Candlestick Chart Coloring

Hi Ray,

Unfortunately there is no built-in functionality which allows to do this out of the box. But you can try to use PaletteProvider API and override colors for candles on your own. In this case you’ll need to iterate over points in render pass data and based on its content set desired colors.

I quickly tried to create a prototype of such palette provider so now you have some code to start from:

public class CandlePaletteProvider extends PaletteProviderBase<FastCandlestickRenderableSeries> implements IStrokePaletteProvider, IFillPaletteProvider {

    private final IntegerValues colors = new IntegerValues();

    public CandlePaletteProvider() {
        super(FastCandlestickRenderableSeries.class);
    }

    @Override
    public void update() {
        final OhlcRenderPassData currentRenderPassData = ((FastCandlestickRenderableSeries<?, ?>) renderableSeries).getCurrentRenderPassData();

        final int pointsCount = currentRenderPassData.pointsCount();
        colors.setSize(pointsCount);

        final int[] colorsItems = colors.getItemsArray();
        final double[] closeValues = currentRenderPassData.closeValues.getItemsArray();

        colorsItems[0] = Color.GREEN;
        for (int i = 1; i < pointsCount; i++) {
            colorsItems[i] = closeValues[i] >= closeValues[i-1] ? Color.GREEN : Color.RED;
        }
    }

    @Override
    public final IntegerValues getFillColors() {
        return colors;
    }

    @Override
    public final IntegerValues getStrokeColors() {
        return colors;
    }
}

Hope this will help you!

In v2.x to make this code working you need to replace this line:

final OhlcRenderPassData currentRenderPassData = ((FastCandlestickRenderableSeries<?, ?>) renderableSeries).getCurrentRenderPassData();

on this line (in v2.x we removed generic params from RenderableSeries so you need to cast render pass data):

final OhlcRenderPassData currentRenderPassData = (OhlcRenderPassData) renderableSeries.getCurrentRenderPassData();

Best regards,
Yura