How can i know what is visible range?(for formatting xAxis depend on range)

Unfortunately, this line( line 7 ) is never called.
and i can’t use https://www.scichart.com/documentation/android/current/articles/chart2d/axisAPIs/Axis%20Labels%20-%20Formatting%20for%20trading%20charts.html?tabs=kotlin because I am using IndexDateAxis

open class FinanceDateXAxis(context: Context?) : IndexDateAxis(DateRange(), NonClippingXAxisModifierSurface(context)) {

init {
    // need to set empty string to use CalendarDateLabelFormatter
    textFormattingProperty.setWeakValue(StringUtil.EMPTY)
    cursorTextFormattingProperty.setWeakValue(StringUtil.EMPTY)
    labelProvider = DateAxisLabelProvider()
    this.setVisibleRangeChangeListener { axis, oldRange, newRange, isAnimating ->
        Log.i("LOGGER","" + newRange.min) // this line
    }
}

class NonClippingXAxisModifierSurface @JvmOverloads constructor(
    context: Context?,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0,
) : AxisModifierSurface(context, attrs, defStyleAttr) {

    override fun layoutChildAt(child: View?, left: Int, top: Int, right: Int, bottom: Int) {
        when {
            left < 0 -> {
                super.layoutChildAt(child, 0, top, right - left, bottom)
            }
            right > width -> {
                super.layoutChildAt(child, left - (right - width), top, width, bottom)
            }
            else -> {
                super.layoutChildAt(child, left, top, right, bottom)
            }
        }
    }
}

}

To make the axis label format range dependant, you need to create a custom labelFormatter. This gets a reference to the axis it is attached to, so you can look at the visible range when formatting the label. Here is a basic example which formats labels as 1.0K, 1.5K etc when the visible range is greater than 1000.

class RangeDependantLabelProvider extends LabelProviderBase<INumericAxis> {

RangeDependantLabelProvider() {
    super(INumericAxis.class);
}

@Override
public CharSequence formatLabel(double dataValue) {
    if (ComparableUtil.toDouble(this.axis.getVisibleRange().getDiff()) > 1000) {
        return String.format("%.1fK", dataValue / 1000.0);
    } else {
        return String.format("%.0f", dataValue);
    }
}

@Override
public CharSequence formatCursorLabel(double dataValue) {
    return String.format("%.0f", dataValue);
}

@Override
public CharSequence formatLabel(Comparable dataValue) {
    final double doubleValue = ComparableUtil.toDouble(dataValue);
    return this.formatLabel(doubleValue);
}

@Override
public CharSequence formatCursorLabel(Comparable dataValue) {
    final double doubleValue = ComparableUtil.toDouble(dataValue);
    return formatCursorLabel(doubleValue);
}

}

Regards
David

Hi Vahid

Check out our documentation on Android Charts – How to Listen to VisibleRange Changes

With this code:

val axis = NumericAxis(context)
axis.setVisibleRangeChangeListener { axis, oldRange, newRange, isAnimating ->
    // TODO handle range changes here
}

You can be notified of axis visiblerange changes.

Also you might be interested in this article on Axis Formatting for trading charts. This shows a built-in way to dynamically change textformatting based on zoom.