rowrendererext.java

ZK 基础介绍 功能操作 模块 结合数据库操作

/* RowRendererExt.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Thu Mar  8 10:57:52     2007, Created by tomyeh
}}IS_NOTE

Copyright (C) 2007 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
	This program is distributed under GPL Version 2.0 in the hope that
	it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zul;

import org.zkoss.zk.ui.Component;

/**
 * Provides additional control to {@link RowRenderer}.
 * 
 * @author tomyeh
 */
public interface RowRendererExt {
	/** Creates an instance of {@link Row} for rendering.
	 * The created component will be passed to {@link RowRenderer#render}.
	 *
	 * <p>Note: remember to invoke {@link Row#applyProperties} to initialize
	 * the properties, defined in the component definition, properly.
	 *
	 * <p>If null is returned, the default row is created as follow.
<pre><code>
final Row row = new Row();
row.applyProperties();
return row;
</code></pre>
	 *
	 * <p>Note: DO NOT call {@link Row#setParent}.
	 *
	 * @return the row if you'd like to create it differently, or null
	 * if you want {@link Grid} to create it for you
	 */
	public Row newRow(Grid grid);
	/** Create a component as the first cell of the row.
	 *
	 * <p>Note: remember to invoke {@link Component#applyProperties} to
	 * initialize the properties, defined in the component definition, properly,
	 * if you create an instance instead of returning null.
	 *
	 * <p>Note: DO NOT call {@link Row#setParent}.
	 *
	 * <p>If null is returned, the default cell is created as follow.
<pre><code>
final Label cell = new Label();
cell.applyProperties();
return cell;
</code></pre>
	 *
	 * <p>Note: DO NOT call {@link Component#setParent}.
	 * Don't create cells for other columns.
	 *
	 * @param row the row. It is the same as that is returned
	 * by {@link #newRow}
	 * @return the cell if you'd like to create it differently, or null
	 * if you want {@link Grid} to create it for you
	 */
	public Component newCell(Row row);

	/** Returned by {@link #getControls} to indicate
	 * to detach the cell adde by {@link #newCell}.
	 *
	 * <p>To simplify the implementation of {@link RowRenderer#render},
	 * {@link Listbox}, by default, detached the cell before calling
	 * {@link RowRenderer#render} -- as if this flag is returned.
	 *
	 * <p>If you don't specify this flag, the implementation of 
	 * {@link RowRenderer#render} must be aware of the existence of
	 * the first cell
	 * (of the passed row).
	 */
	public static final int DETACH_ON_RENDER = 0x0001;
	/** Returned by {@link #getControls} to indicate
	 * whether to detach a rendered row when unloading it.
	 *
	 * <p>When a row has to be cleaned up
	 * (so it can be re-rendered again), the grid
	 * checks whether this flag is returned.
	 * For example, when a new data model is assigned, all rendered rows
	 * (i.e., generated by {@link RowRenderer#render}) will be cleaned up.
	 *
	 *<p>To have the best performance,
	 * the grid, by default, keep using the same row and
	 * the first cell (other cells, if any, are removed).
	 *
	 * <p>Sometimes it could be an issue. For example, you assign attributes
	 * or annotations to a rendered row.
	 * Then, you'd better to return this flag to indicate that.
	 * a new row shall be created (by calling {@link #newRow} and {@link #newCell})
	 * to replace the renderred row.
	 */
	public static final int DETACH_ON_UNLOAD = 0x0002;
	/** Returns how a grid shall render the live data.
	 *
	 * <p>Note: if this interface is not implemented, {@link #DETACH_ON_RENDER}
	 * is assumed.
	 *
	 * @return a combination of {@link #DETACH_ON_RENDER} and
	 * {@link #DETACH_ON_UNLOAD} to indicate how to render the live data.
	 */
	public int getControls();
}