Add QRCode view

Changelog-Added: Add QRCode view for sharing your pubkey
Closes: #418

damus/Views/QRCodeView.swift

@@ -0,0 +1,90 @@
+//
+//  QRCodeView.swift
+//  damus
+//
+//  Created by eric on 1/27/23.
+//
+
+import SwiftUI
+import CoreImage.CIFilterBuiltins
+
+struct QRCodeView: View {
+    let damus_state: DamusState
+    
+    @Environment(\.dismiss) var dismiss
+    @Environment(\.presentationMode) var presentationMode
+
+    var maybe_key: String? {
+        guard let key = bech32_pubkey(damus_state.pubkey) else {
+            return nil
+        }
+
+        return key
+    }
+    
+    var body: some View {
+        ZStack(alignment: .topLeading) {
+            DamusGradient()
+            Button {
+                presentationMode.wrappedValue.dismiss()
+            } label: {
+                Image(systemName: "xmark")
+                    .foregroundColor(.white)
+                    .font(.subheadline)
+                    .padding(.leading, 20)
+            }
+            .zIndex(1)
+        
+            VStack(alignment: .center) {
+                
+                Spacer()
+                
+                if let key = maybe_key {
+                    Image(uiImage: generateQRCode(pubkey: "nostr:" + key))
+                        .interpolation(.none)
+                        .resizable()
+                        .scaledToFit()
+                        .frame(width: 200, height: 200)
+                        .padding()
+                    
+                    Text(key)
+                        .font(.headline)
+                        .foregroundColor(Color(.white))
+                        .padding()
+                }
+                
+                Spacer()
+
+            }
+            
+        }
+        .modifier(SwipeToDismissModifier(minDistance: nil, onDismiss: {
+            presentationMode.wrappedValue.dismiss()
+        }))
+    }
+    
+    func generateQRCode(pubkey: String) -> UIImage {
+        let data = pubkey.data(using: String.Encoding.ascii)
+        let qrFilter = CIFilter(name: "CIQRCodeGenerator")
+        qrFilter?.setValue(data, forKey: "inputMessage")
+        let qrImage = qrFilter?.outputImage
+        
+        let colorInvertFilter = CIFilter(name: "CIColorInvert")
+        colorInvertFilter?.setValue(qrImage, forKey: "inputImage")
+        let outputInvertedImage = colorInvertFilter?.outputImage
+        
+        let maskToAlphaFilter = CIFilter(name: "CIMaskToAlpha")
+        maskToAlphaFilter?.setValue(outputInvertedImage, forKey: "inputImage")
+        let outputCIImage = maskToAlphaFilter?.outputImage
+
+        let context = CIContext()
+        let cgImage = context.createCGImage(outputCIImage!, from: outputCIImage!.extent)!
+        return UIImage(cgImage: cgImage)
+    }
+}
+
+struct QRCodeView_Previews: PreviewProvider {
+    static var previews: some View {
+        QRCodeView(damus_state: test_damus_state())
+    }
+}

damus/Views/SideMenuView.swift

@@ -14,6 +14,8 @@ struct SideMenuView: View {
     @State var confirm_logout: Bool = false
     @StateObject var user_settings = UserSettingsStore()
     
+    @State private var showQRCode = false
+    
     @Environment(\.colorScheme) var colorScheme
     
     var sideBarWidth = min(UIScreen.main.bounds.size.width * 0.65, 400.0)
@@ -124,18 +126,33 @@ struct SideMenuView: View {
                     
                     Spacer()
                     
-                    Button(action: {
-                        //ConfigView(state: damus_state)
-                        if damus_state.keypair.privkey == nil {
-                            notify(.logout, ())
-                        } else {
-                            confirm_logout = true
+                    HStack(alignment: .center) {
+                        Button(action: {
+                            //ConfigView(state: damus_state)
+                            if damus_state.keypair.privkey == nil {
+                                notify(.logout, ())
+                            } else {
+                                confirm_logout = true
+                            }
+                        }, label: {
+                            Label(NSLocalizedString("Sign out", comment: "Sidebar menu label to sign out of the account."), systemImage: "pip.exit")
+                                .font(.title3)
+                                .foregroundColor(textColor())
+                        })
+                        
+                        Spacer()
+                        
+                        Button(action: {
+                            showQRCode.toggle()
+                        }, label: {
+                            Label(NSLocalizedString("", comment: "Sidebar menu label for accessing QRCode view"), systemImage: "qrcode")
+                                .font(.title)
+                                .foregroundColor(textColor())
+                                .padding(.trailing, 20)
+                        }).fullScreenCover(isPresented: $showQRCode) {
+                            QRCodeView(damus_state: damus_state)
                         }
-                    }, label: {
-                        Label(NSLocalizedString("Sign out", comment: "Sidebar menu label to sign out of the account."), systemImage: "pip.exit")
-                            .font(.title3)
-                            .foregroundColor(textColor())
-                    })
+                    }
                 }
                 .padding(.top, 60)
                 .padding(.bottom, 40)