AbstractUndoableEdit.java   [plain text]

/* AbstractTableModel.java --
   Copyright (C) 2002 Free Software Foundation, Inc.

This file is part of GNU Classpath.

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package javax.swing.undo;

// Imports
import java.io.Serializable;

/**
 * AbstractUndoableEdit
 * @author Andrew Selkirk
 */
public class AbstractUndoableEdit	extends		Object
									implements	UndoableEdit,
												Serializable {

	//-------------------------------------------------------------
	// Constants --------------------------------------------------
	//-------------------------------------------------------------

	/**
	 * String returned by getRedoPresentationName()
	 */
	protected static	String	RedoName	= "Redo";

	/**
	 * String returned by getUndoPresentationName()
	 */
	protected static	String	UndoName	= "Undo";


	//-------------------------------------------------------------
	// Variables --------------------------------------------------
	//-------------------------------------------------------------

	/**
	 * TODO
	 */
	private 			boolean	hasBeenDone	= false;

	/**
	 * The edit is alive
	 */
	private				boolean	alive 		= true;


	//-------------------------------------------------------------
	// Initialization ---------------------------------------------
	//-------------------------------------------------------------

	/**
	 * Create new AbstractUndoableEdit
	 */
	public AbstractUndoableEdit() {
	} // AbstractUndoableEdit()


	//-------------------------------------------------------------
	// Interface: UndoableEdit ------------------------------------
	//-------------------------------------------------------------

	/**
	 * addEdit
	 * @param anEdit TODO
	 * @returns TODO
	 */
	public boolean addEdit(UndoableEdit anEdit) {
		return false;
	} // addEdit()

	/**
	 * canRedo()
	 * @returns true if redoable, false otherwise
	 */
	public boolean canRedo() {
		if (alive == true && hasBeenDone == false) {
			return true;
		} // if
		return false;
	} // canRedo()

	/**
	 * canUndo()
	 * @returns true if undoable, false otherwise
	 */
	public boolean canUndo() {
		if (alive == true && hasBeenDone == true) {
			return true;
		} // if
		return false;
	} // canUndo()

	/**
	 * die
	 */
	public void die() {
		alive = false;
	} // die()

	/**
	 * getPresentation
	 * @returns TODO
	 */
	public String getPresentationName() {
		return "";
	} // getPresentationName()

	/**
	 * getRedoPresentationName
	 * @returns TODO
	 */
	public String getRedoPresentationName()	{
		if (getPresentationName().equals("") == true) {
			return RedoName;
		} else {
			return RedoName + " " + getPresentationName();
		}
	} // getRedoPresentationName()

	/**
	 * getUndoPresentationName
	 * @returns TODO
	 */
	public String getUndoPresentationName()	{
		if (getPresentationName().equals("") == true) {
			return UndoName;
		} else {
			return UndoName + " " + getPresentationName();
		}
	} // getUndoPresentationName()

	/**
	 * isSignificant
	 * @returns true
	 */
	public boolean isSignificant() {
		return true;
	} // isSignificant()

	/**
	 * redo
	 * @throws CannotRedoException TODO
	 */
	public void redo() throws CannotRedoException {
		if (canRedo() == false) {
			throw new CannotRedoException();
		}
		hasBeenDone = true;
	} // redo()

	/**
	 * replaceEdit
	 * @param anEdit TODO
	 * @returns TODO
	 */
	public boolean replaceEdit(UndoableEdit anEdit) {
		return false;
	} // replaceEdit()

	/**
	 * String representation
	 * @returns String representation
	 */
	public String toString() {
		return null; // TODO
	} // toString()

	/**
	 * undo
	 * @throws CannotUndoException TODO
	 */
	public void undo() throws CannotUndoException {
		if (canUndo() == false) {
			throw new CannotUndoException();
		}
		hasBeenDone = false;
	} // undo()


} // AbstractUndoableEdit