我创建了一个自定义JavaFX控件，将其称为ComboBoxTablePopup，它是一个Generic Control，它从用户那里获取S类型的项目列表。 在内部，我在TableView（ComboboxTablePopup Contrl的一个孩子）中使用了某种过滤。所以我用过：
FiltredList.setPridcate(S -> {
if (pr == null || pr.isEmpty() || pr.length() == 0)
return true;
if (((Engine) S).getDesignation().toLowerCase().contains(pr.toLowerCase())) {
return true;
} else
return false;).
因为我正在使用泛型类，并且列表可以是任何类型，我必须将filtredlist项目转换为ordre中的已知对象以获得filtring工作。
那么，我怎样才能使谓词函数通用，所以我可以处理任何对象并过滤它？
以下是我的CustomControl的代码：
public class ComboBoxTablePopup<S> extends ComboBoxBase {
private
ObservableList<TableColumn> columns = FXCollections.emptyObservableList();
public ObservableList<TableColumn> getColumns() {
return columns;
}
public void setColumns(ObservableList<TableColumn> columns) {
this.columns = columns;
}
/***************************************************************************
* *
* Static properties and methods *
* *
**************************************************************************/
private static <T> StringConverter<T> defaultStringConverter() {
return new StringConverter<T>() {
@Override
public String toString(T t) {
return t == null ? null : t.toString();
}
@Override
public T fromString(String string) {
return (T) string;
}
};
}
/***************************************************************************
* *
* Constructors *
* *
**************************************************************************/
/**
* Creates a default ComboboxTablePopup instance with an empty
* {@link #itemsProperty() items} list and default
* {@link #selectionModelProperty() selection model}.
*/
public ComboBoxTablePopup() {
this(FXCollections.<S>emptyObservableList());
}
/**
* Creates a default ComboboxTablePopup instance with the provided items list and
* a default {@link #selectionModelProperty() selection model}.
*/
public ComboBoxTablePopup(ObservableList<S> items) {
setItems(items);
getStyleClass().add(DEFAULT_STYLE_CLASS);
setEditable(true);
setPromptText("Plz Search for a pirticular term");
}
public ComboBoxTablePopup(ObservableList<S> items, ObservableList<TableColumn> columns) {
this(items);
this.columns = columns;
}
private static final String DEFAULT_STYLE_CLASS = "combobox-table-popup";
private ReadOnlyObjectWrapper<TextField> editor;
private ObjectProperty<ObservableList<S>> items = new SimpleObjectProperty<ObservableList<S>>(this, "items");
public final void setItems(ObservableList<S> value) {
itemsProperty().set(value);
}
public final ObservableList<S> getItems() {
return items.get();
}
public ObjectProperty<ObservableList<S>> itemsProperty() {
return items;
}
// Converter
public ObjectProperty<StringConverter<S>> converterProperty() {
return converter;
}
private ObjectProperty<StringConverter<S>> converter =
new SimpleObjectProperty<StringConverter<S>>(this, "converter", ComboBoxTablePopup.<S>defaultStringConverter());
public final void setConverter(StringConverter<S> value) {
converterProperty().set(value);
}
public final StringConverter<S> getConverter() {
return converterProperty().get();
}// Create a symmetric (format/parse) converter with the default locale.
// Editor
public TextField getEditor() {
return editorProperty().get();
}
public ReadOnlyObjectProperty<TextField> editorProperty() {
if (editor == null) {
editor = new ReadOnlyObjectWrapper<TextField>(this, "editor");
editor.set(new ComboBoxListViewSkin.FakeFocusTextField());
}
return editor.getReadOnlyProperty();
}
@Override
protected Skin<?> createDefaultSkin() {
return new ComboBoxTablePopupSkin<>(this);
}
}
public class ComboBoxTablePopupSkin<S> extends ComboBoxPopupControl {
private ComboBoxTablePopup comboBoxTablePopup;
private ObservableList<S> comboboxTablePopupItems;
private TextField displayNode;
private TableView<S> tableViewPopupContent;
FilteredList<S> filtredList;
private SortedList<S> sortedList;
private Predicate<S> predicate;
private final InvalidationListener itemsObserver;
private final ListChangeListener<S> tableViewItemsListener = new ListChangeListener<S>() {
@Override
public void onChanged(ListChangeListener.Change<? extends S> c) {
getSkinnable().requestLayout();
}
};
private final WeakListChangeListener<S> weakListViewItemsListener =
new WeakListChangeListener<S>(tableViewItemsListener);
public ComboBoxTablePopupSkin(ComboBoxTablePopup comboBoxTablePopup) {
super(comboBoxTablePopup, new ComboBoxTablePopupBehavior(comboBoxTablePopup));
this.comboBoxTablePopup = comboBoxTablePopup;
setupTablePredicate();
updateComboBoxTablePopupItems();
itemsObserver = observable -> {
updateComboBoxTablePopupItems();
updateTableViewItems();
};
this.comboBoxTablePopup.itemsProperty().addListener(new WeakInvalidationListener(itemsObserver));
tableViewPopupContent = createTableView();
tableViewPopupContent.setManaged(false);
getChildren().add(tableViewPopupContent);
updateTableViewItems();
getEditor().textProperty().addListener((obv, oldValue, newValue) -> {
if (!newValue.isEmpty())
comboBoxTablePopup.show();
filtreData(newValue);
});
registerChangeListener(comboBoxTablePopup.itemsProperty(), "ITEMS");
registerChangeListener(comboBoxTablePopup.valueProperty(), "VALUE");
registerChangeListener(comboBoxTablePopup.editorProperty(), "EDITABLE");
}
private void setupTablePredicate() {
}
private void updateTableViewItems() {
filtredList = new FilteredList<S>(comboboxTablePopupItems, p -> true);
sortedList = new SortedList<S>(filtredList);
sortedList.comparatorProperty().bind(tableViewPopupContent.comparatorProperty());
tableViewPopupContent.setItems(sortedList);
}
private void filtreData(String pr) {
String data = pr;
filtredList.setPredicate(engine -> {
if (pr == null || pr.isEmpty() || pr.length() == 0)
return true;
if (((Engine) engine).getDesignation().toLowerCase().contains(pr.toLowerCase())) {
return true;
} else
return false;
});
}
public void updateComboBoxTablePopupItems() {
comboboxTablePopupItems = comboBoxTablePopup.getItems();
comboboxTablePopupItems = comboboxTablePopupItems == null ? FXCollections.<S>emptyObservableList() : comboboxTablePopupItems;
}
private TableView<S> createTableView() {
final TableView<S> tableView = new TableView<>();
tableView.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
tableView.setFocusTraversable(false);
tableView.getSelectionModel().selectedItemProperty().addListener(o -> {
int index = tableView.getSelectionModel().getSelectedIndex();
System.out.println("selected item changed");
});
for (TableColumn tblColumn : tableColumns()) {
tableView.getColumns().add(tblColumn);
}
tableView.setOnKeyPressed(e -> {
if (e.getCode() == KeyCode.ENTER ||
e.getCode() == KeyCode.ESCAPE ||
e.getCode() == KeyCode.SPACE) {
S selectedItem = tableView.getSelectionModel().getSelectedItem();
if (selectedItem != null) {
System.out.println(((Engine) selectedItem).getDesignation());
getEditor().setText(((Engine) selectedItem).getDesignation());
comboBoxTablePopup.setValue(selectedItem);
comboBoxTablePopup.hide();
}
}
});
return tableView;
}
private ObservableList<TableColumn> tableColumns() {
return ((ComboBoxTablePopup) getSkinnable()).getColumns();
}
@Override
protected Node getPopupContent() {
return this.tableViewPopupContent;
}
@Override
protected TextField getEditor() {
return ((ComboBoxTablePopup) getSkinnable()).getEditor();
}
@Override
protected StringConverter getConverter() {
return ((ComboBoxTablePopup) getSkinnable()).getConverter();
}
@Override
public Node getDisplayNode() {
if (displayNode == null) {
displayNode = getEditableInputNode();
displayNode.getStylesheets().add("ComboBoxTable-display-node");
updateDisplayNode();
}
displayNode.setEditable(comboBoxTablePopup.isEditable());
return displayNode;
}
@Override
protected void handleControlPropertyChanged(String p) {
super.handleControlPropertyChanged(p);
if ("TEXT".equals(p)) {
if (!getEditor().textProperty().get().isEmpty()) {
comboBoxTablePopup.show();
}
filtreData(getEditor().textProperty().get());
} else if ("ITEMS".equals(p)) {
updateComboBoxTablePopupItems();
} else if ("EDITABLE".equals(p)) {
getEditableInputNode();
}
}
}
答案 0 :(得分：1)
使用StringConverter将商品转换为String或使用类似的商品。
public class ComboBoxTablePopupSkin<S> extends ComboBoxPopupControl<S> {
...
private static final StringConverter DEFAULT_CONVERTER = new StringConverter() {
@Override
public String toString(Object o) {
return o == null ? null : o.toString();
}
@Override
public Object fromString(String s) {
throw new UnsupportedOperationException();
}
};
public final StringConverter<S> getConverter() {
StringConverter<S> converter = converterProperty().get();
// fix in case the property is set to a null
return converter == null ? DEFAULT_CONVERTER : converter;
}
private void filtreData(String pr) {
if (pr == null || pr.isEmpty()) {
filtredList.setPredicate(null);
} else {
final StringConverter<S> converter = ((ComboBoxTablePopup<S>) getSkinnable()).getConverter();
final String data = pr.toLowerCase();
filtredList.setPredicate(object -> {
String s = converter.toString(object);
return s != null && s.toLowerCase().contains(data);
});
}
}