swt tree demo with a text editor

项目需要，从XML中读取数据生成一个Tree，然后可以对叶子节点的值（属性不可以）进行编辑，并最后保存。

/**
 * chega
 * 2012-12-17下午2:11:42
 */
package com.java2s.www;

import java.io.File;
import java.io.IOException;

import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.jface.viewers.ITableLabelProvider;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.TreeEditor;
import org.eclipse.swt.events.FocusAdapter;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.FormAttachment;
import org.eclipse.swt.layout.FormData;
import org.eclipse.swt.layout.FormLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.TreeColumn;
import org.eclipse.swt.widgets.TreeItem;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;

public class E10FieldTree
{

	public static void main(String[] args) throws JDOMException, IOException
	{
		final Display display = new Display();
		Shell shell = new Shell(display);
		shell.setLayout(new GridLayout(1, false));
		final E10FieldTree e10 = new E10FieldTree(shell);

		Composite btnComp = new Composite(shell, SWT.NONE);
		GridData gridData = new GridData(GridData.FILL_HORIZONTAL);
		btnComp.setLayoutData(gridData);
		// btnComp.setBackground(display.getSystemColor(SWT.COLOR_RED));
		FormLayout layout = new FormLayout();
		btnComp.setLayout(layout);
		Button btn = new Button(btnComp, SWT.PUSH);
		FormData data = new FormData();
		data.top = new FormAttachment(0, 0);
		data.right = new FormAttachment(100, -40);
		data.bottom = new FormAttachment(100);
		btn.setText("Save");
		btn.setLayoutData(data);

		btn.addSelectionListener(new SelectionAdapter() {

			@Override
			public void widgetSelected(SelectionEvent selectionevent)
			{
				try
				{
					e10.saveXML();
				}
				catch (IOException e)
				{
					e.printStackTrace();
				}
			}

		});
		shell.setSize(new Point(600, 500));
		shell.setVisible(true);
		while (!shell.isDisposed())
		{
			if (!display.readAndDispatch())
			{
				display.sleep();
			}
		}
		display.dispose();
	}

	public void saveXML() throws IOException
	{
		XMLOutputter outputter = new XMLOutputter();
		Format format = Format.getPrettyFormat();
		// jdom在输出到不同的目的地时，中文可能会产生乱码。输出到文件用FileOutputStream而不能用FileWriter，输出到控制台要用PrintWriter而不能直接用System.out(见网上讨论)
		// 还可以强制设定输出编码，这样就不用考虑中文编码问题了
		format.setEncoding("utf-8");
		outputter.output(this.document, System.out);
	}

	private Shell		parent;
	private TreeViewer	treeViewer;
	private Text		text;
	private TreeEditor	editor;
	private Document	document;
	private Document	copyDocument;
	private boolean		isEditing	= false;

	public E10FieldTree(Shell parent) throws JDOMException, IOException
	{
		this.parent = parent;
		this.init();
	}

	private void init() throws JDOMException, IOException
	{
		this.treeViewer = new TreeViewer(this.parent, SWT.SINGLE | SWT.FULL_SELECTION);
		GridData data = new GridData(GridData.FILL_BOTH);
		this.treeViewer.getTree().setLayoutData(data);
		this.treeViewer.getTree().setLinesVisible(true);
		this.treeViewer.getTree().setHeaderVisible(true);
		this.treeViewer.setAutoExpandLevel(1);
		TreeColumn column1 = new TreeColumn(this.treeViewer.getTree(), 0);
		column1.setText("Key");
		column1.setWidth(150);
		TreeColumn column2 = new TreeColumn(this.treeViewer.getTree(), 1);
		column2.setText("Value");
		column2.setWidth(250);
		document = new SAXBuilder().build(new File("Group_ITEM.xml"));
		this.copyDocument = (Document) this.document.clone();
		this.treeViewer.setContentProvider(new ITreeContentProvider() {

			@Override
			public void dispose()
			{
			}

			@Override
			public void inputChanged(Viewer viewer, Object oldInput, Object newInput)
			{
			}

			@Override
			public Object[] getElements(Object inputElement)
			{
				if (inputElement == document)
				{
					return new Element[] { document.getRootElement() };
				}
				else
				{
					Element ele = (Element) inputElement;
					return ele.getChildren().toArray();
				}
			}

			@Override
			public Object[] getChildren(Object parentElement)
			{
				Element ele = (Element) parentElement;
				return ele.getChildren().toArray();
			}

			@Override
			public Object getParent(Object element)
			{
				Element ele = (Element) element;
				return ele.getParentElement();
			}

			@Override
			public boolean hasChildren(Object element)
			{
				return this.getChildren(element).length > 0;
			}

		});
		this.treeViewer.setLabelProvider(new ITableLabelProvider() {

			@Override
			public void addListener(ILabelProviderListener listener)
			{
			}

			@Override
			public void dispose()
			{
			}

			@Override
			public boolean isLabelProperty(Object element, String property)
			{
				return false;
			}

			@Override
			public void removeListener(ILabelProviderListener listener)
			{
			}

			@Override
			public Image getColumnImage(Object element, int columnIndex)
			{
				return null;
			}

			@Override
			public String getColumnText(Object element, int columnIndex)
			{
				Element ele = (Element) element;
				if (columnIndex == 0)
				{
					return ele.getName();
				}
				if (columnIndex == 1)
				{
					if (!((ITreeContentProvider) treeViewer.getContentProvider()).hasChildren(element))
					{
						return ele.getValue();
					}
				}
				return null;
			}
		});
		this.treeViewer.setInput(document);
		this.treeViewer.expandAll();

		editor = new TreeEditor(this.treeViewer.getTree());
		editor.grabHorizontal = true;
		editor.grabVertical = true;
		text = new Text(this.treeViewer.getTree(), SWT.SINGLE | SWT.BORDER);
		text.setVisible(false);

		final FocusListener focusListener = new FocusAdapter() {

			@Override
			public void focusGained(FocusEvent focusevent)
			{
				beginEdit();
			}

			@Override
			public void focusLost(FocusEvent focusevent)
			{
				finishEdit();
			}
		};

		text.addFocusListener(focusListener);

		text.addKeyListener(new KeyAdapter() {

			@Override
			public void keyReleased(KeyEvent keyevent)
			{
				// 回车直接确认修改
				if (keyevent.character == SWT.CR)
				{
					finishEdit();
				}
				// ESC取消修改
				if (keyevent.character == SWT.ESC)
				{
					cancelEdit();
				}
			}

		});

		this.treeViewer.getTree().addMouseListener(new MouseAdapter() {

			@Override
			public void mouseDown(MouseEvent e)
			{
				TreeItem selectedItem = treeViewer.getTree().getItem(new Point(e.x, e.y));
				if (selectedItem == null)
				{
					return;
				}
				// 只有叶节点才允许修改
				if (selectedItem.getItemCount() == 0)
				{
					if (canEdit(e.x, 1))
					{
						editor.setEditor(text, selectedItem, 1);
						text.setText(selectedItem.getText(1));
						text.selectAll();
						text.forceFocus();
					}
				}
			}

		});
	}

	/**
	 * 开始修改
	 */
	protected void beginEdit()
	{
		this.isEditing = true;
		text.setText(editor.getItem().getText(1));
		text.selectAll();
		text.setVisible(true);
	}

	/**
	 * 提交修改（提交修改的时候同时修改Document对象）
	 */
	protected void finishEdit()
	{
		if(!this.isEditing){
			return ;
		}
		System.out.println("finishEdit");
		this.isEditing = false;
		editor.getItem().setText(1, text.getText().trim());
		((Element) editor.getItem().getData()).setText(text.getText().trim());
		text.setText("");
		text.setVisible(false);
	}

	/**
	 * 取消修改
	 */
	protected void cancelEdit()
	{
		this.isEditing = false;
		text.setText("");
		text.setVisible(false);
	}

	/**
	 * 判断x坐标是否在第columnIdx列内(起始列索引为0)
	 * 
	 * @param x
	 * @param columnIdx
	 * @return
	 */
	protected boolean canEdit(int x, int columnIdx)
	{
		if (columnIdx >= this.treeViewer.getTree().getColumnCount())
		{
			return false;
		}
		int leftWidth = 0;
		int rightWidth = 0;
		for (int i = 0; i < columnIdx; i++)
		{
			leftWidth += this.treeViewer.getTree().getColumn(i).getWidth();
		}
		rightWidth = leftWidth + this.treeViewer.getTree().getColumn(columnIdx).getWidth();
		return leftWidth <= x && x <= rightWidth;
	}

	/**
	 * 取得原始的Document
	 * 
	 * @return
	 */
	public Document getOriginalDocument()
	{
		return this.copyDocument;
	}

	public Document getDocumentInUse()
	{
		return this.document;
	}
}

XML文件是我们项目中的文件，就不提供了，随便一个XML都可以拿来测试。