Consider a strategy which by default draws 10 level lines with 2 pip step starting from the last ask price and then prints their keys and prices. The level lines get removed on strategy stop.

package charts.test;

import java.util.ArrayList;
import java.util.List;

import com.dukascopy.api.*;
import com.dukascopy.api.drawings.IHorizontalLineChartObject;

/**
 * The strategy by default draws 10 level lines with 2 pip step starting from
 * the last ask price and then prints their keys and prices. 
 * The level lines get removed on strategy stop.
 *
 */

@RequiresFullAccess
public class LevelLines implements IStrategy {

    private IChart chart;
    private IHistory history;
    private IConsole console;

    @Configurable("")
    public Instrument instrument = Instrument.EURUSD;
    @Configurable("HLine count")
    public int hlineCount = 10;
    @Configurable("HLine step (in pips)")
    public int stepInPips = 2;

    List<IHorizontalLineChartObject> hLines = new ArrayList<IHorizontalLineChartObject>();    

    @Override
    public void onStart(IContext context) throws JFException {
        this.chart = context.getChart(instrument);
        this.history = context.getHistory();
        this.console = context.getConsole();

        ITick tick = history.getLastTick(instrument);
        double basePrice = tick.getBid(); //base price - the last bid price

        //draw HLines
        double price;
        for(int i=0; i< hlineCount; i++){
            price = basePrice + instrument.getPipValue() * stepInPips * i;
            IHorizontalLineChartObject hLine = chart.getChartObjectFactory().createHorizontalLine();
            hLine.setPrice(0, price);
            hLine.setText(String.valueOf(i));
            chart.addToMainChartUnlocked(hLine);
            hLines.add(hLine);
        }    

        //log some information
        for(IHorizontalLineChartObject hLine : hLines){
            console.getOut().println(String.format("hline %s: key=%s, price=%.5f",
                hLine.getText(), hLine.getKey(), hLine.getPrice(0)));
        }        

    }

    @Override
    public void onTick(Instrument instrument, ITick tick) throws JFException {    }

    @Override
    public void onBar(Instrument instrument, Period period, IBar askBar, IBar bidBar) throws JFException {}

    @Override
    public void onMessage(IMessage message) throws JFException {}

    @Override
    public void onAccount(IAccount account) throws JFException {}

    @Override
    public void onStop() throws JFException {
        chart.removeAll();
    }

}

LevelLines.java