/*
 * Copyright (c) 2003, 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
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.swing;

import java.awt.Color;
import java.awt.Insets;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.plaf.ComponentUI;
import sun.awt.AppContext;

DefaultLookup provides a way to customize the lookup done by the
UIManager. The default implementation of DefaultLookup forwards
the call to the UIManager.

WARNING: While this class is public, it should not be treated as
public API and its API may change in incompatable ways between dot dot
releases and even patch releases. You should not rely on this class even
existing.
Author:
Scott Violet/**
 * DefaultLookup provides a way to customize the lookup done by the
 * UIManager. The default implementation of DefaultLookup forwards
 * the call to the UIManager.
 * <p>
 * <b>WARNING:</b> While this class is public, it should not be treated as
 * public API and its API may change in incompatable ways between dot dot
 * releases and even patch releases. You should not rely on this class even
 * existing.
 *
 * @author Scott Violet
 */
public class DefaultLookup {
    
Key used to store DefaultLookup for AppContext.
/**
     * Key used to store DefaultLookup for AppContext.
     */
    private static final Object DEFAULT_LOOKUP_KEY = new Object(); // DefaultLookup
    
Thread that last asked for a default.
/**
     * Thread that last asked for a default.
     */
    private static Thread currentDefaultThread;
    
DefaultLookup for last thread.
/**
     * DefaultLookup for last thread.
     */
    private static DefaultLookup currentDefaultLookup;

    
If true, a custom DefaultLookup has been set.
/**
     * If true, a custom DefaultLookup has been set.
     */
    private static boolean isLookupSet;


    
Sets the DefaultLookup instance to use for the current
AppContext. Null implies the UIManager should be
used.
/**
     * Sets the DefaultLookup instance to use for the current
     * <code>AppContext</code>. Null implies the UIManager should be
     * used.
     */
    public static void setDefaultLookup(DefaultLookup lookup) {
        synchronized(DefaultLookup.class) {
            if (!isLookupSet && lookup == null) {
                // Null was passed in, and no one has invoked setDefaultLookup
                // with a non-null value, we don't need to do anything.
                return;
            }
            else if (lookup == null) {
                // null was passed in, but someone has invoked setDefaultLookup
                // with a non-null value, use an instance of DefautLookup
                // which will fallback to UIManager.
                lookup = new DefaultLookup();
            }
            isLookupSet = true;
            AppContext.getAppContext().put(DEFAULT_LOOKUP_KEY, lookup);
            currentDefaultThread = Thread.currentThread();
            currentDefaultLookup = lookup;
        }
    }

    public static Object get(JComponent c, ComponentUI ui, String key) {
        boolean lookupSet;
        synchronized(DefaultLookup.class) {
            lookupSet = isLookupSet;
        }
        if (!lookupSet) {
            // No one has set a valid DefaultLookup, use UIManager.
            return UIManager.get(key, c.getLocale());
        }
        Thread thisThread = Thread.currentThread();
        DefaultLookup lookup;
        synchronized(DefaultLookup.class) {
            // See if we've already cached the DefaultLookup for this thread,
            // and use it if we have.
            if (thisThread == currentDefaultThread) {
                // It is cached, use it.
                lookup = currentDefaultLookup;
            }
            else {
                // Not cached, get the DefaultLookup to use from the AppContext
                lookup = (DefaultLookup)AppContext.getAppContext().get(
                                                   DEFAULT_LOOKUP_KEY);
                if (lookup == null) {
                    // Fallback to DefaultLookup, which will redirect to the
                    // UIManager.
                    lookup = new DefaultLookup();
                    AppContext.getAppContext().put(DEFAULT_LOOKUP_KEY, lookup);
                }
                // Cache the values to make the next lookup easier.
                currentDefaultThread = thisThread;
                currentDefaultLookup = lookup;
            }
        }
        return lookup.getDefault(c, ui, key);
    }

    //
    // The following are convenience method that all use getDefault.
    //
    public static int getInt(JComponent c, ComponentUI ui, String key,
                             int defaultValue) {
        Object iValue = get(c, ui, key);

        if (iValue == null || !(iValue instanceof Number)) {
            return defaultValue;
        }
        return ((Number)iValue).intValue();
    }

    public static int getInt(JComponent c, ComponentUI ui, String key) {
        return getInt(c, ui, key, -1);
    }

    public static Insets getInsets(JComponent c, ComponentUI ui, String key,
                                   Insets defaultValue) {
        Object iValue = get(c, ui, key);

        if (iValue == null || !(iValue instanceof Insets)) {
            return defaultValue;
        }
        return (Insets)iValue;
    }

    public static Insets getInsets(JComponent c, ComponentUI ui, String key) {
        return getInsets(c, ui, key, null);
    }

    public static boolean getBoolean(JComponent c, ComponentUI ui, String key,
                                     boolean defaultValue) {
        Object iValue = get(c, ui, key);

        if (iValue == null || !(iValue instanceof Boolean)) {
            return defaultValue;
        }
        return ((Boolean)iValue).booleanValue();
    }

    public static boolean getBoolean(JComponent c, ComponentUI ui, String key) {
        return getBoolean(c, ui, key, false);
    }

    public static Color getColor(JComponent c, ComponentUI ui, String key,
                                 Color defaultValue) {
        Object iValue = get(c, ui, key);

        if (iValue == null || !(iValue instanceof Color)) {
            return defaultValue;
        }
        return (Color)iValue;
    }

    public static Color getColor(JComponent c, ComponentUI ui, String key) {
        return getColor(c, ui, key, null);
    }

    public static Icon getIcon(JComponent c, ComponentUI ui, String key,
            Icon defaultValue) {
        Object iValue = get(c, ui, key);
        if (iValue == null || !(iValue instanceof Icon)) {
            return defaultValue;
        }
        return (Icon)iValue;
    }

    public static Icon getIcon(JComponent c, ComponentUI ui, String key) {
        return getIcon(c, ui, key, null);
    }

    public static Border getBorder(JComponent c, ComponentUI ui, String key,
            Border defaultValue) {
        Object iValue = get(c, ui, key);
        if (iValue == null || !(iValue instanceof Border)) {
            return defaultValue;
        }
        return (Border)iValue;
    }

    public static Border getBorder(JComponent c, ComponentUI ui, String key) {
        return getBorder(c, ui, key, null);
    }

    public Object getDefault(JComponent c, ComponentUI ui, String key) {
        // basic
        return UIManager.get(key, c.getLocale());
    }
}