display alert action

src/Android/Services/DeviceActionService.cs

@@ -328,6 +328,79 @@ namespace Bit.Droid.Services
             return Build.Model;
         }
 
+        public Task<string> DisplayAlertAsync(string title, string message, string cancel, params string[] buttons)
+        {
+            var activity = (MainActivity)CrossCurrentActivity.Current.Activity;
+            if(activity == null)
+            {
+                return Task.FromResult<string>(null);
+            }
+
+            var result = new TaskCompletionSource<string>();
+            var alertBuilder = new AlertDialog.Builder(activity);
+            alertBuilder.SetTitle(title);
+
+            if(!string.IsNullOrWhiteSpace(message))
+            {
+                if(buttons != null && buttons.Length > 2)
+                {
+                    if(!string.IsNullOrWhiteSpace(title))
+                    {
+                        alertBuilder.SetTitle($"{title}: {message}");
+                    }
+                    else
+                    {
+                        alertBuilder.SetTitle(message);
+                    }
+                }
+                else
+                {
+                    alertBuilder.SetMessage(message);
+                }
+            }
+
+            if(buttons != null)
+            {
+                if(buttons.Length > 2)
+                {
+                    alertBuilder.SetItems(buttons, (sender, args) =>
+                    {
+                        result.TrySetResult(buttons[args.Which]);
+                    });
+                }
+                else
+                {
+                    if(buttons.Length > 0)
+                    {
+                        alertBuilder.SetPositiveButton(buttons[0], (sender, args) =>
+                        {
+                            result.TrySetResult(buttons[0]);
+                        });
+                    }
+                    if(buttons.Length > 1)
+                    {
+                        alertBuilder.SetNeutralButton(buttons[1], (sender, args) =>
+                        {
+                            result.TrySetResult(buttons[1]);
+                        });
+                    }
+                }
+            }
+
+            if(!string.IsNullOrWhiteSpace(cancel))
+            {
+                alertBuilder.SetNegativeButton(cancel, (sender, args) =>
+                {
+                    result.TrySetResult(cancel);
+                });
+            }
+
+            var alert = alertBuilder.Create();
+            alert.CancelEvent += (o, args) => { result.TrySetResult(null); };
+            alert.Show();
+            return result.Task;
+        }
+
         private bool DeleteDir(Java.IO.File dir)
         {
             if(dir != null && dir.IsDirectory)

src/App/Abstractions/IDeviceActionService.cs

@@ -23,5 +23,6 @@ namespace Bit.App.Abstractions
         bool SupportsAutofillService();
         int SystemMajorVersion();
         string SystemModel();
+        Task<string> DisplayAlertAsync(string title, string message, string cancel, params string[] buttons);
     }
 }

src/iOS/Services/DeviceActionService.cs

@@ -264,6 +264,29 @@ namespace Bit.iOS.Services
             return UIDevice.CurrentDevice.Model;
         }
 
+        public Task<string> DisplayAlertAsync(string title, string message, string cancel, params string[] buttons)
+        {
+            var result = new TaskCompletionSource<string>();
+            var alert = UIAlertController.Create(title ?? string.Empty, message, UIAlertControllerStyle.Alert);
+            if(!string.IsNullOrWhiteSpace(cancel))
+            {
+                alert.AddAction(UIAlertAction.Create(cancel, UIAlertActionStyle.Cancel, x =>
+                {
+                    result.TrySetResult(cancel);
+                }));
+            }
+            foreach(var button in buttons)
+            {
+                alert.AddAction(UIAlertAction.Create(button, UIAlertActionStyle.Default, x =>
+                {
+                    result.TrySetResult(button);
+                }));
+            }
+            var vc = GetPresentedViewController();
+            vc?.PresentViewController(alert, true, null);
+            return result.Task;
+        }
+
         private void ImagePicker_FinishedPickingMedia(object sender, UIImagePickerMediaPickedEventArgs e)
         {
             if(sender is UIImagePickerController picker)