Fixing gap in logic where query was triggering when programatically setting text.

Updating the binding and settext both will trigger the TextChanged event on a seperate event dispatcher.  For this reason we dynamically detect which eventhandler is most approapriate on the textchanging event.

src/modules/launcher/PowerLauncher.UI/LauncherControl.xaml

@@ -375,7 +375,6 @@
             x:FieldModifier="public"
             Style="{StaticResource CustomAutoSuggestBoxTextBoxStyle}"
             PlaceholderText="Start typing"
-            Text="{Binding QueryText}"
             Height="60"
             ScrollViewer.BringIntoViewOnFocusChange="False"
             Canvas.ZIndex="0"

src/modules/launcher/PowerLauncher/MainWindow.xaml.cs

@@ -22,6 +22,7 @@ using System.Threading.Tasks;
 using Windows.UI.Xaml;
 using Windows.UI.Core;
 using System.Windows.Media;
+using Windows.UI.Xaml.Data;
 
 namespace PowerLauncher
 {
@@ -33,11 +34,10 @@ namespace PowerLauncher
         private readonly Storyboard _progressBarStoryboard = new Storyboard();
         private Settings _settings;
         private MainViewModel _viewModel;
-
+        private bool _isTextSetProgramatically;
         const int ROW_COUNT = 4;
         const int ROW_HEIGHT = 75;
         const int MAX_LIST_HEIGHT = 300;
-
         #endregion
 
         public MainWindow(Settings settings, MainViewModel mainVM)
@@ -60,6 +60,7 @@ namespace PowerLauncher
 
         private void OnInitialized(object sender, EventArgs e)
         {
+
         }
 
         private void OnLoaded(object sender, System.Windows.RoutedEventArgs _)
@@ -153,7 +154,7 @@ namespace PowerLauncher
             _launcher = (PowerLauncher.UI.LauncherControl)host.Child;
             _launcher.DataContext = _viewModel;
             _launcher.KeyDown += _launcher_KeyDown;
-            _launcher.TextBox.TextChanged += QueryTextBox_TextChanged;
+            _launcher.TextBox.TextChanging += QueryTextBox_TextChanging;
             _launcher.TextBox.Loaded += TextBox_Loaded;
             _launcher.PropertyChanged += UserControl_PropertyChanged;
             _viewModel.PropertyChanged += (o, e) =>
@@ -177,9 +178,16 @@ namespace PowerLauncher
                         }
                     }
                 }
+                else if(e.PropertyName == nameof(MainViewModel.SystemQueryText))
+                {
+                    this._isTextSetProgramatically = true;
+                    _launcher.TextBox.Text = _viewModel.SystemQueryText;
+                }
             };           
         }
 
+       
+
         private void UserControl_PropertyChanged(object sender, PropertyChangedEventArgs e)
         {
             if (e.PropertyName == "SolidBorderBrush")
@@ -347,8 +355,36 @@ namespace PowerLauncher
             return String.Empty;
         }
 
+        private void QueryTextBox_TextChanging(TextBox sender, TextBoxTextChangingEventArgs args)
+        {
+            ClearAllQueryTextChangedHanlders();
+          
+            if(this._isTextSetProgramatically)
+            {
+                this._launcher.TextBox.TextChanged += QueryTextBox_TextChangedProgramatically;
+            }
+            else
+            {
+                this._launcher.TextBox.TextChanged += QueryTextBox_TextChangedByUserInput;
+            }
+        }
 
-        private void QueryTextBox_TextChanged(object sender, Windows.UI.Xaml.Controls.TextChangedEventArgs e)
+        private void ClearAllQueryTextChangedHanlders()
+        {
+            this._launcher.TextBox.TextChanged -= QueryTextBox_TextChangedProgramatically;
+            this._launcher.TextBox.TextChanged -= QueryTextBox_TextChangedByUserInput;
+        }
+
+        private void QueryTextBox_TextChangedProgramatically(object sender, Windows.UI.Xaml.Controls.TextChangedEventArgs e)
+        {
+            var textBox = ((Windows.UI.Xaml.Controls.TextBox)sender);
+            textBox.SelectionStart = textBox.Text.Length;
+
+            this._isTextSetProgramatically = false;
+        }
+
+
+        private void QueryTextBox_TextChangedByUserInput(object sender, Windows.UI.Xaml.Controls.TextChangedEventArgs e)
         {
             var text = ((Windows.UI.Xaml.Controls.TextBox)sender).Text;
             //To clear the auto-suggest immediately instead of waiting for selection changed
@@ -357,19 +393,11 @@ namespace PowerLauncher
                 _launcher.AutoCompleteTextBox.PlaceholderText = String.Empty;
             }
 
-            if (_viewModel.QueryTextUpdateBySystem)
+            _viewModel.QueryText = text;
-            {
+            var latestTimeOfTyping = DateTime.Now;
-                _launcher.TextBox.SelectionStart = _launcher.TextBox.Text.Length;
-                _viewModel.QueryTextUpdateBySystem = false;
-            }
-            else
-            {
-                _viewModel.QueryText = text;
-                var latestTimeOfTyping = DateTime.Now;
 
-                Task.Run(() => DelayedCheck(latestTimeOfTyping, text));
+            Task.Run(() => DelayedCheck(latestTimeOfTyping, text));
-                s_lastTimeOfTyping = latestTimeOfTyping;
+            s_lastTimeOfTyping = latestTimeOfTyping;
-            }
         }
 
         private async Task DelayedCheck(DateTime latestTimeOfTyping, string text)
@@ -378,13 +406,13 @@ namespace PowerLauncher
             if (latestTimeOfTyping.Equals(s_lastTimeOfTyping))
             {
                 await System.Windows.Application.Current.Dispatcher.BeginInvoke(new Action(() =>
-                 {
+                {
-                     _viewModel.Query();
+                    _viewModel.Query();
-                 }));               
+                }));
             }
         }
 
-        private void WindowsXamlHost_PreviewMouseDown(object sender, MouseButtonEventArgs e)
+private void WindowsXamlHost_PreviewMouseDown(object sender, MouseButtonEventArgs e)
         {
             //    if (sender != null && e.OriginalSource != null)
             //    {

src/modules/launcher/Wox/ViewModel/MainViewModel.cs

@@ -236,16 +236,15 @@ namespace Wox.ViewModel
         /// <param name="requery">Optional Parameter that if true, will automatically execute a query against the updated text</param>
         public void ChangeQueryText(string queryText, bool requery=false)
         {
-            QueryTextUpdateBySystem = true;
+            SystemQueryText = queryText;
-            QueryText = queryText;
+            
-
             if(requery)
             {
-               Query();
+                QueryText = queryText;
+                Query();
             }
         }
         public bool LastQuerySelected { get; set; }
-        public bool QueryTextUpdateBySystem { get; set; }
 
         private ResultsViewModel _selectedResults;
         private ResultsViewModel SelectedResults