com.lyndir.lhunath.opal.wayward.behavior.CSSClassAttributeAppender.java Source code

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Here is the source code for com.lyndir.lhunath.opal.wayward.behavior.CSSClassAttributeAppender.java

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/*
 *   Copyright 2010, Maarten Billemont
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package com.lyndir.lhunath.opal.wayward.behavior;

import com.google.common.base.Function;
import com.google.common.collect.Collections2;
import java.util.*;
import javax.annotation.Nullable;
import org.apache.wicket.behavior.AttributeAppender;
import org.apache.wicket.model.AbstractReadOnlyModel;
import org.apache.wicket.model.IModel;

/**
 * <h2>{@link CSSClassAttributeAppender}<br> <sub>[in short] (TODO).</sub></h2>
 *
 * <p> <i>Mar 12, 2010</i> </p>
 *
 * @author lhunath
 */
public class CSSClassAttributeAppender extends AttributeAppender {

    private static final String CLASS_ATTRIBUTE = "class";
    private static final String CLASS_SEPARATOR = " ";

    /**
     * @param cssClassesModel A model that provides CSS classes to append to the element's <code>class</code> attribute.
     *
     * @return An appender which appends all the CSS classes in the collection from the given model to a component's HTML element.
     */
    public static CSSClassAttributeAppender ofList(final IModel<? extends Collection<String>> cssClassesModel) {

        // noinspection RedundantCast
        return new CSSClassAttributeAppender(cssClassesModel, (Collection<?>) null);
    }

    /**
     * @param cssClassModels Models that provides CSS classes to append to the element's <code>class</code> attribute.
     *
     * @return An appender which appends all the CSS classes in the collection from the given model to a component's HTML element.
     */
    public static CSSClassAttributeAppender of(final IModel<?>... cssClassModels) {

        return ofList(new AbstractReadOnlyModel<Collection<String>>() {

            @Override
            public Collection<String> getObject() {

                return Collections2.transform(Arrays.asList(cssClassModels), new Function<IModel<?>, String>() {

                    @Nullable
                    @Override
                    public String apply(final IModel<?> from) {

                        return from.getObject() == null ? null : String.valueOf(from.getObject());
                    }
                });
            }
        });
    }

    /**
     * @param cssClassModels Models that provides CSS classes to append to the element's <code>class</code> attribute.
     *
     * @return An appender which appends all the CSS classes in the collection from the given model to a component's HTML element.
     */
    public static CSSClassAttributeAppender of(final String... cssClassModels) {

        return new CSSClassAttributeAppender(cssClassModels);
    }

    /**
     * @param cssClassModel A model that provides a CSS class to append to the element's <code>class</code> attribute.
     *
     * @return An appender which appends the CSS class in the model to a component's HTML element.
     */
    public static CSSClassAttributeAppender ofString(final IModel<String> cssClassModel) {

        // noinspection RedundantCast
        return new CSSClassAttributeAppender(cssClassModel, (String) null);
    }

    /**
     * @param cssClass The CSS class to append to the element's <code>class</code> attribute.
     */
    public CSSClassAttributeAppender(final String cssClass) {

        // noinspection RedundantCast
        this(new AbstractReadOnlyModel<String>() {

            @Override
            public String getObject() {

                return cssClass;
            }
        }, (String) null);
    }

    /**
     * @param cssClasses An array of CSS classes to append to the element's <code>class</code> attribute.
     */
    public CSSClassAttributeAppender(final String... cssClasses) {

        // noinspection RedundantCast
        this(new AbstractReadOnlyModel<List<String>>() {

            @Override
            public List<String> getObject() {

                return Arrays.asList(cssClasses);
            }
        }, (Collection<?>) null);
    }

    private CSSClassAttributeAppender(final IModel<? extends Collection<String>> appendModel,
            @Nullable @SuppressWarnings("unused") final Collection<?> x) {

        // noinspection RedundantCast
        this(new AbstractReadOnlyModel<String>() {

            @Override
            public String getObject() {

                StringBuilder stringBuilder = new StringBuilder();

                for (final String item : appendModel.getObject())
                    if (item != null && !item.isEmpty())
                        stringBuilder.append(item).append(CLASS_SEPARATOR);

                if (stringBuilder.length() > 0)
                    stringBuilder.deleteCharAt(stringBuilder.length() - 1);

                return stringBuilder.toString();
            }
        }, (String) null);
    }

    private CSSClassAttributeAppender(final IModel<String> appendModel,
            @Nullable @SuppressWarnings("unused") final String x) {

        super(CLASS_ATTRIBUTE, true, appendModel, CLASS_SEPARATOR);
    }
}