Check that the plugin that returned the result actually put in a selection action in there

src/modules/launcher/Plugins/Wox.Plugin.WindowWalker/Components/InteropAndHelpers.cs

@@ -838,5 +838,8 @@ namespace Wox.Plugin.WindowWalker.Components
         [DllImport("user32.dll", SetLastError = true)]
         [return: MarshalAs(UnmanagedType.Bool)]
         public static extern bool GetWindowPlacement(IntPtr hWnd, out WINDOWPLACEMENT lpwndpl);
+
+        [DllImport("user32.dll", CharSet = CharSet.Unicode)]
+        public static extern IntPtr GetForegroundWindow();
     }
 }

src/modules/launcher/Plugins/Wox.Plugin.WindowWalker/Main.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
+using System.Windows.Interop;
 using Wox.Plugin.WindowWalker.Components;
 
 namespace Wox.Plugin.WindowWalker
@@ -29,7 +30,17 @@ namespace Wox.Plugin.WindowWalker
                 {
                     x.Result.SwitchToWindow();
                     return true;
-                }
+                },
+                SelectionAction = c =>
+                {
+                    var excludeWindowHandle =
+                        OpenWindows.Instance.Windows
+                            .Where(window => window.Title == "PopupHost" 
+                                && window.ProcessName == "PowerLauncher.exe").First().Hwnd;
+
+                    LivePreview.ActivateLivePreview(x.Result.Hwnd, excludeWindowHandle);
+                    return null;
+                },
             }
             ).ToList();
         }

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

@@ -8,7 +8,8 @@
     ActualThemeChanged="UserControl_ActualThemeChanged"
     Loaded="UserControl_Loaded"
     d:DesignHeight="300"
-    d:DesignWidth="720">
+    d:DesignWidth="720"
+    PreviewKeyDown="OnKeyDown">
     <UserControl.Resources>
 
         <Style TargetType="TextBox" x:Key="CustomAutoSuggestBoxTextBoxStyle">

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

@@ -33,6 +33,38 @@ namespace PowerLauncher.UI
             OnPropertyChanged(propertyName);
         }
 
+        private void OnKeyDown(object sender, Windows.UI.Xaml.Input.KeyRoutedEventArgs e)
+        {
+            var NextResultCommand = this.DataContext.GetType().GetMethod("get_SelectNextItemCommand").Invoke(this.DataContext, new object[] { });
+            var NextResult = NextResultCommand.GetType().GetMethod("Execute");
+
+            var PreviousResultCommand = this.DataContext.GetType().GetMethod("get_SelectPrevItemCommand").Invoke(this.DataContext, new object[] { });
+            var PreviousResult = PreviousResultCommand.GetType().GetMethod("Execute");
+
+            var NextPageResultCommand = this.DataContext.GetType().GetMethod("get_SelectNextPageCommand").Invoke(this.DataContext, new object[] { });
+            var NextPageResult = NextResultCommand.GetType().GetMethod("Execute");
+
+            var PreviousPageResultCommand = this.DataContext.GetType().GetMethod("get_SelectPrevPageCommand").Invoke(this.DataContext, new object[] { });
+            var PreviousPageResult = PreviousResultCommand.GetType().GetMethod("Execute");
+
+            if (e.Key == Windows.System.VirtualKey.Down)
+            {
+                NextResult.Invoke(NextResultCommand, new object[] { null });
+            }
+            else if (e.Key == Windows.System.VirtualKey.Up)
+            {
+                PreviousResult.Invoke(PreviousResultCommand, new object[] { null });
+            }
+            else if (e.Key == Windows.System.VirtualKey.PageDown)
+            {
+                NextPageResult.Invoke(NextPageResultCommand, new object[] { null });
+            }
+            else if (e.Key == Windows.System.VirtualKey.PageUp)
+            {
+                PreviousPageResult.Invoke(PreviousPageResultCommand, new object[] { null });
+            }
+        }
+
         private void UserControl_ActualThemeChanged(FrameworkElement sender, object args)
         {
             SolidBorderBrush = Application.Current.Resources["SystemChromeLow"] as SolidColorBrush;
@@ -46,5 +78,5 @@ namespace PowerLauncher.UI
         public event PropertyChangedEventHandler PropertyChanged;
 
         private void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
-    }
+    }
 }

src/modules/launcher/Wox.Plugin/Result.cs

@@ -44,6 +44,11 @@ namespace Wox.Plugin
         /// </summary>
         public Func<ActionContext, bool> Action { get; set; }
 
+        /// <summary>
+        /// Highlighted Action
+        /// </summary>
+        public Func<ActionContext, string> SelectionAction { get; set; }
+
         public int Score { get; set; }
 
         /// <summary>

src/modules/launcher/Wox/PublicAPIInstance.cs

@@ -152,7 +152,7 @@ namespace Wox
                 return GlobalKeyboardEvent((int)keyevent, vkcode, state);
             }
             return true;
-        }
+        }
         #endregion
     }
 }

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

@@ -6,7 +6,7 @@ using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Data;
 using System.Windows.Documents;
-using System.Windows.Input;
+using System.Windows.Input;
 using Wox.Infrastructure.UserSettings;
 using Wox.Plugin;
 
@@ -18,6 +18,10 @@ namespace Wox.ViewModel
 
         public ResultCollection Results { get; }
 
+        private ResultViewModel _selectedItem;
+
+        private int _selectedIndex;
+
         private readonly object _addResultsLock = new object();
         private readonly object _collectionLock = new object();
         private readonly Settings _settings;
@@ -46,33 +50,49 @@ namespace Wox.ViewModel
 
         public int MaxHeight => MaxResults * 50;
 
-        public int SelectedIndex { get; set; }
-
-        private ResultViewModel _selectedItem;
-        public ResultViewModel SelectedItem
+        public int SelectedIndex
         {
-            get { return _selectedItem; }
-            set
-            {
-                //value can be null when selecting an item in a virtualized list
-                if (value != null)
-                {
-                    if (_selectedItem != null)
-                    {
-                        _selectedItem.DeactivateContextButtons(ResultViewModel.ActivationType.Selection);
-                    }
-
-                    _selectedItem = value;
-                    _selectedItem.ActivateContextButtons(ResultViewModel.ActivationType.Selection);
-                }
-                else
-                {
-                    _selectedItem = value;
-                }
+            get
+            {
+                return _selectedIndex;
+            }
+
+            set
+            {
+                if (value != _selectedIndex)
+                {
+                    _selectedIndex = value;
+                    SelectedItem = Results[_selectedIndex];
+                }
             }
         }
 
+        public ResultViewModel SelectedItem
+        {
+            get { return _selectedItem; }
+            set
+            {
+                //value can be null when selecting an item in a virtualized list
+                if (value != null)
+                {
+                    if (_selectedItem != null)
+                    {
+                        _selectedItem.DeactivateContextButtons(ResultViewModel.ActivationType.Selection);
+                    }
 
+                    _selectedItem = value;
+                    _selectedItem.ActivateContextButtons(ResultViewModel.ActivationType.Selection);
+                    if (_selectedItem.Result.SelectionAction != null)
+                    {
+                        _selectedItem.Result.SelectionAction(new ActionContext());
+                    }
+                }
+                else
+                {
+                    _selectedItem = value;
+                }
+            }
+        }
 
         public Thickness Margin { get; set; }
         public Visibility Visbility { get; set; } = Visibility.Hidden;
@@ -153,26 +173,26 @@ namespace Wox.ViewModel
         public void RemoveResultsFor(PluginMetadata metadata)
         {
             Results.RemoveAll(r => r.Result.PluginID == metadata.ID);
-        }
-
-        public void SelectNextTabItem()
-        {
-            if(!SelectedItem.SelectNextContextButton())
-            {
-                SelectNextResult();
-            }
-        }
-
-        public void SelectPrevTabItem()
-        {
-            if (!SelectedItem.SelectPrevContextButton())
-            {
-                //Tabbing backwards should highlight the last item of the previous row
-                SelectPrevResult();
-                SelectedItem.SelectLastContextButton();
-            }
-        }
-
+        }
+
+        public void SelectNextTabItem()
+        {
+            if(!SelectedItem.SelectNextContextButton())
+            {
+                SelectNextResult();
+            }
+        }
+
+        public void SelectPrevTabItem()
+        {
+            if (!SelectedItem.SelectPrevContextButton())
+            {
+                //Tabbing backwards should highlight the last item of the previous row
+                SelectPrevResult();
+                SelectedItem.SelectLastContextButton();
+            }
+        }
+
         /// <summary>
         /// To avoid deadlock, this method should not called from main thread
         /// </summary>