Set axis label color by its value

Hi May Lym,

Yes, it’s possible by returning SpannableString with color from LabelProvider.

You’ll need to implement custom LabelFormatter which uses default implementation for formatting and then wraps it into SpannableString with desired color:

  class CustomLabelFormatter implements ILabelFormatter<NumericAxis> {
    private final NumericLabelFormatter defaultFormatter = new NumericLabelFormatter();

    @Override
    public void update(NumericAxis axis) {
        defaultFormatter.update(axis);
    }

    @Override
    public CharSequence formatLabel(Comparable dataValue) {
        return formatLabelInternal(dataValue, defaultFormatter.formatLabel(dataValue));
    }

    private static CharSequence formatLabelInternal(Comparable dataValue, CharSequence formattedValue) {
        final double doubleValue = ComparableUtil.toDouble(dataValue);

        if(doubleValue < 0d) {
            return formatLabelWithColor(formattedValue, Color.RED);
        } else if(doubleValue > 0d) {
            return formatLabelWithColor(formattedValue, Color.GREEN);
        } else
            return formatLabelWithColor(formattedValue, Color.GRAY);
    }

    private static CharSequence formatLabelWithColor(CharSequence label, int color) {
        final SpannableString coloredString = new SpannableString(label);

        coloredString.setSpan(new ForegroundColorSpan(color), 0, label.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

        return coloredString;
    }


    @Override
    public CharSequence formatCursorLabel(Comparable dataValue) {
        return formatLabelInternal(dataValue, defaultFormatter.formatCursorLabel(dataValue));
    }
  }

Then use this custom LabelFormatter for your axis:

 xAxis.setLabelProvider(new NumericLabelProvider(new CustomLabelFormatter()));

Hope this will help you!

Best regards,
Yura