Java tutorial
// Copyright 2006 Chibacon /* * * Artistic License * * Preamble * * The intent of this document is to state the conditions under which a Package may be copied, such that * the Copyright Holder maintains some semblance of artistic control over the development of the * package, while giving the users of the package the right to use and distribute the Package in a * more-or-less customary fashion, plus the right to make reasonable modifications. * * Definitions: * * "Package" refers to the collection of files distributed by the Copyright Holder, and derivatives * of that collection of files created through textual modification. * * "Standard Version" refers to such a Package if it has not been modified, or has been modified * in accordance with the wishes of the Copyright Holder. * * "Copyright Holder" is whoever is named in the copyright or copyrights for the package. * * "You" is you, if you're thinking about copying or distributing this Package. * * "Reasonable copying fee" is whatever you can justify on the basis of media cost, duplication * charges, time of people involved, and so on. 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THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. * */ package org.chiba.xml.xforms.ui; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.xerces.dom.ElementImpl; import org.chiba.xml.dom.DOMUtil; import org.chiba.xml.events.ChibaEventNames; import org.chiba.xml.events.XMLEvent; import org.chiba.xml.ns.NamespaceConstants; import org.chiba.xml.xforms.XFormsElement; import org.chiba.xml.xforms.core.Bind; import org.chiba.xml.xforms.core.Instance; import org.chiba.xml.xforms.core.Model; import org.chiba.xml.xforms.exception.XFormsException; import org.chiba.xml.xforms.ui.state.RepeatElementState; import org.chiba.xml.xpath.XPathUtil; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.w3c.dom.events.Event; import org.w3c.dom.events.EventListener; import java.util.ArrayList; import java.util.HashMap; import java.util.List; /** * Implementation of <b>9.3.1 The repeat Element</b>. * * @author Ulrich Nicolas Lissé * @version $Id: Repeat.java,v 1.1 2009/02/17 09:00:53 civilis Exp $ */ public class Repeat extends BindingElement implements EventListener { protected static Log LOGGER = LogFactory.getLog(Repeat.class); private int index; private Element prototype; private List items; /** * Creates a new repeat element handler. * * @param element the host document element. * @param model the context model. */ public Repeat(Element element, Model model) { super(element, model); } // event handling methods /** * This method is called whenever an event occurs of the type for which the * <code>EventListener</code> interface was registered. * * @param event The <code>Event</code> contains contextual information about * the event. It also contains the <code>stopPropagation</code> and * <code>preventDefault</code> methods which are used in determining the * event's flow and default action. */ public void handleEvent(Event event) { try { if (ChibaEventNames.NODE_INSERTED.equals(event.getType())) { handleNodeInserted(event); return; } if (ChibaEventNames.NODE_DELETED.equals(event.getType())) { handleNodeDeleted(event); return; } } catch (Exception e) { // handle exception, prevent default action and stop event propagation this.container.handleEventException(e); event.preventDefault(); event.stopPropagation(); } } // repeat specific methods /** * Returns the repeat index. * * @return the repeat index. */ public int getIndex() { return this.index; } /** * Sets the index of this <code>repeat</code>. * * @param index the index of this <code>repeat</code>. */ public void setIndex(int index) throws XFormsException { if (getLogger().isDebugEnabled()) { getLogger().debug(this + " set index: " + index); } // update index this.index = index; notifyIndexChange(); if (isRepeated()) { // set enclosing index RepeatItem repeatItem = (RepeatItem) this.container.lookup(getRepeatItemId()); repeatItem.getRepeat().setIndex(repeatItem.getPosition()); } else { // register repeat item under original id registerRepeatItem(index); } } /** * Returns the context size of this repeat. * <p/> * The context size is the size of the bound nodeset. * * @return the context size of this repeat. */ public int getContextSize() { if (isBound()) { return this.model.getInstance(getInstanceId()).countNodeset(getLocationPath()); } return 0; } /** * Returns the specified repeat item. * * @param position the repeat item position. * @return the specified repeat item or <code>null</code> if there is no * such position. */ public RepeatItem getRepeatItem(int position) { if (position > 0 && position <= this.items.size()) { return (RepeatItem) this.items.get(position - 1); } return null; } /** * Returns the repeat prototype element. * * @return the repeat prototype element. */ public Element getPrototype() { return this.prototype; } // binding related methods /** * Checks wether this element has a model binding. * <p/> * This element has a model binding if it has a <code>bind</code> or a * <code>repeat-bind</code> attribute. * * @return <code>true</code> if this element has a model binding, otherwise * <code>false</code>. */ public boolean hasModelBinding() { return getXFormsAttribute(REPEAT_BIND_ATTRIBUTE) != null || getXFormsAttribute(BIND_ATTRIBUTE) != null; } /** * Checks wether this element has an ui binding. * <p/> * This element has an ui binding if it has a <code>nodeset</code> or a * <code>repeat-nodeset</code> attribute. * * @return <code>true</code> if this element has an ui binding, otherwise * <code>false</code>. */ public boolean hasUIBinding() { return getXFormsAttribute(REPEAT_NODESET_ATTRIBUTE) != null || getXFormsAttribute(NODESET_ATTRIBUTE) != null; } /** * Returns the model binding of this element. * * @return the model binding of this element. */ public Bind getModelBinding() { String bindAttribute = getXFormsAttribute(REPEAT_BIND_ATTRIBUTE); if (bindAttribute != null) { return (Bind) this.container.lookup(bindAttribute); } return super.getModelBinding(); } /** * Returns the binding expression. * * @return the binding expression. */ public String getBindingExpression() { String nodesetAttribute = getXFormsAttribute(REPEAT_NODESET_ATTRIBUTE); if (nodesetAttribute != null) { return nodesetAttribute; } nodesetAttribute = getXFormsAttribute(NODESET_ATTRIBUTE); if (nodesetAttribute != null) { return nodesetAttribute; } return null; } // lifecycle methods /** * Performs element init. * * @throws XFormsException if any error occurred during init. */ public void init() throws XFormsException { if (getLogger().isDebugEnabled()) { getLogger().debug(this + " init"); } initializeDefaultAction(); initializeInstanceNode(); initializePrototype(); initializeElementState(); initializeRepeat(); } /** * Performs element update. * * @throws XFormsException if any error occurred during update. */ public void refresh() throws XFormsException { if (getLogger().isDebugEnabled()) { getLogger().debug(this + " update"); } updateRepeat(); updateElementState(); updateChildren(); } /** * Performs element disposal. * * @throws XFormsException if any error occurred during disposal. */ public void dispose() throws XFormsException { if (getLogger().isDebugEnabled()) { getLogger().debug(this + " dispose"); } disposeDefaultAction(); disposeChildren(); disposeElementState(); disposeRepeat(); disposeSelf(); } // template methods /** * Factory method for the element state. * * @return an element state implementation or <code>null</code> if no state * keeping is required. * @throws XFormsException if an error occurred during creation. */ protected UIElementState createElementState() throws XFormsException { return isBound() ? new RepeatElementState() : null; } // lifecycle template methods /** * Initializes this repeat. * <p/> * The repeat prototype is cloned and removed from the document. The data * element is initialized with the prototype data. */ protected void initializePrototype() throws XFormsException { // create prototype element Document document = this.element.getOwnerDocument(); this.prototype = document.createElementNS(NamespaceConstants.XFORMS_NS, this.xformsPrefix + ":" + GROUP); this.prototype.setAttributeNS(null, "id", this.container.generateId()); this.prototype.setAttributeNS(null, APPEARANCE_ATTRIBUTE, "repeated"); // clone repeat prototype NodeList children = this.element.getChildNodes(); for (int index = 0; index < children.getLength(); index++) { initializePrototype(this.prototype, children.item(index)); } // remove repeat prototype DOMUtil.removeAllChildren(this.element); } /** * Initializes this repeat. * <p/> * The repeat is registered with the instance as event listener. For each * node in the bound nodeset repeat items are created and initialized. The * repeat index is set to 1, unless the bound nodeset is empty. The repeat * is registered with the instance as event listener. */ protected void initializeRepeat() throws XFormsException { // register repeat as event listener *before* items are initialized Instance instance = this.model.getInstance(getInstanceId()); instance.getTarget().addEventListener(ChibaEventNames.NODE_INSERTED, this, false); instance.getTarget().addEventListener(ChibaEventNames.NODE_DELETED, this, false); // initialize repeat items int count = getContextSize(); this.items = new ArrayList(count); if (count > 0) { // set index before item initialization, notify index change later this.index = 1; } if (element.hasAttributeNS(NamespaceConstants.CHIBA_NS, "index")) { //we're initializing a deserialized form this.index = Integer.parseInt(element.getAttributeNS(NamespaceConstants.CHIBA_NS, "index")); } if (getLogger().isDebugEnabled()) { getLogger().debug(this + " init: initializing " + count + " repeat item(s)"); } for (int position = 1; position < count + 1; position++) { this.items.add(initializeRepeatItem(position)); } if (count > 0) { // register selected item with original id registerRepeatItem(this.index); // notify index change notifyIndexChange(); } } /** * Updates this repeat. * <p/> * The list of repeat items is synchronized with the bound nodeset. */ protected void updateRepeat() throws XFormsException { // check context size (bound nodeset count) against ui size (repeat item count) int contextSize = getContextSize(); int uiSize = this.items.size(); if (contextSize < uiSize) { // remove obsolete repeat items if (getLogger().isDebugEnabled()) { getLogger().debug(this + " update: disposing " + (uiSize - contextSize) + " repeat item(s)"); } for (int position = uiSize; position > contextSize; position--) { disposeRepeatItem((RepeatItem) this.items.remove(position - 1)); } if (getIndex() > contextSize) { // set index to last setIndex(contextSize); } } if (contextSize > uiSize) { // add missing repeat items if (getLogger().isDebugEnabled()) { getLogger().debug(this + " update: initializing " + (contextSize - uiSize) + " repeat item(s)"); } for (int position = uiSize + 1; position <= contextSize; position++) { this.items.add(initializeRepeatItem(position)); } if (getIndex() == 0) { // set index to first setIndex(1); } } } /** * Disposes this repeat. * <p/> * The repeat is deregistered as event listener. The list of repeat items * and the repeat prototype are freed. */ protected void disposeRepeat() throws XFormsException { // deregister repeat as event listener Instance instance = this.model.getInstance(getInstanceId()); instance.getTarget().removeEventListener(ChibaEventNames.NODE_INSERTED, this, false); instance.getTarget().removeEventListener(ChibaEventNames.NODE_DELETED, this, false); // free repeat items and prototype this.items.clear(); this.items = null; this.prototype = null; } // event handling template methods protected void handleNodeInserted(Event event) throws XFormsException { if (doHandleInstanceEvent(event)) { // get nodeset position int contextPosition = Integer.parseInt(String.valueOf(((XMLEvent) event).getContextInfo("position"))); // get ui position int uiPosition = computeUIPosition(contextPosition); if (getLogger().isDebugEnabled()) { getLogger().debug(this + " insert: position " + uiPosition); } // insert repeat item this.items.add(uiPosition - 1, initializeRepeatItem(uiPosition)); // update position of following items for (int index = uiPosition; index < this.items.size(); index++) { ((RepeatItem) this.items.get(index)).setPosition(index + 1); } // set index to inserted item setIndex(uiPosition); } } protected void handleNodeDeleted(Event event) throws XFormsException { if (doHandleInstanceEvent(event)) { // get nodeset position int contextPosition = Integer.parseInt(String.valueOf(((XMLEvent) event).getContextInfo("position"))); // get ui position int uiPosition = computeUIPosition(contextPosition); if (getLogger().isDebugEnabled()) { getLogger().debug(this + " delete: position " + uiPosition); } // delete repeat item disposeRepeatItem((RepeatItem) this.items.remove(uiPosition - 1)); // update position of following items for (int index = uiPosition - 1; index < this.items.size(); index++) { ((RepeatItem) this.items.get(index)).setPosition(index + 1); } // set index only if it was pointing to the deleted item // and the deleted item was the last collection member int contextSize = getContextSize(); if (getIndex() > contextSize) { setIndex(contextSize); } } } // helper methods private boolean doHandleInstanceEvent(Event event) { // check context size int contextSize = getContextSize(); if (contextSize == 0) { return false; } // check instance nodeset String canonicalPath = this.model.getInstance(getInstanceId()).getPointer(getLocationPath()).asPath(); String canonicalNodeset = XPathUtil.getNodesetAndPredicates(canonicalPath)[0]; String insertNodeset = String.valueOf(((XMLEvent) event).getContextInfo("nodeset")); if (!canonicalNodeset.equals(insertNodeset)) { return false; } // check context size (bound nodeset count) against ui size (repeat item count) int uiSize = this.items.size(); return contextSize != uiSize; } private int computeUIPosition(int contextPosition) { int contextFirst = 0; int contextLast = 0; if (this.items.size() > 0) { contextFirst = ((RepeatItem) this.items.get(0)).getContextPosition(); contextLast = ((RepeatItem) this.items.get(this.items.size() - 1)).getContextPosition(); } // check lower bounds if (contextPosition <= contextFirst) { return 1; } // check upper bounds if (contextPosition > contextLast) { return this.items.size() + 1; } // search repeat item with a context position greater or equal than the given one RepeatItem repeatItem = (RepeatItem) this.items.get(0); for (int index = 1; index < this.items.size() && repeatItem.getContextPosition() < contextPosition; index++) { repeatItem = (RepeatItem) this.items.get(index); } // return ui position return repeatItem.getPosition(); } private void notifyIndexChange() throws XFormsException { // update element state this.elementState.setProperty("index", new Integer(this.index)); if (this.model.isReady()) { // dispatch internal chiba event HashMap map = new HashMap(); map.put("originalId", this.originalId != null ? this.originalId : this.id); map.put("index", String.valueOf(this.index)); this.container.dispatch(this.target, ChibaEventNames.INDEX_CHANGED, map); } } private void initializePrototype(Node parent, Node prototype) { Node copy = prototype.cloneNode(false); if (copy.getNodeType() == Node.ELEMENT_NODE) { Element element = (Element) copy; if (element.getAttributeNS(null, "id").length() == 0) { element.setAttributeNS(null, "id", this.container.generateId()); } NodeList children = prototype.getChildNodes(); for (int index = 0; index < children.getLength(); index++) { initializePrototype(element, children.item(index)); } } parent.appendChild(copy); } private RepeatItem initializeRepeatItem(int position) throws XFormsException { // detect reference node Node before = DOMUtil.findNthChildNS(this.element, NamespaceConstants.XFORMS_NS, GROUP, position); if (before == null) { before = DOMUtil.findFirstChildNS(this.element, NamespaceConstants.CHIBA_NS, "data"); } // create repeat item Element group = (Element) this.prototype.cloneNode(true); this.element.insertBefore(group, before); if (this.model.isReady()) { // dispatch internal chiba event HashMap map = new HashMap(); map.put("originalId", this.originalId != null ? this.originalId : this.id); map.put("prototypeId", this.prototype.getAttributeNS(null, "id")); this.container.dispatch(this.target, ChibaEventNames.PROTOTYPE_CLONED, map); } // initialize repeat item RepeatItem repeatItem = (RepeatItem) this.container.getElementFactory().createXFormsElement(group, getModel()); repeatItem.setRepeat(this); repeatItem.setPosition(position); repeatItem.setGeneratedId(this.container.generateId()); repeatItem.registerId(); repeatItem.init(); if (this.model.isReady()) { // dispatch internal chiba event HashMap map = new HashMap(); map.put("originalId", this.originalId != null ? this.originalId : this.id); map.put("position", String.valueOf(position)); this.container.dispatch(this.target, ChibaEventNames.ITEM_INSERTED, map); } return repeatItem; } private void disposeRepeatItem(RepeatItem repeatItem) throws XFormsException { // dispose repeat item Element element = repeatItem.getElement(); int position = repeatItem.getPosition(); repeatItem.dispose(); this.element.removeChild(element); if (this.model.isReady()) { // dispatch internal chiba event HashMap map = new HashMap(); map.put("originalId", this.originalId != null ? this.originalId : this.id); map.put("position", String.valueOf(position)); this.container.dispatch(this.target, ChibaEventNames.ITEM_DELETED, map); } } private void registerRepeatItem(int position) { RepeatItem repeatItem = getRepeatItem(position); if (repeatItem != null) { repeatItem.registerId(); registerChildren(repeatItem.getElement()); } } private void registerChildren(Node parent) { NodeList childNodes = parent.getChildNodes(); for (int index = 0; index < childNodes.getLength(); index++) { Node node = childNodes.item(index); if (node instanceof ElementImpl) { ElementImpl elementImpl = (ElementImpl) node; XFormsElement xFormsElement = (XFormsElement) elementImpl.getUserData(); if (xFormsElement != null) { // register current (action or ui) element xFormsElement.registerId(); if (xFormsElement instanceof Repeat) { // register *selected* repeat item only, if any Repeat repeat = (Repeat) xFormsElement; RepeatItem repeatItem = repeat.getRepeatItem(repeat.getIndex()); if (repeatItem != null) { repeatItem.registerId(); registerChildren(repeatItem.getElement()); } } else { // register *all* children registerChildren(xFormsElement.getElement()); } } } } } } // end of class