rows.java

非常接近C/S操作方式的Java Ajax框架－ZK 用ZK框架使你的B/S应用程序更漂亮更易操作。 官网：www.zkoss.org

/* Rows.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Tue Oct 25 16:02:39     2005, Created by tomyeh
}}IS_NOTE

Copyright (C) 2005 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 java.util.Set;
import java.util.HashSet;
import java.util.Iterator;

import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.ext.render.Cropper;

import org.zkoss.zul.impl.XulElement;
import org.zkoss.zul.ext.Paginal;

/**
 * Defines the rows of a grid.
 * Each child of a rows element should be a {@link Row} element.
 *
 * @author tomyeh
 */
public class Rows extends XulElement {
	/** Returns the grid that contains this rows. */
	public Grid getGrid() {
		return (Grid)getParent();
	}

	//Paging//
	/** Returns the index of the first visible child.
	 * <p>Used only for component development, not for application developers.
	 */
	public int getVisibleBegin() {
		final Grid grid = getGrid();
		if (grid == null || !grid.inPagingMold())
			return 0;
		final Paginal pgi = grid.getPaginal();
		return pgi.getActivePage() * pgi.getPageSize();
	}
	/** Returns the index of the last visible child.
	 * <p>Used only for component development, not for application developers.
	 */
	public int getVisibleEnd() {
		final Grid grid = getGrid();
		if (grid == null || !grid.inPagingMold())
			return Integer.MAX_VALUE;
		final Paginal pgi = grid.getPaginal();
		return (pgi.getActivePage() + 1) * pgi.getPageSize() - 1; //inclusive
	}

	//-- Component --//
	public void setParent(Component parent) {
		if (parent != null && !(parent instanceof Grid))
			throw new UiException("Unsupported parent for rows: "+parent);
		final boolean changed = getParent() != parent;
		super.setParent(parent);
		if (changed && parent != null) ((Grid)parent).initAtClient();
	}
	public boolean insertBefore(Component child, Component insertBefore) {
		if (!(child instanceof Row))
			throw new UiException("Unsupported child for rows: "+child);
		return super.insertBefore(child, insertBefore);
	}
	public void onChildAdded(Component child) {
		super.onChildAdded(child);

		final Grid grid = getGrid();
		if (grid != null) {
			grid.initAtClient();
			if (grid.inPagingMold())
				grid.getPaginal().setTotalSize(getChildren().size());
		}
	}
	public void onChildRemoved(Component child) {
		super.onChildRemoved(child);

		final Grid grid = getGrid();
		if (grid != null) {
			grid.initAtClient();
			if (grid.inPagingMold())
				grid.getPaginal().setTotalSize(getChildren().size());
		}
    }

	//-- ComponentCtrl --//
	protected Object newExtraCtrl() {
		return new ExtraCtrl();
	}
	/** A utility class to implement {@link #getExtraCtrl}.
	 * It is used only by component developers.
	 */
	protected class ExtraCtrl extends XulElement.ExtraCtrl implements Cropper {
		//--Cropper--//
		public boolean isCropper() {
			final Grid grid = getGrid();
			return grid != null && grid.inPagingMold();
		}
		public Set getAvailableAtClient() {
			final Grid grid = getGrid();
			if (grid == null || !grid.inPagingMold())
				return null;

			final Set avail = new HashSet(37);
			final Paginal pgi = grid.getPaginal();
			int pgsz = pgi.getPageSize();
			final int ofs = pgi.getActivePage() * pgsz;
			for (final Iterator it = getChildren().listIterator(ofs);
			--pgsz >= 0 && it.hasNext();)
				avail.add(it.next());
			return avail;
		}
	}
}