@Override
public Task prepareDocument() {
Task task = super.prepareDocument();
// Avoid listening to the same task more than once.
if (task != prepareTask2) {
prepareTask2 = task;
task.addTaskListener(
new TaskListener() {
public void taskFinished(Task task) {
QuietUndoManager undo = getUndoManager();
StyledDocument doc = getDocument();
synchronized (undo) {
// Now that the document is ready, pass it to the manager.
undo.setDocument((AbstractDocument) doc);
if (!undo.isCompound()) {
// The superclass prepareDocument() adds the undo/redo
// manager as a listener -- we need to remove it since
// we will initially listen to the model instead.
doc.removeUndoableEditListener(undo);
// If not listening to document, then listen to model.
addUndoManagerToModel(undo);
}
}
prepareTask2 = null;
}
});
}
return task;
}
@Override
public Task reloadDocument() {
Task task = super.reloadDocument();
task.addTaskListener(
new TaskListener() {
public void taskFinished(Task task) {
EventQueue.invokeLater(
new Runnable() {
public void run() {
QuietUndoManager undo = getUndoManager();
StyledDocument doc = getDocument();
// The superclass reloadDocument() adds the undo
// manager as an undoable edit listener.
synchronized (undo) {
if (!undo.isCompound()) {
doc.removeUndoableEditListener(undo);
}
}
}
});
}
});
return task;
}