视图开发-模型

视图可以包含任何多控件，但通常为了界面简洁只包含一个Jface表或树查看器。下面通过一个实例演示如何开发视图。

1定义输入模型，包括元素、模型、内容提供器、标签提供器(也是一个完整的模型-View事件演示)

public class AddressItem {
	private String name;
	private String address;
	private AddressCategory category;
	static AddressItem[] NONE = new AddressItem[]{};
}

//AddressCategory为类别信息
public abstract class AddressCategory implements Comparable{
	private final String categoryName;
	private final int priority;
}

//模型类，模拟事件源
public class AddressManager{
private static AddressManager manager;
	private Collection<AddressItem> addresses;
	private List listeners = new ArrayList();
	
	public static AddressManager getManager()
	{
		if(manager == null)
			manager = new AddressManager();
		return manager;
	}
	public AddressItem[] getAddresses(){	
		return (AddressItem[])addresses.toArray(
				new AddressItem[addresses.size()]);
	}
	public void addAddresses(AddressItem[] items){
		if(addresses == null)
			loadAddresses();
		if(addresses.addAll(Arrays.asList(items)))
		{
			fireAddressesChanged(items, AddressItem.NONE, AddressItem.NONE);
		}
	}
public void removeAddresses(AddressItem[] items)
	{
		if(addresses.removeAll(Arrays.asList(items)))
		{
			fireAddressesChanged(AddressItem.NONE, items, AddressItem.NONE);
		}
	}
//模拟事件源，注册监听器、注销监听器、引发事件
public void addAddressManagerListener(AddressManagerListener listener)
	{
		listeners.add(listener);
	}
	public void removeAddressManagerListener(AddressManagerListener listener)
	{
		listeners.remove(listener);
	}
	private void fireAddressesChanged(AddressItem[] itemsAdded,
			AddressItem[] itemsRemoved, AddressItem[] itemsModified)
	{
		AddressManagerEvent event =
			new AddressManagerEvent(
					this, itemsAdded, itemsRemoved, itemsModified);
		for(Iterator iter = listeners.iterator();iter.hasNext();)
		{
			((AddressManagerListener)iter.next()).addressesChanged(event);
		}
	}

监听器如下

public interface AddressManagerListener {
	 public void addressesChanged(AddressManagerEvent event);
}

事件类如下

public class AddressManagerEvent extends EventObject {
	private final AddressItem[] added;
	private final AddressItem[] removed;
	private final AddressItem[] modified;
	public AddressManagerEvent(AddressManager source,
		      AddressItem[] itemsAdded, AddressItem[] itemsRemoved, AddressItem[] itemsModified) 
	{
		super(source);
		added = itemsAdded;
		removed = itemsRemoved;
		modified = itemsModified;
	}
	public AddressItem[] getItemsAdded() 
	{
		return added;
	}
	public AddressItem[] getItemsRemoved() 
	{
		return removed;
	}
	public AddressItem[] getItemsModified()
	{
		return modified;
	}
}

ContentProvider代码如下，实现对模型AddressManager的监听

public class AddressViewContentProvider implements IStructuredContentProvider,
		AddressManagerListener {
	private TableViewer viewer;
	private AddressManager manager;

	public Object[] getElements(Object inputElement) {
		return manager.getAddresses();
	}

	public void dispose() {

	}

	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
		this.viewer = (TableViewer) viewer;
		if (manager != null)
			manager.removeAddressManagerListener(this);
		manager = (AddressManager) newInput;
		if (manager != null) {
			manager.addAddressManagerListener(this);
		}
	}

	public void addressesChanged(AddressManagerEvent event) {
		viewer.getTable().setRedraw(false);
		try {
			viewer.remove(event.getItemsRemoved());
			viewer.add(event.getItemsAdded());
			viewer.update(event.getItemsModified(), null);
		} finally {
			viewer.getTable().setRedraw(true);
		}
	}
}

标签提供器代码如下

public class AddressViewLabelProvider extends LabelProvider implements
		ITableLabelProvider {

	public Image getColumnImage(Object element, int columnIndex) {
		switch (columnIndex) {
		// 姓名
		case 0:
			return null;
			// 类别
		case 1:
			return ((AddressItem) element).getCategory().getImage();
		default:
			return null;
		}
	}

	public String getColumnText(Object element, int columnIndex) {
		switch (columnIndex) {
		case 0:
			if (element != null)
				return ((AddressItem) element).getName();
			return "";
		case 1:
			if (element != null)
				return ((AddressItem) element).getCategory().getCategoryName();
			return "";
		default:
			return "";
		}
	}
}

AddressView类代码如下：

public class AddressView extends ViewPart{
private static TableViewer viewer;
	private TableColumn nameColumn;
	private TableColumn categoryColumn;
public void createPartControl(Composite parent) {
		// 创建viewer
		viewer = new TableViewer(parent, SWT.MULTI | SWT.H_SCROLL
				| SWT.V_SCROLL | SWT.FULL_SELECTION);

		// 设置表格的显示界面
		final Table table = viewer.getTable();
		nameColumn = new TableColumn(table, SWT.LEFT);
		nameColumn.setText("姓名");
		nameColumn.setImage(ImageCache.getInstance().getImage(
				ImageKeys.getImageDescriptor(ImageKeys.IMAGE_PEOPLE)));
		nameColumn.setWidth(100);

		categoryColumn = new TableColumn(table, SWT.LEFT);
		categoryColumn.setText("类别");
		categoryColumn.setImage(ImageCache.getInstance().getImage(
				ImageKeys.getImageDescriptor(ImageKeys.IMAGE_CATEGORY)));
		categoryColumn.setWidth(100);

		table.setHeaderVisible(true);
		table.setLinesVisible(true);

		viewer.setContentProvider(new AddressViewContentProvider());
		viewer.setLabelProvider(new AddressViewLabelProvider());
		viewer.setInput(AddressManager.getManager());
}