Subversion Repositories openrisc

/* BasicPanelUI.java

   Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the 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, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with GNU Classpath; see the file COPYING.  If not, write to the

Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301 USA.

Linking this library statically or dynamically with other modules is

making a combined work based on this library.  Thus, the terms and

conditions of the GNU General Public License cover the whole

combination.

As a special exception, the copyright holders of this library give you

permission to link this library with independent modules to produce an

executable, regardless of the license terms of these independent

modules, and to copy and distribute the resulting executable under

terms of your choice, provided that you also meet, for each linked

independent module, the terms and conditions of the license of that

module.  An independent module is a module which is not derived from

or based on this library.  If you modify this library, you may extend

this exception to your version of the library, but you are not

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package javax.swing.plaf.basic;

import javax.swing.JComponent;

import javax.swing.JPanel;

import javax.swing.LookAndFeel;

import javax.swing.plaf.ComponentUI;

import javax.swing.plaf.PanelUI;

/**

 * A UI delegate for the {@link JPanel} component.

 */

public class BasicPanelUI extends PanelUI

{

  /**

   * A UI delegate that can be shared by all panels (because the delegate is

   * stateless).

   */

  static BasicPanelUI sharedUI;

  /**

   * Returns a UI delegate for the specified component.

   *

   * @param panel  the panel.

   */

  public static ComponentUI createUI(JComponent panel)

  {

    if (sharedUI == null)

      sharedUI = new BasicPanelUI();

    return sharedUI;

  }

  /**

   * Installs this UI delegate in the specified component.

   *

   * @param c  the component (should be a {@link JPanel}, <code>null</code> not

   *     permitted).

   */

  public void installUI(JComponent c)

  {

    super.installUI(c);

    if (c instanceof JPanel)

      {

        JPanel p = (JPanel) c;

        installDefaults(p);

      }

  }

  /**

   * Installs the defaults for this UI delegate in the specified panel.

   *

   * @param p  the panel (<code>null</code> not permitted).

   */

  protected void installDefaults(JPanel p)

  {

    LookAndFeel.installColorsAndFont(p, "Panel.background", "Panel.foreground",

                                     "Panel.font");

    // A test against the reference implementation shows that this method will

    // install a border if one is defined in the UIDefaults table (even though

    // the BasicLookAndFeel doesn't actually define a "Panel.border").  This

    // test was written after discovering that a null argument to

    // uninstallDefaults throws a NullPointerException in

    // LookAndFeel.uninstallBorder()...

    LookAndFeel.installBorder(p, "Panel.border");

  }

  /**

   * Uninstalls this UI delegate from the specified component.

   *

   * @param c the component (<code>null</code> not permitted).

   */

  public void uninstallUI(JComponent c)

  {

    uninstallDefaults((JPanel) c);

  }

  /**

   * Uninstalls the UI defaults for the specified panel.

   *

   * @param p  the panel (<code>null</code> not permitted).

   */

  protected void uninstallDefaults(JPanel p)

  {

    // Tests on the reference implementation showed this method:

    // (1) doesn't actually remove the installed colors and font installed

    //     by installDefaults(), it isn't necessary;

    // (2) throws a NullPointerException in LookAndFeel.uninstallBorder() if

    //     p is null.  Strangely, no border is installed by the

    //     BasicLookAndFeel - perhaps this is needed by another LAF?

    LookAndFeel.uninstallBorder(p);

  }

}