scan page

src/App/Pages/Vault/ScanPage.xaml.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using Xamarin.Forms;
+
+namespace Bit.App.Pages
+{
+    public partial class ScanPage : BaseContentPage
+    {
+        private readonly Action<string> _callback;
+
+        private DateTime? _timerStarted = null;
+        private TimeSpan _timerMaxLength = TimeSpan.FromMinutes(3);
+
+        public ScanPage(Action<string> callback)
+        {
+            _callback = callback;
+            _zxing.Options = new ZXing.Mobile.MobileBarcodeScanningOptions
+            {
+                UseNativeScanning = true,
+                PossibleFormats = new List<ZXing.BarcodeFormat> { ZXing.BarcodeFormat.QR_CODE },
+                AutoRotate = false,
+            };
+            InitializeComponent();
+        }
+
+        protected override void OnAppearing()
+        {
+            base.OnAppearing();
+            _zxing.IsScanning = true;
+            _timerStarted = DateTime.Now;
+            Device.StartTimer(new TimeSpan(0, 0, 2), () =>
+            {
+                if(_timerStarted == null || (DateTime.Now - _timerStarted) > _timerMaxLength)
+                {
+                    return false;
+                }
+                _zxing.AutoFocus();
+                return true;
+            });
+        }
+
+        protected override void OnDisappearing()
+        {
+            _timerStarted = null;
+            _zxing.IsScanning = false;
+            base.OnDisappearing();
+        }
+
+        private void OnScanResult(ZXing.Result result)
+        {
+            // Stop analysis until we navigate away so we don't keep reading barcodes
+            _zxing.IsAnalyzing = false;
+            _zxing.IsScanning = false;
+            if(!string.IsNullOrWhiteSpace(result?.Text) &&
+                Uri.TryCreate(result.Text, UriKind.Absolute, out Uri uri) &&
+                !string.IsNullOrWhiteSpace(uri?.Query))
+            {
+                var queryParts = uri.Query.Substring(1).ToLowerInvariant().Split('&');
+                foreach(var part in queryParts)
+                {
+                    if(part.StartsWith("secret="))
+                    {
+                        _callback(part.Substring(7)?.ToUpperInvariant());
+                        return;
+                    }
+                }
+            }
+            _callback(null);
+        }
+    }
+}