java - 改变甘特图中子任务颜色的代码

Question

我需要更改 Gantt chart 中子任务的颜色.我的示例基于 GanttDemo2使用以下数据集和渲染器。在不同的论坛中，我发现了一些与此主题相关的讨论，但我没有找到一个清晰简单的有效示例。特别是，我可以更改任务的颜色，但我不知道如何提取子任务。

private IntervalCategoryDataset createSampleDataset() {

    final TaskSeries s1 = new TaskSeries("Scheduled");

    final Task t1 = new Task(
        "Design", date(1, Calendar.APRIL, 2001), date(1, Calendar.MAY, 2001));
    t1.addSubtask(new Task("Design 1", date(1, Calendar.APRIL, 2001), date(15, Calendar.APRIL, 2001)));
    t1.addSubtask(new Task("Design 2", date(16, Calendar.APRIL, 2001), date(25, Calendar.APRIL, 2001)));
    t1.addSubtask(new Task("Design 3", date(26, Calendar.APRIL, 2001), date(1, Calendar.MAY, 2001)));
    s1.add(t1);

    final Task t2 = new Task(
        "Proposal", date(1, Calendar.JUNE, 2001), date(1, Calendar.JULY, 2001));
    t2.addSubtask(new Task("Proposal 1", date(1, Calendar.JUNE, 2001), date(15, Calendar.JUNE, 2001)));
    t2.addSubtask(new Task("Proposal 2", date(16, Calendar.JUNE, 2001), date(25, Calendar.JUNE, 2001)));
    t2.addSubtask(new Task("Proposal 3", date(26, Calendar.JUNE, 2001), date(1, Calendar.JULY, 2001)));
    s1.add(t2);

    final TaskSeriesCollection collection = new TaskSeriesCollection();
    collection.add(s1);
    return collection;
}

class MyRenderer extends GanttRenderer {

    private static final Color subtask1Color = Color.blue;
    private static final Color subtask2Color = Color.cyan;
    private static final Color subtask3Color = Color.green;
    private static final long serialVersionUID = 1L;

    public MyRenderer() {
        super();
    }

    @Override
    public Paint getItemPaint(int row, int col) {
        System.out.println(row + " " + col + " " + super.getItemPaint(row, col));
        if (row == 0) {
            return subtask1Color;
        } else if (row == 1) {
            return subtask2Color;
        } else if (row == 2) {
            return subtask3Color;
        } else {
            return super.getItemPaint(row, col);
        }
    }
}

Answer 1

按照建议here ，自定义渲染器可以查询模型以调节 getItemPaint() 返回的结果.在此示例中，子任务使用给定系列的默认颜色的不同饱和度的调色板呈现。该方法假定渲染器进行两次传递；应注意记录相关性。

/** @see https://stackoverflow.com/questions/8938690 */
private static class MyRenderer extends GanttRenderer {

    private static final int PASS = 2; // assumes two passes
    private final List<Color> clut = new ArrayList<Color>();
    private final TaskSeriesCollection model;
    private int row;
    private int col;
    private int index;

    public MyRenderer(TaskSeriesCollection model) {
        this.model = model;
    }

    @Override
    public Paint getItemPaint(int row, int col) {
        if (clut.isEmpty() || this.row != row || this.col != col) {
            initClut(row, col);
            this.row = row;
            this.col = col;
            index = 0;
        }
        int clutIndex = index++ / PASS;
        return clut.get(clutIndex);
    }

    private void initClut(int row, int col) {
        clut.clear();
        Color c = (Color) super.getItemPaint(row, col);
        float[] a = new float[3];
        Color.RGBtoHSB(c.getRed(), c.getGreen(), c.getBlue(), a);
        TaskSeries series = (TaskSeries) model.getRowKeys().get(row);
        List<Task> tasks = series.getTasks(); // unchecked
        int taskCount = tasks.get(col).getSubtaskCount();
        taskCount = Math.max(1, taskCount);
        for (int i = 0; i < taskCount; i++) {
            clut.add(Color.getHSBColor(a[0], a[1] / i, a[2]));
        }
    }
}