Adding annotation to the chart area


I’m not being able to the SChartAnnotation to the plot canvas when user tapps on some point.

The chart deletgate is correctly set and the following methos is invked when I tapp on the data point, but nothing is displayed.

What am I doing wrong?

- (void)sChart:(ShinobiChart *)chart toggledSelectionForPoint:(SChartDataPoint *)dataPoint inSeries:(SChartSeries *)series atPixelCoordinate:(CGPoint)pixelPoint{
    [self.chart removeAllAnnotations];
    SChartAnnotation *annotation = [SChartAnnotation annotationWithText:@"Hello World"
                                                                andFont:[UIFont boldSystemFontOfSize:12.0f]
                                                            atXPosition:[NSNumber numberWithFloat:pixelPoint.x]
                                                           andYPosition:[NSNumber numberWithFloat:pixelPoint.y]
                                                          withTextColor:[UIColor whiteColor] withBackgroundColor:[UIColor whiteColor]];
    [self.chart addAnnotation:annotation];
    [annotation updateViewWithCanvas:self.chart.canvas];


When I wrote this post I’ve noticed that  atXPosition and  atYPosition are incorrect.

Replced with following values and everything is ok: