Add lock & Improve code quality

Author: Jack251970

Flow.Launcher/ViewModel/MainViewModel.cs

@@ -37,6 +37,9 @@ public partial class MainViewModel : BaseModel, ISavable, IDisposable
         private string _queryTextBeforeLeaveResults;
         private string _ignoredQueryText; // Used to ignore query text change when switching between context menu and query results
 
+        private readonly object _shouldClearExistingResultsLock = new();
+        private bool _shouldClearExistingResults;
+
         private readonly FlowLauncherJsonStorage<History> _historyItemsStorage;
         private readonly FlowLauncherJsonStorage<UserSelectedRecord> _userSelectedRecordStorage;
         private readonly FlowLauncherJsonStorageTopMostRecord _topMostRecord;
@@ -1079,8 +1082,6 @@ private bool QueryResultsPreviewed()
 
         #region Query
 
-        internal bool ShouldClearExistingResults { get; set; }
-
         public void QueryResults()
         {
             _ = QueryResultsAsync(false);
@@ -1439,7 +1440,10 @@ await PluginManager.QueryHomeForPluginAsync(plugin, query, token) :
                 if (shouldClearExistingResults)
                 {
                     // Setup the flag to clear existing results so that ResultsViewModel.NewResults will handle in the next update
-                    ShouldClearExistingResults = true;
+                    lock (_shouldClearExistingResultsLock)
+                    {
+                        _shouldClearExistingResults = true;
+                    }
                 }
                 _lastQuery = query;
                 _previousIsHomeQuery = currentIsHomeQuery;
@@ -1467,7 +1471,10 @@ void QueryHistoryTask(CancellationToken token)
                 if (shouldClearExistingResults)
                 {
                     // Setup the flag to clear existing results so that ResultsViewModel.NewResults will handle in the next update
-                    ShouldClearExistingResults = true;
+                    lock (_shouldClearExistingResultsLock)
+                    {
+                        _shouldClearExistingResults = true;
+                    }
                 }
                 _lastQuery = query;
                 _previousIsHomeQuery = currentIsHomeQuery;
@@ -1708,6 +1715,20 @@ internal bool ResultsSelected(ResultsViewModel results)
             return selected;
         }
 
+        internal bool CheckShouldClearExistingResultsAndReset()
+        {
+            lock (_shouldClearExistingResultsLock)
+            {
+                if (_shouldClearExistingResults)
+                {
+                    _shouldClearExistingResults = false;
+                    return true;
+                }
+
+                return false;
+            }
+        }
+
         #endregion
 
         #region Hotkey

Flow.Launcher/ViewModel/ResultsViewModel.cs

@@ -246,9 +246,8 @@ private List<ResultViewModel> NewResults(ICollection<ResultsForUpdate> resultsFo
             var newResults = resultsForUpdates.SelectMany(u => u.Results, (u, r) => new ResultViewModel(r, _settings));
 
             // If mainVM has flag to clear existing results, handle it here
-            if (_mainVM != null && _mainVM.ShouldClearExistingResults)
+            if (_mainVM != null && _mainVM.CheckShouldClearExistingResultsAndReset())
             {
-                _mainVM.ShouldClearExistingResults = false;
                 App.API.LogDebug("NewResults", $"Existing results are cleared for query");
                 return newResults.OrderByDescending(rv => rv.Result.Score).ToList();
             }