jdk/src/share/classes/javax/swing/LookAndFeel.java
changeset 2 90ce3da70b43
child 3084 67ca55732362
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/swing/LookAndFeel.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,727 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.swing;
+
+import java.awt.Font;
+import java.awt.event.InputEvent;
+import java.awt.event.KeyEvent;
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.SystemColor;
+import java.awt.Toolkit;
+
+import javax.swing.text.*;
+import javax.swing.border.*;
+import javax.swing.plaf.*;
+
+import java.net.URL;
+import sun.swing.SwingUtilities2;
+import sun.swing.DefaultLayoutStyle;
+import sun.swing.ImageIconUIResource;
+
+import java.util.StringTokenizer;
+
+
+/**
+ * {@code LookAndFeel}, as the name implies, encapsulates a look and
+ * feel. Beyond installing a look and feel most developers never need to
+ * interact directly with {@code LookAndFeel}. In general only developers
+ * creating a custom look and feel need to concern themselves with this class.
+ * <p>
+ * Swing is built upon the foundation that each {@code JComponent}
+ * subclass has an implementation of a specific {@code ComponentUI}
+ * subclass. The {@code ComponentUI} is often referred to as "the ui",
+ * "component ui", or "look and feel delegate". The {@code ComponentUI}
+ * subclass is responsible for providing the look and feel specific
+ * functionality of the component. For example, {@code JTree} requires
+ * an implementation of the {@code ComponentUI} subclass {@code
+ * TreeUI}. The implementation of the specific {@code
+ * ComponentUI} subclass is provided by the {@code LookAndFeel}. Each
+ * {@code JComponent} subclass identifies the {@code ComponentUI}
+ * subclass it requires by way of the {@code JComponent} method {@code
+ * getUIClassID}.
+ * <p>
+ * Each {@code LookAndFeel} implementation must provide
+ * an implementation of the appropriate {@code ComponentUI} subclass by
+ * specifying a value for each of Swing's ui class ids in the {@code
+ * UIDefaults} object returned from {@code getDefaults}. For example,
+ * {@code BasicLookAndFeel} uses {@code BasicTreeUI} as the concrete
+ * implementation for {@code TreeUI}. This is accomplished by {@code
+ * BasicLookAndFeel} providing the key-value pair {@code
+ * "TreeUI"-"javax.swing.plaf.basic.BasicTreeUI"}, in the
+ * {@code UIDefaults} returned from {@code getDefaults}. Refer to
+ * {@link UIDefaults#getUI(JComponent)} for defails on how the implementation
+ * of the {@code ComponentUI} subclass is obtained.
+ * <p>
+ * When a {@code LookAndFeel} is installed the {@code UIManager} does
+ * not check that an entry exists for all ui class ids. As such,
+ * random exceptions will occur if the current look and feel has not
+ * provided a value for a particular ui class id and an instance of
+ * the {@code JComponent} subclass is created.
+ *
+ * <h2>Recommendations for Look and Feels</h2>
+ *
+ * As noted in {@code UIManager} each {@code LookAndFeel} has the opportunity
+ * to provide a set of defaults that are layered in with developer and
+ * system defaults. Some of Swing's components require the look and feel
+ * to provide a specific set of defaults. These are documented in the
+ * classes that require the specific default.
+ *
+ * <h3><a name="#defaultRecommendation">ComponentUIs and defaults</a></h2>
+ *
+ * All {@code ComponentUIs} typically need to set various properties
+ * on the {@code JComponent} the {@code ComponentUI} is providing the
+ * look and feel for. This is typically done when the {@code
+ * ComponentUI} is installed on the {@code JComponent}. Setting a
+ * property should only be done if the developer has not set the
+ * property. For non-primitive values it is recommended that the
+ * {@code ComponentUI} only change the property on the {@code
+ * JComponent} if the current value is {@code null} or implements
+ * {@code UIResource}. If the current value is {@code null} or
+ * implements {@code UIResource} it indicates the property has not
+ * been set by the developer, and the ui is free to change it.  For
+ * example, {@code BasicButtonUI.installDefaults} only changes the
+ * font on the {@code JButton} if the return value from {@code
+ * button.getFont()} is {@code null} or implements {@code
+ * UIResource}. On the other hand if {@code button.getFont()} returned
+ * a {@code non-null} value that did not implement {@code UIResource}
+ * then {@code BasicButtonUI.installDefaults} would not change the
+ * {@code JButton}'s font.
+ * <p>
+ * For primitive values, such as {@code opaque}, the method {@code
+ * installProperty} should be invoked.  {@code installProperty} only changes
+ * the correspoding property if the value has not been changed by the
+ * developer.
+ * <p>
+ * {@code ComponentUI} implementations should use the various install methods
+ * provided by this class as they handle the necessary checking and install
+ * the property using the recommended guidelines.
+ * <p>
+ * <h3><a name="exceptions"></a>Exceptions</h3>
+ *
+ * All of the install methods provided by {@code LookAndFeel} need to
+ * access the defaults if the value of the property being changed is
+ * {@code null} or a {@code UIResource}. For example, installing the
+ * font does the following:
+ * <pre>
+ *   JComponent c;
+ *   Font font = c.getFont();
+ *   if (font == null || (font instanceof UIResource)) {
+ *       c.setFont(UIManager.getFont("fontKey"));
+ *   }
+ * </pre>
+ * If the font is {@code null} or a {@code UIResource}, the
+ * defaults table is queried with the key {@code fontKey}. All of
+ * {@code UIDefault's} get methods throw a {@code
+ * NullPointerException} if passed in {@code null}. As such, unless
+ * otherwise noted each of the various install methods of {@code
+ * LookAndFeel} throw a {@code NullPointerException} if the current
+ * value is {@code null} or a {@code UIResource} and the supplied
+ * defaults key is {@code null}. In addition, unless otherwise specified
+ * all of the {@code install} methods throw a {@code NullPointerException} if
+ * a {@code null} component is passed in.
+ *
+ * @author Tom Ball
+ * @author Hans Muller
+ */
+public abstract class LookAndFeel
+{
+
+    /**
+     * Convenience method for setting a component's foreground
+     * and background color properties with values from the
+     * defaults.  The properties are only set if the current
+     * value is either {@code null} or a {@code UIResource}.
+     *
+     * @param c component to set the colors on
+     * @param defaultBgName key for the background
+     * @param defaultFgName key for the foreground
+     *
+     * @see #installColorsAndFont
+     * @see UIManager#getColor
+     * @throws NullPointerException as described in
+     *         <a href="#exceptions">exceptions</a>
+     */
+    public static void installColors(JComponent c,
+                                     String defaultBgName,
+                                     String defaultFgName)
+    {
+        Color bg = c.getBackground();
+        if (bg == null || bg instanceof UIResource) {
+            c.setBackground(UIManager.getColor(defaultBgName));
+        }
+
+        Color fg = c.getForeground();
+        if (fg == null || fg instanceof UIResource) {
+            c.setForeground(UIManager.getColor(defaultFgName));
+        }
+    }
+
+
+    /**
+     * Convenience method for setting a component's foreground,
+     * background and font properties with values from the
+     * defaults.  The properties are only set if the current
+     * value is either {@code null} or a {@code UIResource}.
+     *
+     * @param c component set to the colors and font on
+     * @param defaultBgName key for the background
+     * @param defaultFgName key for the foreground
+     * @param defaultFontName key for the font
+     * @throws NullPointerException as described in
+     *         <a href="#exceptions">exceptions</a>
+     *
+     * @see #installColors
+     * @see UIManager#getColor
+     * @see UIManager#getFont
+     */
+    public static void installColorsAndFont(JComponent c,
+                                         String defaultBgName,
+                                         String defaultFgName,
+                                         String defaultFontName) {
+        Font f = c.getFont();
+        if (f == null || f instanceof UIResource) {
+            c.setFont(UIManager.getFont(defaultFontName));
+        }
+
+        installColors(c, defaultBgName, defaultFgName);
+    }
+
+
+    /**
+     * Convenience method for setting a component's border property with
+     * a value from the defaults. The border is only set if the border is
+     * {@code null} or an instance of {@code UIResource}.
+     *
+     * @param c component to set the border on
+     * @param defaultBorderName key specifying the border
+     * @throws NullPointerException as described in
+     *         <a href="#exceptions">exceptions</a>
+     */
+    public static void installBorder(JComponent c, String defaultBorderName) {
+        Border b = c.getBorder();
+        if (b == null || b instanceof UIResource) {
+            c.setBorder(UIManager.getBorder(defaultBorderName));
+        }
+    }
+
+
+    /**
+     * Convenience method for uninstalling a border. If the border of
+     * the component is a {@code UIResource}, it is set to {@code
+     * null}.
+     *
+     * @param c component to uninstall the border on
+     * @throws NullPointerException if {@code c} is {@code null}
+     */
+    public static void uninstallBorder(JComponent c) {
+        if (c.getBorder() instanceof UIResource) {
+            c.setBorder(null);
+        }
+    }
+
+    /**
+     * Convenience method for installing a property with the specified name
+     * and value on a component if that property has not already been set
+     * by the developer.  This method is intended to be used by
+     * ui delegate instances that need to specify a default value for a
+     * property of primitive type (boolean, int, ..), but do not wish
+     * to override a value set by the client.  Since primitive property
+     * values cannot be wrapped with the {@code UIResource} marker, this method
+     * uses private state to determine whether the property has been set
+     * by the client.
+     *
+     * @throws IllegalArgumentException if the specified property is not
+     *         one which can be set using this method
+     * @throws ClassCastException if the property value has not been set
+     *         by the developer and the type does not match the property's type
+     * @throws NullPointerException if {@code c} is {@code null}, or the
+     *         named property has not been set by the developer and
+     *         {@code propertyValue} is {@code null}
+     * @param c target component to set the property on
+     * @param propertyName name of the property to set
+     * @param propertyValue value of the property
+     * @since 1.5
+     */
+    public static void installProperty(JComponent c,
+                                       String propertyName, Object propertyValue) {
+        // this is a special case because the JPasswordField's ancestor heirarchy
+        // includes a class outside of javax.swing, thus we cannot call setUIProperty
+        // directly.
+        if (c instanceof JPasswordField) {
+            if (!((JPasswordField)c).customSetUIProperty(propertyName, propertyValue)) {
+                c.setUIProperty(propertyName, propertyValue);
+            }
+        } else {
+            c.setUIProperty(propertyName, propertyValue);
+        }
+    }
+
+    /**
+     * Convenience method for building an array of {@code
+     * KeyBindings}. While this method is not deprecated, developers
+     * should instead use {@code ActionMap} and {@code InputMap} for
+     * supplying key bindings.
+     * <p>
+     * This method returns an array of {@code KeyBindings}, one for each
+     * alternating {@code key-action} pair in {@code keyBindingList}.
+     * A {@code key} can either be a {@code String} in the format
+     * specified by the <code>KeyStroke.getKeyStroke</code> method, or
+     * a {@code KeyStroke}. The {@code action} part of the pair is a
+     * {@code String} that corresponds to the name of the {@code
+     * Action}.
+     * <p>
+     * The following example illustrates creating a {@code KeyBinding} array
+     * from six alternating {@code key-action} pairs:
+     * <pre>
+     *  JTextComponent.KeyBinding[] multilineBindings = makeKeyBindings( new Object[] {
+     *          "UP", DefaultEditorKit.upAction,
+     *        "DOWN", DefaultEditorKit.downAction,
+     *     "PAGE_UP", DefaultEditorKit.pageUpAction,
+     *   "PAGE_DOWN", DefaultEditorKit.pageDownAction,
+     *       "ENTER", DefaultEditorKit.insertBreakAction,
+     *         "TAB", DefaultEditorKit.insertTabAction
+     *  });
+     * </pre>
+     * If {@code keyBindingList's} length is odd, the last element is
+     * ignored.
+     * <p>
+     * Supplying a {@code null} value for either the {@code key} or
+     * {@code action} part of the {@code key-action} pair results in
+     * creating a {@code KeyBinding} with the corresponding value
+     * {@code null}. As other parts of Swing's expect {@code non-null} values
+     * in a {@code KeyBinding}, you should avoid supplying {@code null} as
+     * either the {@code key} or {@code action} part of the {@code key-action}
+     * pair.
+     *
+     * @param keyBindingList an array of {@code key-action} pairs
+     * @return an array of {@code KeyBindings}
+     * @throws NullPointerException if {@code keyBindingList} is {@code null}
+     * @throws ClassCastException if the {@code key} part of the pair is
+     *         not a {@code KeyStroke} or {@code String}, or the
+     *         {@code action} part of the pair is not a {@code String}
+     * @see ActionMap
+     * @see InputMap
+     * @see KeyStroke#getKeyStroke
+     */
+    public static JTextComponent.KeyBinding[] makeKeyBindings(Object[] keyBindingList)
+    {
+        JTextComponent.KeyBinding[] rv = new JTextComponent.KeyBinding[keyBindingList.length / 2];
+
+        for(int i = 0; i < keyBindingList.length; i += 2) {
+            KeyStroke keystroke = (keyBindingList[i] instanceof KeyStroke)
+                ? (KeyStroke)keyBindingList[i]
+                : KeyStroke.getKeyStroke((String)keyBindingList[i]);
+            String action = (String)keyBindingList[i+1];
+            rv[i / 2] = new JTextComponent.KeyBinding(keystroke, action);
+        }
+
+        return rv;
+    }
+
+    /**
+     * Creates a {@code InputMapUIResource} from <code>keys</code>. This is
+     * a convenience method for creating a new {@code InputMapUIResource},
+     * invoking {@code loadKeyBindings(map, keys)}, and returning the
+     * {@code InputMapUIResource}.
+     *
+     * @param keys alternating pairs of {@code keystroke-action key}
+     *        pairs as described in {@link #loadKeyBindings}
+     * @return newly created and populated {@code InputMapUIResource}
+     * @see #loadKeyBindings
+     *
+     * @since 1.3
+     */
+    public static InputMap makeInputMap(Object[] keys) {
+        InputMap retMap = new InputMapUIResource();
+        loadKeyBindings(retMap, keys);
+        return retMap;
+    }
+
+    /**
+     * Creates a {@code ComponentInputMapUIResource} from
+     * <code>keys</code>. This is a convenience method for creating a
+     * new {@code ComponentInputMapUIResource}, invoking {@code
+     * loadKeyBindings(map, keys)}, and returning the {@code
+     * ComponentInputMapUIResource}.
+     *
+     * @param c component to create the {@code ComponentInputMapUIResource}
+     *          with
+     * @param keys alternating pairs of {@code keystroke-action key}
+     *        pairs as described in {@link #loadKeyBindings}
+     * @return newly created and populated {@code InputMapUIResource}
+     * @throws IllegalArgumentException if {@code c} is {@code null}
+     *
+     * @see #loadKeyBindings
+     * @see ComponentInputMapUIResource
+     *
+     * @since 1.3
+     */
+    public static ComponentInputMap makeComponentInputMap(JComponent c,
+                                                          Object[] keys) {
+        ComponentInputMap retMap = new ComponentInputMapUIResource(c);
+        loadKeyBindings(retMap, keys);
+        return retMap;
+    }
+
+
+    /**
+     * Populates an {@code InputMap} with the specified bindings.
+     * The bindings are supplied as a list of alternating
+     * {@code keystroke-action key} pairs. The {@code keystroke} is either
+     * an instance of {@code KeyStroke}, or a {@code String}
+     * that identifies the {@code KeyStroke} for the binding. Refer
+     * to {@code KeyStroke.getKeyStroke(String)} for the specific
+     * format. The {@code action key} part of the pair is the key
+     * registered in the {@code InputMap} for the {@code KeyStroke}.
+     * <p>
+     * The following illustrates loading an {@code InputMap} with two
+     * {@code key-action} pairs:
+     * <pre>
+     *   LookAndFeel.loadKeyBindings(inputMap, new Object[] {
+     *     "control X", "cut",
+     *     "control V", "paste"
+     *   });
+     * </pre>
+     * <p>
+     * Supplying a {@code null} list of bindings ({@code keys}) does not
+     * change {@code retMap} in any way.
+     * <p>
+     * Specifying a {@code null} {@code action key} results in
+     * removing the {@code keystroke's} entry from the {@code InputMap}.
+     * A {@code null} {@code keystroke} is ignored.
+     *
+     * @param retMap {@code InputMap} to add the {@code key-action}
+     *               pairs to
+     * @param keys bindings to add to {@code retMap}
+     * @throws NullPointerException if {@code keys} is
+     *         {@code non-null}, not empty, and {@code retMap} is
+     *         {@code null}
+     *
+     * @see KeyStroke#getKeyStroke(String)
+     * @see InputMap
+     *
+     * @since 1.3
+     */
+    public static void loadKeyBindings(InputMap retMap, Object[] keys) {
+        if (keys != null) {
+            for (int counter = 0, maxCounter = keys.length;
+                 counter < maxCounter; counter++) {
+                Object keyStrokeO = keys[counter++];
+                KeyStroke ks = (keyStrokeO instanceof KeyStroke) ?
+                                (KeyStroke)keyStrokeO :
+                                KeyStroke.getKeyStroke((String)keyStrokeO);
+                retMap.put(ks, keys[counter]);
+            }
+        }
+    }
+
+    /**
+     * Creates and returns a {@code UIDefault.LazyValue} that loads an
+     * image. The returned value is an implementation of {@code
+     * UIDefaults.LazyValue}. When {@code createValue} is invoked on
+     * the returned object, the image is loaded. If the image is {@code
+     * non-null}, it is then wrapped in an {@code Icon} that implements {@code
+     * UIResource}. The image is loaded using {@code
+     * Class.getResourceAsStream(gifFile)}.
+     * <p>
+     * This method does not check the arguments in any way. It is
+     * strongly recommended that {@code non-null} values are supplied else
+     * exceptions may occur when {@code createValue} is invoked on the
+     * returned object.
+     *
+     * @param baseClass {@code Class} used to load the resource
+     * @param gifFile path to the image to load
+     * @return a {@code UIDefaults.LazyValue}; when resolved the
+     *         {@code LazyValue} loads the specified image
+     * @see UIDefaults.LazyValue
+     * @see Icon
+     * @see Class#getResourceAsStream(String)
+     */
+    public static Object makeIcon(final Class<?> baseClass, final String gifFile) {
+        return SwingUtilities2.makeIcon(baseClass, baseClass, gifFile);
+    }
+
+    /**
+     * Returns the <code>LayoutStyle</code> for this look
+     * and feel.  This never returns {@code null}.
+     * <p>
+     * You generally don't use the <code>LayoutStyle</code> from
+     * the look and feel, instead use the <code>LayoutStyle</code>
+     * method <code>getInstance</code>.
+     *
+     * @see LayoutStyle#getInstance
+     * @return the <code>LayoutStyle</code> for this look and feel
+     * @since 1.6
+     */
+    public LayoutStyle getLayoutStyle() {
+        return DefaultLayoutStyle.getInstance();
+    }
+
+    /**
+     * Invoked when the user attempts an invalid operation,
+     * such as pasting into an uneditable <code>JTextField</code>
+     * that has focus. The default implementation beeps. Subclasses
+     * that wish different behavior should override this and provide
+     * the additional feedback.
+     *
+     * @param component the <code>Component</code> the error occurred in,
+     *                  may be <code>null</code>
+     *                  indicating the error condition is not directly
+     *                  associated with a <code>Component</code>
+     * @since 1.4
+     */
+    public void provideErrorFeedback(Component component) {
+        Toolkit toolkit = null;
+        if (component != null) {
+            toolkit = component.getToolkit();
+        } else {
+            toolkit = Toolkit.getDefaultToolkit();
+        }
+        toolkit.beep();
+    } // provideErrorFeedback()
+
+    /**
+     * Returns the value of the specified system desktop property by
+     * invoking <code>Toolkit.getDefaultToolkit().getDesktopProperty()</code>.
+     * If the value of the specified property is {@code null},
+     * {@code fallbackValue} is returned.
+     *
+     * @param systemPropertyName the name of the system desktop property being queried
+     * @param fallbackValue the object to be returned as the value if the system value is null
+     * @return the current value of the desktop property
+     *
+     * @see java.awt.Toolkit#getDesktopProperty
+     *
+     * @since 1.4
+     */
+    public static Object getDesktopPropertyValue(String systemPropertyName, Object fallbackValue) {
+        Object value = Toolkit.getDefaultToolkit().getDesktopProperty(systemPropertyName);
+        if (value == null) {
+            return fallbackValue;
+        } else if (value instanceof Color) {
+            return new ColorUIResource((Color)value);
+        } else if (value instanceof Font) {
+            return new FontUIResource((Font)value);
+        }
+        return value;
+    }
+
+    /**
+     * Returns an <code>Icon</code> with a disabled appearance.
+     * This method is used to generate a disabled <code>Icon</code> when
+     * one has not been specified.  For example, if you create a
+     * <code>JButton</code> and only specify an <code>Icon</code> via
+     * <code>setIcon</code> this method will be called to generate the
+     * disabled <code>Icon</code>. If {@code null} is passed as
+     * <code>icon</code> this method returns {@code null}.
+     * <p>
+     * Some look and feels might not render the disabled {@code Icon}, in which
+     * case they will ignore this.
+     *
+     * @param component {@code JComponent} that will display the {@code Icon},
+     *         may be {@code null}
+     * @param icon {@code Icon} to generate the disabled icon from
+     * @return disabled {@code Icon}, or {@code null} if a suitable
+     *         {@code Icon} can not be generated
+     * @since 1.5
+     */
+    public Icon getDisabledIcon(JComponent component, Icon icon) {
+        if (icon instanceof ImageIcon) {
+            return new ImageIconUIResource(GrayFilter.
+                   createDisabledImage(((ImageIcon)icon).getImage()));
+        }
+        return null;
+    }
+
+    /**
+     * Returns an <code>Icon</code> for use by disabled
+     * components that are also selected. This method is used to generate an
+     * <code>Icon</code> for components that are in both the disabled and
+     * selected states but do not have a specific <code>Icon</code> for this
+     * state.  For example, if you create a <code>JButton</code> and only
+     * specify an <code>Icon</code> via <code>setIcon</code> this method
+     * will be called to generate the disabled and selected
+     * <code>Icon</code>. If {@code null} is passed as <code>icon</code> this
+     * methods returns {@code null}.
+     * <p>
+     * Some look and feels might not render the disabled and selected
+     * {@code Icon}, in which case they will ignore this.
+     *
+     * @param component {@code JComponent} that will display the {@code Icon},
+     *        may be {@code null}
+     * @param icon {@code Icon} to generate disabled and selected icon from
+     * @return disabled and selected icon, or {@code null} if a suitable
+     *         {@code Icon} can not be generated.
+     * @since 1.5
+     */
+    public Icon getDisabledSelectedIcon(JComponent component, Icon icon) {
+        return getDisabledIcon(component, icon);
+    }
+
+    /**
+     * Return a short string that identifies this look and feel, e.g.
+     * "CDE/Motif".  This string should be appropriate for a menu item.
+     * Distinct look and feels should have different names, e.g.
+     * a subclass of MotifLookAndFeel that changes the way a few components
+     * are rendered should be called "CDE/Motif My Way"; something
+     * that would be useful to a user trying to select a L&F from a list
+     * of names.
+     *
+     * @return short identifier for the look and feel
+     */
+    public abstract String getName();
+
+
+    /**
+     * Return a string that identifies this look and feel.  This string
+     * will be used by applications/services that want to recognize
+     * well known look and feel implementations.  Presently
+     * the well known names are "Motif", "Windows", "Mac", "Metal".  Note
+     * that a LookAndFeel derived from a well known superclass
+     * that doesn't make any fundamental changes to the look or feel
+     * shouldn't override this method.
+     *
+     * @return identifier for the look and feel
+     */
+    public abstract String getID();
+
+
+    /**
+     * Return a one line description of this look and feel implementation,
+     * e.g. "The CDE/Motif Look and Feel".   This string is intended for
+     * the user, e.g. in the title of a window or in a ToolTip message.
+     *
+     * @return short description for the look and feel
+     */
+    public abstract String getDescription();
+
+
+    /**
+     * Returns {@code true} if the <code>LookAndFeel</code> returned
+     * <code>RootPaneUI</code> instances support providing {@code Window}
+     * decorations in a <code>JRootPane</code>.
+     * <p>
+     * The default implementation returns {@code false}, subclasses that
+     * support {@code Window} decorations should override this and return
+     * {@code true}.
+     *
+     * @return {@code true} if the {@code RootPaneUI} instances created by
+     *         this look and feel support client side decorations
+     * @see JDialog#setDefaultLookAndFeelDecorated
+     * @see JFrame#setDefaultLookAndFeelDecorated
+     * @see JRootPane#setWindowDecorationStyle
+     * @since 1.4
+     */
+    public boolean getSupportsWindowDecorations() {
+        return false;
+    }
+
+    /**
+     * If the underlying platform has a "native" look and feel, and
+     * this is an implementation of it, return {@code true}.  For
+     * example, when the underlying platform is Solaris running CDE
+     * a CDE/Motif look and feel implementation would return {@code
+     * true}.
+     *
+     * @return {@code true} if this look and feel represents the underlying
+     *         platform look and feel
+     */
+    public abstract boolean isNativeLookAndFeel();
+
+
+    /**
+     * Return {@code true} if the underlying platform supports and or permits
+     * this look and feel.  This method returns {@code false} if the look
+     * and feel depends on special resources or legal agreements that
+     * aren't defined for the current platform.
+     *
+     *
+     * @return {@code true} if this is a supported look and feel
+     * @see UIManager#setLookAndFeel
+     */
+    public abstract boolean isSupportedLookAndFeel();
+
+
+    /**
+     * Initializes the look and feel. While this method is public,
+     * it should only be invoked by the {@code UIManager} when a
+     * look and feel is installed as the current look and feel. This
+     * method is invoked before the {@code UIManager} invokes
+     * {@code getDefaults}. This method is intended to perform any
+     * initialization for the look and feel. Subclasses
+     * should do any one-time setup they need here, rather than
+     * in a static initializer, because look and feel class objects
+     * may be loaded just to discover that {@code isSupportedLookAndFeel()}
+     * returns {@code false}.
+     *
+     * @see #uninitialize
+     * @see UIManager#setLookAndFeel
+     */
+    public void initialize() {
+    }
+
+
+    /**
+     * Uninitializes the look and feel. While this method is public,
+     * it should only be invoked by the {@code UIManager} when
+     * the look and feel is uninstalled. For example,
+     * {@code UIManager.setLookAndFeel} invokes this when the look and
+     * feel is changed.
+     * <p>
+     * Subclasses may choose to free up some resources here.
+     *
+     * @see #initialize
+     * @see UIManager#setLookAndFeel
+     */
+    public void uninitialize() {
+    }
+
+    /**
+     * Returns the look and feel defaults. While this method is public,
+     * it should only be invoked by the {@code UIManager} when the
+     * look and feel is set as the current look and feel and after
+     * {@code initialize} has been invoked.
+     *
+     * @return the look and feel defaults
+     * @see #initialize
+     * @see #uninitialize
+     * @see UIManager#setLookAndFeel
+     */
+    public UIDefaults getDefaults() {
+        return null;
+    }
+
+    /**
+     * Returns a string that displays and identifies this
+     * object's properties.
+     *
+     * @return a String representation of this object
+     */
+    public String toString() {
+        return "[" + getDescription() + " - " + getClass().getName() + "]";
+    }
+}