ValueFormatter at MPAndroidChart repeated twice values

Question

I want to create chart by MPAndroidChart:v3.0.3 so in order to i have implemented it's lib into my gradle. for practice after initialize chart in my MainActivity class like this:

barChart = findViewById(R.id.chart_report);
barChart.setDrawBarShadow(false);
barChart.setDrawValueAboveBar(true);
barChart.setPinchZoom(false);
barChart.setDrawGridBackground(true);
barChart.setFitBars(true);

I have Setting up chart like this:

ArrayList<BarEntry> barEntries = new ArrayList<>();
barEntries.add(new BarEntry(1, 40f));
barEntries.add(new BarEntry(2, 20f));
barEntries.add(new BarEntry(3, 35f));
barEntries.add(new BarEntry(4, 15f));

BarDataSet barDataSet = new BarDataSet(barEntries, "DataSet1");
barDataSet.setColors(ColorTemplate.COLORFUL_COLORS);

BarData data = new BarData(barDataSet);
data.setBarWidth(0.3f);

barChart.setData(data);

Now everything is ok but i want to change it's XAxis so in order to i have created a class and implemented IAxisValueFormatter interface like this:

public class ChartAXisValueFormatter implements IAxisValueFormatter {
    private String[] mValues;

    public ChartAXisValueFormatter(String[] values) {
        mValues = values;
    }

    @Override
    public String getFormattedValue(float value, AxisBase axis) {

        int val = (int) (value);
        String label = "";
        if (val >= 0 && val < mValues.length) {
            label = mValues[val];
        } else {
            label = "";
        }
        return label;
    }
}

and use this class like this:

String[] report = new String[]{"A", "B", "C", "D"};
XAxis xAxis = barChart.getXAxis();
xAxis.setValueFormatter(new ChartAXisValueFormatter(report));
xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);

but as you can see C twice repeated !!! What logic i have to use in getFormattedValue for avoided this problem ?

Answer 1

This happens because you have to specify exact number of labels to xAxis:

xAxis.setLabelCount(barEntries.size());

Also see this: https://stackoverflow.com/a/48116532/3101777

Also and a little correction, index should be:

int val = (int) (value) -1;