNodeSelection() {
+	}
+
+	/**
+	 * Cycles through expanding all nodes and collapsing them.
+	 */
+	public void toggleAllNodeExpansion() {
+		boolean canExpand = false;
+		boolean canCollapse = false;
+
+		for ( int i = tree.getRowCount()-1; i >= 0; i-- ) {
+			if ( tree.isCollapsed( i ) ) {
+				canExpand = true;
+			}
+			else if ( tree.isExpanded( i ) ) {
+				canCollapse = true;
+			}
+		}
+
+		if ( canExpand ) {
+			expandAllNodes( tree.getRowCount() );
+		}
+		else if ( canCollapse ) {
+			collapseAllNodes( new TreePath( treeModel.getRoot() ) );
+		}
+	}
+
+	/**
+	 * Expands all nodes by repeatedly expanding until the row count stops
+	 * growing.
+	 */
+	public void expandAllNodes( int prevRowCount ) {
+		for ( int i=0; i < prevRowCount; i++ ) {
+			tree.expandRow( i );
+		}
+		if ( tree.getRowCount() != prevRowCount ) {
+			expandAllNodes( tree.getRowCount() );
+		}
+	}
+
+	/**
+	 * Collapses all nodes by walking the TreeModel.
+	 */
+	public void collapseAllNodes( TreePath currentPath ) {
+		Object currentNode = currentPath.getLastPathComponent();
+		for ( int i = treeModel.getChildCount( currentNode )-1; i >= 0; i-- ) {
+			Object childNode = treeModel.getChild( currentNode, i );
+			TreePath childPath = currentPath.pathByAddingChild( childNode );
+			collapseAllNodes( childPath );
+		}
+		if ( currentNode != treeModel.getRoot() ) tree.collapsePath( currentPath );
+	}
+
+
+	public JTree getTree() {
+		return tree;
+	}
+
+	public DefaultTreeModel getTreeModel() {
+		return treeModel;
+	}
+
+	public ChecklistTreeManager getChecklistManager() {
+		return checklistManager;
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreePathFilter.java b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreePathFilter.java
new file mode 100644
index 0000000..5bb5969
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreePathFilter.java
@@ -0,0 +1,13 @@
+package net.vhati.modmanager.ui.tree;
+
+import javax.swing.tree.TreePath;
+
+
+/**
+ * Decides whether a given TreePath should have a checkbox.
+ */
+public interface ChecklistTreePathFilter {
+
+	public boolean isSelectable( TreePath path );
+
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeSelectionModel.java b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeSelectionModel.java
new file mode 100644
index 0000000..09d82aa
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/ChecklistTreeSelectionModel.java
@@ -0,0 +1,258 @@
+/*
+ * Based on CheckTreeSelectionModel (rev 120, 2007-07-20)
+ * By Santhosh Kumar T
+ * https://java.net/projects/myswing
+ *
+ * https://java.net/projects/myswing/sources/svn/content/trunk/src/skt/swing/tree/check/CheckTreeSelectionModel.java?rev=120
+ */
+
+/**
+ * MySwing: Advanced Swing Utilites
+ * Copyright (C) 2005  Santhosh Kumar T
+ * <p/>
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * <p/>
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ */
+
+package net.vhati.modmanager.ui.tree;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.Stack;
+import javax.swing.tree.DefaultTreeSelectionModel;
+import javax.swing.tree.TreeModel;
+import javax.swing.tree.TreePath;
+import javax.swing.tree.TreeSelectionModel;
+
+import net.vhati.modmanager.ui.tree.PreorderEnumeration;
+
+
+public class ChecklistTreeSelectionModel extends DefaultTreeSelectionModel {
+
+	private TreeModel model;
+	private boolean dig = true;
+
+
+	public ChecklistTreeSelectionModel( TreeModel model, boolean dig ) {
+		this.model = model;
+		this.dig = dig;
+		this.setSelectionMode( TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION );
+	}
+
+	public boolean isDigged() {
+		return dig;
+	}
+
+
+	/**
+	 * Returns true if path1 is a descendant of path2.
+	 */
+	private boolean isDescendant( TreePath path1, TreePath path2 ) {
+		Object obj1[] = path1.getPath();
+		Object obj2[] = path2.getPath();
+		for ( int i=0; i < obj2.length; i++ ) {
+			if ( obj1[i] != obj2[i] ) return false;
+		}
+		return true;
+	}
+
+
+	/**
+	 * Returns true a selected node exists in the subtree of a given unselected path.
+	 * Returns false if the given path is itself selected.
+	 */
+	public boolean isPartiallySelected( TreePath path ) {
+		if ( isPathSelected( path, true ) ) return false;
+
+		TreePath[] selectionPaths = getSelectionPaths();
+		if( selectionPaths == null ) return false;
+
+		for ( int j=0; j < selectionPaths.length; j++ ) {
+			if ( isDescendant( selectionPaths[j], path ) ) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Returns true if a given path is selected.
+	 *
+	 * If dig is true, then the path is assumed to be selected, if
+	 * one of its ancestors is selected.
+	 */
+	public boolean isPathSelected( TreePath path, boolean dig ) {
+		if ( !dig ) return super.isPathSelected( path );
+
+		while ( path != null && !super.isPathSelected( path ) ) {
+			path = path.getParentPath();
+		}
+		return ( path != null );
+	}
+
+
+	@Override
+	public void setSelectionPaths( TreePath[] paths ) {
+		if ( dig ) {
+			throw new UnsupportedOperationException();
+		} else {
+			super.setSelectionPaths( paths );
+		}
+	}
+
+	@Override
+	public void addSelectionPaths( TreePath[] paths ) {
+		if ( !dig ) {
+			super.addSelectionPaths( paths );
+			return;
+		}
+
+		// Unselect all descendants of paths[].
+		for( int i=0; i < paths.length; i++ ) {
+			TreePath path = paths[i];
+			TreePath[] selectionPaths = getSelectionPaths();
+			if ( selectionPaths == null ) break;
+
+			ArrayList toBeRemoved = new ArrayList();
+			for ( int j=0; j < selectionPaths.length; j++ ) {
+				if ( isDescendant( selectionPaths[j], path ) ) {
+					toBeRemoved.add( selectionPaths[j] );
+				}
+			}
+			super.removeSelectionPaths( (TreePath[])toBeRemoved.toArray( new TreePath[0] ) );
+		}
+
+		// If all siblings are selected then unselect them and select parent recursively
+		// otherwize just select that path.
+		for ( int i=0; i < paths.length; i++ ) {
+			TreePath path = paths[i];
+			TreePath temp = null;
+			while ( areSiblingsSelected(path) ) {
+				temp = path;
+				if ( path.getParentPath() == null ) break;
+				path = path.getParentPath();
+			}
+			if ( temp != null ) {
+				if ( temp.getParentPath() != null ) {
+					addSelectionPath( temp.getParentPath() );
+				}
+				else {
+					if ( !isSelectionEmpty() ) {
+						removeSelectionPaths(getSelectionPaths());
+					}
+					super.addSelectionPaths( new TreePath[]{temp} );
+				}
+			}
+			else {
+				super.addSelectionPaths( new TreePath[]{path} );
+			}
+		}
+	}
+
+	@Override
+	public void removeSelectionPaths( TreePath[] paths ) {
+		if( !dig ) {
+			super.removeSelectionPaths( paths );
+			return;
+		}
+
+		for ( int i=0; i < paths.length; i++ ) {
+			TreePath path = paths[i];
+			if ( path.getPathCount() == 1 ) {
+				super.removeSelectionPaths( new TreePath[]{path} );
+			} else {
+				toggleRemoveSelection(path);
+			}
+		}
+	}
+
+
+	/**
+	 * Returns true if all siblings of given path are selected.
+	 */
+	private boolean areSiblingsSelected( TreePath path ) {
+		TreePath parent = path.getParentPath();
+		if ( parent == null ) return true;
+
+		Object node = path.getLastPathComponent();
+		Object parentNode = parent.getLastPathComponent();
+
+		int childCount = model.getChildCount( parentNode );
+		for ( int i=0; i < childCount; i++ ) {
+			Object childNode = model.getChild( parentNode, i );
+			if ( childNode == node ) continue;
+
+			if ( !isPathSelected( parent.pathByAddingChild( childNode ) ) ) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+
+	/**
+	 * Unselects a given path, toggling ancestors if they were entirely selected.
+	 *
+	 * If any ancestor node of the given path is selected, it will be unselected,
+	 * and all its descendants - except any within the given path - will be selected.
+	 * The ancestor will have gone from fully selected to partially selected.
+	 *
+	 * Otherwise, the given path will be unselected, and nothing else will change.
+	 */
+	private void toggleRemoveSelection( TreePath path ) {
+		Stack stack = new Stack();
+		TreePath parent = path.getParentPath();
+
+		while ( parent != null && !isPathSelected( parent ) ) {
+			stack.push( parent );
+			parent = parent.getParentPath();
+		}
+
+		if ( parent != null ) {
+			stack.push( parent );
+		}
+		else {
+			super.removeSelectionPaths( new TreePath[]{path} );
+			return;
+		}
+
+		while ( !stack.isEmpty() ) {
+			TreePath temp = (TreePath)stack.pop();
+			TreePath peekPath = ( stack.isEmpty() ? path : (TreePath)stack.peek() );
+			Object node = temp.getLastPathComponent();
+			Object peekNode = peekPath.getLastPathComponent();
+
+			int childCount = model.getChildCount( node );
+			for ( int i=0; i < childCount; i++ ) {
+				Object childNode = model.getChild( node, i );
+				if ( childNode != peekNode ) {
+					super.addSelectionPaths( new TreePath[]{temp.pathByAddingChild( childNode )} );
+				}
+			}
+		}
+		super.removeSelectionPaths( new TreePath[]{parent} );
+	}
+
+
+	public Enumeration getAllSelectedPaths() {
+		TreePath[] treePaths = getSelectionPaths();
+		if ( treePaths == null ) {
+			return Collections.enumeration( Collections.EMPTY_LIST );
+		}
+
+		Enumeration enumer = Collections.enumeration( Arrays.asList( treePaths ) );
+		if ( dig ) {
+			enumer = new PreorderEnumeration( enumer, model );
+		}
+		return enumer;
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/ChildrenEnumeration.java b/src/main/java/net/vhati/modmanager/ui/tree/ChildrenEnumeration.java
new file mode 100644
index 0000000..0d132ef
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/ChildrenEnumeration.java
@@ -0,0 +1,57 @@
+/**
+ * Based on ChildrenEnumeration (rev 120, 2007-07-20)
+ * By Santhosh Kumar T
+ * https://java.net/projects/myswing
+ *
+ * https://java.net/projects/myswing/sources/svn/content/trunk/src/skt/swing/tree/ChildrenEnumeration.java?rev=120
+ */
+
+/**
+ * MySwing: Advanced Swing Utilites
+ * Copyright (C) 2005  Santhosh Kumar T
+ * <p/>
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * <p/>
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ */
+
+package net.vhati.modmanager.ui.tree;
+
+import java.util.Enumeration;
+import java.util.NoSuchElementException;
+import javax.swing.tree.TreeModel;
+import javax.swing.tree.TreePath;
+
+
+public class ChildrenEnumeration implements Enumeration {
+
+	private TreePath path;
+	private TreeModel model;
+	private int position = 0;
+	private int childCount;
+
+
+	public ChildrenEnumeration( TreePath path, TreeModel model ) {
+		this.path = path;
+		this.model = model;
+		childCount = model.getChildCount( path.getLastPathComponent() );
+	}
+
+	@Override
+	public boolean hasMoreElements() {
+		return position < childCount;
+	}
+
+	@Override
+	public Object nextElement() {
+		if( !hasMoreElements() ) throw new NoSuchElementException();
+
+		return path.pathByAddingChild( model.getChild( path.getLastPathComponent(), position++ ) );
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/GroupAwareTreeNode.java b/src/main/java/net/vhati/modmanager/ui/tree/GroupAwareTreeNode.java
new file mode 100644
index 0000000..63e0120
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/GroupAwareTreeNode.java
@@ -0,0 +1,23 @@
+package net.vhati.modmanager.ui.tree;
+
+import javax.swing.tree.DefaultMutableTreeNode;
+
+
+/**
+ * A TreeNode that remembers whether it allows children when cloned.
+ */
+public class GroupAwareTreeNode extends DefaultMutableTreeNode {
+
+	public GroupAwareTreeNode( Object userObject, boolean allowsChildren ) {
+		super( userObject, allowsChildren );
+	}
+
+
+	@Override
+	public Object clone() {
+		GroupAwareTreeNode newNode = (GroupAwareTreeNode)super.clone();
+		newNode.setAllowsChildren( this.getAllowsChildren() );
+
+		return newNode;
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/GroupTreeCellRenderer.java b/src/main/java/net/vhati/modmanager/ui/tree/GroupTreeCellRenderer.java
new file mode 100644
index 0000000..c969e5c
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/GroupTreeCellRenderer.java
@@ -0,0 +1,39 @@
+package net.vhati.modmanager.ui.tree;
+
+import java.awt.Component;
+import javax.swing.JTree;
+import javax.swing.UIManager;
+import javax.swing.tree.DefaultMutableTreeNode;
+import javax.swing.tree.DefaultTreeCellRenderer;
+
+
+/**
+ * A renderer that sets icons based on whether children are allowed.
+ *
+ * A group with no children will still have a group icon.
+ */
+public class GroupTreeCellRenderer extends DefaultTreeCellRenderer {
+
+	@Override
+	public Component getTreeCellRendererComponent( JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus ) {
+		super.getTreeCellRendererComponent( tree, value, sel, expanded, leaf, row, hasFocus );
+
+		if ( value instanceof DefaultMutableTreeNode ) {
+			DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
+			if ( node.getAllowsChildren() ) {
+				if ( expanded ) {
+					this.setIcon( this.getDefaultOpenIcon() );
+					this.setDisabledIcon( this.getDefaultOpenIcon() );
+				} else {
+					this.setIcon( this.getDefaultClosedIcon() );
+					this.setDisabledIcon( this.getDefaultClosedIcon() );
+				}
+			} else {
+				this.setIcon( this.getDefaultLeafIcon() );
+				this.setDisabledIcon( this.getDefaultLeafIcon() );
+			}
+		}
+
+		return this;
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/PreorderEnumeration.java b/src/main/java/net/vhati/modmanager/ui/tree/PreorderEnumeration.java
new file mode 100644
index 0000000..7ebf789
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/PreorderEnumeration.java
@@ -0,0 +1,67 @@
+/**
+ * Based on PreorderEnumeration (rev 120, 2007-07-20)
+ * By Santhosh Kumar T
+ * https://java.net/projects/myswing
+ *
+ * https://java.net/projects/myswing/sources/svn/content/trunk/src/skt/swing/tree/PreorderEnumeration.java?rev=120
+ */
+
+/**
+ * MySwing: Advanced Swing Utilites
+ * Copyright (C) 2005  Santhosh Kumar T
+ * <p/>
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * <p/>
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ */
+
+package net.vhati.modmanager.ui.tree;
+
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.Stack;
+import javax.swing.tree.TreeModel;
+import javax.swing.tree.TreePath;
+
+
+public class PreorderEnumeration implements Enumeration {
+
+	private TreeModel model;
+	protected Stack<Enumeration> stack = new Stack<Enumeration>();
+
+
+	public PreorderEnumeration( TreePath path, TreeModel model ) {
+		this( Collections.enumeration( Collections.singletonList( path ) ), model );
+	}
+
+	public PreorderEnumeration( Enumeration enumer, TreeModel model ){
+		this.model = model;
+		stack.push( enumer );
+	}
+
+
+	@Override
+	public boolean hasMoreElements() {
+		return ( !stack.empty() && stack.peek().hasMoreElements() );
+	}
+
+	@Override
+	public Object nextElement() {
+		Enumeration	enumer = stack.peek();
+		TreePath path = (TreePath)enumer.nextElement();
+
+		if ( !enumer.hasMoreElements() ) stack.pop();
+
+		if ( model.getChildCount( path.getLastPathComponent() ) > 0 ) {
+			stack.push( new ChildrenEnumeration( path, model ) );
+		}
+
+		return path;
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/TreeTransferHandler.java b/src/main/java/net/vhati/modmanager/ui/tree/TreeTransferHandler.java
new file mode 100644
index 0000000..3ec1edd
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/TreeTransferHandler.java
@@ -0,0 +1,257 @@
+package net.vhati.modmanager.ui.tree;
+
+import java.awt.Cursor;
+import java.awt.datatransfer.DataFlavor;
+import java.awt.datatransfer.Transferable;
+import java.awt.dnd.DragSource;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+import javax.swing.JComponent;
+import javax.swing.JTable;
+import javax.swing.JTree;
+import javax.swing.TransferHandler;
+import javax.swing.tree.DefaultMutableTreeNode;
+import javax.swing.tree.DefaultTreeModel;
+import javax.swing.tree.TreeNode;
+import javax.swing.tree.TreePath;
+
+
+/**
+ * A handler to enable drag-and-drop within a JTree.
+ *
+ * When dropped, copies of highlighted nodes will be made via clone() and
+ * inserted at the drop location, then the originals will be removed.
+ *
+ * Dragging onto a space between nodes will insert at that location.
+ * Dragging onto a node that allows children will insert into it.
+ * Dragging onto a node that doesn't allow children will insert after it.
+ *
+ * All nodes must be instances of DefaultMutableTreeNode (or subclasses).
+ * Set the Jtree's DropMode to ON_OR_INSERT.
+ * The root node must be hidden, to prevent it from being dragged.
+ * The tree's selection model may be set to single or multiple.
+ */
+public class TreeTransferHandler extends TransferHandler {
+
+	private DataFlavor localTreePathFlavor = null;
+	private JTree tree = null;
+
+
+	public TreeTransferHandler( JTree tree ) {
+		super();
+		this.tree = tree;
+
+		try {
+			localTreePathFlavor = new DataFlavor( DataFlavor.javaJVMLocalObjectMimeType + ";class=\""+ TreePath[].class.getName() +"\"" );
+		}
+		catch ( ClassNotFoundException e ) {
+			//log.error( e );
+		}
+	}
+
+	@Override
+	protected Transferable createTransferable( JComponent c ) {
+		assert ( c == tree );
+		TreePath[] highlightedPaths = tree.getSelectionPaths();
+
+		Map<Integer,List<TreePath>> pathsByLengthMap = new TreeMap<Integer,List<TreePath>>();
+		for ( TreePath path : highlightedPaths ) {
+			if ( path.getPath().length == 1 ) continue;  // Omit root node (shouldn't drag it anyway).
+
+			Integer pathLength = new Integer( path.getPath().length );
+			if ( !pathsByLengthMap.containsKey( pathLength ) ) {
+				pathsByLengthMap.put( pathLength, new ArrayList<TreePath>() );
+			}
+			pathsByLengthMap.get( pathLength ).add( path );
+		}
+		// For each length (shortest-first), iterate its paths.
+		// For each of those paths, search longer lengths' lists,
+		// removing any paths that are descendants of those short ancestor nodes.
+		List<Integer> lengthsList = new ArrayList( pathsByLengthMap.keySet() );
+		for ( int i=0; i < lengthsList.size(); i++ ) {
+			for ( TreePath ancestorPath : pathsByLengthMap.get( lengthsList.get( i ) ) ) {
+				for ( int j=i+1; j < lengthsList.size(); j++ ) {
+
+					List<TreePath> childPaths = pathsByLengthMap.get( lengthsList.get( j ) );
+					for ( Iterator<TreePath> childIt = childPaths.iterator(); childIt.hasNext(); ) {
+						TreePath childPath = childIt.next();
+						if ( ancestorPath.isDescendant( childPath ) ) {
+							childIt.remove();
+						}
+					}
+
+				}
+			}
+		}
+		List<TreePath> uniquePathList = new ArrayList<TreePath>();
+		for ( List<TreePath> paths : pathsByLengthMap.values() ) {
+			uniquePathList.addAll( paths );
+		}
+		TreePath[] uniquePathsArray = uniquePathList.toArray( new TreePath[uniquePathList.size()] );
+
+		return new TreePathTransferrable( uniquePathsArray );
+	}
+
+	@Override
+	public boolean canImport( TransferHandler.TransferSupport ts ) {
+		boolean b = ( ts.getComponent() == tree && ts.isDrop() && ts.isDataFlavorSupported(localTreePathFlavor) );
+		tree.setCursor( b ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop );
+		return b;
+	}
+
+	@Override
+	public int getSourceActions( JComponent comp ) {
+		return TransferHandler.MOVE;
+	}
+
+	@Override
+	@SuppressWarnings("Unchecked")
+	public boolean importData( TransferHandler.TransferSupport ts ) {
+		if ( !canImport(ts) ) return false;
+
+		JTree dstTree = (JTree)ts.getComponent();
+		DefaultTreeModel dstTreeModel = (DefaultTreeModel)dstTree.getModel();
+		JTree.DropLocation dl = (JTree.DropLocation)ts.getDropLocation();
+		TreePath dropPath = dl.getPath();    // Dest parent node, or null.
+		int dropIndex = dl.getChildIndex();  // Insertion child index in the dest parent node,
+		                                     // or -1 if dropped onto a group.
+
+		dstTree.setCursor( Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR) );
+		if ( dropPath == null ) return false;
+		DefaultMutableTreeNode dropParentNode = (DefaultMutableTreeNode)dropPath.getLastPathComponent();
+
+		// When dropping onto a non-group node, insert into the position after it instead.
+		if ( !dropParentNode.getAllowsChildren() ) {
+			DefaultMutableTreeNode prevParentNode = dropParentNode;
+			dropPath = dropPath.getParentPath();
+			dropParentNode = (DefaultMutableTreeNode)dropPath.getLastPathComponent();
+			dropIndex = dropParentNode.getIndex( prevParentNode ) + 1;
+		}
+
+		try {
+			TreePath[] draggedPaths = (TreePath[])ts.getTransferable().getTransferData( localTreePathFlavor );
+
+			// Bail if the dropPath was among those dragged.
+			boolean badDrop = false;
+			for ( TreePath path : draggedPaths ) {
+				if ( path.equals( dropPath ) ) {
+					badDrop = true;
+					break;
+				}
+			}
+
+			if ( !badDrop && dropParentNode.getAllowsChildren() ) {
+				for ( TreePath path : draggedPaths ) {
+					// Copy the dragged node and any children.
+					DefaultMutableTreeNode srcNode = (DefaultMutableTreeNode)path.getLastPathComponent();
+					DefaultMutableTreeNode newNode = (DefaultMutableTreeNode)cloneNodes( srcNode );
+
+					if ( dropIndex != -1 ) {
+						// Insert.
+						dropParentNode.insert( newNode, dropIndex );
+						dstTreeModel.nodesWereInserted( dropParentNode, new int[]{dropIndex} );
+						dropIndex++;  // Next insertion will be after this node.
+					}
+					else {
+						// Add to the end.
+						dropParentNode.add( newNode );
+						dstTreeModel.nodesWereInserted( dropParentNode, new int[]{dropParentNode.getChildCount()-1} );
+						if ( !dstTree.isExpanded( dropPath ) ) dstTree.expandPath( dropPath );
+					}
+				}
+				return true;
+			}
+		}
+		catch ( Exception e ) {
+			// UnsupportedFlavorException: if Transferable.getTransferData() fails.
+			// IOException: if Transferable.getTransferData() fails.
+			// IllegalStateException: if insert/add fails because dropPath's node doesn't allow children.
+			//log.error( e );
+		}
+		return false;
+	}
+
+	@Override
+	protected void exportDone( JComponent source, Transferable data, int action ) {
+		if ( action == TransferHandler.MOVE || action == TransferHandler.NONE ) {
+			tree.setCursor( Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR) );
+		}
+
+		JTree srcTree = (JTree)source;
+		DefaultTreeModel srcTreeModel = (DefaultTreeModel)srcTree.getModel();
+
+		if ( action == TransferHandler.MOVE ) {
+			// Remove original dragged rows now that the move completed.
+			// Scan the tree checking equality is fine (DefaultMutableTreeNode's equals() does ==).
+
+			try {
+				TreePath[] draggedPaths = (TreePath[])data.getTransferData( localTreePathFlavor );
+				for ( TreePath path : draggedPaths ) {
+					DefaultMutableTreeNode doomedNode = (DefaultMutableTreeNode)path.getLastPathComponent();
+					TreeNode parentNode = doomedNode.getParent();
+					int doomedIndex = parentNode.getIndex( doomedNode );
+					doomedNode.removeFromParent();
+					srcTreeModel.nodesWereRemoved( parentNode, new int[]{doomedIndex}, new Object[]{doomedNode} );
+				}
+			}
+			catch ( Exception e ) {
+				//log.error( e );
+			}
+		}
+	}
+
+
+	/**
+	 * Recursively clones a node and its descendants.
+	 *
+	 * The clone() methods will reuse userObjects, but the nodes themselves will be new.
+	 */
+	@SuppressWarnings("Unchecked")
+	private DefaultMutableTreeNode cloneNodes( DefaultMutableTreeNode srcNode ) {
+		DefaultMutableTreeNode resultNode = (DefaultMutableTreeNode)srcNode.clone();
+
+		Enumeration enumer = srcNode.children();
+		while ( enumer.hasMoreElements() ) {
+			DefaultMutableTreeNode childNode = (DefaultMutableTreeNode)enumer.nextElement();
+			resultNode.add( cloneNodes( (DefaultMutableTreeNode)childNode ) );
+		}
+
+		return resultNode;
+	}
+
+
+	/**
+	 * Drag and drop TreePath data, constructed with a raw object
+	 * from a drag source, to be transformed into a flavor
+	 * suitable for the drop target.
+	 */
+	private class TreePathTransferrable implements Transferable {
+		private TreePath[] data;
+
+		public TreePathTransferrable( TreePath[] data ) {
+			this.data = data;
+		}
+
+		@Override
+		public Object getTransferData( DataFlavor flavor ) {
+			if ( flavor.equals( localTreePathFlavor ) ) {
+				return data;
+			}
+			return null;
+		}
+
+		@Override
+		public DataFlavor[] getTransferDataFlavors() {
+			return new DataFlavor[] {localTreePathFlavor};
+		}
+
+		@Override
+		public boolean isDataFlavorSupported( DataFlavor flavor ) {
+			return flavor.equals( localTreePathFlavor );
+		}
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/TristateButtonModel.java b/src/main/java/net/vhati/modmanager/ui/tree/TristateButtonModel.java
new file mode 100644
index 0000000..4817243
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/TristateButtonModel.java
@@ -0,0 +1,105 @@
+/**
+ * Copied from "TristateCheckBox Revisited" (2007-05-25)
+ * By Dr. Heinz M. Kabutz
+ * http://www.javaspecialists.co.za/archive/Issue145.html
+ */
+
+package net.vhati.modmanager.ui.tree;
+
+import java.awt.event.ItemEvent;
+import javax.swing.JToggleButton.ToggleButtonModel;
+
+
+public class TristateButtonModel extends ToggleButtonModel {
+
+  private TristateState state = TristateState.DESELECTED;
+
+
+	public TristateButtonModel( TristateState state ) {
+		setState( state );
+	}
+
+	public TristateButtonModel() {
+		this( TristateState.DESELECTED );
+	}
+
+
+	public void setIndeterminate() {
+		setState( TristateState.INDETERMINATE );
+	}
+
+	public boolean isIndeterminate() {
+		return ( state == TristateState.INDETERMINATE );
+	}
+
+
+	@Override
+	public void setEnabled( boolean enabled ) {
+		super.setEnabled(enabled);
+		// Restore state display.
+		displayState();
+	}
+
+	@Override
+	public void setSelected( boolean selected ) {
+		setState( selected ? TristateState.SELECTED : TristateState.DESELECTED );
+	}
+
+	@Override
+	public void setArmed( boolean b ) {
+	}
+
+	@Override
+	public void setPressed( boolean b ) {
+	}
+
+
+	public void iterateState() {
+		setState( state.next() );
+	}
+
+	public void setState( TristateState state ) {
+		this.state = state;
+		displayState();
+		if ( state == TristateState.INDETERMINATE && isEnabled() ) {
+			// Send ChangeEvent.
+			fireStateChanged();
+
+			// Send ItemEvent.
+			int indeterminate = 3;
+			fireItemStateChanged(new ItemEvent( this, ItemEvent.ITEM_STATE_CHANGED, this, indeterminate ));
+		}
+	}
+
+	private void displayState() {
+		super.setSelected( state != TristateState.DESELECTED );
+		super.setArmed( state == TristateState.INDETERMINATE );
+		super.setPressed( state == TristateState.INDETERMINATE );
+	}
+
+	public TristateState getState() {
+		return state;
+	}
+
+
+
+	public static enum TristateState {
+		SELECTED {
+			public TristateState next() {
+				return INDETERMINATE;
+			}
+		},
+		INDETERMINATE {
+			public TristateState next() {
+				return DESELECTED;
+			}
+		},
+		DESELECTED {
+			public TristateState next() {
+				return SELECTED;
+			}
+		};
+
+		public abstract TristateState next();
+	}
+}
diff --git a/src/main/java/net/vhati/modmanager/ui/tree/TristateCheckBox.java b/src/main/java/net/vhati/modmanager/ui/tree/TristateCheckBox.java
new file mode 100644
index 0000000..95a4395
--- /dev/null
+++ b/src/main/java/net/vhati/modmanager/ui/tree/TristateCheckBox.java
@@ -0,0 +1,142 @@
+/*
+ * Based on "TristateCheckBox Revisited" (2007-05-25)
+ * By Dr. Heinz M. Kabutz
+ * http://www.javaspecialists.co.za/archive/Issue145.html
+ */
+
+package net.vhati.modmanager.ui.tree;
+
+import java.awt.AWTEvent;
+import java.awt.EventQueue;
+import java.awt.event.ActionEvent;
+import java.awt.event.InputEvent;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseListener;
+import javax.swing.AbstractAction;
+import javax.swing.ActionMap;
+import javax.swing.ButtonModel;
+import javax.swing.Icon;
+import javax.swing.JCheckBox;
+import javax.swing.SwingUtilities;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+import javax.swing.plaf.ActionMapUIResource;
+
+import net.vhati.modmanager.ui.tree.TristateButtonModel;
+import net.vhati.modmanager.ui.tree.TristateButtonModel.TristateState;
+
+
+public class TristateCheckBox extends JCheckBox {
+
+	private final ChangeListener enableListener;
+
+
+	public TristateCheckBox( String text, Icon icon, TristateState initial ) {
+		super( text, icon );
+
+		setModel( new TristateButtonModel( initial ) );
+
+		enableListener = new ChangeListener() {
+			@Override
+			public void stateChanged( ChangeEvent e ) {
+				TristateCheckBox.this.setFocusable( TristateCheckBox.this.getModel().isEnabled() );
+			}
+		};
+
+		// Add a listener for when the mouse is pressed.
+		super.addMouseListener(new MouseAdapter() {
+			@Override
+			public void mousePressed( MouseEvent e ) {
+				TristateCheckBox.this.iterateState();
+			}
+		});
+
+		// Reset the keyboard action map.
+		ActionMap map = new ActionMapUIResource();
+		map.put( "pressed", new AbstractAction() {
+			@Override
+			public void actionPerformed( ActionEvent e ) {
+				TristateCheckBox.this.iterateState();
+			}
+		});
+		map.put( "released", null );
+		SwingUtilities.replaceUIActionMap( this, map );
+	}
+
+	public TristateCheckBox( String text, TristateState initial ) {
+		this( text, null, initial );
+	}
+
+	public TristateCheckBox( String text ) {
+		this( text, null );
+	}
+
+	public TristateCheckBox() {
+		this( null );
+	}
+
+
+	public void setIndeterminate() {
+		getTristateModel().setIndeterminate();
+	}
+
+	public boolean isIndeterminate() {
+		return getTristateModel().isIndeterminate();
+	}
+
+
+	public void setState( TristateState state ) {
+		getTristateModel().setState( state );
+	}
+
+	public TristateState getState() {
+		return getTristateModel().getState();
+	}
+
+
+	@Override
+	public void setModel( ButtonModel newModel ) {
+		super.setModel( newModel );
+
+		// Listen for enable changes.
+		if ( model instanceof TristateButtonModel ) {
+			model.addChangeListener( enableListener );
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	public TristateButtonModel getTristateModel() {
+		return (TristateButtonModel)super.getModel();
+	}
+
+
+	/**
+	 * No one may add mouse listeners, not even Swing!
+	 */
+	@Override
+	public void addMouseListener( MouseListener l ) {
+	}
+
+
+  private void iterateState() {
+		// Maybe do nothing at all?
+		if ( !super.getModel().isEnabled() ) return;
+
+		this.grabFocus();
+
+		// Iterate state.
+		getTristateModel().iterateState();
+
+		// Fire ActionEvent.
+		int modifiers = 0;
+		AWTEvent currentEvent = EventQueue.getCurrentEvent();
+		if ( currentEvent instanceof InputEvent ) {
+			modifiers = ((InputEvent)currentEvent).getModifiers();
+		}
+		else if ( currentEvent instanceof ActionEvent ) {
+			modifiers = ((ActionEvent)currentEvent).getModifiers();
+		}
+		fireActionPerformed(new ActionEvent( this, ActionEvent.ACTION_PERFORMED, this.getText(), System.currentTimeMillis(), modifiers ));
+	}
+}