org.apache.tapestry.contrib.palette.PaletteColumn Maven / Gradle / Ivy

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// Copyright 2004, 2005 The Apache Software Foundation
//
// 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 org.apache.tapestry.contrib.palette;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRender;
import org.apache.tapestry.IRequestCycle;

/**
 * One of the two columns in a Palette component: the left column lists available options, the right
 * column lists the selected columns.
 * 
 * @author Howard Lewis Ship
 */
public class PaletteColumn implements IRender
{
    private String _name;

    private String _clientId;

    private int _rows;

    private List _options = new ArrayList();

    /**
     * 
     * @author hls
     */
    private static class ValueComparator implements Comparator
    {
        public int compare(Object o1, Object o2)
        {
            PaletteOption option1 = (PaletteOption) o1;
            PaletteOption option2 = (PaletteOption) o2;

            return option1.getValue().compareTo(option2.getValue());
        }
    }

    /**
     * 
     * @author hls
     */
    private static class LabelComparator implements Comparator
    {
        public int compare(Object o1, Object o2)
        {
            PaletteOption option1 = (PaletteOption) o1;
            PaletteOption option2 = (PaletteOption) o2;

            return option1.getLabel().compareTo(option2.getLabel());
        }
    }

    /**
     * @param name
     *            the name of the column (the name attribute of the <select>)
     * @param rows
     *            the number of visible rows (the size attribute of the <select>)
     */
    public PaletteColumn(String name, String clientId, int rows)
    {
        _name = name;
        _clientId = clientId;
        _rows = rows;
    }

    public void addOption(PaletteOption option)
    {
        _options.add(option);
    }

    /**
     * Sorts the options by value (the hidden value for the option that represents the object
     * value). This should be invoked before rendering this PaletteColumn.
     */
    public void sortByValue()
    {
        Collections.sort(_options, new ValueComparator());
    }

    /**
     * Sorts the options by the label visible to the user. This should be invoked before rendering
     * this PaletteColumn.
     */
    public void sortByLabel()
    {
        Collections.sort(_options, new LabelComparator());
    }

    /**
     * Renders the <select> and <option> tags for this column.
     */
    public void render(IMarkupWriter writer, IRequestCycle cycle)
    {
        writer.begin("select");
        writer.attribute("multiple", "multiple");
        writer.attribute("name", _name);

        if (_clientId != null)
            writer.attribute("id", _clientId);

        writer.attribute("size", _rows);
        writer.println();

        int count = _options.size();
        for (int i = 0; i < count; i++)
        {
            PaletteOption o = (PaletteOption) _options.get(i);

            o.render(writer, cycle);
        }

        writer.end();
    }

}