editor. This will update
* the tree accordingly.
*/
public void setEditor(JTextComponent editor) {
if (this.editor == editor) {
return;
}
if (this.editor != null) {
Document oldDoc = this.editor.getDocument();
oldDoc.removeDocumentListener(this);
this.editor.removePropertyChangeListener(this);
this.editor.removeCaretListener(this);
}
this.editor = editor;
if (editor == null) {
treeModel = null;
tree.setModel(null);
}
else {
Document newDoc = editor.getDocument();
newDoc.addDocumentListener(this);
editor.addPropertyChangeListener(this);
editor.addCaretListener(this);
treeModel = new ElementTreeModel(newDoc);
tree.setModel(treeModel);
}
}
// PropertyChangeListener
/**
* Invoked when a property changes. We are only interested in when the
* Document changes to reset the DocumentListener.
*/
public void propertyChange(PropertyChangeEvent e) {
if (e.getSource() == getEditor() &&
e.getPropertyName().equals("document")) {
JTextComponent editor = getEditor();
Document oldDoc = (Document)e.getOldValue();
Document newDoc = (Document)e.getNewValue();
// Reset the DocumentListener
oldDoc.removeDocumentListener(this);
newDoc.addDocumentListener(this);
// Recreate the TreeModel.
treeModel = new ElementTreeModel(newDoc);
tree.setModel(treeModel);
}
}
// DocumentListener
/**
* Gives notification that there was an insert into the document. The
* given range bounds the freshly inserted region.
*
* @param e the document event
*/
public void insertUpdate(DocumentEvent e) {
updateTree(e);
}
/**
* Gives notification that a portion of the document has been
* removed. The range is given in terms of what the view last
* saw (that is, before updating sticky positions).
*
* @param e the document event
*/
public void removeUpdate(DocumentEvent e) {
updateTree(e);
}
/**
* Gives notification that an attribute or set of attributes changed.
*
* @param e the document event
*/
public void changedUpdate(DocumentEvent e) {
updateTree(e);
}
// CaretListener
/**
* Messaged when the selection in the editor has changed. Will update
* the selection in the tree.
*/
public void caretUpdate(CaretEvent e) {
if(!updatingSelection) {
JTextComponent editor = getEditor();
int selBegin = Math.min(e.getDot(), e.getMark());
int end = Math.max(e.getDot(), e.getMark());
Vector paths = new Vector();
TreeModel model = getTreeModel();
Object root = model.getRoot();
int rootCount = model.getChildCount(root);
// Build an array of all the paths to all the character elements
// in the selection.
for(int counter = 0; counter < rootCount; counter++) {
int start = selBegin;
while(start <= end) {
TreePath path = getPathForIndex(start, root,
(Element)model.getChild(root, counter));
Element charElement = (Element)path.
getLastPathComponent();
paths.addElement(path);
if(start >= charElement.getEndOffset())
start++;
else
start = charElement.getEndOffset();
}
}
// If a path was found, select it (them).
int numPaths = paths.size();
if(numPaths > 0) {
TreePath[] pathArray = new TreePath[numPaths];
paths.copyInto(pathArray);
updatingSelection = true;
try {
getTree().setSelectionPaths(pathArray);
getTree().scrollPathToVisible(pathArray[0]);
}
finally {
updatingSelection = false;
}
}
}
}
// TreeSelectionListener
/**
* Called whenever the value of the selection changes.
* @param e the event that characterizes the change.
*/
public void valueChanged(TreeSelectionEvent e) {
JTree tree = getTree();
if(!updatingSelection && tree.getSelectionCount() == 1) {
TreePath selPath = tree.getSelectionPath();
Object lastPathComponent = selPath.getLastPathComponent();
if(!(lastPathComponent instanceof DefaultMutableTreeNode)) {
Element selElement = (Element)lastPathComponent;
updatingSelection = true;
try {
getEditor().select(selElement.getStartOffset(),
selElement.getEndOffset());
}
finally {
updatingSelection = false;
}
}
}
}
// Local methods
/**
* @return tree showing elements.
*/
protected JTree getTree() {
return tree;
}
/**
* @return JTextComponent showing elements for.
*/
protected JTextComponent getEditor() {
return editor;
}
/**
* @return TreeModel implementation used to represent the elements.
*/
public DefaultTreeModel getTreeModel() {
return treeModel;
}
/**
* Updates the tree based on the event type. This will invoke either
* updateTree with the root element, or handleChange.
*/
protected void updateTree(DocumentEvent event) {
updatingSelection = true;
try {
TreeModel model = getTreeModel();
Object root = model.getRoot();
for(int counter = model.getChildCount(root) - 1; counter >= 0;
counter--) {
updateTree(event, (Element)model.getChild(root, counter));
}
}
finally {
updatingSelection = false;
}
}
/**
* Creates TreeModelEvents based on the DocumentEvent and messages
* the treemodel. This recursively invokes this method with children
* elements.
* @param event indicates what elements in the tree hierarchy have
* changed.
* @param element Current element to check for changes against.
*/
protected void updateTree(DocumentEvent event, Element element) {
DocumentEvent.ElementChange ec = event.getChange(element);
if (ec != null) {
Element[] removed = ec.getChildrenRemoved();
Element[] added = ec.getChildrenAdded();
int startIndex = ec.getIndex();
// Check for removed.
if(removed != null && removed.length > 0) {
int[] indices = new int[removed.length];
for(int counter = 0; counter < removed.length; counter++) {
indices[counter] = startIndex + counter;
}
getTreeModel().nodesWereRemoved((TreeNode)element, indices,
removed);
}
// check for added
if(added != null && added.length > 0) {
int[] indices = new int[added.length];
for(int counter = 0; counter < added.length; counter++) {
indices[counter] = startIndex + counter;
}
getTreeModel().nodesWereInserted((TreeNode)element, indices);
}
}
if(!element.isLeaf()) {
int startIndex = element.getElementIndex
(event.getOffset());
int elementCount = element.getElementCount();
int endIndex = Math.min(elementCount - 1,
element.getElementIndex
(event.getOffset() + event.getLength()));
if(startIndex > 0 && startIndex < elementCount &&
element.getElement(startIndex).getStartOffset() ==
event.getOffset()) {
// Force checking the previous element.
startIndex--;
}
if(startIndex != -1 && endIndex != -1) {
for(int counter = startIndex; counter <= endIndex; counter++) {
updateTree(event, element.getElement(counter));
}
}
}
else {
// Element is a leaf, assume it changed
getTreeModel().nodeChanged((TreeNode)element);
}
}
/**
* Returns a TreePath to the element at position.
*/
protected TreePath getPathForIndex(int position, Object root,
Element rootElement) {
TreePath path = new TreePath(root);
Element child = rootElement.getElement
(rootElement.getElementIndex(position));
path = path.pathByAddingChild(rootElement);
path = path.pathByAddingChild(child);
while(!child.isLeaf()) {
child = child.getElement(child.getElementIndex(position));
path = path.pathByAddingChild(child);
}
return path;
}
/**
* ElementTreeModel is an implementation of TreeModel to handle displaying
* the Elements from a Document. AbstractDocument.AbstractElement is
* the default implementation used by the swing text package to implement
* Element, and it implements TreeNode. This makes it trivial to create
* a DefaultTreeModel rooted at a particular Element from the Document.
* Unfortunately each Document can have more than one root Element.
* Implying that to display all the root elements as a child of another
* root a fake node has be created. This class creates a fake node as
* the root with the children being the root elements of the Document
* (getRootElements).
* This subclasses DefaultTreeModel. The majority of the TreeModel * methods have been subclassed, primarily to special case the root. */ public static class ElementTreeModel extends DefaultTreeModel { protected Element[] rootElements; public ElementTreeModel(Document document) { super(new DefaultMutableTreeNode("root"), false); rootElements = document.getRootElements(); } /** * Returns the child of parent at index index in * the parent's child array. parent must be a node * previously obtained from this data source. This should * not return null if index is a valid index for * parent (that is index >= 0 && index * < getChildCount(parent)). * * @param parent a node in the tree, obtained from this data source * @return the child of parent at index index */ public Object getChild(Object parent, int index) { if(parent == root) return rootElements[index]; return super.getChild(parent, index); } /** * Returns the number of children of parent. Returns 0 * if the node is a leaf or if it has no children. * parent must be a node previously obtained from this * data source. * * @param parent a node in the tree, obtained from this data source * @return the number of children of the node parent */ public int getChildCount(Object parent) { if(parent == root) return rootElements.length; return super.getChildCount(parent); } /** * Returns true if node is a leaf. It is possible for * this method to return false even if node has no * children. A directory in a filesystem, for example, may * contain no files; the node representing the directory is * not a leaf, but it also has no children. * * @param node a node in the tree, obtained from this data source * @return true if node is a leaf */ public boolean isLeaf(Object node) { if(node == root) return false; return super.isLeaf(node); } /** * Returns the index of child in parent. */ public int getIndexOfChild(Object parent, Object child) { if(parent == root) { for(int counter = rootElements.length - 1; counter >= 0; counter--) { if(rootElements[counter] == child) return counter; } return -1; } return super.getIndexOfChild(parent, child); } /** * Invoke this method after you've changed how node is to be * represented in the tree. */ public void nodeChanged(TreeNode node) { if(listenerList != null && node != null) { TreeNode parent = node.getParent(); if(parent == null && node != root) { parent = root; } if(parent != null) { int anIndex = getIndexOfChild(parent, node); if(anIndex != -1) { int[] cIndexs = new int[1]; cIndexs[0] = anIndex; nodesChanged(parent, cIndexs); } } } } /** * Returns the path to a particluar node. This is recursive. */ protected TreeNode[] getPathToRoot(TreeNode aNode, int depth) { TreeNode[] retNodes; /* Check for null, in case someone passed in a null node, or they passed in an element that isn't rooted at root. */ if(aNode == null) { if(depth == 0) return null; else retNodes = new TreeNode[depth]; } else { depth++; if(aNode == root) retNodes = new TreeNode[depth]; else { TreeNode parent = aNode.getParent(); if(parent == null) parent = root; retNodes = getPathToRoot(parent, depth); } retNodes[retNodes.length - depth] = aNode; } return retNodes; } } }