javafx - TableView ScrollBar策略

Question

有没有办法在TableView中更改类似于ScrollPane的ScrollBar的策略？我只看到TableView的VirtualFlow计算可见性，但是没有人工干预的可能性。

我需要垂直滚动条始终可见，水平滚动条永远不可见。更改条形的可见状态不起作用。

例：

import java.time.LocalDate;
import java.time.Month;
import java.util.Set;

import javafx.application.Application;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Orientation;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.ScrollBar;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

import com.sun.javafx.scene.control.skin.VirtualFlow;

public class ScrollBarInTableViewDemo extends Application {

    private TableView<Data> table1 = new TableView<>(); // table with scrollbars
    private TableView<Data> table2 = new TableView<>(); // table without scrollbars

    private final ObservableList<Data> data =
            FXCollections.observableArrayList( 
                    new Data( LocalDate.of(2015, Month.JANUARY, 10), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 11), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 12), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 13), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 14), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 15), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 16), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 17), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 18), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 19), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 20), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 21), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 22), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 23), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 24), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 25), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 26), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 27), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 28), 10.0, 20.0, 30.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 29), 40.0, 50.0, 60.0),
                    new Data( LocalDate.of(2015, Month.JANUARY, 30), 10.0, 20.0, 30.0)

            );

    final HBox hb = new HBox();

    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage stage) {

        Scene scene = new Scene(new Group());

        stage.setTitle("Table View Sample");
        stage.setWidth(800);
        stage.setHeight(800);

        // setup table columns
        setupTableColumns( table1);
        setupTableColumns( table2);

        // fill tables with data
        table1.setItems(data);
        table1.setTableMenuButtonVisible(true);

        // create container
        HBox hBox = new HBox();
        hBox.getChildren().addAll( table1, table2);

        ((Group) scene.getRoot()).getChildren().addAll( hBox);

        stage.setScene(scene);
        stage.show();

        ScrollBar table1HorizontalScrollBar = findScrollBar( table1, Orientation.HORIZONTAL);
        ScrollBar table1VerticalScrollBar = findScrollBar( table1, Orientation.VERTICAL);

        // this doesn't work:
        table1HorizontalScrollBar.setVisible(false);
        table1VerticalScrollBar.setVisible(false);

        ScrollBar table2HorizontalScrollBar = findScrollBar( table2, Orientation.HORIZONTAL);
        ScrollBar table2VerticalScrollBar = findScrollBar( table2, Orientation.VERTICAL);

        // this doesn't work:
        table2HorizontalScrollBar.setVisible(true);
        table2VerticalScrollBar.setVisible(true);

        // enforce layout to see if anything has an effect
        VirtualFlow flow1 = (VirtualFlow) table1.lookup(".virtual-flow");
        flow1.requestLayout();

        VirtualFlow flow2 = (VirtualFlow) table2.lookup(".virtual-flow");
        flow2.requestLayout();

    }

    /**
     * Primary table column mapping.
     */
    private void setupTableColumns( TableView table) {


        TableColumn<Data, LocalDate> dateCol = new TableColumn<>("Date");
        dateCol.setPrefWidth(120);
        dateCol.setCellValueFactory(new PropertyValueFactory<>("date"));

        TableColumn<Data, Double> value1Col = new TableColumn<>("Value 1");
        value1Col.setPrefWidth(90);
        value1Col.setCellValueFactory(new PropertyValueFactory<>("value1"));

        TableColumn<Data, Double> value2Col = new TableColumn<>("Value 2");
        value2Col.setPrefWidth(90);
        value2Col.setCellValueFactory(new PropertyValueFactory<>("value2"));

        TableColumn<Data, Double> value3Col = new TableColumn<>("Value 3");
        value3Col.setPrefWidth(90);
        value3Col.setCellValueFactory(new PropertyValueFactory<>("value3"));

        table.getColumns().addAll( dateCol, value1Col, value2Col, value3Col);


    }

    /**
     * Find the horizontal scrollbar of the given table.
     * @param table
     * @return
     */
    private ScrollBar findScrollBar(TableView<?> table, Orientation orientation) {

        // this would be the preferred solution, but it doesn't work. it always gives back the vertical scrollbar
        //      return (ScrollBar) table.lookup(".scroll-bar:horizontal");
        //      
        // => we have to search all scrollbars and return the one with the proper orientation

        Set<Node> set = table.lookupAll(".scroll-bar");
        for( Node node: set) {
            ScrollBar bar = (ScrollBar) node;
            if( bar.getOrientation() == orientation) {
                return bar;
            }
        }

        return null;

    }

    /**
     * Data for primary table rows.
     */
    public static class Data {

        private final ObjectProperty<LocalDate> date;
        private final SimpleDoubleProperty value1;
        private final SimpleDoubleProperty value2;
        private final SimpleDoubleProperty value3;

        public Data( LocalDate date, double value1, double value2, double value3) {

            this.date = new SimpleObjectProperty<LocalDate>( date);

            this.value1 = new SimpleDoubleProperty( value1);
            this.value2 = new SimpleDoubleProperty( value2);
            this.value3 = new SimpleDoubleProperty( value3);
        }

        public final ObjectProperty<LocalDate> dateProperty() {
            return this.date;
        }
        public final LocalDate getDate() {
            return this.dateProperty().get();
        }
        public final void setDate(final LocalDate date) {
            this.dateProperty().set(date);
        }
        public final SimpleDoubleProperty value1Property() {
            return this.value1;
        }
        public final double getValue1() {
            return this.value1Property().get();
        }
        public final void setValue1(final double value1) {
            this.value1Property().set(value1);
        }
        public final SimpleDoubleProperty value2Property() {
            return this.value2;
        }
        public final double getValue2() {
            return this.value2Property().get();
        }
        public final void setValue2(final double value2) {
            this.value2Property().set(value2);
        }
        public final SimpleDoubleProperty value3Property() {
            return this.value3;
        }
        public final double getValue3() {
            return this.value3Property().get();
        }
        public final void setValue3(final double value3) {
            this.value3Property().set(value3);
        }


    }
} 

Answer 1

如果未显示TableView，它也可以工作。它仅在有少量数据时才起作用，因为

private boolean computeBarVisiblity() {
    if (cells.isEmpty()) {
        // In case no cells are set yet, we assume no bars are needed
        needLengthBar = false;
        needBreadthBar = false;
        return true;
    }

    // ... other method code
}

在VirtualFlow代码中。但是您可以扩展此示例。

        public static void alwaysShowVerticalScroll(final TableView view) {
    new Thread(() -> {
        while (true) {
            Set<Node> nodes = view.lookupAll(".scroll-bar");
            if (nodes.isEmpty()) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException ignore) {
                }
                continue;
            }
            Node node = view.lookup(".virtual-flow");
            if (node == null) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException ignore) {
                }
                continue;
            }
            final VirtualFlow flow = (VirtualFlow) node;
            for (Node n : nodes) {
                if (n instanceof ScrollBar) {
                    final ScrollBar bar = (ScrollBar) n;
                    if (bar.getOrientation().equals(Orientation.VERTICAL)) {
                        bar.visibleProperty().addListener(l -> {
                            if (bar.isVisible()) {
                                return;
                            }
                            Field f = getVirtualFlowField("needLengthBar");
                            Method m = getVirtualFlowMethod("updateViewportDimensions");
                            try {
                                f.setBoolean(flow, true);
                                m.invoke(flow);
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                            bar.setVisible(true);
                        });
                        Platform.runLater(() -> {
                            bar.setVisible(true);
                        });
                        break;
                    }
                }
            }
            break;
        }
    }).start();
}

private static Field getVirtualFlowField(String name) {
    Field field = null;
    try {
        field = VirtualFlow.class.getDeclaredField(name);
        field.setAccessible(true);
    } catch (NoSuchFieldException e) {
        e.printStackTrace();
    }
    return field;
}

private static Method getVirtualFlowMethod(String name) {
    Method m = null;
    try {
        m = VirtualFlow.class.getDeclaredMethod(name);
        m.setAccessible(true);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return m;
}