Show multiple crosshair target circles on Shinobicharts with same X position ( iOS )

Question

I have a chart with 3 SChartLineSeries. I would like to show 3 simultaneous target points (from the crosshair that corresponds to his serie) at the same time.

Like I have on this picture with dataPoints, but I would like have it on the same X position with Crosshairs.

How can I achieve that? I tried to recognize the 'long press' event in the delegate method, but I didn't figure out how to do it.

With crosshairs, I only have this:

EDIT:

Ive tried:

- (void)sChart:(ShinobiChart *)chart toggledSelectionForPoint:(SChartDataPoint *)dataPoint inSeries:(SChartSeries *)series atPixelCoordinate:(CGPoint)pixelPoint
{
    for (SChartLineSeries *serie in chart.series) {
        for (SChartDataPoint *dp in serie.dataSeries.dataPoints){
            if (dp.xValue == dataPoint.xValue){
                dp.selected = YES;
                serie.crosshairEnabled = YES;
                serie.style.selectedPointStyle.color = [UIColor blackColor];
                serie.style.selectedPointStyle.radius = [NSNumber numberWithInt:8];
                serie.style.selectedPointStyle.showPoints = YES;
            }
        }
    }
}

And subclassing the object 'SChartCrosshair' I recognize the long press event on 'crosshairChartGotLongPressAt'.

Answer 1

I already managed it, with the help of ShinobiControls team support.

On the 'SChartCrosshair' I subclassed, I had to loop over the points that matched with the 'Crosshair' X position touched, and adding the ones that mathed to an array for using them in 'drawCrosshairLines'. For that, I used, the pixel version of the point, through a method that understands the SChartAxis object: 'pixelValueForDataValue'.

I draw a vertical line on the chart as well.

@implementation CustomCrossHair

-(void)drawCrosshairLines
{
    CGContextRef context = UIGraphicsGetCurrentContext();

    SChartDataPoint *firstDataPixelPoint = arrayPixelPoints[0];
    double xFirst = [firstDataPixelPoint.xValue doubleValue];

    CGContextMoveToPoint(context,xFirst, 0.f);

    CGContextAddLineToPoint(context,xFirst, self.chart.canvas.glView.frame.size.height);

    for (SChartDataPoint *dataPixelPoint in arrayPixelPoints){
        double yVal = [dataPixelPoint.yValue doubleValue];
        double xVal = [dataPixelPoint.xValue doubleValue];

        CGRect rectangle = CGRectMake(xVal,yVal, 7, 7);
        CGContextAddEllipseInRect(context, rectangle);
    }

    CGContextStrokePath(context);
}


-(void)moveToPosition:(SChartPoint)coords andDisplayDataPoint:(SChartPoint)dataPoint fromSeries:(SChartCartesianSeries *)series andSeriesDataPoint:(id<SChartData>)dataseriesPoint
{
    [super moveToPosition:coords andDisplayDataPoint:dataPoint fromSeries:series andSeriesDataPoint:dataseriesPoint];
    arrayPixelPoints = [NSMutableArray array];
    SChartDataPoint *dataSPoint = dataseriesPoint;
    int i = 0;
    for (SChartLineSeries *serie in self.chart.series){
        i++;
        for (SChartDataPoint *dp in serie.dataSeries.dataPoints){
            if ([dp.xValue doubleValue] == [dataSPoint.xValue doubleValue]){
                float yPixel = [self.chart.yAxis pixelValueForDataValue:dp.yValue];
                float xPixel = [self.chart.xAxis pixelValueForDataValue:dp.xValue];

                SChartDataPoint *dataPointPixel = [[SChartDataPoint alloc] init];
                dataPointPixel.xValue = [NSNumber numberWithFloat:xPixel];
                dataPointPixel.yValue = [NSNumber numberWithFloat:yPixel];

                [arrayPixelPoints addObject:dataPointPixel];
            }
        }
    }

    if (i == self.chart.series.count) [self drawCrosshairLines];
}