com.swtxml.util.parser.ConstantParser.java Source code

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Here is the source code for com.swtxml.util.parser.ConstantParser.java

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/*******************************************************************************
 * Copyright (c) 2008 Ralf Ebert
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Ralf Ebert - initial API and implementation
 *******************************************************************************/
package com.swtxml.util.parser;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang.StringUtils;

import com.swtxml.util.reflector.Reflector;
import com.swtxml.util.reflector.ReflectorException;
import com.swtxml.util.reflector.Subclasses;
import com.swtxml.util.reflector.Visibility;

public class ConstantParser {

    private Map<String, Integer> constantMap = new HashMap<String, Integer>();

    public static final Splitter SPLITTER = new Splitter(",;|");

    public ConstantParser(Class<?>... constantClasses) {
        for (Class<?> cl : constantClasses) {
            if (!constantMap.containsKey(cl)) {
                constantMap.putAll(extractConstants(cl));
            }
        }
    }

    private ConstantParser(Map<String, Integer> constantMap) {
        this.constantMap = constantMap;
    }

    private Map<String, Integer> extractConstants(Class<?> cl) {
        Map<String, Integer> constants = new HashMap<String, Integer>();
        try {
            Collection<Field> fields = Reflector.findFields(Visibility.PUBLIC, Subclasses.NONE).isStatic(true)
                    .type(Integer.TYPE).all(cl);
            for (Field field : fields) {
                constants.put(field.getName(), field.getInt(cl));
            }
        } catch (Exception e) {
            throw new ReflectorException(e);
        }
        return constants;
    }

    public int getIntValue(String value) {
        int style = 0;
        if (value == null) {
            return style;
        }
        String[] values = SPLITTER.split(value);
        for (String v : values) {
            v = v.trim().toUpperCase();

            Integer constant = null;
            constant = constantMap.get(v);

            if (constant == null) {
                List<String> constants = new ArrayList<String>(constantMap.keySet());
                Collections.sort(constants);
                throw new ParseException(
                        "Unknown style constant: " + v + ", allowed are: " + SPLITTER.join(constants));
            }

            style |= constant;
        }
        return style;

    }

    public ConstantParser filter(String value) {
        return filter(Arrays.asList(SPLITTER.split(value)));
    }

    public ConstantParser filter(Iterable<String> values) {
        Map<String, Integer> matches = new HashMap<String, Integer>();
        for (String v : values) {
            v = v.trim().toUpperCase();
            Integer constant = null;
            constant = constantMap.get(v);
            if (constant == null) {
                List<String> constants = new ArrayList<String>(constantMap.keySet());
                Collections.sort(constants);
                throw new ParseException(
                        "Unknown style constant: " + v + ", allowed are: " + StringUtils.join(constants, ", "));
            }

            matches.put(v, constant);
        }
        return new ConstantParser(matches);

    }

    public Collection<String> getConstants() {
        return constantMap.keySet();
    }
}