59 lines
1.4 KiB
Swift
59 lines
1.4 KiB
Swift
// Copyright © 2021 Metabolist. All rights reserved.
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import UIKit
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final class LineChartView: UIView {
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var values = [Int]() {
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didSet { setNeedsDisplay() }
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}
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override init(frame: CGRect) {
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super.init(frame: frame)
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backgroundColor = .clear
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}
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required init?(coder: NSCoder) {
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fatalError("init(coder:) has not been implemented")
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}
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override var intrinsicContentSize: CGSize {
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UIView.layoutFittingExpandedSize
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}
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override func draw(_ rect: CGRect) {
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let path = UIBezierPath()
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path.lineWidth = Self.lineWidth
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path.lineCapStyle = .round
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let valueCount = values.count
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guard valueCount > 0, let maxValue = values.max() else { return }
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let inset = Self.lineWidth / 2
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for (index, value) in values.enumerated() {
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let x = CGFloat(index) / CGFloat(valueCount) * rect.width
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let y = rect.height - CGFloat(value) / max(CGFloat(maxValue), CGFloat(0).nextUp) * rect.height
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let point = CGPoint(
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x: min(max(x, inset), rect.width - inset),
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y: min(max(y, inset), rect.height - inset))
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if index > 0 {
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path.addLine(to: point)
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}
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path.move(to: point)
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}
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path.close()
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UIColor.link.setStroke()
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path.stroke()
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}
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}
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private extension LineChartView {
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static let lineWidth: CGFloat = 2
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}
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