eclipse 查看器

查看器的框架构成：
* 模型和元素：存储着要显示在控件中的数据模型（由开发者编写）
* 内容提供者和标签提供者：负责将数据模型转化成可显示的图片和文字（由开发者编写）
* 控件：显示内容
* 查看器：负责协调上面各部分的工作

============Demo============

public class User {

	private String id;

	private String name;
	
	public User(String id, String name) {
		this.id = id;
		this.name = name;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

}

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.Vector;

public class ListModel {

	public static final String ADD_ELEMENT = "addElement";

	public static final String REMOVE_ELEMENT = "removeElement";

	private PropertyChangeSupport delegate;

	private Vector content;

	public ListModel() {
		content = new Vector();
		delegate = new PropertyChangeSupport(this);
	}

	public void addPropertyChangeListener(PropertyChangeListener listener) {
		delegate.addPropertyChangeListener(listener);
	}

	public void firePropertyChange(PropertyChangeEvent evt) {
		delegate.firePropertyChange(evt);
	}

	public void removePropertyChangeListener(PropertyChangeListener listener) {
		delegate.removePropertyChangeListener(listener);
	}

	public void add(Object element) {
		if (content.add(element))
			firePropertyChange(new PropertyChangeEvent(this, ADD_ELEMENT, null,
					element));
	}

	public void remove(Object element) {
		if (content.remove(element))
			firePropertyChange(new PropertyChangeEvent(this, REMOVE_ELEMENT,
					null, element));
	}

	public Object[] elements() {
		return content.toArray();
	}
}

import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.swt.graphics.Image;

public class ListLabelProvider implements ILabelProvider {

	public Image getImage(Object element) {
		return null;
	}

	public String getText(Object element) {
		if(element instanceof User)
			return ((User)element).getName();
		return element.toString();
	}

	public boolean isLabelProperty(Object element, String property) {
		return false;
	}
	
	public void dispose() {}
	
	public void addListener(ILabelProviderListener listener) {}
	
	public void removeListener(ILabelProviderListener listener) {}
}

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.ListViewer;
import org.eclipse.jface.viewers.Viewer;

public class ListContentProvider implements IStructuredContentProvider,
		PropertyChangeListener {

	private ListViewer viewer;

	private ListModel model;

	public Object[] getElements(Object inputElement) {
		return model.elements();
	}

	public void dispose() {
	}

	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
		this.viewer = (ListViewer) viewer;

		if (oldInput instanceof ListModel)
			((ListModel) oldInput).removePropertyChangeListener(this);

		if (newInput instanceof ListModel) {
			this.model = (ListModel) newInput;
			((ListModel) newInput).addPropertyChangeListener(this);
		}

	}

	public void propertyChange(PropertyChangeEvent evt) {
		if (ListModel.ADD_ELEMENT.equals(evt.getPropertyName()))
			viewer.add(evt.getNewValue());
		if (ListModel.REMOVE_ELEMENT.equals(evt.getPropertyName()))
			viewer.remove(evt.getNewValue());
	}
}

import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.IDoubleClickListener;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ListViewer;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class UsingListViewer {

	public static void main(String[] args) {
		Display display = Display.getDefault();
		final Shell shell = new Shell(display);
		shell.setSize(400, 400);
		shell.setLayout(new FillLayout());

		ListViewer viewer = new ListViewer(shell, SWT.BORDER);

		viewer.setContentProvider(new ListContentProvider());
		viewer.setLabelProvider(new ListLabelProvider());

		final ListModel input = new ListModel();
		viewer.setInput(input);
		
		shell.open();
		shell.layout();
		
		input.add(new User("1","张三"));
		input.add(new User("2","李四"));
		input.add(new User("3","王五"));
		
		viewer.addDoubleClickListener(new IDoubleClickListener() {

			@Override
			public void doubleClick(DoubleClickEvent event) {
				input.add(new User("4","hzy"));
			}
		});
		
		viewer.addSelectionChangedListener(new ISelectionChangedListener() {

			@Override
			public void selectionChanged(SelectionChangedEvent event) {
				System.out.println(((User)((StructuredSelection)event.getSelection()).getFirstElement()).getName());
			}
		});

		while (!shell.isDisposed())
			if (!display.readAndDispatch())
				display.sleep();
	}

}