refactoring, remove Loaded property from database. instead, make GetDb() return null if database is not loaded.

src/Kp2aBusinessLogic/database/Database.cs

@@ -45,7 +45,7 @@ namespace keepass2android
 		{
 			get
 			{
-				return KpDatabase == null ? null : KpDatabase.IOConnectionInfo;
+				return KpDatabase?.IOConnectionInfo;
 			}
 		}
 
@@ -74,8 +74,6 @@ namespace keepass2android
 			CanWrite = true; //default
         }
 
-		private bool _loaded;
-
         private bool _reloadRequested;
 		private IDatabaseFormat _databaseFormat = new KdbxDatabaseFormat(KdbxFormat.Default);
 
@@ -85,19 +83,9 @@ namespace keepass2android
             set { _reloadRequested = value; }
         }
 
-		public bool Loaded {
-			get { return _loaded;}
-			set { _loaded = value; }
-		}
-
 		public bool DidOpenFileChange()
 		{
-			if (Loaded == false)
-			{
-				return false;
-			}
 			return _app.GetFileStorage(Ioc).CheckForFileChangeFast(Ioc, LastFileVersion);
-			
 		}
 
 
@@ -112,32 +100,20 @@ namespace keepass2android
 			Stream s = databaseData ?? fileStorage.OpenFileForRead(iocInfo);
 			var fileVersion = _app.GetFileStorage(iocInfo).GetCurrentFileVersionFast(iocInfo);
 			PopulateDatabaseFromStream(pwDatabase, s, iocInfo, compositeKey, status, databaseFormat);
-			try
+		    LastFileVersion = fileVersion;
-			{
-				LastFileVersion = fileVersion;
 
-				status.UpdateSubMessage("");
+		    status.UpdateSubMessage("");
 
-				Root = pwDatabase.RootGroup;
+		    Root = pwDatabase.RootGroup;
-				PopulateGlobals(Root);
+		    PopulateGlobals(Root);
 
 				
-				KpDatabase = pwDatabase;
+		    KpDatabase = pwDatabase;
-				SearchHelper = new SearchDbHelper(app);
+		    SearchHelper = new SearchDbHelper(app);
-
-				_databaseFormat = databaseFormat;
-
-				CanWrite = databaseFormat.CanWrite && !fileStorage.IsReadOnly(iocInfo);
-				Loaded = true;
-			}
-			catch (Exception)
-			{
-				Clear();				
-				throw;
-			}
-			
 
+		    _databaseFormat = databaseFormat;
 
+		    CanWrite = databaseFormat.CanWrite && !fileStorage.IsReadOnly(iocInfo);
 		}
 
 		/// <summary>
@@ -267,24 +243,7 @@ namespace keepass2android
 			PopulateGlobals(currentGroup, _app.CheckForDuplicateUuids);
 		}
 
-		public void Clear() {
+	    public void MarkAllGroupsAsDirty() {
-			_loaded = false; 
-			
-			Groups.Clear();
-			Entries.Clear();
-			Dirty.Clear();
-			DrawableFactory.Clear();
-			
-			Root = null;
-			KpDatabase = null;
-			
-			CanWrite = true;
-			_reloadRequested = false;
-			OtpAuxFileIoc = null;
-		    LastOpenedEntry = null;
-		}
-		
-		public void MarkAllGroupsAsDirty() {
 			foreach ( PwGroup group in Groups.Values ) {
 				Dirty.Add(group);
 			}

src/Kp2aBusinessLogic/database/edit/CreateDB.cs

@@ -74,7 +74,6 @@ namespace keepass2android
 			
 			// Set Database state
 			db.Root = db.KpDatabase.RootGroup;
-			db.Loaded = true;
 			db.SearchHelper = new SearchDbHelper(_app);
 
 			// Add a couple default groups

src/keepass2android/EntryActivity.cs

@@ -391,7 +391,7 @@ namespace keepass2android
 
 			Database db = App.Kp2a.GetDb();
 			// Likely the app has been killed exit the activity 
-			if (!db.Loaded || (App.Kp2a.QuickLocked))
+			if (db == null || (App.Kp2a.QuickLocked))
 			{
 				Finish();
 				return;

src/keepass2android/GroupBaseActivity.cs

@@ -407,7 +407,7 @@ namespace keepass2android
             AppTask = AppTask.GetTaskInOnCreate(savedInstanceState, Intent);
 
             // Likely the app has been killed exit the activity 
-            if (!App.Kp2a.GetDb().Loaded)
+            if (App.Kp2a.GetDb() == null)
             {
                 Finish();
                 return;

src/keepass2android/LockingActivity.cs

@@ -43,35 +43,30 @@ namespace keepass2android
 	    {
 	        base.OnStart();
 
-	        if (App.Kp2a.GetDb().Loaded)
+	        var xcKey = App.Kp2a.GetDb()?.KpDatabase.MasterKey.GetUserKey<ChallengeXCKey>();
+	        if (xcKey != null)
 	        {
-	            var xcKey = App.Kp2a.GetDb().KpDatabase.MasterKey.GetUserKey<ChallengeXCKey>();
+	            xcKey.Activity = this;
-	            if (xcKey != null)
+	            _currentlyWaitingKey = xcKey;
-	            {
-	                xcKey.Activity = this;
-	                _currentlyWaitingKey = xcKey;
-
-	            }
 
 	        }
 
-        }
+
+
+	    }
 
 	    protected override void OnStop()
 	    {
 	        base.OnStop();
-	        if (App.Kp2a.GetDb().Loaded)
+	        var xcKey = App.Kp2a.GetDb()?.KpDatabase.MasterKey.GetUserKey<ChallengeXCKey>();
+	        if (xcKey != null)
 	        {
-	            var xcKey = App.Kp2a.GetDb().KpDatabase.MasterKey.GetUserKey<ChallengeXCKey>();
+	            //don't store a pointer to this activity in the static database object to avoid memory leak
-	            if (xcKey != null)
+	            if (xcKey.Activity == this) //don't reset if another activity has come to foreground already
-	            {
+	                xcKey.Activity = null;
-                    //don't store a pointer to this activity in the static database object to avoid memory leak
-                    if (xcKey.Activity == this) //don't reset if another activity has come to foreground already
-	                    xcKey.Activity = null;
-	            }
-
 	        }
-        }
+
+	    }
 
 	    protected override void OnPause() {
 			base.OnPause();

src/keepass2android/NfcOtpActivity.cs

@@ -93,7 +93,7 @@ namespace keepass2android
 				return;
 			}
 
-			if (App.Kp2a.GetDb().Loaded)
+			if (App.Kp2a.GetDb() != null)
 			{
 				Toast.MakeText(this, GetString(Resource.String.otp_discarded_because_db_open), ToastLength.Long).Show();
 			}

src/keepass2android/PasswordActivity.cs

@@ -737,8 +737,7 @@ namespace keepass2android
 				}
 			}
 
-			if (App.Kp2a.GetDb().Loaded && App.Kp2a.GetDb().Ioc != null &&
+			if (App.Kp2a.GetDb()?.Ioc != null && App.Kp2a.GetDb().Ioc.GetDisplayName() != _ioConnection.GetDisplayName())
-				App.Kp2a.GetDb().Ioc.GetDisplayName() != _ioConnection.GetDisplayName())
 			{
 				// A different database is currently loaded, unload it before loading the new one requested
 				App.Kp2a.LockDatabase(false);

src/keepass2android/QuickUnlock.cs

@@ -427,7 +427,7 @@ namespace keepass2android
 
 		private void CheckIfUnloaded()
 		{
-			if ((App.Kp2a.GetDb() == null) || (App.Kp2a.GetDb().Loaded == false))
+			if (App.Kp2a.GetDb() == null)
 			{
 				Finish();
 			}

src/keepass2android/StackBaseActivity.cs

@@ -46,7 +46,7 @@ namespace keepass2android
             base.OnResume();
             if (!IsFinishing)
             {
-                if (!App.Kp2a.GetDb().Loaded)
+                if (App.Kp2a.GetDb() == null)
                 {
                     // Load default database
                     ISharedPreferences prefs = Android.Preferences.PreferenceManager.GetDefaultSharedPreferences(this);
@@ -128,7 +128,7 @@ namespace keepass2android
                     break;
                 case KeePass.ExitReloadDb:
 
-                    if (App.Kp2a.GetDb().Loaded)
+                    if (App.Kp2a.GetDb() != null)
                     {
                         //remember the composite key for reloading:
                         var compositeKey = App.Kp2a.GetDb().KpDatabase.MasterKey;

src/keepass2android/app/App.cs

@@ -102,19 +102,18 @@ namespace keepass2android
 	{
 		public void LockDatabase(bool allowQuickUnlock = true)
 		{
-			if (GetDb().Loaded)
+			if (GetDb() != null)
 			{
 				if (QuickUnlockEnabled && allowQuickUnlock &&
-					_db.KpDatabase.MasterKey.ContainsType(typeof(KcpPassword)) &&
+					GetDb().KpDatabase.MasterKey.ContainsType(typeof(KcpPassword)) &&
 					!((KcpPassword)App.Kp2a.GetDb().KpDatabase.MasterKey.GetUserKey(typeof(KcpPassword))).Password.IsEmpty)
 				{
 					if (!QuickLocked)
 					{
 						Kp2aLog.Log("QuickLocking database");
-						BroadcastDatabaseAction(Application.Context, Strings.ActionLockDatabase);
+					    QuickLocked = true;
-
+					    GetDb().LastOpenedEntry = null;
-						QuickLocked = true;
+                        BroadcastDatabaseAction(Application.Context, Strings.ActionLockDatabase);
-						_db.LastOpenedEntry = null;
 					}
 					else
 					{
@@ -127,8 +126,8 @@ namespace keepass2android
 
 					BroadcastDatabaseAction(Application.Context, Strings.ActionCloseDatabase);
 
-					// Couldn't quick-lock, so unload database instead
+                    // Couldn't quick-lock, so unload database instead
-					_db.Clear();
+				    _db = null;
 					QuickLocked = false;
 				}
 			}
@@ -181,7 +180,7 @@ namespace keepass2android
 	            memoryStream.Seek(0, SeekOrigin.Begin);
 	        }
 
-
+	        _db = CreateNewDatabase();
 	        _db.LoadData(this, ioConnectionInfo, memoryStream, compositeKey, statusLogger, databaseFormat);
 
 		    if (createBackup)
@@ -259,7 +258,7 @@ namespace keepass2android
         
 		public bool DatabaseIsUnlocked
 		{
-			get { return _db.Loaded && !QuickLocked; }
+			get { return GetDb() != null && !QuickLocked; }
 		}
 
 		#region QuickUnlock
@@ -300,11 +299,6 @@ namespace keepass2android
 
 		public Database GetDb()
         {
-            if (_db == null)
-            {
-                _db = CreateNewDatabase();
-            }
-
             return _db;
         }
 
@@ -331,9 +325,9 @@ namespace keepass2android
 
         public void CheckForOpenFileChanged(Activity activity)
         {
-            if (_db.DidOpenFileChange())
+            if (GetDb()?.DidOpenFileChange() == true)
             {
-                if (_db.ReloadRequested)
+                if (GetDb().ReloadRequested)
                 {
 	                LockDatabase(false);
                     activity.SetResult(KeePass.ExitReloadDb);
@@ -353,7 +347,7 @@ namespace keepass2android
 			builder.SetPositiveButton(activity.GetString(Android.Resource.String.Yes),
 				(dlgSender, dlgEvt) =>
 				{
-					_db.ReloadRequested = true;
+				    GetDb().ReloadRequested = true;
 					activity.SetResult(KeePass.ExitReloadDb);
 					activity.Finish();
 
@@ -729,15 +723,14 @@ namespace keepass2android
 
 		internal void OnTerminate()
         {
-            if (_db != null)
+            
-            {
+            _db = null;
-                _db.Clear();
-            }
             
             if (FileDbHelper != null && FileDbHelper.IsOpen())
             {
                 FileDbHelper.Close();
             }
+            GC.Collect();
         }
 
         internal void OnCreate(Application app)

src/keepass2android/app/AppTask.cs

@@ -943,7 +943,7 @@ namespace keepass2android
 					PwUuid nextGroupPwUuid = new PwUuid (MemUtil.HexStringToByteArray (nextGroupUuid));
 
 					// Create Group Activity
-					PwGroup nextGroup = App.Kp2a.GetDb ().Groups [nextGroupPwUuid];
+					PwGroup nextGroup = App.Kp2a.GetDb ().Groups[nextGroupPwUuid];
 					GroupActivity.Launch (groupBaseActivity, nextGroup, this);
 				}
 				return;

src/keepass2android/fileselect/FileSelectActivity.cs

@@ -461,7 +461,7 @@ namespace keepass2android
 			Kp2aLog.Log("FileSelect.OnStart");
 
 			var db = App.Kp2a.GetDb();
-			if (db.Loaded)
+			if (db != null)
 			{
 				LaunchPasswordActivityForIoc(db.Ioc);
 			}

src/keepass2android/search/SearchProvider.cs

@@ -48,8 +48,6 @@ namespace keepass2android.search
 		private const string IconIdParameter = "IconId";
 		private const string CustomIconUuidParameter = "CustomIconUuid";
 
-		private Database _db;
-
 		private static UriMatcher UriMatcher = BuildUriMatcher();
 
 		static UriMatcher BuildUriMatcher()
@@ -65,7 +63,6 @@ namespace keepass2android.search
 
 		public override bool OnCreate()
 		{
-			_db = App.Kp2a.GetDb();
 			return true;
 		}
 
@@ -82,7 +79,7 @@ namespace keepass2android.search
 							try
 							{
 								var resultsContexts = new Dictionary<PwUuid, KeyValuePair<string, string>>();
-								var result = _db.Search(new SearchParameters { SearchString = searchString }, resultsContexts );
+								var result = App.Kp2a.GetDb().Search(new SearchParameters { SearchString = searchString }, resultsContexts );
 								return new GroupCursor(result, resultsContexts);
 							}
 							catch (Exception e)
@@ -120,8 +117,8 @@ namespace keepass2android.search
 					var iconId = (PwIcon)Enum.Parse(typeof(PwIcon), uri.GetQueryParameter(IconIdParameter));
 					var customIconUuid = new PwUuid(MemUtil.HexStringToByteArray(uri.GetQueryParameter(CustomIconUuidParameter)));
 
-					var iconDrawable = _db.DrawableFactory.GetIconDrawable(App.Context, _db.KpDatabase, iconId, customIconUuid, false) as BitmapDrawable;
+					var iconDrawable = App.Kp2a.GetDb().DrawableFactory.GetIconDrawable(App.Context, App.Kp2a.GetDb().KpDatabase, iconId, customIconUuid, false) as BitmapDrawable;
-					if ((iconDrawable != null) && (iconDrawable.Bitmap != null))
+					if (iconDrawable?.Bitmap != null)
 
                     {
 						var pipe = ParcelFileDescriptor.CreatePipe();

src/keepass2android/services/Kp2aAutofill/ChooseForAutofillActivity.cs

@@ -39,7 +39,7 @@ namespace keepass2android.services.Kp2aAutofill
 
         protected override FilledAutofillFieldCollection GetDataset(Intent data)
         {
-            if (!App.Kp2a.GetDb().Loaded || (App.Kp2a.QuickLocked))
+            if (App.Kp2a.GetDb()==null || (App.Kp2a.QuickLocked))
                 return null;
             var entryOutput = App.Kp2a.GetDb().LastOpenedEntry;
 

src/keepass2android/settings/DatabaseSettingsActivity.cs

@@ -424,7 +424,7 @@ namespace keepass2android
 	        FindPreference(GetString(Resource.String.design_key)).PreferenceChange += (sender, args) => Activity.Recreate();
             
             Database db = App.Kp2a.GetDb();
-            if (db.Loaded)
+            if (db != null)
             {
 	            ListPreference kdfPref = (ListPreference) FindPreference(GetString(Resource.String.kdf_key));
 	            kdfPref.SetEntries(KdfPool.Engines.Select(eng => eng.Name).ToArray());
@@ -791,7 +791,7 @@ namespace keepass2android
         private void OnUseOfflineCacheChanged(object sender, Preference.PreferenceChangeEventArgs e)
         {
             //ensure the user gets a matching database
-            if (App.Kp2a.GetDb().Loaded && !App.Kp2a.GetDb().Ioc.IsLocalFile())
+            if (App.Kp2a.GetDb() != null && !App.Kp2a.GetDb().Ioc.IsLocalFile())
                 App.Kp2a.LockDatabase(false);
 
             if (!(bool)e.NewValue)

src/keepass2android/timeout/TimeoutHelper.cs

@@ -83,7 +83,7 @@ namespace keepass2android
 		
 		public static void Resume(Activity act) 
 		{
-			if ( App.Kp2a.GetDb().Loaded ) 
+			if ( App.Kp2a.GetDb() != null) 
 			{
 				Timeout.Cancel(act);
 			}