Java tutorial
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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.jxpath.JXPathContext; import org.apache.log4j.Category; import org.chiba.xml.xforms.Model; import org.chiba.xml.xforms.NamespaceCtx; import org.chiba.xml.xforms.XFormsConstants; import org.chiba.xml.xforms.events.EventFactory; import org.chiba.xml.xforms.exception.XFormsException; import org.w3c.dom.Element; import java.util.Iterator; /** * Implementation of both <b>8.1.10 The select Element</b> and * <b>8.1.11 The select1 Element</b>. * * @author Ulrich Nicolas Lissé * @version $Id: Selector.java,v 1.3 2004/12/17 01:43:11 unl Exp $ */ public class Selector extends AbstractFormControl { private static final Category LOGGER = Category.getInstance(Selector.class); private boolean multiple; private JXPathContext context; /** * Creates a new selector. * * @param element the DOM Element of this selector. * @param model the Model this select1 is bound to. */ public Selector(Element element, Model model) { super(element, model); } /** * Checks wether this is a multiple selector or not. * * @return <code>true</code> if this is a multiple selector, otherwise * <code>false</code>. */ public boolean isMultiple() { return this.multiple; } /** * Specifies the behaviour of this selector. * * @param multiple specifies wether to allow multiple selections. */ public void setMultiple(boolean multiple) { this.multiple = multiple; } /** * Sets the value of this form control. * <p/> * The bound instance data is updated and the event sequence for this * control is executed. Event sequences are described in Chapter 4.6 of * XForms 1.0 Recommendation. * * @param value the value to be set. */ public void setValue(String value) throws XFormsException { if (isBound()) { this.model.getInstance(getInstanceId()).setNodeValue(getLocationPath(), value); dispatchSelectionWithoutValueChange(); dispatchValueChangeSequence(); } } // 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"); } initializeInstanceNode(); initializeDataElement(); initializeChildren(); initializeSelection(); initializeActions(); } /** * Performs element update. * * @throws XFormsException if any error occurred during update. */ public void update() throws XFormsException { if (getLogger().isDebugEnabled()) { getLogger().debug(this + " update"); } updateDataElement(); updateChildren(); updateSelection(); } // lifecycle template methods /** * Initializes all items' selection state. * <p/> * The selection state of all items is set according to the bound instance * value of this select. */ protected void initializeSelection() throws XFormsException { if (isBound()) { setSelection(true, false); } } /** * Updates all items' selection state. * <p/> * The selection state of any items which is not set according to the bound * instance value of this select is updated. */ protected void updateSelection() throws XFormsException { if (isBound()) { setSelection(false, false); } } /** * Updates all items' selection state and dispatches the appropriate * <code>xforms-select</code> and <code>xforms-deselect events</code>. * <p/> * The selection state of any items which is not set according to the bound * instance value of this select is updated. */ protected void dispatchSelectionWithoutValueChange() throws XFormsException { if (isBound()) { setSelection(false, true); } } /** * Returns the logger object. * * @return the logger object. */ protected Category getLogger() { return LOGGER; } // helper private void setSelection(boolean force, boolean dispatch) throws XFormsException { if (this.context == null) { this.context = JXPathContext.newContext(this.element); } Item item; String itemId; String value = getValue(); boolean selectable = true; Iterator iterator = this.context.iterate("//" + this.xformsPrefix + ":" + XFormsConstants.ITEM + "[not(ancestor::" + NamespaceCtx.CHIBA_PREFIX + ":data)]/@id"); while (iterator.hasNext()) { itemId = iterator.next().toString(); item = (Item) this.container.lookup(itemId); if (selectable && isInRange(value, item.getValue())) { if (force || !item.isSelected()) { if (getLogger().isDebugEnabled()) { getLogger().debug(this + " selecting item " + itemId); } item.select(); if (dispatch) { this.container.dispatch(item.getTarget(), EventFactory.SELECT, null); } } // allow only one first selection for non-multiple selectors selectable = isMultiple(); } else { if (force || item.isSelected()) { if (getLogger().isDebugEnabled()) { getLogger().debug(this + " deselecting item " + itemId); } item.deselect(); if (dispatch) { this.container.dispatch(item.getTarget(), EventFactory.DESELECT, null); } } } } } private boolean isInRange(String boundValue, String itemValue) { if (boundValue == null || itemValue == null) { return false; } if (boundValue == itemValue) { return true; } if (isMultiple()) { String bound = " " + boundValue + " "; String item = " " + itemValue + " "; return bound.indexOf(item) > -1; } return boundValue.equals(itemValue); } } // end of class