listbox.java

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	throws ClassNotFoundException, NoSuchMethodException,
	InstantiationException, java.lang.reflect.InvocationTargetException {
		if (clsnm != null)
			setItemRenderer((ListitemRenderer)Classes.newInstanceByThread(clsnm));
	}

	/** Synchronizes the listbox to be consistent with the specified model.
	 * @param min the lower index that a range of invalidated items
	 * @param max the higher index that a range of invalidated items
	 */
	private void syncModel(int min, int max) {
		final int newsz = _model.getSize();
		final int oldsz = getItemCount();
		if (oldsz > 0) {
			if (newsz > 0 && min < oldsz) {
				if (max < 0 || max >= oldsz) max = oldsz - 1;
				if (max >= newsz) max = newsz - 1;
				if (min < 0) min = 0;

				for (Iterator it = _items.listIterator(min);
				min <= max && it.hasNext(); ++min)
					clearItemAsUnloaded((Listitem)it.next());
			}

			for (int j = newsz; j < oldsz; ++j)
				getItemAtIndex(newsz).detach(); //detach and remove
		}

		for (int j = oldsz; j < newsz; ++j)
			newUnloadedItem().setParent(this);
	}
	/** Creates an new and unloaded listitem. */
	private static Listitem newUnloadedItem() {
		final Listitem item = new Listitem();
		item.applyProperties();
		item.setLoaded(false);

		final Listcell cell = new Listcell();
		cell.applyProperties();
		cell.setParent(item); //an empty listheader
		return item;
	}
	/** Clears a listitem as if it is not loaded. */
	private static void clearItemAsUnloaded(Listitem item) {
		final List cells = item.getChildren();
		if (cells.isEmpty()) {
			final Listcell cell = new Listcell();
			cell.applyProperties();
			cell.setParent(item);
		} else {
			final Listcell listcell = (Listcell)cells.get(0);
			listcell.setLabel(null);
			listcell.setImage(null);
			for (int k = cells.size(); --k > 0;)
				((Component)cells.get(1)).detach(); //detach and remove
		}
		item.setLoaded(false);
	}
	/** Handles a private event, onInitRender. It is used only for
	 * implementation, and you rarely need to invoke it explicitly.
	 */
	public void onInitRender() {
		final Renderer renderer = new Renderer();
		try {
			final int pgsz = inSelectMold() ? getItemCount():
				inPagingMold() ? _pgi.getPageSize(): _rows;
			int j = 0;
			for (Iterator it = getItems().iterator(); j < pgsz && it.hasNext(); ++j)
				renderer.render((Listitem)it.next());
		} catch (Throwable ex) {
			renderer.doCatch(ex);
		} finally {
			renderer.doFinally();
		}
	}

	/** Handles when the list model's content changed.
	 */
	private void onListDataChange(ListDataEvent event) {
		if (inSelectMold()) {
			invalidate();
			syncModel(-1, -1);
			Events.postEvent("onInitRender", this, null);
			return;
		}

		//when this is called _model is never null
		final int newsz = _model.getSize(), oldsz = getItemCount();
		int min = event.getIndex0(), max = event.getIndex1();
		if (min < 0) min = 0;

		boolean done = false;
		switch (event.getType()) {
		case ListDataEvent.INTERVAL_ADDED:
			if (max < 0) max = newsz - 1;
			if ((max - min + 1) != (newsz - oldsz)) {
				log.warning("Conflict event: number of added items not matched: "+event);
				break; //handle it as CONTENTS_CHANGED
			}
			final Listitem before = min < oldsz ? getItemAtIndex(min): null;
			for (int j = min; j <= max; ++j)
				insertBefore(newUnloadedItem(), before);
			done = true;
			break;

		case ListDataEvent.INTERVAL_REMOVED:
			if (max < 0) max = oldsz - 1;
			if ((max - min + 1) != (oldsz - newsz)) {
				log.warning("Conflict event: number of removed items not matched: "+event);
				break; //handle it as CONTENTS_CHANGED
			}
			for (int j = min; j <= max; ++j)
				getItemAtIndex(min).detach(); //detach and remove
			done = true;
			break;
		}

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

		initAtClient();
			//client have to send back for what have to reload
	}

	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);
		}
	};

	/** 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 = Listbox.this._renderer != null ?
				Listbox.this._renderer: getDefaultItemRenderer();
		}
		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.getChildren().get(0);
			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 (_rendered)
				initAtClient();
					//reason: after rendering, the column width might change
					//Also: Mozilla remembers scrollTop when user's pressing
					//RELOAD, it makes init more desirable.
			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.
	 */
	public void renderItem(Listitem li) {
		if (_model == null) return;

		final Renderer renderer = new Renderer();
		try {
			renderer.render(li);
		} catch (Throwable ex) {
			renderer.doCatch(ex);
		} finally {
			renderer.doFinally();
		}
	}
	/** Renders all {@link Listitem} if not loaded yet,
	 * with {@link #getItemRenderer}.
	 */
	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();
		}
	}

	//-- RenderOnDemand --//
	public void renderItems(Set items) {
		if (_model == null) { //just in case that app dev might change it
			if (log.debugable()) log.debug("No model no render");
			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 void setHeight(String height) {
		if (!Objects.equals(height, getHeight())) {
			super.setHeight(height);
			if (!inSelectMold()) initAtClient();
		}
	}
	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 (_readonly)
				HTMLs.appendAttribute(sb, "readonly", "readonly");
		} else {
			HTMLs.appendAttribute(sb, "z.name", _name);
			HTMLs.appendAttribute(sb, "z.size",  _rows);
			if (_disabled)
				HTMLs.appendAttribute(sb, "z.disabled",  true);
			if (_readonly)
				HTMLs.appendAttribute(sb, "z.readonly", 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);
		}

		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) {
				int v = _j;
				if (_listhead != null) ++v;
				_it = getChildren().listIterator(v);
			}
		}
	}

	//Cloneable//
	public Object clone() {
		final Listbox clone = (Listbox)super.clone();
		int cnt = clone._selItems.size();

		clone.init();

		if (clone._listhead != null) ++cnt;
		if (clone._listfoot != null) ++cnt;
		if (cnt > 0) clone.afterUnmarshal(cnt);

		return clone;
	}
	/** @param cnt # of children that need special handling (used for optimization).
	 * -1 means process all of them
	 */
	private void afterUnmarshal(int cnt) {
		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.setIndex(index ++); //since Listitem.clone() resets index
				if (li.isSelected()) {
					_selItems.add(li);
					if (--cnt == 0) break;
				}
			} else if (child instanceof Listhead) {
				_listhead = (Listhead)child;
				if (--cnt == 0) break;
			} else if (child instanceof Listfoot) {
				_listfoot = (Listfoot)child;
				if (--cnt == 0) break;
			} else if (child instanceof Paging) {
				_pgi = _paging = (Paging)child;
				if (--cnt == 0) break;
			}
		}
	}

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

		init();

		afterUnmarshal(-1);
		//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 Selectable, ChildChangedAware, Cropper {
		//ChildChangedAware//
		public boolean isChildChangedAware() {
			return !inSelectMold();
		}

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

			final Set avail = new HashSet(37);
			if (_listhead != null) avail.add(_listhead);
			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;
			}
		}
	}
}