学步园

试验代码如下：

package demo;<br /> import java.util.Vector;<br /> import org.eclipse.jface.dialogs.MessageDialog;<br /> import org.eclipse.jface.viewers.DoubleClickEvent;<br /> import org.eclipse.jface.viewers.IDoubleClickListener;<br /> import org.eclipse.jface.viewers.ITreeContentProvider;<br /> import org.eclipse.jface.viewers.ITreeViewerListener;<br /> import org.eclipse.jface.viewers.LabelProvider;<br /> import org.eclipse.jface.viewers.TreeExpansionEvent;<br /> import org.eclipse.jface.viewers.TreeViewer;<br /> import org.eclipse.jface.viewers.Viewer;<br /> import org.eclipse.swt.SWT;<br /> import org.eclipse.swt.widgets.Display;<br /> import org.eclipse.swt.widgets.Shell;<br /> import org.eclipse.swt.widgets.Tree;<br /> public class TreeTest {<br /> public static void main(String[] args) {</p> <p> Display display = new Display();<br /> Shell shell = new Shell(display);<br /> Tree tree = new Tree(shell, SWT.BORDER);<br /> TreeViewer treeViewer = new TreeViewer(tree);</p> <p>// tree.addMouseListener(new MouseAdapter(){<br /> // @Override<br /> // public void mouseDoubleClick(MouseEvent e) {<br /> // MessageDialog.openInformation(e.display.getActiveShell(), "DoubleClicked", ((Tree)e.getSource()).getSelection()[0].getText());<br /> // }<br /> // });</p> <p> treeViewer.addTreeListener(new ITreeViewerListener(){<br /> public void treeCollapsed(TreeExpansionEvent e) {<br /> MessageDialog.openInformation(((TreeViewer)e.getSource()).getTree().getShell(), "TreeCollapsed", ((Category)e.getElement()).getName());<br /> }<br /> public void treeExpanded(TreeExpansionEvent e) {<br /> MessageDialog.openInformation(((TreeViewer)e.getSource()).getTree().getShell(), "TreeExpanded", ((Category)e.getElement()).getName());<br /> }<br /> });</p> <p> treeViewer.addDoubleClickListener(new IDoubleClickListener(){<br /> public void doubleClick(DoubleClickEvent e) {<br /> MessageDialog.openInformation(((TreeViewer)e.getSource()).getTree().getShell(), "DoubleClicked", ((TreeViewer)e.getSource()).getTree().getSelection()[0].getText());<br /> //JOptionPane.showMessageDialog(null, ((TreeViewer)e.getSource()).getTree().getShell());<br /> }<br /> });</p> <p> treeViewer.setContentProvider(new ITreeContentProvider() {<br /> public Object[] getChildren(Object parentElement) {<br /> Vector<Category> subcats = ((Category)parentElement).getSubCategories();<br /> return subcats == null ? new Object[0] : subcats.toArray();<br /> }</p> <p> public Object getParent(Object element) {<br /> return ((Category)element).getParent();<br /> }</p> <p> public boolean hasChildren(Object element) {<br /> return ((Category)element).getSubCategories() != null;<br /> }</p> <p> public Object[] getElements(Object inputElement) {<br /> if(inputElement != null && inputElement instanceof Vector) {<br /> return ((Vector<?>)inputElement).toArray();<br /> }<br /> return new Object[0];<br /> }</p> <p> public void dispose() {<br /> }</p> <p> public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {<br /> }<br /> });</p> <p> treeViewer.setLabelProvider(new LabelProvider() {<br /> public String getText(Object element) {<br /> return ((Category)element).getName();<br /> }<br /> });</p> <p> Vector<Category> categories = new Vector<Category>();<br /> Category category = new Category("Java libraries", null);<br /> categories.add(category);<br /> category = new Category("UI Toolkits", category);<br /> new Category("AWT", category);<br /> new Category("Swing", category);<br /> new Category("SWT/JFace", category);<br /> category = new Category("Java IDEs", null);<br /> categories.add(category);<br /> new Category("Eclipse", category);<br /> new Category("JBuilder", category);</p> <p> treeViewer.setInput(categories);</p> <p> tree.setSize(300, 200);<br /> shell.setSize(300, 200);<br /> shell.open();</p> <p> while (!shell.isDisposed()) {<br /> if (!display.readAndDispatch()) {<br /> display.sleep();<br /> }<br /> }<br /> display.dispose();<br /> }</p> <p> static class Category {</p> <p> private String name;<br /> private Vector<Category> subCategories;<br /> private Category parent;</p> <p> public Category(String name, Category parent) {<br /> this.name = name;<br /> this.parent = parent;<br /> if(parent != null)<br /> parent.addSubCategory(this);<br /> }</p> <p> public Vector<Category> getSubCategories() {<br /> return subCategories;<br /> }</p> <p> private void addSubCategory(Category subcategory) {<br /> if(subCategories == null) subCategories = new Vector<Category>();<br /> if(!subCategories.contains(subcategory)) subCategories.add(subcategory);<br /> }</p> <p> public String getName() {<br /> return name;<br /> }</p> <p> public Category getParent() {<br /> return parent;<br /> }<br /> }<br /> }