Dactyloidae iOS initial commit

mobile/ios/Client/Frontend/Widgets/ChevronView.swift

@@ -0,0 +1,123 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import Foundation
+
+enum ChevronDirection {
+    case left
+    case up
+    case right
+    case down
+}
+
+enum ChevronStyle {
+    case angular
+    case rounded
+}
+
+class ChevronView: UIView {
+    fileprivate let Padding: CGFloat = 2.5
+    fileprivate var direction = ChevronDirection.right
+    fileprivate var lineCapStyle = CGLineCap.round
+    fileprivate var lineJoinStyle = CGLineJoin.round
+
+    var lineWidth: CGFloat = 3.0
+    
+    var style: ChevronStyle = .rounded {
+        didSet {
+            switch style {
+            case .rounded:
+                lineCapStyle = CGLineCap.round
+                lineJoinStyle = CGLineJoin.round
+            case .angular:
+                lineCapStyle = CGLineCap.butt
+                lineJoinStyle = CGLineJoin.miter
+
+            }
+        }
+    }
+
+    init(direction: ChevronDirection) {
+        super.init(frame: CGRect.zero)
+
+        self.direction = direction
+        if UIApplication.shared.userInterfaceLayoutDirection == .rightToLeft {
+            if direction == .left {
+                self.direction = .right
+            } else if direction == .right {
+                self.direction = .left
+            }
+        }
+        self.backgroundColor = UIColor.clear
+        self.contentMode = UIViewContentMode.redraw
+    }
+
+    required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    override func draw(_ rect: CGRect) {
+        super.draw(rect)
+
+        let strokeLength = (rect.size.height / 2) - Padding
+
+        let path: UIBezierPath
+
+        switch direction {
+        case .left:
+            path = drawLeftChevronAt(CGPoint(x: rect.size.width - (strokeLength + Padding), y: strokeLength + Padding), strokeLength: strokeLength)
+        case .up:
+            path = drawUpChevronAt(CGPoint(x: (rect.size.width - Padding) - strokeLength, y: (strokeLength / 2) + Padding), strokeLength: strokeLength)
+        case .right:
+            path = drawRightChevronAt(CGPoint(x: rect.size.width - Padding, y: strokeLength + Padding), strokeLength: strokeLength)
+        case .down:
+            path = drawDownChevronAt(CGPoint(x: (rect.size.width - Padding) - strokeLength, y: (strokeLength * 1.5) + Padding), strokeLength: strokeLength)
+        }
+
+        tintColor.set()
+
+        // The line thickness needs to be proportional to the distance from the arrow head to the tips.  Making it half seems about right.
+        path.lineCapStyle = lineCapStyle
+        path.lineJoinStyle = lineJoinStyle
+        path.lineWidth = lineWidth
+        path.stroke()
+    }
+
+    fileprivate func drawUpChevronAt(_ origin: CGPoint, strokeLength: CGFloat) -> UIBezierPath {
+        return drawChevron(CGPoint(x: origin.x-strokeLength, y: origin.y+strokeLength),
+            head: CGPoint(x: origin.x, y: origin.y),
+            rightTip: CGPoint(x: origin.x+strokeLength, y: origin.y+strokeLength))
+    }
+
+    fileprivate func drawDownChevronAt(_ origin: CGPoint, strokeLength: CGFloat) -> UIBezierPath {
+        return drawChevron(CGPoint(x: origin.x-strokeLength, y: origin.y-strokeLength),
+            head: CGPoint(x: origin.x, y: origin.y),
+            rightTip: CGPoint(x: origin.x+strokeLength, y: origin.y-strokeLength))
+    }
+
+    fileprivate func drawLeftChevronAt(_ origin: CGPoint, strokeLength: CGFloat) -> UIBezierPath {
+        return drawChevron(CGPoint(x: origin.x+strokeLength, y: origin.y-strokeLength),
+            head: CGPoint(x: origin.x, y: origin.y),
+            rightTip: CGPoint(x: origin.x+strokeLength, y: origin.y+strokeLength))
+    }
+
+    fileprivate func drawRightChevronAt(_ origin: CGPoint, strokeLength: CGFloat) -> UIBezierPath {
+        return drawChevron(CGPoint(x: origin.x-strokeLength, y: origin.y+strokeLength),
+            head: CGPoint(x: origin.x, y: origin.y),
+            rightTip: CGPoint(x: origin.x-strokeLength, y: origin.y-strokeLength))
+    }
+
+    fileprivate func drawChevron(_ leftTip: CGPoint, head: CGPoint, rightTip: CGPoint) -> UIBezierPath {
+        let path = UIBezierPath()
+
+        // Left tip
+        path.move(to: leftTip)
+        // Arrow head
+        path.addLine(to: head)
+        // Right tip
+        path.addLine(to: rightTip)
+
+        return path
+    }
+}