https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * version 2 for more details (a copy is included in the LICENSE file that
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 *
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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 sun.awt.SunToolkit;

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;



LookAndFeel, as the name implies, encapsulates a look and feel. Beyond installing a look and feel most developers never need to interact directly with LookAndFeel. In general only developers creating a custom look and feel need to concern themselves with this class. 
 Swing is built upon the foundation that each JComponent subclass has an implementation of a specific ComponentUI subclass. The ComponentUI is often referred to as "the ui", "component ui", or "look and feel delegate". The ComponentUI subclass is responsible for providing the look and feel specific functionality of the component. For example, JTree requires an implementation of the ComponentUI subclass 
TreeUI. The implementation of the specific 
ComponentUI subclass is provided by the LookAndFeel. Each JComponent subclass identifies the ComponentUI subclass it requires by way of the JComponent method 
getUIClassID. 
 Each LookAndFeel implementation must provide an implementation of the appropriate ComponentUI subclass by specifying a value for each of Swing's ui class ids in the 
UIDefaults object returned from getDefaults. For example, BasicLookAndFeel uses BasicTreeUI as the concrete implementation for TreeUI. This is accomplished by 
BasicLookAndFeel providing the key-value pair 
"TreeUI"-"javax.swing.plaf.basic.BasicTreeUI", in the UIDefaults returned from getDefaults. Refer to UIDefaults.getUI(JComponent) for details on how the implementation of the ComponentUI subclass is obtained. 
 When a LookAndFeel is installed the 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 JComponent subclass is created. 
Recommendations for Look and Feels
 As noted in UIManager each 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. 
ComponentUIs and defaults
 All ComponentUIs typically need to set various properties on the JComponent the ComponentUI is providing the look and feel for. This is typically done when the 
ComponentUI is installed on the 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 ComponentUI only change the property on the 
JComponent if the current value is null or implements UIResource. If the current value is null or implements UIResource it indicates the property has not been set by the developer, and the ui is free to change it. For example, BasicButtonUI.installDefaults only changes the font on the JButton if the return value from 
button.getFont() is null or implements 
UIResource. On the other hand if button.getFont() returned a non-null value that did not implement UIResource then BasicButtonUI.installDefaults would not change the JButton's font. 
 For primitive values, such as opaque, the method 
installProperty should be invoked. installProperty only changes the corresponding property if the value has not been changed by the developer. 
 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. 
Exceptions
 All of the install methods provided by LookAndFeel need to access the defaults if the value of the property being changed is null or a UIResource. For example, installing the font does the following: 
  JComponent c;
  Font font = c.getFont();
  if (font == null || (font instanceof UIResource)) {
      c.setFont(UIManager.getFont("fontKey"));
  }

 If the font is null or a UIResource, the defaults table is queried with the key fontKey. All of UIDefault's get methods throw a 
NullPointerException if passed in null. As such, unless otherwise noted each of the various install methods of 
LookAndFeel throw a NullPointerException if the current value is null or a UIResource and the supplied defaults key is null. In addition, unless otherwise specified all of the install methods throw a NullPointerException if a null component is passed in. 
Author:Tom Ball, Hans Muller
/**
 * {@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 details 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></h3>
 *
 * 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 corresponding 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.
 *
 * <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 null or a UIResource. 
Params:
  • c – component to set the colors on
  • defaultBgName – key for the background
  • defaultFgName – key for the foreground
Throws:
See Also:
/**
     * 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 null or a UIResource. 
Params:
  • c – component set to the colors and font on
  • defaultBgName – key for the background
  • defaultFgName – key for the foreground
  • defaultFontName – key for the font
Throws:
See Also:
/**
     * 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 null or an instance of UIResource. 
Params:
  • c – component to set the border on
  • defaultBorderName – key specifying the border
Throws:
/**
     * 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 UIResource, it is set to 
null. 
Params:
  • c – component to uninstall the border on
Throws:
/**
     * 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 UIResource marker, this method uses private state to determine whether the property has been set by the client. 
Params:
  • c – target component to set the property on
  • propertyName – name of the property to set
  • propertyValue – value of the property
Throws:
  • IllegalArgumentException – if the specified property is not
        one which can be set using this method
  • ClassCastException – if the property value has not been set
        by the developer and the type does not match the property's type
  • NullPointerException – if c is null, or the named property has not been set by the developer and propertyValue is null
Since:1.5
/**
     * 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 hierarchy
        // includes a class outside of javax.swing, thus we cannot call setUIProperty
        // directly.
        if (SunToolkit.isInstanceOf(c, "javax.swing.JPasswordField")) {
            if (!((JPasswordField)c).customSetUIProperty(propertyName, propertyValue)) {
                c.setUIProperty(propertyName, propertyValue);
            }
        } else {
            c.setUIProperty(propertyName, propertyValue);
        }
    }

    
Convenience method for building an array of 
KeyBindings. While this method is not deprecated, developers should instead use ActionMap and InputMap for supplying key bindings. 
 This method returns an array of KeyBindings, one for each alternating key-action pair in keyBindingList. A key can either be a String in the format specified by the KeyStroke.getKeyStroke method, or a KeyStroke. The action part of the pair is a String that corresponds to the name of the 
Action. 
 The following example illustrates creating a KeyBinding array from six alternating key-action pairs: 
 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
 });

 If keyBindingList's length is odd, the last element is ignored. 
 Supplying a null value for either the key or action part of the key-action pair results in creating a KeyBinding with the corresponding value null. As other parts of Swing's expect non-null values in a KeyBinding, you should avoid supplying null as either the key or action part of the key-action pair. 
Params:
  • keyBindingList – an array of key-action pairs
Throws:
See Also:
Returns:an array of KeyBindings
/**
     * 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 < rv.length; i ++) {
            Object o = keyBindingList[2 * i];
            KeyStroke keystroke = (o instanceof KeyStroke)
                ? (KeyStroke) o
                : KeyStroke.getKeyStroke((String) o);
            String action = (String) keyBindingList[2 * i + 1];
            rv[i] = new JTextComponent.KeyBinding(keystroke, action);
        }

        return rv;
    }

    
Creates a InputMapUIResource from keys. This is a convenience method for creating a new InputMapUIResource, invoking loadKeyBindings(map, keys), and returning the InputMapUIResource. 
Params:
  • keys – alternating pairs of keystroke-action key pairs as described in loadKeyBindings
See Also:
Returns:newly created and populated InputMapUIResource
Since:1.3
/**
     * 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 ComponentInputMapUIResource from keys. This is a convenience method for creating a new ComponentInputMapUIResource, invoking 
loadKeyBindings(map, keys), and returning the 
ComponentInputMapUIResource. 
Params:
  • c – component to create the ComponentInputMapUIResource with
  • keys – alternating pairs of keystroke-action key pairs as described in loadKeyBindings
Throws:
See Also:
Returns:newly created and populated InputMapUIResource
Since:1.3
/**
     * 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 InputMap with the specified bindings. The bindings are supplied as a list of alternating keystroke-action key pairs. The keystroke is either an instance of KeyStroke, or a String that identifies the KeyStroke for the binding. Refer to KeyStroke.getKeyStroke(String) for the specific format. The action key part of the pair is the key registered in the InputMap for the KeyStroke. 
 The following illustrates loading an InputMap with two key-action pairs: 
  LookAndFeel.loadKeyBindings(inputMap, new Object[] {
    "control X", "cut",
    "control V", "paste"
  });



 Supplying a null list of bindings (keys) does not change retMap in any way. 
 Specifying a null action key results in removing the keystroke's entry from the InputMap. A null keystroke is ignored. 
Params:
  • retMap – InputMap to add the key-action pairs to
  • keys – bindings to add to retMap
Throws:
See Also:
Since:1.3
/**
     * 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 UIDefault.LazyValue that loads an image. The returned value is an implementation of 
UIDefaults.LazyValue. When createValue is invoked on the returned object, the image is loaded. If the image is 
non-null, it is then wrapped in an Icon that implements 
UIResource. The image is loaded using 
Class.getResourceAsStream(gifFile). 
 This method does not check the arguments in any way. It is strongly recommended that non-null values are supplied else exceptions may occur when createValue is invoked on the returned object. 
Params:
  • baseClass – Class used to load the resource
  • gifFile – path to the image to load
See Also:
Returns:a UIDefaults.LazyValue; when resolved the LazyValue loads the specified image
/**
     * 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 LayoutStyle for this look and feel. This never returns null. 

You generally don't use the LayoutStyle from
the look and feel, instead use the LayoutStyle
method getInstance.

See Also:
Returns:the LayoutStyle for this look and feel
Since:1.6
/**
     * 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 JTextField
that has focus. The default implementation beeps. Subclasses
that wish different behavior should override this and provide
the additional feedback.

Params:
  • component – the Component the error occurred in,
                 may be null
                 indicating the error condition is not directly
                 associated with a Component
Since:1.4
/**
     * 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 Toolkit.getDefaultToolkit().getDesktopProperty(). If the value of the specified property is null, fallbackValue is returned. 
Params:
  • systemPropertyName – the name of the system desktop property being queried
  • fallbackValue – the object to be returned as the value if the system value is null
See Also:
Returns:the current value of the desktop property
Since:1.4
/**
     * 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 Icon with a disabled appearance.
This method is used to generate a disabled Icon when
one has not been specified.  For example, if you create a
JButton and only specify an Icon via
setIcon this method will be called to generate the
disabled Icon. If null is passed as icon this method returns null. 
 Some look and feels might not render the disabled Icon, in which case they will ignore this. 
Params:
  • component – JComponent that will display the Icon, may be null
  • icon – Icon to generate the disabled icon from
Returns:disabled Icon, or null if a suitable Icon can not be generated
Since:1.5
/**
     * 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 Icon for use by disabled
components that are also selected. This method is used to generate an
Icon for components that are in both the disabled and
selected states but do not have a specific Icon for this
state.  For example, if you create a JButton and only
specify an Icon via setIcon this method
will be called to generate the disabled and selected
Icon. If null is passed as icon this methods returns null. 
 Some look and feels might not render the disabled and selected Icon, in which case they will ignore this. 
Params:
  • component – JComponent that will display the Icon, may be null
  • icon – Icon to generate disabled and selected icon from
Returns:disabled and selected icon, or null if a suitable Icon can not be generated.
Since:1.5
/**
     * 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.

Returns:short identifier for the look and feel
/**
     * 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&amp;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.

Returns:identifier for the look and feel
/**
     * 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.

Returns:short description for the look and feel
/**
     * 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 true if the LookAndFeel returned
RootPaneUI instances support providing Window decorations in a JRootPane.

 The default implementation returns false, subclasses that support Window decorations should override this and return true. 
See Also:
Returns:true if the RootPaneUI instances created by this look and feel support client side decorations
Since:1.4
/**
     * 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 true. For example, when the underlying platform is Solaris running CDE a CDE/Motif look and feel implementation would return 
true. 
Returns:true if this look and feel represents the underlying platform look and feel
/**
     * 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 true if the underlying platform supports and or permits this look and feel. This method returns false if the look and feel depends on special resources or legal agreements that aren't defined for the current platform. 
See Also:
Returns:true if this is a supported look and feel
/**
     * 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 UIManager when a look and feel is installed as the current look and feel. This method is invoked before the UIManager invokes 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 isSupportedLookAndFeel() returns false. 
See Also:
/**
     * 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 UIManager when the look and feel is uninstalled. For example, UIManager.setLookAndFeel invokes this when the look and feel is changed. 

Subclasses may choose to free up some resources here.

See Also:
/**
     * 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 UIManager when the look and feel is set as the current look and feel and after initialize has been invoked. 
See Also:
Returns:the look and feel defaults
/**
     * 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.

Returns:a String representation of this object
/**
     * 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() + "]";
    }
}