Ecco un esempio completo e molto semplice per aggiungere/rimuovere dinamicamente i nodi a un albero di celle. Il mio esempio non funziona molto bene. Sembra che lo sia un problema di aggiornamento. Solo la chiusura/espansione dei nodi mostrerà il risultato corretto . Anche in questo forum non ho trovato alcuna risposta adatta a questo problema. Forse qualcuno può provare il mio esempio e dirmi dove si trova il problema. Anche altri suggerimenti sono molto apprezzati.GWT - Aggiungi e rimuovi nodi nell'albero di cella
Saluti, Marco
import java.util.ArrayList;
import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.user.cellview.client.CellTree;
import com.google.gwt.user.client.ui.AbsolutePanel;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.view.client.ListDataProvider;
import com.google.gwt.view.client.SingleSelectionModel;
import com.google.gwt.view.client.TreeViewModel;
public class MyCelltreeTest implements EntryPoint {
private AbsolutePanel absolutePanel;
private CellTree cellTree;
private Button btnAdd;
private Button btnRemove;
private MyTreeModel myTreeModel;
private SingleSelectionModel<MyNode> selectionModelCellTree = null;
@Override
public void onModuleLoad() {
RootPanel rootPanel = RootPanel.get();
rootPanel.add(getAbsolutePanel(), 0, 0);
}
private AbsolutePanel getAbsolutePanel() {
if (absolutePanel == null) {
absolutePanel = new AbsolutePanel();
absolutePanel.setSize("612px", "482px");
absolutePanel.add(getCellTree(), 0, 0);
absolutePanel.add(getBtnAdd(), 265, 428);
absolutePanel.add(getBtnRemove(), 336, 428);
}
return absolutePanel;
}
private CellTree getCellTree() {
if (cellTree == null) {
myTreeModel = new MyTreeModel();
cellTree = new CellTree(myTreeModel, null);
cellTree.setSize("285px", "401px");
}
return cellTree;
}
private Button getBtnAdd() {
if (btnAdd == null) {
btnAdd = new Button("Add");
btnAdd.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
MyNode node = selectionModelCellTree.getSelectedObject();
if(node != null)
myTreeModel.addNew(node, "Bla");
}
});
}
return btnAdd;
}
private Button getBtnRemove() {
if (btnRemove == null) {
btnRemove = new Button("Remove");
btnRemove.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
MyNode node = selectionModelCellTree.getSelectedObject();
if(node != null)
myTreeModel.remove(node);
}
});
}
return btnRemove;
}
public class MyNode {
private String name;
private ArrayList<MyNode> childs; //nodes childrens
private MyNode parent; //track internal parent
private MyCell cell; //for refresh - reference to visual component
public MyNode(String name) {
super();
parent = null;
this.name = name;
childs = new ArrayList<MyNode>();
}
public void addSubMenu(MyNode m) {
m.parent = this;
childs.add(m);
}
public void removeMenu(MyNode m) {
m.getParent().childs.remove(m);
}
public boolean hasChildrens() {
return childs.size()>0;
}
public ArrayList<MyNode> getList() {
return childs;
}
public MyNode getParent() {
return parent;
}
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 class MyTreeModel implements TreeViewModel {
private MyNode officialRoot; //default not dynamic
private MyNode studentRoot; //default not dynamic
private MyNode testRoot; //default not dynamic
private MyNode root;
public MyNode getRoot() { // to set CellTree root
return root;
}
public MyTreeModel() {
selectionModelCellTree = new SingleSelectionModel<MyNode>();
root = new MyNode("root");
// Default items
officialRoot = new MyNode("Cat"); //some basic static data
studentRoot = new MyNode("Dog");
testRoot = new MyNode("Fish");
root.addSubMenu(officialRoot);
root.addSubMenu(studentRoot);
root.addSubMenu(testRoot);
}
//example of add add logic
public void addNew(MyNode myparent, String name) {
myparent.addSubMenu(new MyNode(name));
myparent.refresh(); //HERE refresh tree
}
public void remove(MyNode objToRemove) {
objToRemove.removeMenu(objToRemove);
objToRemove.refresh();
}
@Override
public <T> NodeInfo<?> getNodeInfo(T value) {
ListDataProvider<MyNode> dataProvider;
MyNode myValue = null;
if (value == null) { // root is not set
dataProvider = new ListDataProvider<MyNode>(root.getList());
} else {
myValue = (MyNode) value;
dataProvider = new ListDataProvider<MyNode>(myValue.getList());
}
MyCell cell = new MyCell(dataProvider); //HERE Add reference
if (myValue != null)
myValue.setCell(cell);
return new DefaultNodeInfo<MyNode>(dataProvider, cell, selectionModelCellTree, null);
}
@Override
public boolean isLeaf(Object value) {
if (value instanceof MyNode) {
MyNode t = (MyNode) value;
if (!t.hasChildrens())
return true;
return false;
}
return false;
}
}
public class MyCell extends AbstractCell<MyNode> {
ListDataProvider<MyNode> dataProvider; //for refresh
public MyCell(ListDataProvider<MyNode> dataProvider) {
super();
this.dataProvider = dataProvider;
}
public void refresh() {
dataProvider.refresh();
}
@Override
public void render(Context context, MyNode value, SafeHtmlBuilder sb) {
if (value == null) {
return;
}
sb.appendEscaped(value.getName());
}
}
}
Grazie Ümit per la spiegazione. Ho provato la versione close-reopen. Ho sostituito il mio metodo di aggiornamento con i metodi seguenti. L'aggiunta sta funzionando ma non rimuovendo. Molto strano l'intero argomento. Sono molto sorpreso che queste funzioni di base non siano realmente supportate da GWT. Qualcuno può darmi più aiuto per eseguire un vero esempio di lavoro.
public void refresh() {
closeReopenTreeNodes(cellTree.getRootTreeNode());
}
private void closeReopenTreeNodes(TreeNode node) {
if(node == null) {
return;
}
for(int i = 0; i < node.getChildCount(); i++) {
if(node.getChildValue(i).equals(this)){
if(node.getParent() != null){
node.getParent().setChildOpen(i, false);
//node.getParent().setChildOpen(i, true);
}
node.setChildOpen(i, false);
node.setChildOpen(i, true);
}
TreeNode child = node.setChildOpen(i, node.isChildOpen(i));
closeReopenTreeNodes(child);
}
}
Qui il mio terzo tentativo: In questo modo è consigliato da GWT-commiter. Si prega di vedere seguente problema: http://code.google.com/p/google-web-toolkit/issues/detail?id=7160
Stato attuale: * Aggiunta è possibile * La rimozione è possibile se non ultimo figlio!
Quindi, ultimo punto di apertura, aggiornare l'albero se l'ultimo figlio è aperto!
package com.test;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.user.cellview.client.CellTree;
import com.google.gwt.user.client.ui.AbsolutePanel;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.view.client.ListDataProvider;
import com.google.gwt.view.client.SingleSelectionModel;
import com.google.gwt.view.client.TreeViewModel;
public class MyCelltreeTest2 implements EntryPoint {
private AbsolutePanel absolutePanel;
private CellTree cellTree;
private Button btnAdd;
private Button btnRemove;
private MyTreeModel myTreeModel;
private SingleSelectionModel<MyNode> selectionModelCellTree = null;
private Map<MyNode, ListDataProvider<MyNode>> mapDataProviders = null;
private ListDataProvider<MyNode> rootDataProvider = null;
public void onModuleLoad() {
RootPanel rootPanel = RootPanel.get();
rootPanel.add(getAbsolutePanel(), 0, 0);
}
private AbsolutePanel getAbsolutePanel() {
if (absolutePanel == null) {
absolutePanel = new AbsolutePanel();
absolutePanel.setSize("612px", "482px");
absolutePanel.add(getCellTree(), 0, 0);
absolutePanel.add(getBtnAdd(), 265, 428);
absolutePanel.add(getBtnRemove(), 336, 428);
}
return absolutePanel;
}
private CellTree getCellTree() {
if (cellTree == null) {
myTreeModel = new MyTreeModel();
cellTree = new CellTree(myTreeModel, null);
cellTree.setSize("285px", "401px");
}
return cellTree;
}
private Button getBtnAdd() {
if (btnAdd == null) {
btnAdd = new Button("Add");
btnAdd.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
MyNode node = selectionModelCellTree.getSelectedObject();
myTreeModel.add(node, "Bla");
}
});
}
return btnAdd;
}
private Button getBtnRemove() {
if (btnRemove == null) {
btnRemove = new Button("Remove");
btnRemove.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
MyNode node = selectionModelCellTree.getSelectedObject();
myTreeModel.remove(node);
}
});
}
return btnRemove;
}
public class MyNode {
private String name;
private ArrayList<MyNode> childs; //nodes childrens
private MyNode parent; //track internal parent
public MyNode(String name) {
super();
parent = null;
this.name = name;
childs = new ArrayList<MyNode>();
}
public boolean hasChildrens() {
return childs.size()>0;
}
public ArrayList<MyNode> getList() {
return childs;
}
public MyNode getParent() {
return parent;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
public class MyTreeModel implements TreeViewModel {
public MyTreeModel() {
selectionModelCellTree = new SingleSelectionModel<MyNode>();
mapDataProviders = new HashMap<MyCelltreeTest2.MyNode, ListDataProvider<MyNode>>();
}
public void add(MyNode myparent, String name) {
MyNode child = new MyNode(name);
//root-node
if(myparent == null){
rootDataProvider.getList().add(child);
mapDataProviders.put(child, rootDataProvider);
}
else{
ListDataProvider<MyNode> dataprovider = mapDataProviders.get(myparent);
myparent.childs.add(child);
child.parent = myparent;
dataprovider.refresh();
}
}
public void remove(MyNode objToRemove) {
ListDataProvider<MyNode> dataprovider = mapDataProviders.get(objToRemove);
dataprovider.getList().remove(objToRemove);
// mapDataProviders.remove(objToRemove);
dataprovider.refresh();
dataprovider.flush();
if(objToRemove.parent != null){
ListDataProvider<MyNode> dataproviderParent = mapDataProviders.get(objToRemove.parent);
objToRemove.parent.childs.remove(objToRemove);
dataproviderParent.refresh();
dataproviderParent.flush();
}
else{
rootDataProvider.refresh();
rootDataProvider.flush();
}
}
@Override
public <T> NodeInfo<?> getNodeInfo(T value) {
if (value == null) { // root is not set
rootDataProvider = new ListDataProvider<MyNode>(new ArrayList<MyNode>());
MyCell cell = new MyCell();
return new DefaultNodeInfo<MyNode>(rootDataProvider, cell,
selectionModelCellTree, null);
} else {
MyNode myValue = (MyNode) value;
ListDataProvider<MyNode> dataProvider =
new ListDataProvider<MyNode>(myValue.childs);
MyCell cell = new MyCell();
for(MyNode currentNode : myValue.childs){
mapDataProviders.put(currentNode, dataProvider);
}
return new DefaultNodeInfo<MyNode>(dataProvider, cell,
selectionModelCellTree, null);
}
}
@Override
public boolean isLeaf(Object value) {
if (value instanceof MyNode) {
MyNode t = (MyNode) value;
if (!t.hasChildrens())
return true;
return false;
}
return false;
}
}
public class MyCell extends AbstractCell<MyNode> {
public MyCell() {
super();
}
@Override
public void render(Context context, MyNode value, SafeHtmlBuilder sb) {
if (value == null) {
return;
}
sb.appendEscaped(value.getName());
}
}
}
Qualcuno ha capito come funziona? Frustrantemente questo è chiuso come previsto in issuelist GWT - http://code.google.com/p/google-web-toolkit/issues/detail?id=7160 – SSR