工作示例。添加对 DataProvider（和父节点）的引用（MyMenuItem 和 MyCell 在我的代码中带有 DataProvider）。添加元素刷新父级后。
public class MyMenuItem {
private String name;
private String action; //some data
private int level; //if needed
private ArrayList<MyMenuItem> list; //nodes childrens
private MyMenuItem parent; //track internal parent
private MyCell cell; //for refresh - reference to visual component
public void setCell(MyCell cell) {
this.cell = cell;
}
public void refresh() {
if(parent!=null) {
parent.refresh();
}
if (cell!=null) {
cell.refresh(); //refresh tree
}
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAction() {
return action;
}
public void setAction(String action) {
this.action = action;
}
public MyMenuItem(String name, String action) {
super();
parent = null;
level = 0;
this.name = name;
this.action = action;
list = new ArrayList<MyMenuItem>();
}
public MyMenuItem(String name) {
this(name, "");
}
public void addSubMenu(MyMenuItem m) {
m.level = this.level+1;
m.parent = this;
list.add(m);
}
public boolean hasChildrens() {
return list.size()>0;
}
public int getLevel() {
return level;
}
public void setLevel(int level) {
this.level = level;
}
public ArrayList<MyMenuItem> getList() {
return list;
}
public MyMenuItem getParent() {
return parent;
}
}
public class MyTreeModel implements TreeViewModel {
private MyMenuItem officialRoot; //default not dynamic
private MyMenuItem studentRoot; //default not dynamic
private MyMenuItem testRoot; //default not dynamic
private MyMenuItem root;
public MyMenuItem getRoot() { // to set CellTree root
return root;
}
public MyTreeModel() {
root = new MyMenuItem("root");
// Default items
officialRoot = new MyMenuItem("Official"); //some basic static data
studentRoot = new MyMenuItem("Student");
testRoot = new MyMenuItem("Test");
root.addSubMenu(officialRoot);
root.addSubMenu(studentRoot);
root.addSubMenu(testRoot);
}
//example of add add logic
private void addNew(MyMenuItem myparent, String name, String uid) {
myparent.addSubMenu(new MyMenuItem(name, uid));
myparent.refresh(); //HERE refresh tree
}
@Override
public <T> NodeInfo<?> getNodeInfo(T value) {
ListDataProvider<MyMenuItem> dataProvider;
MyMenuItem myValue = null;
if (value == null) { // root is not set
dataProvider = new ListDataProvider<MyMenuItem>(root.getList());
} else {
myValue = (MyMenuItem) value;
dataProvider = new ListDataProvider<MyMenuItem>(myValue.getList());
}
MyCell cell = new MyCell(dataProvider); //HERE Add reference
if (myValue != null)
myValue.setCell(cell);
return new DefaultNodeInfo<MyMenuItem>(dataProvider, cell);
}
@Override
public boolean isLeaf(Object value) {
if (value instanceof MyMenuItem) {
MyMenuItem t = (MyMenuItem) value;
if (!t.hasChildrens())
return true;
return false;
}
return false;
}
}
public class MyCell extends AbstractCell<MyMenuItem> {
ListDataProvider<MyMenuItem> dataProvider; //for refresh
public MyCell(ListDataProvider<MyMenuItem> dataProvider) {
super("keydown","dblclick");
this.dataProvider = dataProvider;
}
public void refresh() {
dataProvider.refresh();
}
@Override
public void onBrowserEvent(Context context, Element parent, MyMenuItem value,
NativeEvent event, ValueUpdater<MyMenuItem> valueUpdater) {
if (value == null) {
return;
}
super.onBrowserEvent(context, parent, value, event, valueUpdater);
if ("click".equals(event.getType())) {
this.onEnterKeyDown(context, parent, value, event, valueUpdater);
}
if ("dblclick".equals(event.getType())) {
this.onEnterKeyDown(context, parent, value, event, valueUpdater);
}
}
@Override
public void render(Context context, MyMenuItem value, SafeHtmlBuilder sb) {
if (value == null) {
return;
}
sb.appendEscaped(value.getName());
//add HERE for better formating
}
@Override
protected void onEnterKeyDown(Context context, Element parent,
MyMenuItem value, NativeEvent event, ValueUpdater<MyMenuItem> valueUpdater) {
Window.alert("You clicked "+event.getType()+" " + value.getName());
}
}
在模块中添加
treeModel = new MyTreeModel();
tree = new CellTree(treeModel,treeModel.getRoot());