Example: quartzcore framework pi chart
import Foundation
import UIKit
@IBDesignable class PieChart: UIView {
var dataPoints: Dictionary<String,Double> = ["Alpha":1,"Beta":2,"Charlie":3,"Delta":4,"Echo":2.5,"Foxtrot":1.4] {
didSet { setNeedsDisplay() }
}
@IBInspectable var lineWidth: CGFloat = 1.0 {
didSet { setNeedsDisplay()
}
}
@IBInspectable var lineColor: UIColor = uicolor_normal {
didSet { setNeedsDisplay() }
}
required init(coder aDecoder: NSCoder) {
super.init(coder:aDecoder)!
self.contentMode = .Redraw
}
override init(frame: CGRect) {
super.init(frame: frame)
self.backgroundColor = UIColor.clearColor()
self.contentMode = .Redraw
}
override func drawRect(rect: CGRect) {
let fieldColor: UIColor = UIColor.darkGrayColor()
let fieldFont = uifont_piechartkey
var fieldAttributes: NSDictionary = [
NSForegroundColorAttributeName: fieldColor,
NSFontAttributeName: fieldFont!
]
let ctx = UIGraphicsGetCurrentContext()
let margin: CGFloat = lineWidth
let box0 = CGRectInset(self.bounds, margin, margin)
let keyHeight = CGFloat( ceil( Double(dataPoints.count) / 3.0) * 24 ) + 16
let side : CGFloat = min(box0.width, box0.height-keyHeight)
let box = CGRectMake((self.bounds.width-side)/2, (self.bounds.height-side-keyHeight)/2,side,side)
let radius : CGFloat = min(box.width, box.height)/2.0
func percent_to_rad(p: Double) -> CGFloat {
let rad = CGFloat(p * 0.02 * M_PI)
return rad
}
func draw_arc(start: CGFloat, end: CGFloat, color: CGColor) {
CGContextBeginPath(ctx)
CGContextMoveToPoint(ctx, box.midX, box.midY)
CGContextSetFillColorWithColor(ctx, color)
CGContextAddArc(ctx,box.midX,box.midY,radius-lineWidth/2,start,end,0)
CGContextClosePath(ctx)
CGContextFillPath(ctx)
}
func draw_key(keyName: String, keyValue: Double, color: CGColor, keyX: CGFloat, keyY: CGFloat) {
CGContextBeginPath(ctx)
CGContextMoveToPoint(ctx, keyX, keyY)
CGContextSetFillColorWithColor(ctx, color)
CGContextAddArc(ctx,keyX,keyY,8,0,CGFloat(2 * M_PI),0)
CGContextClosePath(ctx)
CGContextFillPath(ctx)
keyName.drawInRect(CGRectMake(keyX + 12,keyY-8,self.bounds.width/3,16),withAttributes: fieldAttributes as? [String : AnyObject])
}
let total = Double(dataPoints.values.reduce(0, combine: +))
let dataPointsArray = dictionary_to_sorted_array(dataPoints)
var start = -CGFloat(M_PI_2)
var end: CGFloat
var i = 0
for dataPoint in dataPointsArray {
end = percent_to_rad(Double( (dataPoint.value)/total) * 100 )+start
draw_arc(start,end:end,color: uicolors_chart[i%uicolors_chart.count].CGColor)
start = end
i++
}
var keyX = self.bounds.minX + 8
var keyY = self.bounds.height - keyHeight + 32
i = 0
for dataPoint in dataPointsArray {
draw_key(dataPoint.key, keyValue: dataPoint.value, color: uicolors_chart[i%uicolors_chart.count].CGColor, keyX: keyX, keyY: keyY)
if((i+1)%3 == 0) {
keyX = self.bounds.minX + 8
keyY += 24
} else {
keyX += self.bounds.width / 3
}
i++
}
}
}
func dictionary_to_sorted_array(dict:Dictionary<String,Double>) ->Array<(key:String,value:Double)> {
var tuples: Array<(key:String,value:Double)> = Array()
let sortedKeys = (dict as NSDictionary).keysSortedByValueUsingSelector("compare:")
for key in sortedKeys {
tuples.append((key:key as! String,value:dict[key as! String]!))
}
return tuples
}