Java tutorial
/******************************************************************************* * Copyright (c) 2007 Red Hat, Inc. * Distributed under license by Red Hat, Inc. All rights reserved. * This program is made available under the terms of the * Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html * * Contributor: * Red Hat, Inc. - initial API and implementation ******************************************************************************/ package org.hibernate.eclipse.console.viewers.xpl; import java.util.ArrayList; import java.util.List; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.viewers.AbstractTreeViewer; import org.eclipse.jface.viewers.TreePath; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Item; import org.eclipse.swt.widgets.TreeItem; import org.eclipse.swt.widgets.Widget; /** * TreeViewer has the next lack design to work with the objects as TreeItem id: * internalFindItems always return array of size <= 1 * cause doFindItems & internalFindItem returns FIRST proper item which it find * but in common case this is not the TRUTH - so TreeViewer add method doesn't work * as we expected. * * So MTreeViewer fix the problem. * It redefine add method taking into account what for one parentElementOrTreePath as id * could exist several ( >= 0 ) widgets. * doFindItems & internalFindItem returns ALL proper items which it find. * * We expect what TreeViewer developers fix the bug in future versions, * but we can't wait it. * * more info is here http://jira.jboss.com/jira/browse/JBIDE-1482 * * @author Vitali */ public class MTreeViewer extends TreeViewer { public MTreeViewer(Composite parent, int style) { super(parent, style); } public void clearChildren(Object node) { Widget widget = null; if (node instanceof Widget) { widget = (Widget) node; } else if (node == null) { widget = getTree(); } Widget[] items = null; if (widget == null && node != null) { items = internalFindItems(node); } else { items = getChildren(widget); } for (int j = 0; j < items.length; j++) { clearChildren(items[j]); if (items[j] instanceof TreeItem) { ((TreeItem) items[j]).setExpanded(false); ((TreeItem) items[j]).clearAll(true); } } } /** * Adds the given child elements to this viewer as children of the given * parent element. If this viewer does not have a sorter, the elements are * added at the end of the parent's list of children in the order given; * otherwise, the elements are inserted at the appropriate positions. * <p> * This method should be called (by the content provider) when elements have * been added to the model, in order to cause the viewer to accurately * reflect the model. This method only affects the viewer, not the model. * </p> * * @param parentElementOrTreePath * the parent element * @param childElements * the child elements to add */ public void add(Object parentElementOrTreePath, Object[] childElements) { Assert.isNotNull(parentElementOrTreePath); assertElementsNotNull(childElements); if (isBusy()) return; Widget[] widgets = internalFindItems2(parentElementOrTreePath); // If parent hasn't been realized yet, just ignore the add. if (widgets.length == 0) { return; } for (int i = 0; i < widgets.length; i++) { internalAdd(widgets[i], parentElementOrTreePath, childElements); // call this to refresh icon of parent item updateItem(widgets[i], parentElementOrTreePath); } } /** * Find the items for the given element of tree path * * @param parentElementOrTreePath * the element or tree path * @return the items for that element */ protected Widget[] internalFindItems2(Object parentElementOrTreePath) { Widget[] widgets; if (parentElementOrTreePath instanceof TreePath) { widgets = internalFindItems(parentElementOrTreePath); } else { widgets = findItems2(parentElementOrTreePath); } return widgets; } /** * Finds the widgets which represent the given element. The returned array * must not be changed by clients; it might change upon calling other * methods on this viewer. * <p> * This method was introduced to support multiple equal elements in a viewer * (@see {@link AbstractTreeViewer}). Multiple equal elements are only * supported if the element map is enabled by calling * {@link #setUseHashlookup(boolean)} and passing <code>true</code>. * </p> * <p> * The default implementation of this method tries first to find the widget * for the given element assuming that it is the viewer's input; this is * done by calling <code>doFindInputItem</code>. If it is not found * there, the widgets are looked up in the internal element map provided * that this feature has been enabled. If the element map is disabled, the * widget is found via <code>doFindInputItem</code>. * </p> * * @param element * the element * @return the corresponding widgets */ protected Widget[] findItems2(Object element) { Widget result = doFindInputItem(element); if (result != null) { return new Widget[] { result }; } // if we have an element map use it, otherwise search for the item. if (usingElementMap()) { return findItems2(element); } return doFindItems(element); } /** * Recursively tries to find the given element. * * @param parent * the parent item * @param element * the element * @return Widget */ protected List<Item> internalFindItem(Item parent, Object element) { List<Item> ret = new ArrayList<Item>(); // compare with node Object data = parent.getData(); if (data != null) { if (equals(data, element)) { ret.add(parent); return ret; } } // recurse over children Item[] items = getChildren(parent); for (int i = 0; i < items.length; i++) { Item item = items[i]; List<Item> o = internalFindItem(item, element); if (null != o) { ret.addAll(o); } } return ret; } protected Widget[] doFindItems(Object element) { Widget[] ret = new Widget[0]; // compare with root Object root = getRoot(); if (null == root) { return ret; } List<Widget> res = new ArrayList<Widget>(); Item[] items = getChildren(getControl()); if (items != null) { for (int i = 0; i < items.length; i++) { List<Item> o = internalFindItem(items[i], element); if (null != o) { res.addAll(o); } } } ret = res.toArray(new Widget[0]); return ret; } }