/*
* Copyright (C) 2010 Markus Echterhoff <tam@edu.uni-klu.ac.at>
*
* This file is part of EvoPaint.
*
* EvoPaint is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with EvoPaint. If not, see <http://www.gnu.org/licenses/>.
*/
package evopaint.gui.util;
import evopaint.pixel.rulebased.RuleSetCollection;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import javax.swing.DropMode;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.TransferHandler;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;
/**
* @author Craig Wood (http://www.coderanch.com/t/346509/Swing-AWT-SWT-JFace/java/JTree-drag-drop-inside-one)
* @author Markus Echterhoff <tam@edu.uni-klu.ac.at>
*/
public class DragDropTree extends JTree {
public DragDropTree() {
setDragEnabled(true);
setDropMode(DropMode.ON);
setTransferHandler(new TreeTransferHandler());
getSelectionModel().setSelectionMode(
TreeSelectionModel.CONTIGUOUS_TREE_SELECTION);
}
private JScrollPane getContent() {
expandTree(this);
return new JScrollPane(this);
}
private void expandTree(JTree tree) {
DefaultMutableTreeNode root =
(DefaultMutableTreeNode) tree.getModel().getRoot();
Enumeration e = root.breadthFirstEnumeration();
while (e.hasMoreElements()) {
DefaultMutableTreeNode node =
(DefaultMutableTreeNode) e.nextElement();
if (node.isLeaf()) {
continue;
}
int row = tree.getRowForPath(new TreePath(node.getPath()));
tree.expandRow(row);
}
}
public static void main(String[] args) {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new DragDropTree().getContent());
f.setSize(400, 400);
f.setLocation(200, 200);
f.setVisible(true);
}
}
class TreeTransferHandler extends TransferHandler {
DataFlavor nodesFlavor;
DataFlavor[] flavors = new DataFlavor[1];
DefaultMutableTreeNode[] nodesToRemove;
public TreeTransferHandler() {
try {
String mimeType = DataFlavor.javaJVMLocalObjectMimeType
+ ";class=\""
+ javax.swing.tree.DefaultMutableTreeNode[].class.getName()
+ "\"";
nodesFlavor = new DataFlavor(mimeType);
flavors[0] = nodesFlavor;
} catch (ClassNotFoundException e) {
System.out.println("ClassNotFound: " + e.getMessage());
}
}
public boolean canImport(TransferHandler.TransferSupport support) {
if (!support.isDrop()) {
return false;
}
support.setShowDropLocation(true);
if (!support.isDataFlavorSupported(nodesFlavor)) {
return false;
}
// Do not allow a drop on the drag source selections.
JTree.DropLocation dl =
(JTree.DropLocation) support.getDropLocation();
JTree tree = (JTree) support.getComponent();
//int dropRow = tree.getRowForPath(dl.getPath());
//int[] selRows = tree.getSelectionRows();
//for (int i = 0; i < selRows.length; i++) {
// if (selRows[i] == dropRow) {
// return false;
// }
// }
// forbid moving collection nodes because they will be reordered on
// restart anyways
TreePath dest = dl.getPath();
DefaultMutableTreeNode target =
(DefaultMutableTreeNode) dest.getLastPathComponent();
if (((DefaultMutableTreeNode)tree.getSelectionPath().getLastPathComponent()).getAllowsChildren()) {
return false;
}
// and forbid rule set nodes to be moved onto anything but collection nodes
if (false == ((DefaultMutableTreeNode)tree.getSelectionPath().getLastPathComponent()).getAllowsChildren() &&
false == target.getUserObject() instanceof RuleSetCollection) {
return false;
}
// Do not allow MOVE-action drops if a non-leaf node is
// selected unless all of its children are also selected.
//int action = support.getDropAction();
// if (action == MOVE) {
// return haveCompleteNode(tree);
//}
// Do not allow a non-leaf node to be copied to a level
// which is less than its source level.
// TreePath path = tree.getPathForRow(selRows[0]);
// DefaultMutableTreeNode firstNode =
// (DefaultMutableTreeNode) path.getLastPathComponent();
// if (firstNode.getChildCount() > 0
// && target.getLevel() < firstNode.getLevel()) {
// return false;
// }
return true;
}
private boolean haveCompleteNode(JTree tree) {
int[] selRows = tree.getSelectionRows();
TreePath path = tree.getPathForRow(selRows[0]);
DefaultMutableTreeNode first =
(DefaultMutableTreeNode) path.getLastPathComponent();
int childCount = first.getChildCount();
// first has children and no children are selected.
if (childCount > 0 && selRows.length == 1) {
return false;
}
// first may have children.
for (int i = 1; i < selRows.length; i++) {
path = tree.getPathForRow(selRows[i]);
DefaultMutableTreeNode next =
(DefaultMutableTreeNode) path.getLastPathComponent();
if (first.isNodeChild(next)) {
// Found a child of first.
if (childCount > selRows.length - 1) {
// Not all children of first are selected.
return false;
}
}
}
return true;
}
protected Transferable createTransferable(JComponent c) {
JTree tree = (JTree) c;
TreePath[] paths = tree.getSelectionPaths();
if (paths != null) {
// Make up a node array of copies for transfer and
// another for/of the nodes that will be removed in
// exportDone after a successful drop.
List<DefaultMutableTreeNode> copies =
new ArrayList<DefaultMutableTreeNode>();
List<DefaultMutableTreeNode> toRemove =
new ArrayList<DefaultMutableTreeNode>();
DefaultMutableTreeNode node =
(DefaultMutableTreeNode) paths[0].getLastPathComponent();
DefaultMutableTreeNode copy = copy(node);
copies.add(copy);
toRemove.add(node);
for (int i = 1; i < paths.length; i++) {
DefaultMutableTreeNode next =
(DefaultMutableTreeNode) paths[i].getLastPathComponent();
// Do not allow higher level nodes to be added to list.
if (next.getLevel() < node.getLevel()) {
break;
} else if (next.getLevel() > node.getLevel()) { // child node
copy.add(copy(next));
// node already contains child
} else { // sibling
copies.add(copy(next));
toRemove.add(next);
}
}
DefaultMutableTreeNode[] nodes =
copies.toArray(new DefaultMutableTreeNode[copies.size()]);
nodesToRemove =
toRemove.toArray(new DefaultMutableTreeNode[toRemove.size()]);
return new NodesTransferable(nodes);
}
return null;
}
/** Defensive copy used in createTransferable. */
private DefaultMutableTreeNode copy(DefaultMutableTreeNode node) {
return new DefaultMutableTreeNode(node.getUserObject(), node.getAllowsChildren());
}
protected void exportDone(JComponent source, Transferable data, int action) {
if ((action & MOVE) == MOVE) {
JTree tree = (JTree) source;
DefaultTreeModel model = (DefaultTreeModel) tree.getModel();
// Remove nodes saved in nodesToRemove in createTransferable.
for (int i = 0; i < nodesToRemove.length; i++) {
model.removeNodeFromParent(nodesToRemove[i]);
}
}
}
public int getSourceActions(JComponent c) {
return MOVE;
}
public boolean importData(TransferHandler.TransferSupport support) {
if (!canImport(support)) {
return false;
}
// Extract transfer data.
DefaultMutableTreeNode[] nodes = null;
try {
Transferable t = support.getTransferable();
nodes = (DefaultMutableTreeNode[]) t.getTransferData(nodesFlavor);
} catch (UnsupportedFlavorException ufe) {
System.out.println("UnsupportedFlavor: " + ufe.getMessage());
} catch (java.io.IOException ioe) {
System.out.println("I/O error: " + ioe.getMessage());
}
// Get drop location info.
JTree.DropLocation dl =
(JTree.DropLocation) support.getDropLocation();
int childIndex = dl.getChildIndex();
TreePath dest = dl.getPath();
DefaultMutableTreeNode parent =
(DefaultMutableTreeNode) dest.getLastPathComponent();
JTree tree = (JTree) support.getComponent();
DefaultTreeModel model = (DefaultTreeModel) tree.getModel();
// Configure for drop mode.
int index = childIndex; // DropMode.INSERT
if (childIndex == -1) { // DropMode.ON
index = parent.getChildCount();
}
// Add data to model.
for (int i = 0; i < nodes.length; i++) {
model.insertNodeInto(nodes[i], parent, index++);
}
return true;
}
public String toString() {
return getClass().getName();
}
public class NodesTransferable implements Transferable {
DefaultMutableTreeNode[] nodes;
public NodesTransferable(DefaultMutableTreeNode[] nodes) {
this.nodes = nodes;
}
public Object getTransferData(DataFlavor flavor)
throws UnsupportedFlavorException {
if (!isDataFlavorSupported(flavor)) {
throw new UnsupportedFlavorException(flavor);
}
return nodes;
}
public DataFlavor[] getTransferDataFlavors() {
return flavors;
}
public boolean isDataFlavorSupported(DataFlavor flavor) {
return nodesFlavor.equals(flavor);
}
}
}