我正在尝试创建一个具有复选框树项的JavaFX树视图。我要求所有具有子节点的节点都应禁用。但是这些节点的所有子节点都应该是可点击的。
基本上，如果树项是叶子，则应将其启用并单击。
这是我使用的当前代码。这会禁用带有子节点的节点，但是问题是，因为它被禁用，所以我无法访问父节点中的代码。
public class App extends Application
{
public static void main( String[] args )
{
launch(args);
}
private List<Dependant> myList = new ArrayList();
@SuppressWarnings("unchecked")
@Override
public void start(Stage primaryStage) {
CheckBoxTreeItem<String> rootItem = new CheckBoxTreeItem("Root");
final List<CheckBoxTreeItem<String>> treeItems = new ArrayList(6);
for (int i = 0; i < 6; i++) {
CheckBoxTreeItem<String> item = new CheckBoxTreeItem("L0"+i+"");
item.setIndependent(true);
treeItems.add(item);
myList.add(new Dependant("0"+i+"", "type1"));
}
rootItem.getChildren().addAll(treeItems);
rootItem.setExpanded(true);
rootItem.setIndependent(true);
CheckBoxTreeItem<String> rootItem2 = new CheckBoxTreeItem("folder");
final List<CheckBoxTreeItem<String>> treeItems2 = new ArrayList(6);
for (int i = 0; i < 6; i++) {
CheckBoxTreeItem<String> item = new CheckBoxTreeItem("L1"+i+"");
item.setIndependent(true);
treeItems2.add(item);
myList.add(new Dependant("0"+i+"", "type2"));
}
rootItem2.getChildren().addAll(treeItems2);
rootItem2.setIndependent(true);
rootItem.getChildren().set(2,rootItem2);
TreeView tree = new TreeView(rootItem);
tree.setCellFactory((Object item) -> {
final CheckBoxTreeCell<String> cell = new CheckBoxTreeCell();
cell.itemProperty().addListener((obs,s,s1)->{
cell.disableProperty().unbind();
if(s1!=null && !s1.isEmpty()){
BooleanProperty prop = new SimpleBooleanProperty();
prop.set((s1.equals("folder")));
cell.disableProperty().bind(prop);
}
});
return cell;
});
tree.setRoot(rootItem);
StackPane root = new StackPane();
root.getChildren().add(tree);
primaryStage.setScene(new Scene(root, 300, 250));
primaryStage.show();
}
}
这不是我的应用程序的最终代码，它只是我在完成最终实现之前尝试过的示例代码。
从代码中可以看到，由于方法isLeaf()不可用，单元格的disable属性绑定到名称是否等于“ folder”。
如果有人想知道为什么我需要禁用所有父节点，那是因为在最终实现中，我只需要在整个树视图中选择一项（因为单击父节点也将选择它的所有子节点！）。
谢谢。
答案 0 :(得分：1)
虽然问题是一个典型的XY-problem（寻求解决通过试图以错误的方式解决实际需求而引入的问题），但真正的问题很有趣，可以快速尝试一下：）
据我了解，真正的要求：
一如既往，基本方法是将此类逻辑添加到通用模型中（相对于view =单元格）。对于Treeview，模型是treeItem-它本身无法处理项目间的逻辑，因此它需要具有更广泛知识的控制器。
幸运的是，fx支持多选一选： one 的角色由Toggle扮演，许多的角色由ToggleGroup扮演。现在，我们要做的就是将这种支持应用到我们的上下文中：
一些代码示例（请注意：实现不完整且未经正式测试-只是为了指明方向！）
public class TreeSingleSelectedCheckboxWithToggle extends Application {
/**
* A custom CheckBoxTreeItem that implements Toggle.
*
* To control which/how many items can be selected at any
* time, add them to one or several ToggleGroups.
*
* @author Jeanette Winzenburg, Berlin
*/
public static class ToggleTreeItem<T> extends CheckBoxTreeItem<T>
implements Toggle {
public ToggleTreeItem() {
super();
init();
}
public ToggleTreeItem(T value) {
super(value);
init();
}
private void init() {
// basically c&p from ToggleButton
selectedProperty().addListener(ov -> {
final boolean selected = isSelected();
final ToggleGroup tg = getToggleGroup();
// Note: these changes need to be done before selectToggle/clearSelectedToggle since
// those operations change properties and can execute user code, possibly modifying selected property again
if (tg != null) {
if (selected) {
tg.selectToggle(ToggleTreeItem.this);
} else if (tg.getSelectedToggle() == ToggleTreeItem.this) {
// reflective access to package-private api - use your own utility method
FXUtils.invokeMethod(ToggleGroup.class, tg, "clearSelectedToggle");
// tg.clearSelectedToggle();
}
}
});
}
/**
* The {@link ToggleGroup} to which this {@code ToggleButton} belongs. A
* {@code ToggleButton} can only be in one group at any one time. If the
* group is changed, then the button is removed from the old group prior to
* being added to the new group.
*/
private ObjectProperty<ToggleGroup> toggleGroup;
@Override
public final void setToggleGroup(ToggleGroup value) {
toggleGroupProperty().set(value);
}
@Override
public final ToggleGroup getToggleGroup() {
return toggleGroup == null ? null : toggleGroup.get();
}
@Override
public final ObjectProperty<ToggleGroup> toggleGroupProperty() {
if (toggleGroup == null) {
toggleGroup = new ObjectPropertyBase<ToggleGroup>() {
private ToggleGroup old;
@Override protected void invalidated() {
final ToggleGroup tg = get();
if (tg != null && !tg.getToggles().contains(ToggleTreeItem.this)) {
if (old != null) {
old.getToggles().remove(ToggleTreeItem.this);
}
tg.getToggles().add(ToggleTreeItem.this);
} else if (tg == null) {
old.getToggles().remove(ToggleTreeItem.this);
}
old = tg;
}
@Override
public Object getBean() {
return ToggleTreeItem.this;
}
@Override
public String getName() {
return "toggleGroup";
}
};
}
return toggleGroup;
}
@Override
public Object getUserData() {
// TODO Auto-generated method stub
return null;
}
@Override
public void setUserData(Object value) {
// TODO Auto-generated method stub
}
@Override
public ObservableMap<Object, Object> getProperties() {
// TODO Auto-generated method stub
return null;
}
}
@SuppressWarnings("unchecked")
@Override
public void start(Stage primaryStage) {
ToggleGroup toggleGroup = new ToggleGroup();
ToggleTreeItem<String> rootItem = new ToggleTreeItem<>("Root");
toggleGroup.getToggles().add(rootItem);
final List<ToggleTreeItem<String>> treeItems = new ArrayList<>(6);
for (int i = 0; i < 6; i++) {
ToggleTreeItem<String> item = new ToggleTreeItem<>("L0" + i + "");
item.setIndependent(true);
treeItems.add(item);
toggleGroup.getToggles().add(item);
myList.add(new Dependant("0" + i + "", "type1"));
}
rootItem.getChildren().addAll(treeItems);
rootItem.setExpanded(true);
rootItem.setIndependent(true);
ToggleTreeItem<String> rootItem2 = new ToggleTreeItem<>("folder");
toggleGroup.getToggles().add(rootItem2);
final List<ToggleTreeItem<String>> treeItems2 = new ArrayList<>(6);
for (int i = 0; i < 6; i++) {
ToggleTreeItem<String> item = new ToggleTreeItem<>("L1" + i + "");
item.setIndependent(true);
treeItems2.add(item);
toggleGroup.getToggles().add(item);
myList.add(new Dependant("0" + i + "", "type2"));
}
rootItem2.getChildren().addAll(treeItems2);
rootItem2.setIndependent(true);
rootItem.getChildren().set(2, rootItem2);
TreeView tree = new TreeView<>(rootItem);
tree.setCellFactory(CheckBoxTreeCell.forTreeView());
tree.setRoot(rootItem);
StackPane root = new StackPane();
root.getChildren().add(tree);
primaryStage.setScene(new Scene(root, 300, 250));
primaryStage.show();
}
public static class Dependant {
String one;
String two;
public Dependant(String one, String two) {
this.one = one;
this.two = two;
}
}
private List<Dependant> myList = new ArrayList();
public static void main(String[] args) {
launch(args);
}
}