Refactoring visibility related events

1. remove unnecessary events from MainViewModel
2. remove usage of Obsolete api (show, hide etc)
3. fix space problem in #660
4. part of #486
5. fix up/down key bug introduced in 92b7ca6a1bafd254e39ee92812ff691906cd85c1
6. fix #678

Plugins/Wox.Plugin.PluginManagement/Main.cs

@@ -152,7 +152,6 @@ namespace Wox.Plugin.PluginManagement
                             if (!Directory.Exists(folder)) Directory.CreateDirectory(folder);
                             string filePath = Path.Combine(folder, Guid.NewGuid().ToString() + ".wox");
 
-                            context.API.StartLoadingBar();
                             string pluginUrl = APIBASE + "/media/" + r1.plugin_file;
 
                             try
@@ -168,7 +167,6 @@ namespace Wox.Plugin.PluginManagement
                                 return false;
                             }
                             context.API.InstallPlugin(filePath);
-                            context.API.StopLoadingBar();
                         }
                         return false;
                     }

Plugins/Wox.Plugin.Shell/Main.cs

@@ -3,13 +3,14 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
-using System.Windows.Forms;
+using System.Windows;
 using WindowsInput;
-using WindowsInput.Native;
 using Wox.Infrastructure.Hotkey;
 using Wox.Infrastructure.Logger;
 using Wox.Infrastructure.Storage;
+using Application = System.Windows.Application;
 using Control = System.Windows.Controls.Control;
+using Keys = System.Windows.Forms.Keys;
 
 namespace Wox.Plugin.CMD
 {
@@ -191,7 +192,7 @@ namespace Wox.Plugin.CMD
             }
             else if (_settings.Shell == Shell.RunCommand)
             {
-                var parts = command.Split(new[] {' '}, 2);
+                var parts = command.Split(new[] { ' ' }, 2);
                 if (parts.Length == 2)
                 {
                     var filename = parts[0];
@@ -283,17 +284,16 @@ namespace Wox.Plugin.CMD
                 if (keyevent == (int)KeyEvent.WM_KEYUP && WinRStroked && vkcode == (int)Keys.LWin)
                 {
                     WinRStroked = false;
-                    keyboardSimulator.ModifiedKeyStroke(VirtualKeyCode.LWIN, VirtualKeyCode.CONTROL);
                     return false;
                 }
             }
-            return true;
+            return false;
         }
 
         private void OnWinRPressed()
         {
-            context.API.ShowApp();
             context.API.ChangeQuery($"{context.CurrentPluginMetadata.ActionKeywords[0]}{Plugin.Query.TermSeperater}");
+            Application.Current.MainWindow.Visibility = Visibility.Visible;
         }
 
         public Control CreateSettingPanel()
@@ -311,8 +311,6 @@ namespace Wox.Plugin.CMD
             return context.API.GetTranslation("wox_plugin_cmd_plugin_description");
         }
 
-        public bool IsInstantQuery(string query) => false;
-
         public List<Result> LoadContextMenus(Result selectedResult)
         {
             return new List<Result>
@@ -322,7 +320,6 @@ namespace Wox.Plugin.CMD
                             Title = context.API.GetTranslation("wox_plugin_cmd_run_as_administrator"),
                             Action = c =>
                             {
-                                context.API.HideApp();
                                 Execute(selectedResult.Title, true);
                                 return true;
                             },

Plugins/Wox.Plugin.Sys/Main.cs

@@ -161,7 +161,7 @@ namespace Wox.Plugin.Sys
                     IcoPath = "Images\\app.png",
                     Action = c =>
                     {
-                        context.API.CloseApp();
+                        Application.Current.MainWindow.Close();
                         return true;
                     }
                 },