net.cbtltd.client.field.table.ListCell.java Source code

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Here is the source code for net.cbtltd.client.field.table.ListCell.java

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/*
 * Copyright 2010 Google Inc.
 *
 * 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 net.cbtltd.client.field.table;

import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.cell.client.ValueUpdater;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;

/**
 * A cell that renders a list
 * @param <C> the type that this Cell represents
 */
public class ListCell<C> extends AbstractCell<C> {
    private static int id = 0; // to provide unique id
    private String[] text;
    private String selected;
    private String style;
    private final Delegate<C> delegate;

    public interface Delegate<T> {
        void execute(T object);
    }

    //TODO: also use ArrayList<NameId> for separate value and text elements in list 
    public ListCell(String[] text, String selected, String style, Delegate<C> delegate) {
        super("change");
        id++;
        this.text = text;
        this.selected = selected;
        this.style = style;
        this.delegate = delegate;
    }

    private String getId() {
        return "ListCell" + id;
    }

    /**
     * If you override this method to add support for events, remember to pass the
     * event types that the cell expects into the constructor.
     */
    @Override
    public void onBrowserEvent(Context context, Element parent, C value, NativeEvent event,
            ValueUpdater<C> valueUpdater) {
        if ("change".equals(event.getType())) {
            selected = getValueJS(getId());
            delegate.execute(value);
        }
    }

    @Override
    public void render(Context context, C value, SafeHtmlBuilder sb) {
        sb.appendHtmlConstant("<select id='ListCell" + id + "' class='" + style + "'>");
        for (int index = 0; index < text.length; index++) {
            if (text[index].equalsIgnoreCase(selected)) {
                sb.appendHtmlConstant("<option selected='selected'>" + text[index] + "</option>");
            } else {
                sb.appendHtmlConstant("<option value='" + text[index] + "'>" + text[index] + "</option>");
            }
        }
        sb.appendHtmlConstant("</select>");
    }

    public String getValue() {
        return selected;
    }

    /*****************************************************************************************
     * Get list value
     ****************************************************************************************/
    private native String getValueJS(String id) /*-{
                                                return $doc.getElementById(id).value;
                                                }-*/;
}