For Zoomer, how to get actual start index and end index of data in the range

[yezhengli-Mr9]

Describe the bug
A clear and concise description of what the bug is. Please use the issue feature only for actual bugs. If you have usage questions or are unsure if/how a certain functionality is supported in chart-fx please use the q&a secton in the discussions feature or our gitter channel.

For Zoomer, how to get actual starting index and end index of data in the range? For example, start and end index of a list of bars.
To Reproduce
Steps to reproduce the behavior. Ideally the problem can be reproduced in the samples provided with chart-fx or by adapting them slightly. Alternatively provide a minimal working example.

chart-fx/chartfx-samples/src/main/java/io/fair_acc/sample/financial/AbstractBasicFinancialApplication.java

Lines 189 to 245 in f8a5094

	protected Chart getDefaultFinancialTestChart(final FinancialTheme theme) {
	// load datasets
	DefaultDataSet indiSet = null;
	if (resource.startsWith("REALTIME")) {
	try {
	Interval<Calendar> timeRangeInt = CalendarUtils.createByDateTimeInterval(timeRange);
	Interval<Calendar> ttInt = CalendarUtils.createByTimeInterval(tt);
	Calendar replayFromCal = CalendarUtils.createByDateTime(replayFrom);
	ohlcvDataSet = new SimpleOhlcvReplayDataSet(
	DataInput.valueOf(resource.substring("REALTIME-".length())),
	period,
	timeRangeInt,
	ttInt,
	replayFromCal,
	consolidationAddons);
	} catch (ParseException e) {
	throw new IllegalArgumentException(e.getMessage(), e);
	}
	} else {
	ohlcvDataSet = new OhlcvDataSet(resource);
	indiSet = new DefaultDataSet("MA(24)");
	try {
	loadTestData(resource, ohlcvDataSet, indiSet);
	} catch (IOException e) {
	throw new IllegalArgumentException(e.getMessage(), e);
	}
	}
	// prepare axis
	final DefaultNumericAxis xAxis1 = new DefaultNumericAxis("time", "iso");
	xAxis1.setOverlapPolicy(AxisLabelOverlapPolicy.SKIP_ALT);
	xAxis1.setAutoRangeRounding(false);
	xAxis1.setTimeAxis(true);
	// set localised time offset
	if (xAxis1.isTimeAxis() && xAxis1.getAxisLabelFormatter() instanceof DefaultTimeFormatter) {
	final DefaultTimeFormatter axisFormatter = (DefaultTimeFormatter) xAxis1.getAxisLabelFormatter();
	axisFormatter.setTimeZoneOffset(ZoneOffset.ofHoursMinutes(2, 0));
	}
	// category axis support tests
	// final CategoryAxis xAxis = new CategoryAxis("time [iso]");
	// xAxis.setTickLabelRotation(90);
	// xAxis.setOverlapPolicy(AxisLabelOverlapPolicy.SKIP_ALT);
	final DefaultNumericAxis yAxis1 = new DefaultNumericAxis("price", "points");
	// prepare chart structure
	final XYChart chart = new XYChart(xAxis1, yAxis1);
	chart.setTitle(theme.name());
	chart.setLegendVisible(true);
	chart.setPrefSize(prefChartWidth, prefChartHeight);
	// set them false to make the plot faster
	chart.setAnimated(false);
	// prepare plugins
	chart.getPlugins().add(new Zoomer(AxisMode.X));

dataSet.recomputeLimits(DIM_X); // please use markdown code formatting for logs and code snippets

Environment:

• OS: [e.g. Ubuntu 20.04]
• Java version:
• JavaFx version:
• ChartFx version: [master, 11.2.2, ...]

[yezhengli-Mr9]

Replaced by #687