Also see:

javax.swing.UIDefaults

Also see:

javax.swing.UIDefaults

 public AbstractUndoableEdit() 
{
                   
        super();
        hasBeenDone = true;
        alive = true;
}

Creates an AbstractUndoableEdit which defaults hasBeenDone and alive to true.

 public boolean addEdit(UndoableEdit anEdit) 
{
        return false;
}

This default implementation returns false.

 public boolean canRedo() 
{
        return alive && !hasBeenDone;
}

Returns true if this edit is alive and hasBeenDone is false.

 public boolean canUndo() 
{
        return alive && hasBeenDone;
}

Returns true if this edit is alive and hasBeenDone is true.

 public  void die() 
{
        alive = false;
}

Sets alive to false. Note that this is a one way operation; dead edits cannot be resurrected. Sending undo or redo to a dead edit results in an exception being thrown.

Typically an edit is killed when it is consolidated by another edit's addEdit or replaceEdit method, or when it is dequeued from an UndoManager.

 public String getPresentationName() 
{
        return "";
}

This default implementation returns "". Used by getUndoPresentationName and getRedoPresentationName to construct the strings they return. Subclasses should override to return an appropriate description of the operation this edit represents.

 public String getRedoPresentationName() 
{
        String name = getPresentationName();
        if (!"".equals(name)) {
            name = UIManager.getString("AbstractUndoableEdit.redoText") +
                " " + name;
        } else {
            name = UIManager.getString("AbstractUndoableEdit.redoText");
        }
        return name;
}

Retreives the value from the defaults table with key AbstractUndoableEdit.redoText and returns that value followed by a space, followed by getPresentationName. If getPresentationName returns "", then the defaults value is returned alone.

 public String getUndoPresentationName() 
{
        String name = getPresentationName();
        if (!"".equals(name)) {
            name = UIManager.getString("AbstractUndoableEdit.undoText") +
                " " + name;
        } else {
            name = UIManager.getString("AbstractUndoableEdit.undoText");
        }
        return name;
}

Retreives the value from the defaults table with key AbstractUndoableEdit.undoText and returns that value followed by a space, followed by getPresentationName. If getPresentationName returns "", then the defaults value is returned alone.

 public boolean isSignificant() 
{
        return true;
}

This default implementation returns true.

 public  void redo() throws CannotRedoException 
{
        if (!canRedo()) {
            throw new CannotRedoException();
        }
        hasBeenDone = true;
}

Throws CannotRedoException if canRedo returns false. Sets hasBeenDone to true. Subclasses should override to redo the operation represented by this edit. Override should begin with a call to super.

 public boolean replaceEdit(UndoableEdit anEdit) 
{
        return false;
}

This default implementation returns false.

 public String toString() 
{
        return super.toString()
            + " hasBeenDone: " + hasBeenDone
            + " alive: " + alive;
}

Returns a string that displays and identifies this object's properties.

 public  void undo() throws CannotUndoException 
{
        if (!canUndo()) {
            throw new CannotUndoException();
        }
        hasBeenDone = false;
}

Throws CannotUndoException if canUndo returns false. Sets hasBeenDone to false. Subclasses should override to undo the operation represented by this edit. Override should begin with a call to super.