Input Smooth & Search delay

Flow.Launcher.Infrastructure/UserSettings/Settings.cs

@@ -275,6 +275,18 @@ public bool HideNotifyIcon
         public bool LeaveCmdOpen { get; set; }
         public bool HideWhenDeactivated { get; set; } = true;
 
+        bool _searchQueryResultsWithDelay { get; set; }
+        public bool SearchQueryResultsWithDelay
+        {
+            get => _searchQueryResultsWithDelay;
+            set
+            {
+                _searchQueryResultsWithDelay = value;
+                OnPropertyChanged();
+            }
+        }
+        public int SearchInputDelay { get; set; } = 120;
+
         [JsonConverter(typeof(JsonStringEnumConverter))]
         public SearchWindowScreens SearchWindowScreen { get; set; } = SearchWindowScreens.Cursor;
 

Flow.Launcher/Flow.Launcher.csproj

@@ -104,6 +104,7 @@
     <PackageReference Include="NHotkey.Wpf" Version="3.0.0" />
     <PackageReference Include="PropertyChanged.Fody" Version="3.4.0" />
     <PackageReference Include="SemanticVersioning" Version="3.0.0" />
+    <PackageReference Include="System.Reactive.Linq" Version="6.0.1" />
     <PackageReference Include="TaskScheduler" Version="2.12.1" />
     <PackageReference Include="VirtualizingWrapPanel" Version="2.1.1" />
   </ItemGroup>

Flow.Launcher/Languages/en.xaml

@@ -94,6 +94,10 @@
     <system:String x:Key="hideOnStartupToolTip">Flow Launcher search window is hidden in the tray after starting up.</system:String>
     <system:String x:Key="hideNotifyIcon">Hide tray icon</system:String>
     <system:String x:Key="hideNotifyIconToolTip">When the icon is hidden from the tray, the Settings menu can be opened by right-clicking on the search window.</system:String>
+    <system:String x:Key="searchDelay">Search Delay</system:String>
+    <system:String x:Key="searchDelayToolTip">Delay for a while to search when typing. This reduces interface jumpiness and result load.</system:String>
+    <system:String x:Key="searchDelayTime">Search Delay Time</system:String>
+    <system:String x:Key="searchDelayTimeToolTip">Delay time after which search results appear when typing is stopped. Default is 120ms.</system:String>
     <system:String x:Key="querySearchPrecision">Query Search Precision</system:String>
     <system:String x:Key="querySearchPrecisionToolTip">Changes minimum match score required for results.</system:String>
     <system:String x:Key="SearchPrecisionNone">None</system:String>

Flow.Launcher/MainWindow.xaml.cs

@@ -5,7 +5,6 @@
 using System.Windows.Input;
 using System.Windows.Media.Animation;
 using System.Windows.Controls;
-using System.Windows.Forms;
 using Flow.Launcher.Core.Plugin;
 using Flow.Launcher.Core.Resource;
 using Flow.Launcher.Helper;
@@ -27,6 +26,7 @@
 using System.Windows.Media;
 using System.Windows.Interop;
 using Windows.Win32;
+using System.Reactive.Linq;
 
 namespace Flow.Launcher
 {
@@ -195,6 +195,8 @@ private void OnLoaded(object sender, RoutedEventArgs _)
             InitializePosition();
             InitializePosition();
             PreviewReset();
+            // Setup search text box reactiveness
+            SetupSearchTextBoxReactiveness(_settings.SearchQueryResultsWithDelay);
             // since the default main window visibility is visible
             // so we need set focus during startup
             QueryTextBox.Focus();
@@ -204,63 +206,63 @@ private void OnLoaded(object sender, RoutedEventArgs _)
                 switch (e.PropertyName)
                 {
                     case nameof(MainViewModel.MainWindowVisibilityStatus):
-                    {
-                        Dispatcher.Invoke(() =>
                         {
-                            if (_viewModel.MainWindowVisibilityStatus)
+                            Dispatcher.Invoke(() =>
                             {
-                                if (_settings.UseSound)
+                                if (_viewModel.MainWindowVisibilityStatus)
                                 {
-                                    SoundPlay();
+                                    if (_settings.UseSound)
+                                    {
+                                        SoundPlay();
+                                    }
+
+                                    UpdatePosition();
+                                    PreviewReset();
+                                    Activate();
+                                    QueryTextBox.Focus();
+                                    _settings.ActivateTimes++;
+                                    if (!_viewModel.LastQuerySelected)
+                                    {
+                                        QueryTextBox.SelectAll();
+                                        _viewModel.LastQuerySelected = true;
+                                    }
+
+                                    if (_viewModel.ProgressBarVisibility == Visibility.Visible &&
+                                        isProgressBarStoryboardPaused)
+                                    {
+                                        _progressBarStoryboard.Begin(ProgressBar, true);
+                                        isProgressBarStoryboardPaused = false;
+                                    }
+
+                                    if (_settings.UseAnimation)
+                                        WindowAnimator();
                                 }
-
-                                UpdatePosition();
-                                PreviewReset();
-                                Activate();
-                                QueryTextBox.Focus();
-                                _settings.ActivateTimes++;
-                                if (!_viewModel.LastQuerySelected)
+                                else if (!isProgressBarStoryboardPaused)
                                 {
-                                    QueryTextBox.SelectAll();
-                                    _viewModel.LastQuerySelected = true;
+                                    _progressBarStoryboard.Stop(ProgressBar);
+                                    isProgressBarStoryboardPaused = true;
                                 }
-
-                                if (_viewModel.ProgressBarVisibility == Visibility.Visible &&
-                                    isProgressBarStoryboardPaused)
+                            });
+                            break;
+                        }
+                    case nameof(MainViewModel.ProgressBarVisibility):
+                        {
+                            Dispatcher.Invoke(() =>
+                            {
+                                if (_viewModel.ProgressBarVisibility == Visibility.Hidden && !isProgressBarStoryboardPaused)
+                                {
+                                    _progressBarStoryboard.Stop(ProgressBar);
+                                    isProgressBarStoryboardPaused = true;
+                                }
+                                else if (_viewModel.MainWindowVisibilityStatus &&
+                                         isProgressBarStoryboardPaused)
                                 {
                                     _progressBarStoryboard.Begin(ProgressBar, true);
                                     isProgressBarStoryboardPaused = false;
                                 }
-
-                                if (_settings.UseAnimation)
-                                    WindowAnimator();
-                            }
-                            else if (!isProgressBarStoryboardPaused)
-                            {
-                                _progressBarStoryboard.Stop(ProgressBar);
-                                isProgressBarStoryboardPaused = true;
-                            }
-                        });
-                        break;
-                    }
-                    case nameof(MainViewModel.ProgressBarVisibility):
-                    {
-                        Dispatcher.Invoke(() =>
-                        {
-                            if (_viewModel.ProgressBarVisibility == Visibility.Hidden && !isProgressBarStoryboardPaused)
-                            {
-                                _progressBarStoryboard.Stop(ProgressBar);
-                                isProgressBarStoryboardPaused = true;
-                            }
-                            else if (_viewModel.MainWindowVisibilityStatus &&
-                                     isProgressBarStoryboardPaused)
-                            {
-                                _progressBarStoryboard.Begin(ProgressBar, true);
-                                isProgressBarStoryboardPaused = false;
-                            }
-                        });
-                        break;
-                    }
+                            });
+                            break;
+                        }
                     case nameof(MainViewModel.QueryTextCursorMovedToEnd):
                         if (_viewModel.QueryTextCursorMovedToEnd)
                         {
@@ -296,6 +298,9 @@ private void OnLoaded(object sender, RoutedEventArgs _)
                     case nameof(Settings.WindowTop):
                         Top = _settings.WindowTop;
                         break;
+                    case nameof(Settings.SearchQueryResultsWithDelay):
+                        SetupSearchTextBoxReactiveness(_settings.SearchQueryResultsWithDelay);
+                        break;
                 }
             };
         }
@@ -415,10 +420,10 @@ private void InitializeNotifyIcon()
             {
                 switch (e.Button)
                 {
-                    case MouseButtons.Left:
+                    case System.Windows.Forms.MouseButtons.Left:
                         _viewModel.ToggleFlowLauncher();
                         break;
-                    case MouseButtons.Right:
+                    case System.Windows.Forms.MouseButtons.Right:
 
                         contextMenu.IsOpen = true;
                         // Get context menu handle and bring it to the foreground
@@ -857,5 +862,78 @@ private void QueryTextBox_KeyUp(object sender, KeyEventArgs e)
                 be.UpdateSource();
             }
         }
+
+        #region Search Delay
+
+        // Edited from: https://github.com/microsoft/PowerToys
+
+        private IDisposable _reactiveSubscription;
+
+        private void SetupSearchTextBoxReactiveness(bool showResultsWithDelay)
+        {
+            if (_reactiveSubscription != null)
+            {
+                _reactiveSubscription.Dispose();
+                _reactiveSubscription = null;
+            }
+
+            QueryTextBox.TextChanged -= QueryTextBox_TextChanged;
+
+            if (showResultsWithDelay)
+            {
+                _reactiveSubscription = Observable.FromEventPattern<TextChangedEventHandler, TextChangedEventArgs>(
+                    conversion => (sender, eventArg) => conversion(sender, eventArg),
+                    add => QueryTextBox.TextChanged += add,
+                    remove => QueryTextBox.TextChanged -= remove)
+                    .Do(@event => ClearAutoCompleteText((TextBox)@event.Sender))
+                    .Throttle(TimeSpan.FromMilliseconds(_settings.SearchInputDelay))
+                    .Do(@event => Dispatcher.Invoke(() => PerformSearchQuery((TextBox)@event.Sender)))
+                    .Subscribe();
+            }
+            else
+            {
+                QueryTextBox.TextChanged += QueryTextBox_TextChanged;
+            }
+        }
+
+        private void QueryTextBox_TextChanged(object sender, TextChangedEventArgs e)
+        {
+            var textBox = (TextBox)sender;
+            ClearAutoCompleteText(textBox);
+            PerformSearchQuery(textBox);
+        }
+
+        private void ClearAutoCompleteText(TextBox textBox)
+        {
+            var text = textBox.Text;
+            var autoCompleteText = QueryTextSuggestionBox.Text;
+
+            if (ShouldAutoCompleteTextBeEmpty(text, autoCompleteText))
+            {
+                QueryTextSuggestionBox.Text = string.Empty;
+            }
+        }
+
+        private static bool ShouldAutoCompleteTextBeEmpty(string queryText, string autoCompleteText)
+        {
+            if (string.IsNullOrEmpty(autoCompleteText))
+            {
+                return false;
+            }
+            else
+            {
+                // Using Ordinal this is internal
+                return string.IsNullOrEmpty(queryText) || !autoCompleteText.StartsWith(queryText, StringComparison.Ordinal);
+            }
+        }
+
+        private void PerformSearchQuery(TextBox textBox)
+        {
+            var text = textBox.Text;
+            _viewModel.QueryText = text;
+            _viewModel.Query();
+        }
+
+        #endregion
     }
 }

Flow.Launcher/SettingPages/ViewModels/SettingsPaneGeneralViewModel.cs

@@ -139,6 +139,11 @@ public bool PortableMode
         }
     }
 
+    public IEnumerable<int> SearchInputDelayRange => new List<int>()
+    {
+        30, 60, 90, 120, 150, 180, 210, 240, 270, 300
+    };
+
     public List<LastQueryModeData> LastQueryModes { get; } =
         DropdownDataGeneric<LastQueryMode>.GetValues<LastQueryModeData>("LastQuery");
 

Flow.Launcher/SettingPages/Views/SettingsPaneGeneral.xaml

@@ -172,6 +172,28 @@
                     OnContent="{DynamicResource enable}" />
             </cc:Card>
 
+            <cc:CardGroup Margin="0 14 0 0">
+                <cc:Card
+                    Title="{DynamicResource searchDelay}"
+                    Icon="&#xE961;"
+                    Sub="{DynamicResource searchDelayToolTip}">
+                    <ui:ToggleSwitch
+                        IsOn="{Binding Settings.SearchQueryResultsWithDelay}"
+                        OffContent="{DynamicResource disable}"
+                        OnContent="{DynamicResource enable}" />
+                </cc:Card>
+
+                <cc:Card
+                    Title="{DynamicResource searchDelayTime}"
+                    Icon="&#xE916;"
+                    Sub="{DynamicResource searchDelayTimeToolTip}">
+                    <ComboBox
+                        Width="100"
+                        ItemsSource="{Binding SearchInputDelayRange}"
+                        SelectedItem="{Binding Settings.SearchInputDelay}" />
+                </cc:Card>
+            </cc:CardGroup>
+
             <cc:CardGroup Margin="0 14 0 0">
                 <cc:Card Title="{DynamicResource querySearchPrecision}" Sub="{DynamicResource querySearchPrecisionToolTip}">
                     <ComboBox

Flow.Launcher/ViewModel/MainViewModel.cs

@@ -569,7 +569,6 @@ public string QueryText
             {
                 _queryText = value;
                 OnPropertyChanged();
-                Query();
             }
         }
 
@@ -631,6 +630,7 @@ public void ChangeQueryText(string queryText, bool isReQuery = false)
                 {
                     // re-query is done in QueryText's setter method
                     QueryText = queryText;
+                    Query();
                     // set to false so the subsequent set true triggers
                     // PropertyChanged and MoveQueryTextToEnd is called
                     QueryTextCursorMovedToEnd = false;
@@ -695,6 +695,7 @@ private ResultsViewModel SelectedResults
                     else
                     {
                         QueryText = string.Empty;
+                        Query();
                     }
                 }