Mobile App Dev 2021W: Assignment 2

This assignment is still being developed.

Code

<syntaxhighlight lang="swift" line> // // ContentView.swift // 1601picviewer-2 // COMP 1601 Winter 2021, Carleton University //

import SwiftUI

struct ContentView: View {

   @State private var theImage = "kittens"
   @State private var moved = false
   @State private var magnification: CGFloat = 1
   @State private var angleS = "0"

   func resetState() {
       moved = false
       magnification = 1
       angleS = "0"
   }
       
   var body: some View {
       VStack {
           Menu("Animals!") {
                   Button("Kittens", action: {
                       theImage = "kittens"
                       resetState()
                   })
                   Button("Sad Dog", action: {
                       theImage = "sadDog"
                       resetState()
                   })
               }
           ActiveImage(theImage: $theImage, moved: $moved, finalAmount: $magnification,
                       angleS: $angleS)
           HStack{
               Text("D:")
               TextField("", text: $angleS, onCommit: {
                   if Double(angleS) == nil {
                       angleS = "0"
                   }
               })
           }.padding()
       }
   }

}

struct ActiveImage: View {

   @State private var position = CGPoint(x: 0, y: 0)
   @State private var currentAmount: CGFloat = 0

   @Binding var theImage: String
   @Binding var moved: Bool
   @Binding var finalAmount: CGFloat
   @Binding var angleS: String
   
   var body: some View {
       GeometryReader {g in
           Image(theImage)
                   .resizable()
                   .scaledToFit()
                   .position(moved ? position :
                           CGPoint(x: g.size.width / 2, y: g.size.height / 2))
                   .scaleEffect(finalAmount + currentAmount)
                   .rotationEffect(currentAngle())
                   .gesture(dragging)
                   .gesture(SimultaneousGesture(rotating, magnifying))
                   .onTapGesture(count: 1, perform: tapReset)
       }
   }

   func currentAngle() -> Angle {
       if let a = Double(self.angleS) {
           return Angle(degrees: a)
       } else {
           return Angle(degrees: 0)
       }
   }
   
   func tapReset() {
       self.finalAmount = 1
       self.moved = false
       self.angleS = "0"
   }
       
   var rotating: some Gesture {
       RotationGesture()
           .onChanged { angle in
               self.angleS = String(format: "%.0f", angle.degrees)
           }
   }

   var magnifying: some Gesture {
       MagnificationGesture().onChanged { amount in
           self.currentAmount = amount - 1
       }
       .onEnded { amount in
           self.finalAmount += self.currentAmount
           self.currentAmount = 0
       }
   }
   
   var dragging: some Gesture {
       DragGesture()
           .onChanged {s in
               self.moved = true
               self.position = s.location
           }
           .onEnded {s in
               self.moved = true
               self.position = s.location
           }
   }

}

</syntaxhighight>