MarkerView is not showing up using MPAndroidChart

Question

I am using MPandroidchart for showing line charts in my application.I have added following code to show Marker View, but it isn't showing on

private void initializeChart(LineChart chart, String chartName) {
    // Chart view
    chart.setDrawGridBackground(false);
    chart.setDescription("");
    chart.getLegend().setEnabled(true);
    //chart.setTouchEnabled(false);
    int color = getResources().getColor(R.color.white);
    chart.getAxisLeft().setTextColor(color); // left y-axis
    chart.getXAxis().setTextColor(color);

    chart.setTouchEnabled(true);
    CustomMarkerView mv = new CustomMarkerView(this.getActivity(), R.layout.marker_view_tv);
    chart.setMarkerView(mv);

    //X axis
    XAxis xAxis = chart.getXAxis();
    xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);
    xAxis.setDrawGridLines(false);
    xAxis.setDrawLabels(true);

    //Y axis
    YAxis leftAxis = chart.getAxisLeft();
    YAxis rightAxis = chart.getAxisRight();
    rightAxis.setDrawLabels(false);
    rightAxis.setDrawGridLines(false);
    leftAxis.setDrawLabels(true);
    leftAxis.setDrawGridLines(false);
    leftAxis.setStartAtZero(false);

    SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(getActivity());


    leftAxis.setLabelCount(Constants.KEY_LINE_YAXIS_SCALECOUNT, true);
    ChartItem item = CannonJsonParser.parseCanonJson(act, act.res);
    int maxYVal = pref.getInt(Constants.KEY_YAXIS_VALUE, 0);
    leftAxis.setAxisMaxValue(maxYVal);
    leftAxis.setAxisMinValue(0);
    setLineData(item, chartName);
    // set data
    chart.setData(lineData);

    chart.getLegend().setEnabled(false);
    //animate
    //chart.animateX(2000, Easing.EasingOption.EaseInExpo);
    chart.setDragEnabled(true);
    chart.setScaleXEnabled(true);
    chart.setScaleYEnabled(false);
    chart.setHighlightPerDragEnabled(false);
    chart.setHighlightPerTapEnabled(false);


}

My CustomMarkerView class

public class CustomMarkerView extends MarkerView {
private TextView tvContent;

public CustomMarkerView(Context context, int layoutResource) {
    super(context, layoutResource);

    tvContent = (TextView) findViewById(R.id.tvContent);
}

// callbacks everytime the MarkerView is redrawn, can be used to update the
// content (user-interface)
@Override
public void refreshContent(Entry e, Highlight highlight) {

    if (e instanceof CandleEntry) {

        CandleEntry ce = (CandleEntry) e;

        tvContent.setText("" + Utils.formatNumber(ce.getHigh(), 0, true));
    } else {

        tvContent.setText("" + Utils.formatNumber(e.getVal(), 0, true));
    }
}

@Override
public int getXOffset(float xpos) {
    // this will center the marker-view horizontally
    return -(getWidth() / 2);
}

@Override
public int getYOffset(float ypos) {
    // this will cause the marker-view to be above the selected value
    return -getHeight();
}

}

Note: I am using fragment to show charts.

Answer 1

Your MarkerView is not showing because you have not highlighted any entry in your chart. The MarkerView is only displayed for entries that are highlighted.

Since you disabled the functionality to highlight entries per tap (by calling chart.setHighlightPerTapEnabled(false)), you can only highlight values programmatically, like this:

chart.highlightValue(...)

More on that in the documentation.