动态更改JFreeChart直方图颜色？

Question

我正在尝试显示一张图片的直方图，并仅显示某些颜色。我已经使用JFreeChart和createXYLineChart完成了这项任务，并通过迭代所有像素来获取所有数据。

为了加快速度，我正在尝试使用“createHistogram”完成。我遵循了这个代码。

为了使用新值更新图表，我使用了以下两种方法：

XYPlot plot = (XYPlot) chart.getPlot();
plot.setDataset(setHistogram(red, green, blue));

设置setHistogram方法根据勾选的复选框（红色，绿色和蓝色）返回一个HistogramDataset。这个方法按预期工作。

当我这样做时，第二件事情是更新每个系列的颜色，否则它们会得到默认值。我按照与值大致相同的过程进行了操作：

private void setHistogramColors(boolean red, boolean green, boolean blue) {
    XYPlot plot = (XYPlot) chart.getPlot();
    XYBarRenderer renderer = (XYBarRenderer) plot.getRenderer();
    renderer.setBarPainter(new StandardXYBarPainter());
    Paint[] paintArray = null;
    if (red) {
        if (green) {
            if (blue) {
                paintArray = new Paint[3];
                paintArray[0] = new Color(0x80ff0000, true);// translucent red, green & blue
                paintArray[1] = new Color(0x8000ff00, true);
                paintArray[2] = new Color(0x800000ff, true);
            } else {
                paintArray = new Paint[2];
                paintArray[0] = new Color(0x80ff0000, true);
                paintArray[1] = new Color(0x8000ff00, true);
            }
        } else {
            paintArray = new Paint[1];
            paintArray[0] = new Color(0x80ff0000, true);
        }
    } else if (green) {
        if (blue) {
            paintArray = new Paint[2];
            paintArray[0] = new Color(0x8000ff00, true);
            paintArray[1] = new Color(0x800000ff, true);
        } else {
            paintArray = new Paint[1];
            paintArray[0] = new Color(0x8000ff00, true);
        }
    } else if (blue){
        paintArray = new Paint[1];
        paintArray[0] = new Color(0x800000ff, true);
    }
    else {
        return;
    }
    plot.setDrawingSupplier(new DefaultDrawingSupplier(
            paintArray,
            DefaultDrawingSupplier.DEFAULT_FILL_PAINT_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_OUTLINE_PAINT_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_STROKE_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_OUTLINE_STROKE_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_SHAPE_SEQUENCE));
}

但根据我所见，这只在我第一次绘制代码时有效，接下来对不同系列的绘图将采用相同的颜色。下面是一个例子，RGB是它们应该是的颜色： [ 当我使用红色更新时，红色转到绿色直方图，绿色转到蓝色直方图： 有没有办法解决这个问题？

- nck

Answer 1

根据您的代码片段和此 评论，看起来您正在尝试通过在复选框处理程序中添加和删除数据集中的系列来更改显示。而不是更改 模型，请更改 视图 中系列的可见性。在这种情况下，您可以为每个复选框提供适当的 Action，如 此处 和下面所示。特别注意，VisibleAction 使用与自定义 DrawingSupplier 中相应颜色匹配的系列索引。

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Paint;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.awt.image.Raster;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.ImageIcon;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.DefaultDrawingSupplier;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.StandardXYBarPainter;
import org.jfree.chart.renderer.xy.XYBarRenderer;
import org.jfree.data.statistics.HistogramDataset;

/**
 * @see https://dev59.com/xJzha4cB1Zd3GeqPEWRR
 * @see https://dev59.com/B2fWa4cB1Zd3GeqPdA_f
 * @see https://dev59.com/NYfca4cB1Zd3GeqPot9M#28519356
 */
public class Histogram {

    private static final int BINS = 256;
    private final BufferedImage image = getImage();
    private HistogramDataset dataset;
    private XYBarRenderer renderer;

    private BufferedImage getImage() {
        try {
            return ImageIO.read(new URL(
                "http://i.imgur.com/kxXhIH1.jpg"));
        } catch (IOException e) {
            e.printStackTrace(System.err);
        }
        return null;
    }

    private ChartPanel createChartPanel() {
        // dataset
        dataset = new HistogramDataset();
        Raster raster = image.getRaster();
        final int w = image.getWidth();
        final int h = image.getHeight();
        double[] r = new double[w * h];
        r = raster.getSamples(0, 0, w, h, 0, r);
        dataset.addSeries("Red", r, BINS);
        r = raster.getSamples(0, 0, w, h, 1, r);
        dataset.addSeries("Green", r, BINS);
        r = raster.getSamples(0, 0, w, h, 2, r);
        dataset.addSeries("Blue", r, BINS);
        // chart
        JFreeChart chart = ChartFactory.createHistogram("Histogram", "Value",
            "Count", dataset, PlotOrientation.VERTICAL, true, true, false);
        XYPlot plot = (XYPlot) chart.getPlot();
        renderer = (XYBarRenderer) plot.getRenderer();
        renderer.setBarPainter(new StandardXYBarPainter());
        // translucent red, green & blue
        Paint[] paintArray = {
            new Color(0x80ff0000, true),
            new Color(0x8000ff00, true),
            new Color(0x800000ff, true)
        };
        plot.setDrawingSupplier(new DefaultDrawingSupplier(
            paintArray,
            DefaultDrawingSupplier.DEFAULT_FILL_PAINT_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_OUTLINE_PAINT_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_STROKE_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_OUTLINE_STROKE_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_SHAPE_SEQUENCE));
        ChartPanel panel = new ChartPanel(chart);
        panel.setMouseWheelEnabled(true);
        return panel;
    }

    private JPanel createControlPanel() {
        JPanel panel = new JPanel();
        panel.add(new JCheckBox(new VisibleAction(0)));
        panel.add(new JCheckBox(new VisibleAction(1)));
        panel.add(new JCheckBox(new VisibleAction(2)));
        return panel;
    }

    private class VisibleAction extends AbstractAction {

        private final int i;

        public VisibleAction(int i) {
            this.i = i;
            this.putValue(NAME, (String) dataset.getSeriesKey(i));
            this.putValue(SELECTED_KEY, true);
            renderer.setSeriesVisible(i, true);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            renderer.setSeriesVisible(i, !renderer.getSeriesVisible(i));
        }
    }

    private void display() {
        JFrame f = new JFrame("Histogram");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(createChartPanel());
        f.add(createControlPanel(), BorderLayout.SOUTH);
        f.add(new JLabel(new ImageIcon(image)), BorderLayout.WEST);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            new Histogram().display();
        });
    }
}

- trashgod

---

我无法感谢你的足够，昨天当我看到你关于使用VisibleAction的评论时，我花了几个小时尝试做到这一点，查找JFreeChart、XYPload和ChartPanels中的所有方法，试图找到隐藏系列的方法，但是一直没有找到解决方案。今天你让我开心了一整天。非常感谢你。 - nck

@nck：很高兴能帮忙；这种方法对你的使用情况似乎更快。 - trashgod