listbox.java

ZK 基础介绍 功能操作 模块 结合数据库操作

				log.warning("Conflict event: number of removed items not matched: "+event);
				break; //handle it as CONTENTS_CHANGED
			}

			//detach and remove
			for (Iterator it = getItems().listIterator(min);
			--cnt >= 0 && it.hasNext();) {
				it.next();
				it.remove();
			}

			done = true;
			break;
		}

		if (!done) //CONTENTS_CHANGED
			syncModel(min, max);

		postOnInitRender();
			//Bug 1823236: though fixed in JS, it improves performance
			//to save one roundtrip
	}

	private static final ListitemRenderer getDefaultItemRenderer() {
		return _defRend;
	}
	private static final ListitemRenderer _defRend = new ListitemRenderer() {
		public void render(Listitem item, Object data) {
			item.setLabel(Objects.toString(data));
			item.setValue(data);
		}
	};
	/** Returns the renderer used to render items.
	 */
	private ListitemRenderer getRealRenderer() {
		return _renderer != null ? _renderer: getDefaultItemRenderer();
	}

	/** Used to render listitem if _model is specified. */
	private class Renderer implements java.io.Serializable {
		private final ListitemRenderer _renderer;
		private boolean _rendered, _ctrled;

		private Renderer() {
			_renderer = getRealRenderer();
		}
		private void render(Listitem item) throws Throwable {
			if (item.isLoaded())
				return; //nothing to do

			if (!_rendered && (_renderer instanceof RendererCtrl)) {
				((RendererCtrl)_renderer).doTry();
				_ctrled = true;
			}

			final Listcell cell = (Listcell)item.getFirstChild();
			if (!(_renderer instanceof ListitemRendererExt)
			|| (((ListitemRendererExt)_renderer).getControls() & 
				ListitemRendererExt.DETACH_ON_RENDER) != 0) { //detach (default)
				cell.detach();
			}

			try {
				_renderer.render(item, _model.getElementAt(item.getIndex()));
			} catch (Throwable ex) {
				try {
					item.setLabel(Exceptions.getMessage(ex));
				} catch (Throwable t) {
					log.error(t);
				}
				item.setLoaded(true);
				throw ex;
			} finally {
				if (item.getChildren().isEmpty())
					cell.setParent(item);
			}

			item.setLoaded(true);
			_rendered = true;
		}
		private void doCatch(Throwable ex) {
			if (_ctrled) {
				try {
					((RendererCtrl)_renderer).doCatch(ex);
				} catch (Throwable t) {
					throw UiException.Aide.wrap(t);
				}
			} else {
				throw UiException.Aide.wrap(ex);
			}
		}
		private void doFinally() {
			if (_ctrled)
				((RendererCtrl)_renderer).doFinally();
		}
	}

	/** Renders the specified {@link Listitem} if not loaded yet,
	 * with {@link #getItemRenderer}.
	 *
	 * <p>It does nothing if {@link #getModel} returns null.
	 * In other words, it is meaningful only if live data model is used.
	 *
	 * @see #renderItems
	 * @see #renderAll
	 * @return the list item being passed to this method
	 */
	public Listitem renderItem(Listitem li) {
		if (_model != null && !li.isLoaded()) {
			final Renderer renderer = new Renderer();
			try {
				renderer.render(li);
			} catch (Throwable ex) {
				renderer.doCatch(ex);
			} finally {
				renderer.doFinally();
			}
		}
		return li;
	}
	/** Renders all {@link Listitem} if not loaded yet,
	 * with {@link #getItemRenderer}.
	 *
	 * @see #renderItem
	 * @see #renderItems
	 */
	public void renderAll() {
		if (_model == null) return;

		final Renderer renderer = new Renderer();
		try {
			for (Iterator it = getItems().iterator(); it.hasNext();)
				renderer.render((Listitem)it.next());
		} catch (Throwable ex) {
			renderer.doCatch(ex);
		} finally {
			renderer.doFinally();
		}
	}
	public void renderItems(Set items) {
		if (_model == null) return;

		if (items.isEmpty())
			return; //nothing to do

		final Renderer renderer = new Renderer();
		try {
			for (Iterator it = items.iterator(); it.hasNext();)
				renderer.render((Listitem)it.next());
		} catch (Throwable ex) {
			renderer.doCatch(ex);
		} finally {
			renderer.doFinally();
		}
	}

	//-- super --//
	public void setMold(String mold) {
		final String old = getMold();
		if (!Objects.equals(old, mold)) {
			super.setMold(mold);

			if ("paging".equals(old)) { //change from paging
				if (_paging != null) {
					removePagingListener(_paging);
					_paging.detach();
				} else if (_pgi != null) {
					removePagingListener(_pgi);
				}
			} else if (inPagingMold()) { //change to paging
				if (_pgi != null) addPagingListener(_pgi);
				else newInternalPaging();
			}
		}
	}
	
	public String getOuterAttrs() {
		final StringBuffer sb =
			new StringBuffer(80).append(super.getOuterAttrs());

		if (inSelectMold()) {
			HTMLs.appendAttribute(sb, "name", _name);
			HTMLs.appendAttribute(sb, "size",  getRows());

			if (isMultiple())
				HTMLs.appendAttribute(sb, "multiple",  "multiple");
			if (_disabled)
				HTMLs.appendAttribute(sb, "disabled",  "disabled");
			if (_tabindex >= 0)
				HTMLs.appendAttribute(sb, "tabindex", _tabindex);
		} else {
			HTMLs.appendAttribute(sb, "z.name", _name);
			HTMLs.appendAttribute(sb, "z.size",  _rows);
			if (_disabled)
				HTMLs.appendAttribute(sb, "z.disabled",  true);
			if (_multiple)
				HTMLs.appendAttribute(sb, "z.multiple", true);
			HTMLs.appendAttribute(sb, "z.selId", getSelectedId());
			//if (_checkmark)
			//	HTMLs.appendAttribute(sb, "z.checkmark",  true);
			if (_vflex)
				HTMLs.appendAttribute(sb, "z.vflex", true);
			if (_model != null)
				HTMLs.appendAttribute(sb, "z.model", true);

			if (_scOddRow != null)
				HTMLs.appendAttribute(sb, "z.scOddRow", _scOddRow);
		}

		appendAsapAttr(sb, Events.ON_SELECT);
		return sb.toString();
	}

	private class ItemIter implements ListIterator, java.io.Serializable {
		private ListIterator _it;
		private int _j;
		private boolean _bNxt;
		private ItemIter(int index) {
			_j = index;
		}
		public void add(Object o) {
			prepare();
			_it.add(o);
			++_j;
		}
		public boolean hasNext() {
			return _j < _items.size();
		}
		public boolean hasPrevious() {
			return _j > 0;
		}
		public Object next() {
			if (!hasNext())
				throw new NoSuchElementException();

			prepare();
			final Object o = _it.next();
			++_j;
			_bNxt = true;
			return o;
		}
		public Object previous() {
			if (!hasPrevious())
				throw new NoSuchElementException();

			prepare();
			final Object o = _it.previous();
			--_j;
			_bNxt = false;
			return o;
		}
		public int nextIndex() {
			return _j;
		}
		public int previousIndex() {
			return _j - 1;
		}
		public void remove() {
			if (_it == null) throw new IllegalStateException();
			_it.remove();
			if (_bNxt) --_j;
		}
		public void set(Object o) {
			if (_it == null) throw new IllegalStateException();
			_it.set(o);
		}
		private void prepare() {
			if (_it == null)
				_it = getChildren().listIterator(_j + _hdcnt);
		}
	}

	//Cloneable//
	public Object clone() {
		final Listbox clone = (Listbox)super.clone();
		clone.init();
		clone.afterUnmarshal();
		if (clone._model != null) {
			//we use the same data model but we have to create a new listener
			clone._dataListener = null;
			clone.initDataListener();
		}
		return clone;
	}
	private void afterUnmarshal() {
		int index = 0;
		for (Iterator it = getChildren().iterator(); it.hasNext();) {
			final Object child = it.next();
			if (child instanceof Listitem) {
				final Listitem li = (Listitem)child;
				li.setIndexDirectly(index ++); //since Listitem.clone() resets index
				if (li.isSelected()) {
					_selItems.add(li);
				}
			} else if (child instanceof Listhead) {
				_listhead = (Listhead)child;
			} else if (child instanceof Listfoot) {
				_listfoot = (Listfoot)child;
			} else if (child instanceof Paging) {
				_pgi = _paging = (Paging)child;
			}
		}
	}

	//-- Serializable --//
	private synchronized void readObject(java.io.ObjectInputStream s)
	throws java.io.IOException, ClassNotFoundException {
		s.defaultReadObject();

		init();

		afterUnmarshal();
		//TODO: how to marshal _pgi if _pgi != _paging
		//TODO: re-register event listener for onPaging

		if (_model != null) initDataListener();
	}

	//-- 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 InnerWidth, Selectable, Cropper, RenderOnDemand {
		//InnerWidth//
		public void setInnerWidthByClient(String width) {
			_innerWidth = width == null ? "100%": width;
		}

		//RenderOnDemand//
		public void renderItems(Set items) {
			int cnt = items.size();
			if (cnt == 0)
				return; //nothing to do
			cnt = 20 - cnt;

			if (cnt > 0 && _preloadsz > 0) { //Feature 1740072: pre-load
				if (cnt > _preloadsz) cnt = _preloadsz; //at most 8 more to load

				//1. locate the first item found in items
				final List toload = new LinkedList();
				Iterator it = _items.iterator();
				while (it.hasNext()) {
					final Listitem li = (Listitem)it.next();
					if (items.contains(li)) //found
						break;
					if (!li.isLoaded())
						toload.add(0, li); //reverse order
				}

				//2. add unload items before the found one
				if (!toload.isEmpty()) {
					int bfcnt = cnt/3;
					for (Iterator e = toload.iterator();
					bfcnt > 0 && e.hasNext(); --bfcnt, --cnt) {
						items.add(e.next());
					}
				}

				//3. add unloaded after the found one
				while (cnt > 0 && it.hasNext()) {
					final Listitem li = (Listitem)it.next();
					if (!li.isLoaded() && items.add(li))
						--cnt;
				}
			}

			Listbox.this.renderItems(items);
		}

		//--Cropper--//
		public boolean isCropper() {
			return inPagingMold();
		}
		public Set getAvailableAtClient() {
			if (!inPagingMold())
				return null;

			final Set avail = new HashSet(37);
			avail.addAll(_heads);
			if (_listfoot != null) avail.add(_listfoot);
			if (_paging != null) avail.add(_paging);
	
			final Paginal pgi = getPaginal();
			int pgsz = pgi.getPageSize();
			final int ofs = pgi.getActivePage() * pgsz;
			for (final Iterator it = getItems().listIterator(ofs);
			--pgsz >= 0 && it.hasNext();)
				avail.add(it.next());
			return avail;
		}

		//-- Selectable --//
		public void selectItemsByClient(Set selItems) {
			_noSmartUpdate = true;
			try {
				final boolean paging = inPagingMold();
				if (!_multiple
				|| (!paging && (selItems == null || selItems.size() <= 1))) {
					final Listitem item =
						selItems != null && selItems.size() > 0 ?
							(Listitem)selItems.iterator().next(): null;
					selectItem(item);
				} else {
					int from, to;
					if (paging) {
						final Paginal pgi = getPaginal();
						int pgsz = pgi.getPageSize();
						from = pgi.getActivePage() * pgsz;
						to = from + pgsz; //excluded
					} else {
						from = to = 0;
					}

					int j = 0;
					for (Iterator it = _items.iterator(); it.hasNext(); ++j) {
						final Listitem item = (Listitem)it.next();
						if (selItems.contains(item)) {
							addItemToSelection(item);
						} else if (!paging) {
							removeItemFromSelection(item);
						} else {
							final int index = item.getIndex();
							if (index >= from && index < to)
								removeItemFromSelection(item);
						}
					}
				}
			} finally {
				_noSmartUpdate = false;
			}
		}
	}
	/** An iterator used by _heads.
	 */
	private class Iter implements Iterator {
		private final Iterator _it = getChildren().iterator();
		private int _j;

		public boolean hasNext() {
			return _j < _hdcnt;
		}
		public Object next() {
			final Object o = _it.next();
			++_j;
			return o;
		}
		public void remove() {
			throw new UnsupportedOperationException();
		}
	}
}