JavaFX-检测并突出显示被拖动到的TableColumn

JavaFX-检测并突出显示被拖动到的TableColumn

为此，您需要在每个单元格中注册拖动侦听器，这会导致在单元格被拖动时该列更新其样式。我将使用

ObjectProperty

来代表当前的“放置目标列”（即在其上发生拖动的列）来进行此 *** 作，并观察它并从单元格中对其进行更新。要访问单元，您需要一个单元工厂。

下面的方法会将这种支持添加到列中。它还尊重先前连接的单元工厂中定义的任何功能：

private <S,T> void configureDropTargetColumn(TableColumn<S,T> column, ObjectProperty<TableColumn<?,?>> dropTarget) {    Callback<TableColumn<S,T>, TableCell<S,T>> currentCellFactory = column.getCellFactory() ;    column.setCellFactory(tc -> {        TableCell<S,T> cell = currentCellFactory.call(tc);        dropTarget.addListener((obs, oldColumn, newColumn) ->      cell.pseudoClassStateChanged(PseudoClass.getPseudoClass("drop-target"), newColumn==column));        cell.setonDragEntered(e -> dropTarget.set(column));        cell.setonDragExited(e -> dropTarget.set(null));        return cell ;    });}

这是使用通常的“联系表”示例的SSCCE：

import java.util.Arrays;import java.util.List;import java.util.function.Function;import javafx.application.Application;import javafx.beans.property.ObjectProperty;import javafx.beans.property.SimpleObjectProperty;import javafx.beans.property.SimpleStringProperty;import javafx.beans.property.StringProperty;import javafx.beans.value.Observablevalue;import javafx.css.PseudoClass;import javafx.geometry.Pos;import javafx.scene.Scene;import javafx.scene.control.Label;import javafx.scene.control.TableCell;import javafx.scene.control.TableColumn;import javafx.scene.control.TableView;import javafx.scene.input.ClipboardContent;import javafx.scene.input.Dragboard;import javafx.scene.input.TransferMode;import javafx.scene.layout.BorderPane;import javafx.stage.Stage;import javafx.util.Callback;public class TableColumnDropTargetExample extends Application {    @Override    public void start(Stage primaryStage) {        TableView<Person> table = new TableView<>();        table.getColumns().add(column("First Name", Person::firstNameProperty));        table.getColumns().add(column("Last Name", Person::lastNameProperty));        table.getColumns().add(column("Email", Person::emailProperty));        ObjectProperty<TableColumn<?,?>> dropTargetColumn = new SimpleObjectProperty<>();        table.getColumns().forEach(col -> configureDropTargetColumn(col, dropTargetColumn));        table.getItems().addAll(createData());        Label label = new Label("Drag me");        label.getStyleClass().add("drag-source");        label.setonDragDetected(e -> { Dragboard db = label.startDragAndDrop(TransferMode.COPY_OR_MOVE); ClipboardContent cc = new ClipboardContent(); cc.putString(label.getText()); db.setContent(cc);        });        label.setonDragDone(e -> dropTargetColumn.set(null));        BorderPane root = new BorderPane(table);        root.setTop(label);        BorderPane.setAlignment(label, Pos.CENTER);        Scene scene = new Scene(root, 800, 600);        scene.getStylesheets().add("style.css");        primaryStage.setScene(scene);        primaryStage.show();    }    private <S,T> void configureDropTargetColumn(TableColumn<S,T> column, ObjectProperty<TableColumn<?,?>> dropTarget) {        Callback<TableColumn<S,T>, TableCell<S,T>> currentCellFactory = column.getCellFactory() ;        column.setCellFactory(tc -> { TableCell<S,T> cell = currentCellFactory.call(tc); dropTarget.addListener((obs, oldColumn, newColumn) ->          cell.pseudoClassStateChanged(PseudoClass.getPseudoClass("drop-target"), newColumn==column)); cell.setonDragEntered(e -> dropTarget.set(column)); cell.setonDragExited(e -> dropTarget.set(null)); return cell ;        });    }    private static <S,T> TableColumn<S,T> column(String text, Function<S, Observablevalue<T>> property) {        TableColumn<S,T> col = new TableColumn<>(text);        col.setCellValueFactory(cellData -> property.apply(cellData.getValue()));        return col ;    }    private List<Person> createData() {        return Arrays.asList(     new Person("Jacob", "Smith", "jacob.smith@example.com"),     new Person("Isabella", "Johnson", "isabella.johnson@example.com"),     new Person("Ethan", "Williams", "ethan.williams@example.com"),     new Person("Emma", "Jones", "emma.jones@example.com"),     new Person("Michael", "Brown", "michael.brown@example.com")  );    }    public static class Person {        private final StringProperty firstName = new SimpleStringProperty();        private final StringProperty lastName = new SimpleStringProperty();        private final StringProperty email = new SimpleStringProperty();        public Person(String firstName, String lastName, String email) { setFirstName(firstName); setLastName(lastName); setEmail(email);        }        public final StringProperty firstNameProperty() { return this.firstName;        }        public final String getFirstName() { return this.firstNameProperty().get();        }        public final void setFirstName(final String firstName) { this.firstNameProperty().set(firstName);        }        public final StringProperty lastNameProperty() { return this.lastName;        }        public final String getLastName() { return this.lastNameProperty().get();        }        public final void setLastName(final String lastName) { this.lastNameProperty().set(lastName);        }        public final StringProperty emailProperty() { return this.email;        }        public final String getEmail() { return this.emailProperty().get();        }        public final void setEmail(final String email) { this.emailProperty().set(email);        }    }    public static void main(String[] args) {        launch(args);    }}

和样式表：

.table-cell:drop-target {    -fx-background-color: -fx-background ;    -fx-background: yellow ;    -fx-border-color: -fx-table-cell-border-color -fx-table-cell-border-color transparent transparent ;}.drag-source {    -fx-font-size: 18 ;    -fx-padding: 10 ;}