Display Bar Values in Chart

[Steve Dyke]

Can someone help me with the following code syntax? I need to display the x values on top of the bars in my chart.

// create plot ...
		this.array1 = scheduledarray();
        final IntervalXYDataset data1 = createDataset1();
        final XYBarRenderer renderer1 = new ClusteredXYBarRenderer(0.5, false);
        //final ClusteredXYBarRenderer renderer1 = new ClusteredXYBarRenderer(0.5, true);
        renderer1.setItemLabelGenerator(new XYItemLabelGenerator());
        renderer1.setItemLabelsVisible(true);

[Ulf Dittmer]

My guess would be that this calls for a subclass of ClusteredXYBarRenderer that does some extra drawing (of the numeric value) on top of the bar. You'd override the drawItem method for that.

[Steve Dyke]

Ulf Dittmer wrote:My guess would be that this calls for a subclass of ClusteredXYBarRenderer that does some extra drawing (of the numeric value) on top of the bar. You'd override the drawItem method for that.

Can you explain a little more in detail?

[Ulf Dittmer]

Something like this:

private class MyClusteredXYBarRenderer extends ClusteredXYBarRenderer {

    public MyClusteredXYBarRenderer (double margin, boolean centerBarAtStartValue) {
        super(margin, centerBarAtStartValue);
    }

    @Override
    drawItem(Graphics2D g2, XYItemRendererState state, Rectangle2D dataArea, PlotRenderingInfo info,
            XYPlot plot, ValueAxis domainAxis, ValueAxis rangeAxis, XYDataset dataset, int series, int item,
            CrosshairState crosshairState, int pass) {
        super(g2, state, dataArea, info, plot, domainAxis, rangeAxis, dataset, series, item, crosshairState, pass);
    // ... draw whatever text you want on top of the newly drawn bar here ...
    }
}

...

final XYBarRenderer renderer1 = new MyClusteredXYBarRenderer(0.5, false);

[Steve Dyke]

Maybe I am missing somthing and I am surely not questioning your advice and expertise. Is all this necessary just to do what I thought would be a simple, turn on or display x value labels.

[Ulf Dittmer]

Maybe I'm misunderstanding what you're trying to do. I interpreted "I need to display the x values on top of the bars in my chart. " to mean that you want the values to be drawn inside of the rectangle defined by each bar. Since FreeChart has no provisions for doing that, you'd have to go the route I outlined.

If you actually meant something else, please elaborate.

Out of the box, JFreeChart can only display values as part of an Axis, which can be left or right of a chart (for value axes) or above or below a chart (for domain axes); see the AxisLocation class for details.

[Steve Dyke]

Right now my chart displays horizontal bars, seven sets of five bars. It is showing a weeks worth of department activity. What the Management wants to see in addition to what I have is the values of the bars also displayed above each bar.

[Ulf Dittmer]

You could check out what the AbstractRenderer.setBaseItemLabelsVisible
and setBasePositiveItemLabelPosition methods can do.

[Steve Dyke]

Ulf Dittmer wrote:You could check out what the AbstractRenderer.setBaseItemLabelsVisible
and setBasePositiveItemLabelPosition methods can do.

Is there any way you could provide an example of this?

[Ulf Dittmer]

It would be something like this:

renderer1.setBaseItemLabelsVisible(true);
renderer1.setBaseItemLabelGenerator(new StandardXYItemLabelGenerator());
for (int i=0; i<5; i++)
	renderer1.setSeriesPositiveItemLabelPosition(i,
		new ItemLabelPosition(ItemLabelAnchor.OUTSIDE3, TextAnchor.CENTER_LEFT));

[Steve Dyke]

Thanks a lot for the example, I got it to work.