org.pentaho.reporting.libraries.css.model.StyleKeyRegistry.java Source code

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Here is the source code for org.pentaho.reporting.libraries.css.model.StyleKeyRegistry.java

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/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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 Lesser General Public License for more details.
*
* Copyright (c) 2002-2017 Hitachi Vantara..  All rights reserved.
*/

package org.pentaho.reporting.libraries.css.model;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.reporting.libraries.base.config.Configuration;
import org.pentaho.reporting.libraries.base.util.LinkedMap;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;
import org.pentaho.reporting.libraries.css.LibCssBoot;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Iterator;

/**
 * This class should not be static, or we might create a memory leak.
 *
 * @author Thomas Morgner
 */
public class StyleKeyRegistry {
    private static final Log logger = LogFactory.getLog(StyleKeyRegistry.class);
    private static StyleKeyRegistry registry;

    public static synchronized StyleKeyRegistry getRegistry() {
        if (registry == null) {
            throw new IllegalStateException("You have to boot LibCSS to make all style-keys known");
        }
        return registry;
    }

    public static void performBoot() {
        if (registry != null) {
            return;
        }

        registry = new StyleKeyRegistry();
        registry.registerDefaults();
        registry.locked = true;
    }

    private LinkedMap knownStyleKeys;
    private boolean locked;

    private StyleKeyRegistry() {
        knownStyleKeys = new LinkedMap();
    }

    public StyleKey findKeyByName(final String name) {
        return (StyleKey) knownStyleKeys.get(name);
    }

    public int getKeyCount() {
        return knownStyleKeys.size();
    }

    public synchronized void registerDefaults() {
        if (locked) {
            throw new IllegalStateException(
                    "All StyleKeys must be registered during the bootup. The registry is locked now.");
        }
        final Configuration config = LibCssBoot.getInstance().getGlobalConfig();
        final Iterator it = config.findPropertyKeys("org.pentaho.reporting.libraries.css.stylekeys.");
        final ClassLoader classLoader = ObjectUtilities.getClassLoader(StyleKeyRegistry.class);

        while (it.hasNext()) {
            final String key = (String) it.next();
            try {
                final String className = config.getConfigProperty(key);
                final Class c = Class.forName(className, false, classLoader);
                registerClass(c);
            } catch (ClassNotFoundException e) {
                // ignore that class
            } catch (NullPointerException e) {
                // ignore invalid values as well.
            }
        }

    }

    private void registerClass(final Class c) {
        // Log.debug ("Registering stylekeys from " + c);
        try {
            final Field[] fields = c.getFields();
            for (int i = 0; i < fields.length; i++) {
                final Field field = fields[i];
                final int modifiers = field.getModifiers();
                if (Modifier.isPublic(modifiers) && Modifier.isStatic(modifiers)) {
                    if (Modifier.isFinal(modifiers) == false) {
                        logger.warn("Invalid implementation: StyleKeys should be 'public static final': " + c);
                    }
                    if (field.getType().isAssignableFrom(StyleKey.class)) {
                        final StyleKey value = (StyleKey) field.get(null);
                        if (value == null) {
                            logger.warn("Invalid implementation: StyleKeys fields must not be null: " + c);
                        }
                        // ignore the returned value, all we want is to trigger the key
                        // creation
                        // Log.debug ("Loaded key " + value);
                    }
                }
            }
        } catch (IllegalAccessException e) {
            // wont happen, we've checked it..
        }
    }

    public synchronized StyleKey createKey(final String name, final boolean trans, final boolean inherited,
            final int validity) {
        final StyleKey existingKey = findKeyByName(name);
        if (existingKey != null) {
            return existingKey;
        }

        if (locked) {
            throw new IllegalStateException(
                    "All StyleKeys must be registered during the bootup. The registry is locked now.");
        }

        final StyleKey createdKey = new StyleKey(name, trans, inherited, knownStyleKeys.size(), validity);
        knownStyleKeys.put(name, createdKey);
        return createdKey;
    }

    public synchronized StyleKey[] getKeys() {
        return (StyleKey[]) knownStyleKeys.values(new StyleKey[knownStyleKeys.size()]);
    }

    public synchronized StyleKey[] getKeys(final StyleKey[] input) {
        return (StyleKey[]) knownStyleKeys.values(input);
    }

}