JavaFX StackedBarChart自动在不同系列上重复使用相同的颜色:如何避免呢? [英] JavaFX StackedBarChart automatically reuse the same color on different series: how to avoid it?

问题描述

在JavaFx中，我使用以下代码创建一个StackedBarChart:

In JavaFx I'm creating a a StackedBarChart with this code:

        String[] ACTIVITIES = new String[10]{ ... };// there are 10 activity names here
        for (String activityName : ACTIVITIES) { 
            Series<String, Number> activitySerie = new Series<String, Number>();
            activitySerie.setName(activityName);
            stackedBarChart.getData().add(activitySerie);

        }

结果是从1到8的系列具有不同的颜色. 9-10系列与1-2系列具有相同的颜色.我试图在style.css文件中为条形图指定默认颜色，但似乎9-10系列实际上使用了颜色0和1.我认为这是一个错误.有谁知道解决方法?

The result is that series from 1 to 8 has different colors. Series 9-10 have the same colors as series 1-2. I tried to specify default colors for bar charts in the style.css file but it seems that Series 9-10 actually use colors 0 and 1. I think it's a bug. Does anyone know a workaround for it?

推荐答案

颜色在8系列之后被回收(原因是必须对定义的颜色数量进行一定的硬编码限制:JavaFX CSS语法根本无法提供用于计算任意值的足够语法，并且对于超出该限制的系列，需要定义一些颜色.

The colors are recycled after 8 series (the reason is that there has to be some hard-coded limit to the number of colors that are defined: the JavaFX CSS syntax simply does not provide enough syntax for computing arbitrary values, and for series beyond that limit some color needs to be defined).

要为8号以后的系列创建颜色，您需要做两件事:在表示其他系列的节点上设置样式类，并为CSS中的样式设置样式.

To create colors for series beyond the 8th, you need to do two things: set a style class on the nodes representing the additional series, and set the style for those in CSS.

SSCCE:

import java.util.Random;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.StackedBarChart;
import javafx.scene.chart.XYChart.Data;
import javafx.scene.chart.XYChart.Series;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class StackedBarChartExample extends Application {

    @Override
    public void start(Stage primaryStage) {
        StackedBarChart<String, Number> chart = new StackedBarChart<>(new CategoryAxis(), new NumberAxis());

        Random rng = new Random();

        int numSeries = 10 ;
        int defaultColorsDefined = 8 ;


        for (int i = 0; i < numSeries; i++) {
            Series<String, Number> series = new Series<>();
            Data<String, Number> untreated = new Data<>("Untreated", rng.nextDouble());
            series.getData().add(untreated);
            Data<String, Number> treated = new Data<>("Treated", rng.nextDouble());
            series.getData().add(treated);
            series.setName("Series "+i);

            chart.getData().add(series);

            // add style classes for additional series beyond the default support:
            // Note this must be done after adding the series to the chart...
            if (i >= defaultColorsDefined) {
                untreated.getNode().getStyleClass().add("default-color"+i);
                treated.getNode().getStyleClass().add("default-color"+i);
            }
        }

        BorderPane root = new BorderPane(chart);
        Scene scene = new Scene(root);
        scene.getStylesheets().add("stacked-bar-chart.css");
        primaryStage.setScene(scene);
        primaryStage.show();


    }

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

然后按照通常的方式在CSS中定义一些颜色:

And then just define some colors in css in the usual way:

.default-color8.chart-bar {
    -fx-bar-fill: black ;
}
.default-color9.chart-bar {
    -fx-bar-fill: green ;
}

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