SWT/JFace treeViewer 的 使用

上边介绍了，tableviewer，这里介绍一下treeViewer，总的流程类似。
一、构造一个树形结构的数据出来，这里选择国家、城市、人来构造一个树形结构，代码如下:
1，定义一个接口

package model;

import java.util.List;

public interface Itree {
    public String getName();
    public void setName(String name);
    public void setChildren(List Children);
    public List getChildren();
}

2，国家

package model;

import java.util.ArrayList;
import java.util.List;

public class Country implements Itree{
    private Long id;
    private String name;
    private List children = new ArrayList();
    public Country(){
    }
    public Country(String name){
        this.name = name;
    }
    public List getChildren() {
        return children;
    }
    public void setChildren(List children) {
        this.children = children;
    }
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    
}

3，城市

package model;

import java.util.ArrayList;
import java.util.List;

public class City implements Itree{
    private Long id;
    private String name;
    private List children = new ArrayList();
    public City(){
    }
    public City(String name){
        this.name = name;
    }
    public List getChildren() {
        return children;
    }
    public void setChildren(List children) {
        this.children = children;
    }
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

4，人

package model;

import java.util.ArrayList;
import java.util.List;

public class People implements Itree{
    private Long id;
    private String name;
    public People(){
    }
    public People(String name){
        this.name = name;
    }
    public List getChildren() {
        return null;
    }
    public void setChildren(List children) {
    }
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

5,把这些元素组织起来 -- 工厂

package model;

import java.util.ArrayList;
import java.util.List;

public class Factory {
    @SuppressWarnings("unchecked")
    public static List createTree(){
        //生成国家
        Country cn = new Country("中国");
        Country us = new Country("美国");
        Country jp = new Country("日本");
        //生成城市
        City beijing  = new City("北京");
        City shanghai = new City("上海");
        City newyork = new City("纽约");
        City la = new City("洛杉矶");
        City tokyo = new City("东京");
        City osaka = new City("大阪");
        //北京人
        ArrayList list = new ArrayList();
        list.add(new People("张三"));
        list.add(new People("李四"));
        list.add(new People("王五"));
        beijing.setChildren(list);
        //上海人
        list = new ArrayList();
        list.add(new People("翠花"));
        list.add(new People("小红"));
        list.add(new People("小崔"));
        shanghai.setChildren(list);
        //纽约人
        list = new ArrayList();
        list.add(new People("tom"));
        list.add(new People("rose"));
        list.add(new People("john"));
        newyork.setChildren(list);
        //洛杉矶人
        list = new ArrayList();
        list.add(new People("Sofia"));
        list.add(new People("sarah"));
        list.add(new People("Jennifer"));
        la.setChildren(list);
        //东京人
        list = new ArrayList();
        list.add(new People("渡边"));
        list.add(new People("鬼冢"));
        list.add(new People("山本"));
        tokyo.setChildren(list);
        //大阪人
        list = new ArrayList();
        list.add(new People("奈奈子"));
        list.add(new People("菜菜子"));
        list.add(new People("新垣结衣"));
        osaka.setChildren(list);
        
        //关联城市与国家
        //中国
        ArrayList citys = new ArrayList();
        citys.add(beijing);
        citys.add(shanghai);
        cn.setChildren(citys);
        //美国
        citys = new ArrayList();
        citys.add(newyork);
        citys.add(la);
        us.setChildren(citys);
        //日本
        citys = new ArrayList();
        citys.add(tokyo);
        citys.add(osaka);
        jp.setChildren(citys);
        //国家列表
        ArrayList countrys = new ArrayList();
        countrys.add(cn);
        countrys.add(us);
        countrys.add(jp);
        return countrys;
    }
}

二、定义内容器和标签器

1,内容器 ContentProvider，用来提供给Viewer中的内容显示的

import java.util.List;

import model.Itree;

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

public class TreeContentProvider implements IStructuredContentProvider, ITreeContentProvider {
        
        public Object[] getElements(Object inputElement) {
            if (inputElement instanceof List){
                List input = (List)inputElement;
                return input.toArray();
            }
            return new Object[0];
        }
        public Object[] getChildren(Object parentElement) {
            Itree node = (Itree)parentElement;
            List list = node.getChildren();
            if(list == null){
                return new Object[0];
            }
            return list.toArray();
        }
        
        public boolean hasChildren(Object element) {
            Itree node = (Itree)element;
            List list = node.getChildren();
            return !(list == null || list.isEmpty());
        }
        //以下三个函数根据需要填充
        public Object getParent(Object element) {
            return null;
        }
        public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
        }
        public void dispose() {
        }
    }

2，标签器 LabelProvider，用来显示Viewer的一些标题之类的信息

import model.Itree;

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

public class TreeLabelProvider extends LabelProvider implements ILabelProvider {
        public String getText(Object element) {
            Itree node = (Itree)element;
            return node.getName();
        }
        public Image getImage(Object element) {
            return null;
        }
    }

三、好了，准备工作做好了，把上边的内容利用起来就好了。

import model.Factory;

import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;


public class TestTreeViewer {
    
    private static Tree tree;
    public static void main(String[] args) {
        final Display display = Display.getDefault();
        final Shell shell = new Shell();
        shell.setSize(500, 375);
        shell.setText("SWT Application");
        //
        final TreeViewer treeViewer = new TreeViewer(shell, SWT.BORDER|SWT.H_SCROLL);
        tree = treeViewer.getTree();
        tree.setBounds(83, 75, 264, 185);
        
        treeViewer.setLabelProvider(new TreeLabelProvider());
        treeViewer.setContentProvider(new TreeContentProvider());
        treeViewer.setInput(Factory.createTree());
        
        shell.open();
        shell.setLayout(new FillLayout());
        shell.layout();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
    }

}

看看是不是已经实现了treeViewer
四、上边是简单的treeViewer，如果我们需要带checkbox的treeViewer，简单，只需要更改

final TreeViewer treeViewer = new TreeViewer(shell, SWT.BORDER|SWT.H_SCROLL);

把TreeViewer换成CheckboxTreeViewer。这就是mvc的好处了。
但现实中我们多用 ContainerCheckedTreeViewer代替CheckboxTreeViewer，因为这个提供了更多的功能。
CheckboxTreeViewer 是TreeViewer的子类,  ContainerCheckedTreeViewer是CheckboxTreeViewer的子类，所以可以随便替换。
替换后：

final ContainerCheckedTreeViewer treeViewer = new ContainerCheckedTreeViewer(shell, SWT.BORDER|SWT.H_SCROLL);

五、treeviewer和tableviewer都介绍过了，考虑一下把两个结合起来是不是我们经常需要的情况。尝试一下吧。
六、souce下载:http://www.blogjava.net/Files/dreamstone/jface-6.rar

source：http://www.blogjava.net/dreamstone/archive/2007/08/05/134512.html