let database sync run in the background. not handling all cases yet.

src/Kp2aBusinessLogic/BlockingOperationRunner.cs

@@ -19,9 +19,195 @@ using Android.App;
 using Android.Content;
 using Android.OS;
 using Java.Lang;
+using Java.Security;
+using KeePassLib.Interfaces;
+using System.Threading.Tasks;
+using Enum = System.Enum;
 
 namespace keepass2android
 {
+    public class BackgroundOperationRunner
+    {
+        //singleton instance
+        private static BackgroundOperationRunner _instance = null;
+
+        public static BackgroundOperationRunner Instance
+        {
+            get
+            {
+                if (_instance == null)
+                {
+                    _instance = new BackgroundOperationRunner();
+                }
+
+                return _instance;
+            }
+        }
+
+        private BackgroundOperationRunner()
+        {
+            //private constructor
+        }
+
+		private readonly Queue<OperationWithFinishHandler> _taskQueue = new Queue<OperationWithFinishHandler>();
+		private readonly object _taskQueueLock = new object();
+		private Java.Lang.Thread? _thread = null;
+        private ProgressUiAsStatusLoggerAdapter _statusLogger = null;
+
+        public void Run(Activity activity, IKp2aApp app, OperationWithFinishHandler operation)
+        {
+            lock (Instance._taskQueueLock)
+            {
+                _taskQueue.Enqueue(operation);
+                SetNewActiveActivity(activity, app);
+
+                // Start thread to run the task (unless it's already running)
+                if (_thread == null)
+                {
+                    _statusLogger.StartLogging("", false);
+                    _thread = new Java.Lang.Thread(() =>
+                    {
+                        while (true)
+                        {
+                            OperationWithFinishHandler task;
+                            lock (_taskQueueLock)
+                            {
+                                if (!_taskQueue.Any())
+                                {
+                                    _thread = null;
+                                    _statusLogger.EndLogging();
+                                    break;
+                                }
+                                else
+                                {
+                                    task = _taskQueue.Dequeue();
+                                }
+                            }
+                            task.Run();
+                        }
+
+                    });
+                    _thread.Start();
+                }
+                
+            }
+               
+        }
+
+        public void SetNewActiveActivity(Activity? activity, IKp2aApp app)
+        {
+            lock (_taskQueueLock)
+            {
+                var progressUi = (activity as IProgressUiProvider)?.ProgressUi;
+                if (_statusLogger == null)
+                {
+                    _statusLogger = new ProgressUiAsStatusLoggerAdapter(progressUi, app);
+                }
+                else
+                {
+                    _statusLogger.SetNewProgressUi(progressUi);
+                }
+					
+                foreach (var task in _taskQueue)
+                {
+					task.ActiveActivity = activity;
+					task.SetStatusLogger(_statusLogger);
+                }
+                
+            }
+
+
+        }
+    }
+
+    public class ProgressUiAsStatusLoggerAdapter : IKp2aStatusLogger
+    {
+        private IProgressUi? _progressUi;
+        private readonly IKp2aApp _app;
+
+        private string _lastMessage = "";
+        private string _lastSubMessage = "";
+        private bool _isVisible = false;
+
+        public ProgressUiAsStatusLoggerAdapter(IProgressUi progressUi, IKp2aApp app)
+        {
+            _progressUi = progressUi;
+            _app = app;
+        }
+
+        public void SetNewProgressUi(IProgressUi progressUi)
+        {
+            _progressUi = progressUi;
+            if (_isVisible)
+            {
+                progressUi?.Show();
+                progressUi?.UpdateMessage(_lastMessage);
+                progressUi?.UpdateSubMessage(_lastSubMessage);
+            }
+            else
+            {
+                progressUi?.Hide();
+            }
+        }
+
+        public void StartLogging(string strOperation, bool bWriteOperationToLog)
+        {
+            _progressUi?.Show();
+            _isVisible = true;
+        }
+
+        public void EndLogging()
+        {
+            _progressUi?.Hide();
+            _isVisible = false;
+        }
+
+        public bool SetProgress(uint uPercent)
+        {
+            return true;
+        }
+
+        public bool SetText(string strNewText, LogStatusType lsType)
+        {
+            if (strNewText.StartsWith("KP2AKEY_"))
+            {
+                UiStringKey key;
+                if (Enum.TryParse(strNewText.Substring("KP2AKEY_".Length), true, out key))
+                {
+                    UpdateMessage(_app.GetResourceString(key));
+                    return true;
+                }
+            }
+            UpdateMessage(strNewText);
+
+            return true;
+        }
+
+        public void UpdateMessage(string message)
+        {
+            _progressUi?.UpdateMessage(message);
+            _lastMessage = message;
+        }
+
+        public void UpdateSubMessage(string submessage)
+        {
+            _progressUi?.UpdateSubMessage(submessage);
+            _lastSubMessage = submessage;
+        }
+
+        public bool ContinueWork()
+        {
+            return true;
+        }
+
+        public void UpdateMessage(UiStringKey stringKey)
+        {
+            if (_app != null)
+                UpdateMessage(_app.GetResourceString(stringKey));
+        }
+    }
+
+
     /// <summary>
         /// Class to run a task while a progress dialog is shown
         /// </summary>

src/Kp2aBusinessLogic/ProgressDialogStatusLogger.cs

@@ -27,6 +27,20 @@ namespace keepass2android
         void UpdateMessage(UiStringKey stringKey);
     }
 
+    public interface IProgressUi
+    {
+        void Show();
+        void Hide();
+        void UpdateMessage(String message);
+        void UpdateSubMessage(String submessage);
+    }
+
+    public interface IProgressUiProvider
+    {
+        IProgressUi? ProgressUi { get; }
+    }
+
+
     public class Kp2aNullStatusLogger : IKp2aStatusLogger
     {
         public void StartLogging(string strOperation, bool bWriteOperationToLog)

src/keepass2android-app/EntryActivity.cs

@@ -56,6 +56,7 @@ using Android.Util;
 using AndroidX.Core.Content;
 using Google.Android.Material.Dialog;
 using keepass2android;
+using keepass2android.views;
 
 namespace keepass2android
 {
@@ -97,7 +98,7 @@ namespace keepass2android
 
 	[Activity (Label = "@string/app_name", ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.Keyboard | ConfigChanges.KeyboardHidden,
         Theme = "@style/Kp2aTheme_ActionBar")]
-	public class EntryActivity : LockCloseActivity 
+	public class EntryActivity : LockCloseActivity, IProgressUiProvider
 	{
 		public const String KeyEntry = "entry";
         public const String KeyRefreshPos = "refresh_pos";
@@ -1603,5 +1604,7 @@ namespace keepass2android
 			imageViewerIntent.PutExtra("EntryKey", key);
 			StartActivity(imageViewerIntent);
 		}
+
+        public IProgressUi? ProgressUi => FindViewById<BackgroundOperationContainer>(Resource.Id.background_ops_container);
     }
 }

src/keepass2android-app/GroupBaseActivity.cs

@@ -43,11 +43,12 @@ using keepass2android;
 using KeeTrayTOTP.Libraries;
 using AndroidX.AppCompat.Widget;
 using Google.Android.Material.Dialog;
+using keepass2android.views;
 using SearchView = AndroidX.AppCompat.Widget.SearchView;
 
 namespace keepass2android
 {
-    public abstract class GroupBaseActivity : LockCloseActivity
+    public abstract class GroupBaseActivity : LockCloseActivity, IProgressUiProvider
     {
         public const String KeyEntry = "entry";
         public const String KeyMode = "mode";
@@ -1408,6 +1409,14 @@ namespace keepass2android
         {
             GroupEditActivity.Launch(this, pwGroup.ParentGroup, pwGroup);
         }
+
+        public IProgressUi ProgressUi
+        {
+            get
+            {
+                return FindViewById<BackgroundOperationContainer>(Resource.Id.background_ops_container);
+            }
+        }
     }
 
     public class GroupListFragment : ListFragment, AbsListView.IMultiChoiceModeListener

src/keepass2android-app/LifecycleAwareActivity.cs

@@ -105,6 +105,7 @@ namespace keepass2android
         protected override void OnStart()
         {
             BlockingOperationRunner.SetNewActiveActivity(this);
+            BackgroundOperationRunner.Instance.SetNewActiveActivity(this, App.Kp2a);
             base.OnStart();
             Kp2aLog.Log(ClassName + ".OnStart" + " " + ID);
         }

src/keepass2android-app/Resources/layout/background_operation_container.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+	xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/background_ops_container"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="@color/md_theme_surfaceVariant"
+    android:orientation="vertical"   
+>
+
+        
+    <com.google.android.material.progressindicator.LinearProgressIndicator
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:indeterminate="true" />
+        
+
+    <TextView 
+      android:id="@+id/background_ops_message"
+        android:layout_width="wrap_content"
+              android:layout_height="wrap_content"
+              android:layout_marginLeft="10dp"
+              android:layout_marginRight="10dp"
+              android:layout_marginTop="0dp"
+              android:layout_marginBottom="3dp"
+              android:text="" />
+    
+    <TextView 
+      android:id="@+id/background_ops_submessage"
+        android:layout_width="wrap_content"
+              android:layout_height="wrap_content"
+                android:layout_marginLeft="10dp"
+                android:layout_marginRight="10dp"
+                android:layout_marginTop="0dp"
+                android:layout_marginBottom="3dp"
+                android:textSize="12sp"
+              android:text="" />
+
+
+  </LinearLayout>
+		

src/keepass2android-app/Resources/layout/entry_view.xml

@@ -4,18 +4,35 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fitsSystemWindows="true">
+    <LinearLayout android:layout_width="fill_parent"
+        android:layout_height="fill_parent"
+        android:orientation="vertical">
+    
+    
+    
+    
+  <keepass2android.views.BackgroundOperationContainer
+    android:visibility="gone"
+    android:id="@+id/background_ops_container"
+    android:layout_below="@id/top"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+
+  />
+    
     <ScrollView
         android:id="@+id/entry_scroll"
         android:layout_width="fill_parent"
         android:layout_height="fill_parent"
-        android:fillViewport="true"
         android:background="?android:attr/colorBackground"
         android:scrollbarStyle="insideOverlay">
+        
         <keepass2android.view.EntryContentsView
             android:id="@+id/entry_contents"
             android:layout_height="wrap_content"
             android:layout_width="fill_parent" />
     </ScrollView>
+    </LinearLayout>
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/entry_edit"
         android:layout_width="wrap_content"

src/keepass2android-app/Resources/layout/group.xml

@@ -355,29 +355,14 @@
         android:layout_above="@id/bottom_bar"
         android:background="#b8b8b8" />
 
-    <LinearLayout
+   <keepass2android.views.BackgroundOperationContainer
+        android:visibility="gone"
      android:id="@+id/background_ops_container"
-      android:layout_width="match_parent"
-      android:layout_height="wrap_content"
-      android:background="@color/md_theme_surfaceVariant"
-      
      android:layout_below="@id/top"
-      android:orientation="vertical" >
-
-        
-      <com.google.android.material.progressindicator.LinearProgressIndicator
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
-        android:indeterminate="true" />
 
-
+        />
-      <TextView android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:padding="10dp"
-                android:text="Synchronisierung läuft..." />
-
-
-        </LinearLayout>
   
     <androidx.coordinatorlayout.widget.CoordinatorLayout
         android:id="@+id/main_content"

src/keepass2android-app/SyncUtil.cs

@@ -1,5 +1,6 @@
 using System;
 using Android.App;
+using Android.OS;
 using Android.Widget;
 using keepass2android.Io;
 using KeePassLib.Serialization;
@@ -56,17 +57,17 @@ namespace keepass2android
             OnOperationFinishedHandler onOperationFinishedHandler = new ActionOnOperationFinished(_activity, (success, message, activity) =>
             {
                 if (!String.IsNullOrEmpty(message))
-                    App.Kp2a.ShowMessage(activity, message,  MessageSeverity.Error);
+                    App.Kp2a.ShowMessage(activity, message, success ? MessageSeverity.Info : MessageSeverity.Error);
 
                 // Tell the adapter to refresh it's list
                 BaseAdapter adapter = (activity as GroupBaseActivity)?.ListAdapter; 
-                adapter?.NotifyDataSetChanged();
+                new Handler(Looper.MainLooper).Post(() => adapter?.NotifyDataSetChanged());
 
                 if (App.Kp2a.CurrentDb?.OtpAuxFileIoc != null)
                 {
                     var task2 = new SyncOtpAuxFile(_activity, App.Kp2a.CurrentDb.OtpAuxFileIoc);
 
-                    //TODO new BackgroundOperationRunner(App.Kp2a, activity, task2).Run(true);
+                    BackgroundOperationRunner.Instance.Run(_activity, App.Kp2a, task2);
                 }
                
             });
@@ -82,8 +83,7 @@ namespace keepass2android
                 task = new CheckDatabaseForChanges(_activity, App.Kp2a, onOperationFinishedHandler);
             }
 
-            //TODO var backgroundTaskRunner = new BackgroundOperationRunner(App.Kp2a, _activity, task);
+            BackgroundOperationRunner.Instance.Run(_activity, App.Kp2a, task);
-            //TODO backgroundTaskRunner.Run();
 
         }
     }

src/keepass2android-app/views/Kp2aShortHelpView.cs

@@ -18,6 +18,7 @@ using Android.Views;
 using Android.Widget;
 using Google.Android.Material.Dialog;
 using keepass2android;
+using KeePassLib.Interfaces;
 
 namespace keepass2android.views
 {
@@ -103,4 +104,92 @@ namespace keepass2android.views
 		
 		}
 	}
+
+
+    public class BackgroundOperationContainer : LinearLayout, IProgressUi
+    {
+        protected BackgroundOperationContainer(IntPtr javaReference, JniHandleOwnership transfer) : base(
+            javaReference, transfer)
+        {
+        }
+
+        public BackgroundOperationContainer(Context context) : base(context)
+        {
+        }
+
+        public BackgroundOperationContainer(Context context, IAttributeSet attrs) : base(context, attrs)
+        {
+            Initialize(attrs);
+        }
+
+        public BackgroundOperationContainer(Context context, IAttributeSet attrs, int defStyle) : base(context,
+            attrs, defStyle)
+        {
+            Initialize(attrs);
+        }
+
+        private void Initialize(IAttributeSet attrs)
+        {
+
+            LayoutInflater inflater = (LayoutInflater)Context.GetSystemService(Context.LayoutInflaterService);
+            inflater.Inflate(Resource.Layout.background_operation_container, this);
+
+
+        }
+
+        public void Show()
+        {
+            new Handler(Looper.MainLooper).Post(() =>
+            {
+                Visibility = ViewStates.Visible;
+                FindViewById<TextView>(Resource.Id.background_ops_message)!.Visibility = ViewStates.Gone;
+                FindViewById<TextView>(Resource.Id.background_ops_submessage)!.Visibility = ViewStates.Gone;
+            });
+
+        }
+
+        public void Hide()
+        {
+            new Handler(Looper.MainLooper).Post(() =>
+            {
+                String activityType = Context.GetType().FullName;
+                Kp2aLog.Log("Hiding background ops container in" + activityType);
+                Visibility = ViewStates.Gone;
+            });
+        }
+
+        public void UpdateMessage(string message)
+        {
+            new Handler(Looper.MainLooper).Post(() =>
+            {
+                TextView messageTextView = FindViewById<TextView>(Resource.Id.background_ops_message)!;
+                if (string.IsNullOrEmpty(message))
+                {
+                    messageTextView.Visibility = ViewStates.Gone;
+                }
+                else
+                {
+                    messageTextView.Visibility = ViewStates.Visible;
+                    messageTextView.Text = message;
+                }
+            });
+        }
+
+        public void UpdateSubMessage(string submessage)
+        {
+            new Handler(Looper.MainLooper).Post(() =>
+            {
+                TextView subMessageTextView = FindViewById<TextView>(Resource.Id.background_ops_submessage)!;
+                if (string.IsNullOrEmpty(submessage))
+                {
+                    subMessageTextView.Visibility = ViewStates.Gone;
+                }
+                else
+                {
+                    subMessageTextView.Visibility = ViewStates.Visible;
+                    subMessageTextView.Text = submessage;
+                }
+            });
+        }
+    }
 }