Removing CustomTitleChanged event (#604)

* Dispatcher reviewed and improved.

* Minor refactoring.

* XtermTerminalView initialization simplified.

* Additionally simplifying XtermTerminalView initialization.

* Replacing SemaphoreSlim with lighter TaskCompletionSource.

* Some async/await simplification.

* Resize locking mechanism in XtermTerminalView simplified.

* Resize handling improved.

* Trivial change in a code comment.

* After merge fixes, and some minor changes.

* DelayedAction fixed and some UI bug fixed.

* Removing TerminalViewModel.CustomTitleChanged event because it's covered by PropertyChanged anyway.

FluentTerminal.App.ViewModels/MainViewModel.cs

@@ -15,8 +15,6 @@ using Windows.UI.Core;
 using FluentTerminal.App.ViewModels.Menu;
 using FluentTerminal.Models.Messages;
 using GalaSoft.MvvmLight.Command;
-using Windows.ApplicationModel.Core;
-using Windows.UI.Xaml;
 using FluentTerminal.App.ViewModels.Infrastructure;
 using System.Windows.Input;
 
@@ -377,9 +375,7 @@ namespace FluentTerminal.App.ViewModels
                     _applicationSettings, profile, ApplicationView, _dispatcherTimer, _clipboardService, terminalState);
 
                 terminal.PropertyChanged += Terminal_PropertyChanged;
-
                 terminal.Closed += OnTerminalClosed;
-                terminal.CustomTitleChanged += Terminal_CustomTitleChanged;
                 terminal.CloseLeftTabsRequested += Terminal_CloseLeftTabsRequested;
                 terminal.CloseRightTabsRequested += Terminal_CloseRightTabsRequested;
                 terminal.CloseOtherTabsRequested += Terminal_CloseOtherTabsRequested;
@@ -402,17 +398,26 @@ namespace FluentTerminal.App.ViewModels
             switch (e.PropertyName)
             {
                 case nameof(TerminalViewModel.ShellTitle):
+                case nameof(TerminalViewModel.TabTitle):
 
-                    if (terminalViewModel.IsSelected && !_applicationSettings.ShowCustomTitleInTitlebar)
-                    {
-                        ApplicationView.ExecuteOnUiThreadAsync(() => WindowTitle = terminalViewModel.ShellTitle,
-                            CoreDispatcherPriority.Low);
-                    }
+                    SetWindowTitle(terminalViewModel);
 
                     break;
             }
         }
 
+        // ReSharper disable once UnusedMethodReturnValue.Local
+        private Task SetWindowTitle(TerminalViewModel terminalViewModel)
+        {
+            return ApplicationView.ExecuteOnUiThreadAsync(() =>
+            {
+                WindowTitle = !_applicationSettings.ShowCustomTitleInTitlebar ||
+                              string.IsNullOrEmpty(terminalViewModel?.TabTitle)
+                    ? terminalViewModel?.ShellTitle
+                    : terminalViewModel.TabTitle;
+            }, CoreDispatcherPriority.Low);
+        }
+
         private async void Terminal_DuplicateTabRequested(object sender, EventArgs e)
         {
             if (sender is TerminalViewModel terminal)
@@ -462,35 +467,12 @@ namespace FluentTerminal.App.ViewModels
             }
         }
 
-        private void Terminal_CustomTitleChanged(object sender, string e)
-        {
-            if (sender is TerminalViewModel terminal)
-            {
-                if (terminal.IsSelected && _applicationSettings.ShowCustomTitleInTitlebar)
-                {
-                    if (string.IsNullOrWhiteSpace(e))
-                    {
-                        WindowTitle = terminal.ShellTitle;
-                    }
-                    else
-                    {
-                        WindowTitle = e;
-                    }
-                }
-            }
-        }
-
-        private void Terminal_ShellTitleChanged(object sender, string e)
-        {
-        }
-
         public async Task CloseAllTerminals()
         {
             foreach (var terminal in Terminals)
             {
                 terminal.PropertyChanged -= Terminal_PropertyChanged;
                 terminal.Closed -= OnTerminalClosed;
-                terminal.CustomTitleChanged -= Terminal_CustomTitleChanged;
                 terminal.CloseLeftTabsRequested -= Terminal_CloseLeftTabsRequested;
                 terminal.CloseRightTabsRequested -= Terminal_CloseRightTabsRequested;
                 terminal.CloseOtherTabsRequested -= Terminal_CloseOtherTabsRequested;
@@ -515,26 +497,19 @@ namespace FluentTerminal.App.ViewModels
 
             _applicationSettings = message.ApplicationSettings;
 
+            SetWindowTitle(SelectedTerminal);
+
             ApplicationView.ExecuteOnUiThreadAsync(() =>
             {
                 TabsPosition = message.ApplicationSettings.TabsPosition;
                 RaisePropertyChanged(nameof(ShowTabsOnTop));
                 RaisePropertyChanged(nameof(ShowTabsOnBottom));
+            });
 
-                if (message.ApplicationSettings.ShowCustomTitleInTitlebar)
-                {
-                    WindowTitle = SelectedTerminal?.TabTitle;
-                }
-                else
-                {
-                    WindowTitle = SelectedTerminal?.ShellTitle;
-                }
-
-                if (updateMenu)
-                {
-                    CreateMenuViewModel();
-                }
-            }, enforceNewSchedule:true);
+            if (updateMenu)
+            {
+                ApplicationView.ExecuteOnUiThreadAsync(CreateMenuViewModel, CoreDispatcherPriority.Low, true);
+            }
         }
 
         private async Task OnCloseRequest(object sender, CancelableEventArgs e)
@@ -579,7 +554,6 @@ namespace FluentTerminal.App.ViewModels
 
             terminal.PropertyChanged -= Terminal_PropertyChanged;
             terminal.Closed -= OnTerminalClosed;
-            terminal.CustomTitleChanged -= Terminal_CustomTitleChanged;
             terminal.CloseLeftTabsRequested -= Terminal_CloseLeftTabsRequested;
             terminal.CloseRightTabsRequested -= Terminal_CloseRightTabsRequested;
             terminal.CloseOtherTabsRequested -= Terminal_CloseOtherTabsRequested;

FluentTerminal.App.ViewModels/TerminalViewModel.cs

@@ -166,7 +166,6 @@ namespace FluentTerminal.App.ViewModels
         public event EventHandler<string> FindPreviousRequested;
         public event EventHandler SearchStarted;
         public event EventHandler<TerminalTheme> ThemeChanged;
-        public event EventHandler<string> CustomTitleChanged;
         public event EventHandler CloseLeftTabsRequested;
         public event EventHandler CloseRightTabsRequested;
         public event EventHandler CloseOtherTabsRequested;
@@ -336,10 +335,7 @@ namespace FluentTerminal.App.ViewModels
                     }
                 }
 
-                if (Set(ref _tabTitle, title))
-                {
-                    CustomTitleChanged?.Invoke(this, title);
-                }
+                Set(ref _tabTitle, title);
             }
         }
 
@@ -440,9 +436,9 @@ namespace FluentTerminal.App.ViewModels
 
         public ITerminalView TerminalView { get; set; }
 
-        public async Task<string> SerializeXtermState()
+        public Task<string> SerializeXtermState()
         {
-            return await TerminalView?.SerializeXtermState();
+            return TerminalView?.SerializeXtermState() ?? Task.FromResult(string.Empty);
         }
 
         private void FindPrevious()