Allow PieChartView to hide value line for tiny slices in Swift - swift

Question

I'm building a pie chart by chart iOS framework. I'm able to hide the value and label when the the slice is tiny but I can't hide the value line for tiny slice.
If I add this code on setDataCount()
set.valueLineWidth = 0.0
It will hide all the value line. How to hide it by the size of slice?
#IBOutlet weak var myChart: PieChartView!
var valueColors = [UIColor]()
var dataEntries = [PieChartDataEntry]()
var record = [Record]()
var category = [String]()
var categoryTotal : [Double] = []
var categoryArray : [String] = []
func setDataCount() {
var totalValue = 0.0
for a in categoryTotal {
totalValue += a
}
UserDefaults.standard.set(totalValue, forKey: "totalValue")
valueAndColor()
let set = PieChartDataSet(values: dataEntries, label: nil)
set.colors = valueColors
set.valueLinePart1OffsetPercentage = 0.8
set.valueLinePart1Length = 0.2
set.valueLinePart2Length = 0.4
set.xValuePosition = .outsideSlice
set.yValuePosition = .outsideSlice
set.selectionShift = 0.0
let data = PieChartData(dataSet: set)
let Formatter:ChartFormatter = ChartFormatter()
data.setValueFormatter(Formatter)
data.setValueFont(.systemFont(ofSize: 11, weight: .light))
data.setValueTextColor(.black)
myChart.data = data
myChart.highlightValues(nil)
}
func valueAndColor(){
for i in 0..<categoryArray.count{
let dataEntry = PieChartDataEntry(value: categoryTotal[i], label: categoryArray[i % categoryArray.count])
dataEntries.append(dataEntry)
//I'm using this code to hide the label
let value = categoryTotal[i]
let total = UserDefaults.standard.double(forKey: "totalValue")
var valueToUse = value/total * 100
valueToUse = Double(round(10*valueToUse)/10)
let minNumber = 10.0
if(valueToUse < minNumber) {
dataEntries[i].label = ""
}else{
dataEntries[i].label = categoryArray[i % categoryArray.count]
}
if categoryArray[i] == "吃喝" {
valueColors.append(UIColor.yellow)
}...
}
I'm using this code to hide the value %
public class ChartFormatter: NSObject, IValueFormatter{
public func stringForValue(_ value: Double, entry: ChartDataEntry, dataSetIndex: Int, viewPortHandler: ViewPortHandler?) -> String {
let total = UserDefaults.standard.double(forKey: "totalValue")
var valueToUse = value/total * 100
valueToUse = Double(round(10*valueToUse)/10)
let minNumber = 10.0
if(valueToUse < minNumber) {
return ""
}
else {
let pFormatter = NumberFormatter()
pFormatter.numberStyle = .percent
pFormatter.maximumFractionDigits = 1
pFormatter.multiplier = 1
pFormatter.percentSymbol = " %"
let hideValue = pFormatter.string(from: NSNumber(value: value))
return String(hideValue ?? "0")
}
}
}

Answer 1

Inside the file PieChartRenderer change from this:
if dataSet.valueLineColor != nil
{
context.setStrokeColor(dataSet.valueLineColor!.cgColor)
context.setLineWidth(dataSet.valueLineWidth)
context.move(to: CGPoint(x: pt0.x, y: pt0.y))
context.addLine(to: CGPoint(x: pt1.x, y: pt1.y))
context.addLine(to: CGPoint(x: pt2.x, y: pt2.y))
context.drawPath(using: CGPathDrawingMode.stroke)
}
to this:
if dataSet.valueLineColor != nil
{
if(valueText == "") {
context.setStrokeColor(UIColor.clear.cgColor)
}
else {
context.setStrokeColor(dataSet.valueLineColor!.cgColor)
}
context.setLineWidth(dataSet.valueLineWidth)
context.move(to: CGPoint(x: pt0.x, y: pt0.y))
context.addLine(to: CGPoint(x: pt1.x, y: pt1.y))
context.addLine(to: CGPoint(x: pt2.x, y: pt2.y))
context.drawPath(using: CGPathDrawingMode.stroke)
}
The change basically checks if the valueText is the empty string, and if so it changes the linecolor to a clear color.