tree.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

/* Tree.java

{{IS_NOTE
	Purpose:
		
	Description:
		
	History:
		Wed Jul  6 18:51:33     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.List;
import java.util.Set;
import java.util.LinkedHashSet;
import java.util.Iterator;
import java.util.Collection;
import java.util.Collections;
import java.util.ArrayList;

import org.zkoss.lang.Objects;
import org.zkoss.xml.HTMLs;

import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.WrongValueException;
import org.zkoss.zk.ui.ext.client.Selectable;
import org.zkoss.zk.ui.ext.render.ChildChangedAware;
import org.zkoss.zk.ui.event.Events;

import org.zkoss.zul.impl.XulElement;

/**
 *  A container which can be used to hold a tabular
 * or hierarchical set of rows of elements.
 *
 * <p>Event:
 * <ol>
 * <li>org.zkoss.zk.ui.event.SelectEvent is sent when user changes
 * the selection.</li>
 * </ol>
 *
 * <p>Default {@link #getSclass}: tree.
 *
 * @author tomyeh
 */
public class Tree extends XulElement {
	private transient Treecols _treecols;
	private transient Treechildren _treechildren;
	/** A list of selected items. */
	private transient Set _selItems;
	/** The first selected item. */
	private transient Treeitem _sel;
	private int _rows = 0;
	/** The name. */
	private String _name;
	private boolean _multiple, _checkmark;
	private boolean _vflex;
	/** disable smartUpdate; usually caused by the client. */
	private transient boolean _noSmartUpdate;

	public Tree() {
		init();
		setSclass("tree");
	}
	private void init() {
		_selItems = new LinkedHashSet(5);
	}

	/** Returns the treecols that this tree owns (might null).
	 */
	public Treecols getTreecols() {
		return _treecols;
	}
	/** Returns the treechildren that this tree owns (might null).
	 */
	public Treechildren getTreechildren() {
		return _treechildren;
	}

	/** Returns the rows. Zero means no limitation.
	 * <p>Default: 0.
	 */
	public int getRows() {
		return _rows;
	}
	/** Sets the rows.
	 * <p>Note: if both {@link #setHeight} is specified with non-empty,
	 * {@link #setRows} is ignored
	 */
	public void setRows(int rows) throws WrongValueException {
		if (rows < 0)
			throw new WrongValueException("Illegal rows: "+rows);

		if (_rows != rows) {
			_rows = rows;
			smartUpdate("z.size", Integer.toString(_rows));
			initAtClient();
				//Don't use smartUpdate because client has to extra job
				//besides maintaining HTML DOM
		}
	}

	/** Returns the name of this component.
	 * <p>Default: null.
	 * <p>Don't use this method if your application is purely based
	 * on ZK's event-driven model.
	 * <p>The name is used only to work with "legacy" Web application that
	 * handles user's request by servlets.
	 * It works only with HTTP/HTML-based browsers. It doesn't work
	 * with other kind of clients.
	 */
	public String getName() {
		return _name;
	}
	/** Sets the name of this component.
	 * <p>Don't use this method if your application is purely based
	 * on ZK's event-driven model.
	 * <p>The name is used only to work with "legacy" Web application that
	 * handles user's request by servlets.
	 * It works only with HTTP/HTML-based browsers. It doesn't work
	 * with other kind of clients.
	 *
	 * @param name the name of this component.
	 */
	public void setName(String name) {
		if (name != null && name.length() == 0) name = null;
		if (!Objects.equals(_name, name)) {
			if (_name != null) smartUpdate("z.name", _name);
			else invalidate(); //1) generate _value; 2) add submit listener
			_name = name;
		}
	}

	/** Returns whether the check mark shall be displayed in front
	 * of each item.
	 * <p>Default: false.
	 */
	public final boolean isCheckmark() {
		return _checkmark;
	}
	/** Sets whether the check mark shall be displayed in front
	 * of each item.
	 * <p>The check mark is a checkbox if {@link #isMultiple} returns
	 * true. It is a radio button if {@link #isMultiple} returns false.
	 */
	public void setCheckmark(boolean checkmark) {
		if (_checkmark != checkmark) {
			_checkmark = checkmark;
			invalidate();
		}
	}

	/** Returns whether to grow and shrink vertical to fit their given space,
	 * so called vertial flexibility.
	 *
	 * <p>Note: this attribute is ignored if {@link #setRows} is specified
	 *
	 * <p>Default: false.
	 */
	public final boolean isVflex() {
		return _vflex;
	}
	/** Sets whether to grow and shrink vertical to fit their given space,
	 * so called vertial flexibility.
	 *
	 * <p>Note: this attribute is ignored if {@link #setRows} is specified
	 */
	public void setVflex(boolean vflex) {
		if (_vflex != vflex) {
			_vflex = vflex;
			smartUpdate("z.flex", _vflex);
		}
	}

	/** Returns the seltype.
	 * <p>Default: "single".
	 */
	public String getSeltype() {
		return _multiple ? "multiple": "single";
	}
	/** Sets the seltype.
	 * Currently, only "single" is supported.
	 */
	public void setSeltype(String seltype) throws WrongValueException {
		if ("single".equals(seltype)) setMultiple(false);
		else if ("multiple".equals(seltype)) setMultiple(true);
		else throw new WrongValueException("Unknown seltype: "+seltype);
	}
	/** Returns whether multiple selections are allowed.
	 * <p>Default: false.
	 */
	public boolean isMultiple() {
		return _multiple;
	}
	/** Sets whether multiple selections are allowed.
	 */
	public void setMultiple(boolean multiple) {
		if (_multiple != multiple) {
			_multiple = multiple;
			if (!_multiple && _selItems.size() > 1) {
				final Treeitem item = getSelectedItem();
				_selItems.clear();
				if (item != null)
					_selItems.add(item);
				//No need to update z.selId because z.multiple will do the job
			}
			if (isCheckmark()) invalidate(); //change check mark
			else smartUpdate("z.multiple", _multiple);
		}
	}
	/** Returns the ID of the selected item (it is stored as the z.selId
	 * attribute of the tree).
	 */
	private String getSelectedId() {
		//NOTE: Treerow's uuid; not Treeitem's
		final Treerow tr = _sel != null ? _sel.getTreerow(): null;
		return tr != null ? tr.getUuid(): "zk_n_a";
	}

	/** Returns a readonly list of all descending {@link Treeitem}
	 * (children's children and so on).
	 *
	 * <p>Note: the performance of the size method of returned collection
	 * is no good.
	 */
	public Collection getItems() {
		return _treechildren != null ? _treechildren.getItems(): Collections.EMPTY_LIST;
	}
	/** Returns the number of child {@link Treeitem}.
	 * The same as {@link #getItems}.size().
	 * <p>Note: the performance of this method is no good.
	 */
	public int getItemCount() {
		return _treechildren != null ? _treechildren.getItemCount(): 0;
	}

	/**  Deselects all of the currently selected items and selects
	 * the given item.
	 * <p>It is the same as {@link #setSelectedItem}.
	 * @param item the item to select. If null, all items are deselected.
	 */
	public void selectItem(Treeitem item) {
		if (item == null) {
			clearSelection();
		} else {
			if (item.getTree() != this)
				throw new UiException("Not a child: "+item);

			if (_sel != item
			|| (_multiple && _selItems.size() > 1)) {
				for (Iterator it = _selItems.iterator(); it.hasNext();) {
					final Treeitem ti = (Treeitem)it.next();
					ti.setSelectedDirectly(false);
				}
				_selItems.clear();

				_sel = item;
				item.setSelectedDirectly(true);
				_selItems.add(item);

				final Treerow tr = item.getTreerow();
				if (tr != null)
					smartUpdate("select", tr.getUuid());
			}
		}
	}
	/** Selects the given item, without deselecting any other items
	 * that are already selected..
	 */
	public void addItemToSelection(Treeitem item) {
		if (item.getTree() != this)
			throw new UiException("Not a child: "+item);

		if (!item.isSelected()) {
			if (!_multiple) {
				selectItem(item);
			} else {
				item.setSelectedDirectly(true);
				_selItems.add(item);
				smartUpdateSelection();
				if (fixSelected())
					smartUpdate("z.selId", getSelectedId());
			}
		}
	}
	/**  Deselects the given item without deselecting other items.
	 */
	public void removeItemFromSelection(Treeitem item) {
		if (item.getTree() != this)
			throw new UiException("Not a child: "+item);

		if (item.isSelected()) {
			if (!_multiple) {
				clearSelection();
			} else {
				item.setSelectedDirectly(false);
				_selItems.remove(item);
				smartUpdateSelection();
				if (fixSelected())
					smartUpdate("z.selId", getSelectedId());
				//No need to use response because such info is carried on tags
			}
		}
	}
	/** Note: we have to update all selection at once, since addItemToSelection
	 * and removeItemFromSelection might be called interchangeably.
	 */
	private void smartUpdateSelection() {
		final StringBuffer sb = new StringBuffer(80);
		for (Iterator it = _selItems.iterator(); it.hasNext();) {
			final Treeitem item = (Treeitem)it.next();
			final Treerow tr = item.getTreerow();
			if (tr != null) {
				if (sb.length() > 0) sb.append(',');
				sb.append(tr.getUuid());
			}			
		}
		smartUpdate("chgSel", sb.toString());
	}
	/** If the specified item is selected, it is deselected.
	 * If it is not selected, it is selected. Other items in the tree
	 * that are selected are not affected, and retain their selected state.
	 */
	public void toggleItemSelection(Treeitem item) {
		if (item.isSelected()) removeItemFromSelection(item);
		else addItemToSelection(item);
	}
	/** Clears the selection.
	 */
	public void clearSelection() {
		if (!_selItems.isEmpty()) {
			for (Iterator it = _selItems.iterator(); it.hasNext();) {
				final Treeitem item = (Treeitem)it.next();
				item.setSelectedDirectly(false);
			}