/* Toolkit.java -- AWT Toolkit superclass   Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005   Free Software Foundation, Inc.This file is part of GNU Classpath.GNU Classpath is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2, or (at your option)any later version.GNU Classpath is distributed in the hope that it will be useful, butWITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNUGeneral Public License for more details.You should have received a copy of the GNU General Public Licensealong with GNU Classpath; see the file COPYING.  If not, write to theFree Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA02110-1301 USA.Linking this library statically or dynamically with other modules ismaking a combined work based on this library.  Thus, the terms andconditions of the GNU General Public License cover the wholecombination.As a special exception, the copyright holders of this library give youpermission to link this library with independent modules to produce anexecutable, regardless of the license terms of these independentmodules, and to copy and distribute the resulting executable underterms of your choice, provided that you also meet, for each linkedindependent module, the terms and conditions of the license of thatmodule.  An independent module is a module which is not derived fromor based on this library.  If you modify this library, you may extendthis exception to your version of the library, but you are notobligated to do so.  If you do not wish to do so, delete thisexception statement from your version. */package java.awt;import java.awt.datatransfer.Clipboard;import java.awt.dnd.DragGestureEvent;import java.awt.dnd.DragGestureListener;import java.awt.dnd.DragGestureRecognizer;import java.awt.dnd.DragSource;import java.awt.dnd.peer.DragSourceContextPeer;import java.awt.event.AWTEventListener;import java.awt.event.KeyEvent;import java.awt.im.InputMethodHighlight;import java.awt.image.ColorModel;import java.awt.image.ImageObserver;import java.awt.image.ImageProducer;import java.awt.peer.ButtonPeer;import java.awt.peer.CanvasPeer;import java.awt.peer.CheckboxMenuItemPeer;import java.awt.peer.CheckboxPeer;import java.awt.peer.ChoicePeer;import java.awt.peer.DialogPeer;import java.awt.peer.FileDialogPeer;import java.awt.peer.FontPeer;import java.awt.peer.FramePeer;import java.awt.peer.LabelPeer;import java.awt.peer.LightweightPeer;import java.awt.peer.ListPeer;import java.awt.peer.MenuBarPeer;import java.awt.peer.MenuItemPeer;import java.awt.peer.MenuPeer;import java.awt.peer.PanelPeer;import java.awt.peer.PopupMenuPeer;import java.awt.peer.ScrollPanePeer;import java.awt.peer.ScrollbarPeer;import java.awt.peer.TextAreaPeer;import java.awt.peer.TextFieldPeer;import java.awt.peer.WindowPeer;import java.beans.PropertyChangeListener;import java.beans.PropertyChangeSupport;import java.net.URL;import java.util.Map;import java.util.Properties;/** * The AWT system uses a set of native peer objects to implement its * widgets.  These peers are provided by a peer toolkit, that is accessed * via a subclass of this superclass.  The system toolkit is retrieved * by the static methods <code>getDefaultToolkit</code>.  This method * determines the system toolkit by examining the system property * <code>awt.toolkit</code>.  That property is set to the name of the * <code>Toolkit</code> subclass for the specified peer set.  If the * <code>awt.toolkit</code> property is not set, then the default * toolkit <code>gnu.java.awt.peer.gtk.GtkToolkit</code> is used.  This * toolkit creates its peers using the GTK+ toolkit. * * @author Aaron M. Renn (arenn@urbanophile.com) */public abstract class Toolkit{  /** The default toolkit name. */  private static String default_toolkit_name    = gnu.classpath.Configuration.default_awt_peer_toolkit;  /**   * The toolkit in use.  Once we load it, we don't ever change it   * if the awt.toolkit property is set.   */  private static Toolkit toolkit;  /** The toolkit properties. */  private static Properties props = new Properties();  protected final Map desktopProperties = new Properties();  protected final PropertyChangeSupport desktopPropsSupport    = new PropertyChangeSupport(this);  /**   * Default constructor for subclasses.   */  public Toolkit()  {  }  /**   * Creates a peer object for the specified <code>Button</code>.   *   * @param target The <code>Button</code> to create the peer for.   *    * @return The peer for the specified <code>Button</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract ButtonPeer createButton(Button target);  /**   * Creates a peer object for the specified <code>TextField</code>.   *   * @param target The <code>TextField</code> to create the peer for.   *   * @return The peer for the specified <code>TextField</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract TextFieldPeer createTextField(TextField target);  /**   * Creates a peer object for the specified <code>Label</code>.   *   * @param target The <code>Label</code> to create the peer for.   *   * @return The peer for the specified <code>Label</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract LabelPeer createLabel(Label target);  /**   * Creates a peer object for the specified <code>List</code>.   *   * @param target The <code>List</code> to create the peer for.   *   * @return The peer for the specified <code>List</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract ListPeer createList(List target);  /**   * Creates a peer object for the specified <code>Checkbox</code>.   *   * @param target The <code>Checkbox</code> to create the peer for.   *   * @return The peer for the specified <code>Checkbox</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract CheckboxPeer createCheckbox(Checkbox target);  /**   * Creates a peer object for the specified <code>Scrollbar</code>.   *   * @param target The <code>Scrollbar</code> to create the peer for.   *   * @return The peer for the specified <code>Scrollbar</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract ScrollbarPeer createScrollbar(Scrollbar target);  /**   * Creates a peer object for the specified <code>ScrollPane</code>.   *   * @param target The <code>ScrollPane</code> to create the peer for.   *   * @return The peer for the specified <code>ScrollPane</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract ScrollPanePeer createScrollPane(ScrollPane target);  /**   * Creates a peer object for the specified <code>TextArea</code>.   *   * @param target The <code>TextArea</code> to create the peer for.   *   * @return The peer for the specified <code>TextArea</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract TextAreaPeer createTextArea(TextArea target);  /**   * Creates a peer object for the specified <code>Choice</code>.   *   * @param target The <code>Choice</code> to create the peer for.   *   * @return The peer for the specified <code>Choice</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract ChoicePeer createChoice(Choice target);  /**   * Creates a peer object for the specified <code>Frame</code>.   *   * @param target The <code>Frame</code> to create the peer for.   *   * @return The peer for the specified <code>Frame</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract FramePeer createFrame(Frame target);  /**   * Creates a peer object for the specified <code>Canvas</code>.   *   * @param target The <code>Canvas</code> to create the peer for.   *   * @return The peer for the specified <code>Canvas</code> object.   */  protected abstract CanvasPeer createCanvas(Canvas target);  /**   * Creates a peer object for the specified <code>Panel</code>.   *   * @param target The <code>Panel</code> to create the peer for.   *   * @return The peer for the specified <code>Panel</code> object.   */  protected abstract PanelPeer createPanel(Panel target);  /**   * Creates a peer object for the specified <code>Window</code>.   *   * @param target The <code>Window</code> to create the peer for.   *   * @return The peer for the specified <code>Window</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract WindowPeer createWindow(Window target);  /**   * Creates a peer object for the specified <code>Dialog</code>.   *   * @param target The dialog to create the peer for   *   * @return The peer for the specified font name.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract DialogPeer createDialog(Dialog target);  /**   * Creates a peer object for the specified <code>MenuBar</code>.   *   * @param target The <code>MenuBar</code> to create the peer for.   *   * @return The peer for the specified <code>MenuBar</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract MenuBarPeer createMenuBar(MenuBar target);  /**   * Creates a peer object for the specified <code>Menu</code>.   *   * @param target The <code>Menu</code> to create the peer for.   *   * @return The peer for the specified <code>Menu</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract MenuPeer createMenu(Menu target);  /**   * Creates a peer object for the specified <code>PopupMenu</code>.   *   * @param target The <code>PopupMenu</code> to create the peer for.   *   * @return The peer for the specified <code>PopupMenu</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract PopupMenuPeer createPopupMenu(PopupMenu target);  /**   * Creates a peer object for the specified <code>MenuItem</code>.   *   * @param target The <code>MenuItem</code> to create the peer for.   *   * @return The peer for the specified <code>MenuItem</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract MenuItemPeer createMenuItem(MenuItem target);  /**   * Creates a peer object for the specified <code>FileDialog</code>.   *   * @param target The <code>FileDialog</code> to create the peer for.   *   * @return The peer for the specified <code>FileDialog</code> object.   *   * @exception HeadlessException If GraphicsEnvironment.isHeadless() is true.   */  protected abstract FileDialogPeer createFileDialog(FileDialog target);  /**   * Creates a peer object for the specified <code>CheckboxMenuItem</code>.   *   * @param target The <code>CheckboxMenuItem</code> to create the peer for.   *   * @return The peer for the specified <code>CheckboxMenuItem</code> object.   *