sf.wicklet.gwt.client.util.DomCache.java Source code

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Here is the source code for sf.wicklet.gwt.client.util.DomCache.java

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/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You should have received a copy of  the license along with this library.
 * You may also obtain a copy of the License at
 *         http://www.apache.org/licenses/LICENSE-2.0.
 */
package sf.wicklet.gwt.client.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import com.google.gwt.user.client.Element;

public class DomCache {

    public static final String TAGS = "#tags";

    private final String[] names;
    private final Map<String, Element> byids = new TreeMap<String, Element>();
    private final Map<String, List<Element>> byclasses = new TreeMap<String, List<Element>>();
    private final Map<String, List<Element>> bytags = new TreeMap<String, List<Element>>();
    private final Map<String, Map<String, List<Element>>> bynames = new TreeMap<String, Map<String, List<Element>>>();

    public static Element byId(final Element top, final String id) {
        for (com.google.gwt.dom.client.Element e = top; e != null; e = e.getNextSiblingElement()) {
            final String eid = e.getId();
            if (id.equals(eid)) {
                return e.cast();
            }
        }
        return null;
    }

    public static List<Element> byTag(final Element top, final String tag) {
        final List<Element> ret = new ArrayList<Element>();
        for (com.google.gwt.dom.client.Element e = top; e != null; e = e.getNextSiblingElement()) {
            if (tag.equals(e.getTagName())) {
                ret.add((Element) e.cast());
            }
        }
        return ret;
    }

    /**
     * Create attribute value to elements mappings.
     * @param names Name of attributes to be indexed.
     * A special token #tags would create a tag to elements mapping. CSS class attribute value is split
     * and create the individual CSS class value to element mapping.
     */
    public DomCache(final Element top, final String... names) {
        this.names = names;
        init(top);
    }

    private void init(final com.google.gwt.dom.client.Element top) {
        for (com.google.gwt.dom.client.Element e = top; e != null; e = e.getNextSiblingElement()) {
            final Element elm = e.cast();
            for (final String name : names) {
                if ("id".equals(name)) {
                    final String id = elm.getId();
                    if (!GwtTextUtil.isEmpty(id)) {
                        byids.put(id, elm);
                    }
                } else if ("class".equals(name)) {
                    final String css = elm.getClassName();
                    if (!GwtTextUtil.isEmpty(css)) {
                        for (final String s : GwtTextUtil.tokenize(css)) {
                            GwtStructUtil.addToList(byclasses, s, elm);
                        }
                    }
                } else if (TAGS.equals(name)) {
                    GwtStructUtil.addToList(bytags, elm.getTagName(), elm);
                } else {
                    final String value = elm.getAttribute(name);
                    if (value != null) {
                        Map<String, List<Element>> m = bynames.get(name);
                        if (m == null) {
                            bynames.put(name, m = new TreeMap<String, List<Element>>());
                        }
                        List<Element> a = m.get(value);
                        if (a == null) {
                            m.put(value, a = new ArrayList<Element>());
                        }
                        a.add(elm);
                    }
                }
            }
            init(e.getFirstChildElement());
        }
    }

    public Collection<String> byIdKeys() {
        return byids.keySet();
    }

    public Collection<String> byClassKeys() {
        return byclasses.keySet();
    }

    public Collection<String> byTagKeys() {
        return bytags.keySet();
    }

    public Element byId(final Object id) {
        if (id == null) {
            return null;
        }
        return byids.get(id.toString());
    }

    public List<Element> byClass(final Object name) {
        if (name == null) {
            return null;
        }
        return byclasses.get(name.toString());
    }

    public List<Element> byTag(final Object tag) {
        if (tag == null) {
            return null;
        }
        return bytags.get(tag.toString().toUpperCase());
    }

    public List<Element> by(final String name, final Object value) {
        final Map<String, List<Element>> m = bynames.get(name);
        if (m == null) {
            return null;
        }
        return m.get(value.toString());
    }
}