Import the source code for Window Walker (#1177)

Import the codebase for Window Walker 

- Not loaded into the module list 
- Not added it to the installer list.

src/modules/windowwalker/app/Window Walker/ViewModels/WindowWalkerViewModel.cs

@@ -0,0 +1,283 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.  Code forked from Betsegaw Tadele's https://github.com/betsegaw/windowwalker/
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Windows.Interop;
+using Microsoft.Win32;
+using WindowWalker.Components;
+using WindowWalker.MVVMHelpers;
+
+namespace WindowWalker.ViewModels
+{
+    internal class WindowWalkerViewModel : PropertyChangedBase
+    {
+        private readonly HotKeyHandler _hotKeyHandler;
+        private readonly List<string> _hints = new List<string>()
+        {
+            "search...",
+            "you can reinvoke this app using CTRL + WIN",
+        };
+
+        private string _searchText = string.Empty;
+        private List<SearchResult> _results = new List<SearchResult>();
+        private SearchResult _selectedWindow;
+        private bool _windowVisibility = true;
+        private string _hint = string.Empty;
+        private int _hintCounter = 0;
+
+        private void WireCommands()
+        {
+            SwitchToSelectedWindowCommand = new RelayCommand(SwitchToSelectedWindow)
+            {
+                IsEnabled = true,
+            };
+            WindowNavigateToNextResultCommand = new RelayCommand(WindowNavigateToNextResult)
+            {
+                IsEnabled = true,
+            };
+            WindowNavigateToPreviousResultCommand = new RelayCommand(WindowNavigateToPreviousResult)
+            {
+                IsEnabled = true,
+            };
+            WindowHideCommand = new RelayCommand(WindowHide)
+            {
+                IsEnabled = true,
+            };
+            WindowShowCommand = new RelayCommand(WindowShow)
+            {
+                IsEnabled = true,
+            };
+        }
+
+        public string SearchText
+        {
+            get => _searchText;
+
+            set
+            {
+                if (_searchText != value)
+                {
+                    _searchText = value;
+                    SearchController.Instance.SearchText = value;
+                    NotifyPropertyChanged("SearchText");
+                }
+            }
+        }
+
+        public string Hint
+        {
+            get => _hint;
+
+            set
+            {
+                if (_hint != value)
+                {
+                    _hint = value;
+                    NotifyPropertyChanged("Hint");
+                }
+            }
+        }
+
+        public List<SearchResult> Results
+        {
+            get => _results;
+
+            set
+            {
+                if (_results != value)
+                {
+                    _results = value;
+                    NotifyPropertyChanged("Results");
+                }
+            }
+        }
+
+        public SearchResult SelectedWindowResult
+        {
+            get => _selectedWindow;
+            set
+            {
+                if (_selectedWindow != value)
+                {
+                    _selectedWindow = value;
+                    WindowResultSelected();
+                    NotifyPropertyChanged("SelectedWindowResult");
+                }
+            }
+        }
+
+        public IntPtr Hwnd { get; private set; }
+
+        public bool WindowVisibility
+        {
+            get
+            {
+                return _windowVisibility;
+            }
+
+            set
+            {
+                if (_windowVisibility != value)
+                {
+                    _windowVisibility = value;
+                    NotifyPropertyChanged("WindowVisibility");
+                }
+            }
+        }
+
+        public RelayCommand SwitchToSelectedWindowCommand
+        {
+            get;
+            private set;
+        }
+
+        public RelayCommand WindowNavigateToNextResultCommand
+        {
+            get;
+            private set;
+        }
+
+        public RelayCommand WindowNavigateToPreviousResultCommand
+        {
+            get;
+            private set;
+        }
+
+        public RelayCommand WindowHideCommand
+        {
+            get;
+            private set;
+        }
+
+        public RelayCommand WindowShowCommand
+        {
+            get;
+            private set;
+        }
+
+        public WindowWalkerViewModel(System.Windows.Window mainWindow)
+        {
+            // The path to the key where Windows looks for startup applications
+            RegistryKey rkApp = Registry.CurrentUser.OpenSubKey(
+                                @"SOFTWARE\Microsoft\Windows\CurrentVersion\Run", true);
+
+            // Path to launch shortcut
+            string startPath = Environment.GetFolderPath(Environment.SpecialFolder.Programs)
+                               + @"\WindowWalker\WindowWalker.appref-ms";
+
+            rkApp.SetValue("WindowWalker", startPath);
+
+            rkApp.Close();
+
+            SearchController.Instance.OnSearchResultUpdate += SearchResultUpdated;
+            OpenWindows.Instance.UpdateOpenWindowsList();
+            Hwnd = new WindowInteropHelper(mainWindow).Handle;
+            LivePreview.SetWindowExlusionFromLivePreview(Hwnd);
+
+            _hotKeyHandler = new HotKeyHandler(mainWindow);
+            _hotKeyHandler.OnHotKeyPressed += HotKeyPressedHandler;
+
+            _hints.AddRange(Commands.GetTips());
+            Hint = _hints[_hintCounter];
+
+            WireCommands();
+        }
+
+        private void HotKeyPressedHandler(object sender, EventArgs e)
+        {
+            if (SearchText == string.Empty && WindowVisibility)
+            {
+                WindowHide();
+            }
+            else
+            {
+                WindowShow();
+            }
+        }
+
+        private void WindowResultSelected()
+        {
+            if (SelectedWindowResult != null)
+            {
+                LivePreview.ActivateLivePreview(SelectedWindowResult.Result.Hwnd, Hwnd);
+            }
+        }
+
+        private void WindowNavigateToPreviousResult()
+        {
+            if (SelectedWindowResult == null && Results.Count > 0)
+            {
+                SelectedWindowResult = Results.Last();
+                return;
+            }
+
+            if (Results.Count > 0)
+            {
+                SelectedWindowResult = Results[(Results.IndexOf(SelectedWindowResult) + Results.Count - 1) % Results.Count];
+            }
+        }
+
+        private void WindowNavigateToNextResult()
+        {
+            if (SelectedWindowResult == null && Results.Count > 0)
+            {
+                SelectedWindowResult = Results.First();
+                return;
+            }
+
+            if (Results.Count > 0)
+            {
+                SelectedWindowResult = Results[(Results.IndexOf(SelectedWindowResult) + 1) % Results.Count];
+            }
+        }
+
+        private void WindowHide()
+        {
+            LivePreview.DeactivateLivePreview();
+            WindowVisibility = false;
+            ApplicationUpdates.InstallUpdateSyncWithInfo();
+        }
+
+        private void WindowShow()
+        {
+            _hintCounter = (_hintCounter + 1) % _hints.Count;
+            Hint = _hints[_hintCounter];
+
+            SearchText = string.Empty;
+            OpenWindows.Instance.UpdateOpenWindowsList();
+            LivePreview.DeactivateLivePreview();
+            WindowVisibility = true;
+            InteropAndHelpers.SetForegroundWindow(Hwnd);
+        }
+
+        public void SwitchToSelectedWindow()
+        {
+            if (SearchText.StartsWith(":"))
+            {
+                LivePreview.DeactivateLivePreview();
+                WindowHide();
+                Commands.ProcessCommand(SearchText);
+            }
+            else if (SelectedWindowResult != null)
+            {
+                LivePreview.DeactivateLivePreview();
+                SelectedWindowResult.Result.SwitchToWindow();
+                WindowHide();
+            }
+            else if (Results != null && Results.Count > 0)
+            {
+                LivePreview.DeactivateLivePreview();
+                Results.First().Result.SwitchToWindow();
+                WindowHide();
+            }
+        }
+
+        private void SearchResultUpdated(object sender, SearchController.SearchResultUpdateEventArgs e)
+        {
+            Results = SearchController.Instance.SearchMatches;
+        }
+    }
+}