Class AbstractEditableCell<C,V>

Example

public class EditableCellExample implements EntryPoint {
 /**
 * A simple data type that represents a contact.
 */
 private static class Contact {
 private final String address;
 private final String name;
 public Contact(String name, String address) {
 this.name = name;
 this.address = address;
 }
 }
 /**
 * A custom {@link Cell} used to render a {@link Contact}. We extend
 * {@link AbstractCell} because it provides reasonable implementations of
 * methods that work for most use cases.
 */
 private class ContactCell extends AbstractCell<Contact> {
 public ContactCell() {
 // Our cell responds to change events and keydown events.
 super("change", "keydown");
 }
 @Override
 public void onBrowserEvent(Context context, Element parent, Contact value,
 NativeEvent event, ValueUpdater<Contact> valueUpdater) {
 // Check that the value is not null.
 if (value == null) {
 return;
 }
 // Call the super handler, which handlers the enter key.
 super.onBrowserEvent(context, parent, value, event, valueUpdater);
 // Handle click events.
 if ("change".equals(event.getType())) {
 updateFavorites(parent, value);
 showCurrentFavorites();
 }
 }
 @Override
 public void render(Context context, Contact value, SafeHtmlBuilder sb) {
 /*
 * Always do a null check on the value. Cell widgets can pass null to
 * cells if the underlying data contains a null, or if the data arrives
 * out of order.
 */
 if (value == null) {
 return;
 }
 // Add a checkbox. If the contact is a favorite, the box will be checked.
 sb.appendHtmlConstant("<table><tr><td valign=\"top\">");
 if (favorites.contains(value)) {
 sb.appendHtmlConstant("<input type=\"checkbox\" checked=checked/>");
 } else {
 sb.appendHtmlConstant("<input type=\"checkbox\" />");
 }
 sb.appendHtmlConstant("</td><td>");
 // Display the name in big letters.
 sb.appendHtmlConstant("<div style=\"size:200%;font-weight:bold;\">");
 sb.appendEscaped(value.name);
 sb.appendHtmlConstant("</div>");
 // Display the address in normal text.
 sb.appendHtmlConstant("<div style=\"padding-left:10px;\">");
 sb.appendEscaped(value.address);
 sb.appendHtmlConstant("</div>");
 sb.appendHtmlConstant("</td></tr></table>");
 }
 /**
 * By convention, cells that respond to user events should handle the enter
 * key. This provides a consistent user experience when users use keyboard
 * navigation in the widget. Our cell will toggle the checkbox on Enter.
 */
 @Override
 protected void onEnterKeyDown(Context context, Element parent,
 Contact value, NativeEvent event, ValueUpdater<Contact> valueUpdater) {
 // Toggle the checkbox.
 InputElement input = getInputElement(parent);
 input.setChecked(!input.isChecked());
 // Update the favorites based on the new state.
 updateFavorites(parent, value);
 // Show the new list of favorites.
 showCurrentFavorites();
 }
 /**
 * Get the checkbox input element from the parent element that wraps our
 * cell.
 * 
 * @param parent the parent element
 * @return the checkbox
 */
 private InputElement getInputElement(Element parent) {
 // We need to navigate down to our input element.
 TableElement table = parent.getFirstChildElement().cast();
 TableRowElement tr = table.getRows().getItem(0);
 TableCellElement td = tr.getCells().getItem(0);
 InputElement input = td.getFirstChildElement().cast();
 return input;
 }
 /**
 * Update the favorites list based on the state of the input element.
 */
 private void updateFavorites(Element parent, Contact value) {
 // Get the input element.
 InputElement input = getInputElement(parent);
 // Update the favorites based on the checked state.
 if (input.isChecked()) {
 favorites.add(value);
 } else {
 favorites.remove(value);
 }
 }
 }
 /**
 * The list of data to display.
 */
 private static final List<Contact> CONTACTS = Arrays.asList(new Contact(
 "John", "123 Fourth Avenue"), new Contact("Joe", "22 Lance Ln"),
 new Contact("Michael", "1283 Berry Blvd"), new Contact("Sarah",
 "100 Hundred St."), new Contact("George", "1600 Pennsylvania Avenue"));
 /**
 * Our list of favorite contacts.
 */
 private final List<Contact> favorites = new ArrayList<EditableCellExample.Contact>();
 public void onModuleLoad() {
 // Create a cell to render each value.
 ContactCell contactCell = new ContactCell();
 // Use the cell in a CellList.
 CellList<Contact> cellList = new CellList<Contact>(contactCell);
 // Push the data into the widget.
 cellList.setRowData(0, CONTACTS);
 // Add it to the root panel.
 RootPanel.get().add(cellList);
 }
 /**
 * Show the list of favorites.
 */
 private void showCurrentFavorites() {
 if (favorites.size() > 0) {
 String text = "You favorite contacts are ";
 boolean first = true;
 for (Contact contact : favorites) {
 if (!first) {
 text += ", ";
 } else {
 first = false;
 }
 text += contact.name;
 }
 Window.alert(text);
 } else {
 Window.alert("You have not selected any favorites.");
 }
 }
}