JavaFX 缺少 Legend 类

Question

I have this code:

List<Node> legends = new ArrayList<>(lineChart.lookupAll("Label.chart-legend-item"));
Legend legend1 = (Legend)legends.get(0);

The problem is that my IDE can't find any Legend class to import it.

I'm talking about this class: https://docs.oracle.com/javafx/2/api/javafx/scene/doc-files/cssref.html#legend

I'm using Java 10. Why my IDE don't find Legend class?

What I want to achieve is to take the name of legend.

Answer 1

It looks like Legend is from an internal api:

import com.sun.javafx.charts.Legend;

Probably removed in Java9+

Answer 2

You have export the module com.sun.javafx.charts to access the Legend class as the Legend class is part of the internal API. In IntelliJ you have to add an override to the compiler:

(Settings -->Build, Execution, Deployment --> Compiler --> Java compiler -->Override compiler parameters)

--add-exports=javafx.controls/com.sun.javafx.charts=ALL-UNNAMED

And in the run configuration add to the VM Options.

The import is:

import com.sun.javafx.charts.Legend;

Edit: It has not been removed as the accepted answer says.

Example code:

import com.sun.javafx.charts.Legend;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;

public class Main extends Application {

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

    @Override
    public void start(Stage primaryStage) throws Exception {
        Legend legend = new Legend();
        Legend.LegendItem legendItem = new Legend.LegendItem("Test legend item");
        ObservableList<Legend.LegendItem> items = FXCollections.observableArrayList(legendItem);
        legend.setItems(items);
        AnchorPane anchorPane = new AnchorPane(legend);
        Scene scene = new Scene(anchorPane, 400, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

And to compiler options add:

If you use gradle you have to add the compiler option to the build.gradle too.

compileJava {
    options.compilerArgs += ["--add-exports=javafx.controls/com.sun.javafx.charts=ALL-UNNAMED"]
}

Answer 3

TilePane is super class of Legend. So you can cast to TilePane.

List<Node> legends = new ArrayList<>(lineChart.lookupAll("Label.chart-legend-item"));
TilePane legend1 = (TilePane) legends.get(0);    
legend1.setHgap(10);
legend1.getChildren().remove(..);
...