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  1. JDK
  2. JDK-8243128

[Charts] Setting LineChart series data to a new list silently breaks line chart

    Details

    • Type: Enhancement
    • Status: Open
    • Priority: P4
    • Resolution: Unresolved
    • Affects Version/s: 8u241, 9, openjfx11, openjfx14
    • Fix Version/s: tbd
    • Component/s: javafx
    • Subcomponent:
    • CPU:
      x86
    • OS:
      linux_ubuntu

      Description

      A DESCRIPTION OF THE PROBLEM :
      Using series.setData with a new list containing extra chart data breaks chart display:
      - lines between data points disappear
      - resizing chart leaves some data points on the same place, while others are moving

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      1. Run executable test case
      2. Click button "Add Chart data"

      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      Lines in the line chart don't disappear, a new data point is added. When resizing the window, all data points are moving to their positions on the chart.
      ACTUAL -
      Lines and some points getting removed. Resizing the window makes some points move while other stay where they were.

      ---------- BEGIN SOURCE ----------
      import javafx.application.Application;
      import javafx.collections.FXCollections;
      import javafx.scene.Scene;
      import javafx.scene.chart.LineChart;
      import javafx.scene.chart.NumberAxis;
      import javafx.scene.chart.XYChart;
      import javafx.scene.control.Button;
      import javafx.scene.layout.VBox;
      import javafx.stage.Stage;

      import java.util.ArrayList;
      import java.util.Arrays;
      import java.util.Collections;

      public class LineChartRepro extends Application {
          public void start(Stage stage) throws Exception {
              LineChart<Number, Number> chart = new LineChart<>(new NumberAxis(), new NumberAxis());
              XYChart.Series<Number, Number> series = new XYChart.Series<>();
              series.setData(FXCollections.observableList(Arrays.asList(
                      new XYChart.Data<>(0,0),
                      new XYChart.Data<>(1,1))));
              chart.getData().setAll(Collections.singletonList(series));
              Button addChartData = new Button("Add Chart data");
              addChartData.setOnAction(e -> {
                  ArrayList<XYChart.Data<Number, Number>> newList = new ArrayList<>(series.getData());
                  newList.add(new XYChart.Data<>(newList.size(), newList.size()));
                  series.setData(FXCollections.observableList(newList));
              });
              stage.setScene(new Scene(new VBox(chart, addChartData)));
              stage.show();
          }

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

      ---------- END SOURCE ----------

      CUSTOMER SUBMITTED WORKAROUND :
      Instead of setting series data one could use observable list and modify that:

      ObservableList<XYChart.Data<Number, Number>> data = FXCollections.observableList(new ArrayList<>());
      data.add(new XYChart.Data<>(0,0));
      data.add(new XYChart.Data<>(1,1));
      series.setData(data);
      ...
      addChartData.setOnAction(e -> {
          data.add(new XYChart.Data<>(data.size(), data.size()));
      });

      Unfortunately, that's not a workaround for my use case. I'm the author of cljfx — https://github.com/cljfx/cljfx — a react-like wrapper of JavaFX that uses immutable values instead of observable cells for reactivity, so I need to use setters.

      FREQUENCY : always


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            • Assignee:
              aghaisas Ajit Ghaisas
              Reporter:
              webbuggrp Webbug Group
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              Dates

              • Created:
                Updated: