Line Chart with callouts

[HPRaval]

I want to show only max values in multiple line charts, like below. But i don't know how can i achieve this.

[liuxuan30]

I don't know what's max value from your screenshot. But you can override drawValues() to only draw the 'max value'

[HPRaval]

Thanx for replay.Sorry but i can't find darValues(). Can you please give me some example? I am using Charts 2.3.0.

[liuxuan30]

you would find it if you simply search drawValues in LineChartRenderer

[HPRaval]

Thanx...i have created a custom class CustomLineLinear which extends LineChartRenderer

import UIKit
import Charts

class CustomLineLinear : LineChartRenderer {
    
    
    
    override func drawValues(context context: CGContext) {
        guard let
            dataProvider = dataProvider,
            lineData = dataProvider.lineData,
            animator = animator
            else { return }
        
        if (CGFloat(lineData.yValCount) < CGFloat(dataProvider.maxVisibleValueCount) * viewPortHandler.scaleX)
        {
            var dataSets = lineData.dataSets
            
            let phaseX = max(0.0, min(1.0, animator.phaseX))
            let phaseY = animator.phaseY
            
            var pt = CGPoint()
            
            for i in 0 ..< dataSets.count
            {
                guard let dataSet = dataSets[i] as? ILineChartDataSet else { continue }
                
                if !dataSet.isDrawValuesEnabled || dataSet.entryCount == 0
                {
                    continue
                }
                
                let valueFont = dataSet.valueFont
                
                guard let formatter = dataSet.valueFormatter else { continue }
                
                let trans = dataProvider.getTransformer(dataSet.axisDependency)
                let valueToPixelMatrix = trans.valueToPixelMatrix
                
                // make sure the values do not interfear with the circles
                var valOffset = Int(dataSet.circleRadius * 1.75)
                
                if (!dataSet.isDrawCirclesEnabled)
                {
                    valOffset = valOffset / 2
                }
                
                let entryCount = dataSet.entryCount
                
                guard let
                    entryFrom = dataSet.entryForXIndex(self.minX < 0 ? 0 : self.minX, rounding: .Down),
                    entryTo = dataSet.entryForXIndex(self.maxX, rounding: .Up)
                    else { continue }
                
                var diff = (entryFrom == entryTo) ? 1 : 0
                if dataSet.mode == .CubicBezier
                {
                    diff += 1
                }
                
                let minx = max(dataSet.entryIndex(entry: entryFrom) - diff, 0)
                let maxx = min(max(minx + 2, dataSet.entryIndex(entry: entryTo) + 1), entryCount)
                
                for j in minx.stride(to: Int(ceil(CGFloat(maxx - minx) * phaseX + CGFloat(minx))), by: 1)
                {
                    guard let e = dataSet.entryForIndex(j) else { break }
                    
                    pt.x = CGFloat(e.xIndex)
                    pt.y = CGFloat(e.value) * phaseY
                    pt = CGPointApplyAffineTransform(pt, valueToPixelMatrix)
                    
                    if (!viewPortHandler.isInBoundsRight(pt.x))
                    {
                        break
                    }
                    
                    if (!viewPortHandler.isInBoundsLeft(pt.x) || !viewPortHandler.isInBoundsY(pt.y))
                    {
                        continue
                    }
                    
                    ChartUtils.drawText(context: context,
                                        text: formatter.stringFromNumber(e.value)!,
                                        point: CGPoint(
                                            x: pt.x,
                                            y: pt.y - CGFloat(valOffset) - valueFont.lineHeight),
                                        align: .Center,
                                        attributes: [NSFontAttributeName: valueFont, NSForegroundColorAttributeName: dataSet.valueTextColorAt(j)])
                  
                }
            }
        }

    }
}

In this i have removed my custom login its just copy and paste, and in my line chart view controller

self.lineChartView.renderer = CustomLineLinear(dataProvider: self.lineChartView,animator:nil,viewPortHandler: self.lineChartView.viewPortHandler)
        self.lineChartView.data = data

But when i run this code, it shows me nothing

[liuxuan30]

Are you sure your CustomLineLinear is being used and work?
I would normally replace it in subclassing LineChartView

[HPRaval]

Hi, Now i have moved to swift 3.0, but i am facing some issue with customise CustomLineLinear.

lineChart.renderer = CustomLineLinear(dataProvider: lineChart, animator: nil, viewPortHandler: lineChart.viewPortHandler)

And in my custom class

guard
let dataProvider = dataProvider,
let lineData = dataProvider.lineData,
let animator = animator, //this is nil always
let viewPortHandler = self.viewPortHandler
else { return }

This is working fine with swift 2.3.

[liuxuan30]

I suggest add breakpoints to debug, I am not sure what's going on