Fixes #3691 - Adds ViewArrangement.Popover

Terminal.Gui/Application/Application.Initialization.cs

@@ -162,6 +162,8 @@ internal static void InternalInit (
 
         SynchronizationContext.SetSynchronizationContext (new MainLoopSyncContext ());
 
+        PopoverHost.Init ();
+
         MainThreadId = Thread.CurrentThread.ManagedThreadId;
         bool init = Initialized = true;
         InitializedChanged?.Invoke (null, new (init));

Terminal.Gui/Application/Application.Keyboard.cs

@@ -20,6 +20,14 @@ public static bool RaiseKeyDownEvent (Key key)
             return true;
         }
 
+        if (PopoverHost is { Visible: true })
+        {
+            if (PopoverHost.NewKeyDownEvent (key))
+            {
+                return true;
+            }
+        }
+
         if (Top is null)
         {
             foreach (Toplevel topLevel in TopLevels.ToList ())

Terminal.Gui/Application/Application.Mouse.cs

@@ -1,5 +1,6 @@
 #nullable enable
 using System.ComponentModel;
+using System.Diagnostics;
 
 namespace Terminal.Gui;
 
@@ -168,6 +169,22 @@ internal static void RaiseMouseEvent (MouseEventArgs mouseEvent)
             return;
         }
 
+        // Dismiss the Popover if the user clicked outside of it
+        if (PopoverHost is { Visible: true }
+            && View.IsInHierarchy (PopoverHost, deepestViewUnderMouse, includeAdornments: true) is false
+            && (mouseEvent.Flags.HasFlag (MouseFlags.Button1Pressed)
+                || mouseEvent.Flags.HasFlag (MouseFlags.Button2Pressed)
+                || mouseEvent.Flags.HasFlag (MouseFlags.Button3Pressed)))
+        {
+
+            PopoverHost.Visible = false;
+
+            // Recurse once
+            RaiseMouseEvent (mouseEvent);
+
+            return;
+        }
+
         if (HandleMouseGrab (deepestViewUnderMouse, mouseEvent))
         {
             return;
@@ -216,6 +233,7 @@ internal static void RaiseMouseEvent (MouseEventArgs mouseEvent)
         else
         {
             // The mouse was outside any View's Viewport.
+            //Debug.Fail ("this should not happen.");
 
             // Debug.Fail ("This should never happen. If it does please file an Issue!!");
 

Terminal.Gui/Application/Application.Popover.cs

@@ -0,0 +1,21 @@
+#nullable enable
+using static Unix.Terminal.Curses;
+
+namespace Terminal.Gui;
+
+public static partial class Application // Popover handling
+{
+    /// <summary>Gets the Application <see cref="PopoverHost"/>.</summary>
+    /// <remarks>
+    ///     <para>
+    ///         Any View added as a SubView will be a Popover.
+    ///     </para>
+    ///     <para>
+    ///         To show or hide a Popover, set the <see cref="View.Visible"/> property of the PopoverHost.
+    ///     </para>
+    ///     <para>
+    ///         If the user clicks anywhere not occulded by a SubView of the PopoverHost, the PopoverHost will be hidden.
+    ///     </para>
+    /// </remarks>
+    public static PopoverHost? PopoverHost { get; set; }
+}

Terminal.Gui/Application/Application.Run.cs

@@ -426,7 +426,16 @@ public static T Run<T> (Func<Exception, bool>? errorHandler = null, IConsoleDriv
 
     internal static void LayoutAndDrawImpl (bool forceDraw = false)
     {
-        bool neededLayout = View.Layout (TopLevels.Reverse (), Screen.Size);
+        List<View> tops = new (TopLevels);
+
+        if (PopoverHost is { Visible: true })
+        {
+            //PopoverHost.SetNeedsDraw();
+            //PopoverHost.SetNeedsLayout ();
+            tops.Insert (0, PopoverHost);
+        }
+
+        bool neededLayout = View.Layout (tops.ToArray ().Reverse (), Screen.Size);
 
         if (ClearScreenNextIteration)
         {
@@ -440,7 +449,7 @@ internal static void LayoutAndDrawImpl (bool forceDraw = false)
         }
 
         View.SetClipToScreen ();
-        View.Draw (TopLevels, neededLayout || forceDraw);
+        View.Draw (tops, neededLayout || forceDraw);
         View.SetClipToScreen ();
         Driver?.Refresh ();
     }
@@ -554,6 +563,7 @@ internal static void OnNotifyStopRunState (Toplevel top)
     public static void End (RunState runState)
     {
         ArgumentNullException.ThrowIfNull (runState);
+        PopoverHost.Cleanup();
 
         runState.Toplevel.OnUnloaded ();
 

Terminal.Gui/Application/Application.cs

@@ -103,6 +103,7 @@ internal static List<CultureInfo> GetAvailableCulturesFromEmbeddedResources ()
                        .ToList ();
     }
 
+    // BUGBUG: This does not return en-US even though it's supported by default
     internal static List<CultureInfo> GetSupportedCultures ()
     {
         CultureInfo [] cultures = CultureInfo.GetCultures (CultureTypes.AllCultures);
@@ -148,6 +149,8 @@ internal static void ResetState (bool ignoreDisposed = false)
             t!.Running = false;
         }
 
+        PopoverHost.Cleanup ();
+
         TopLevels.Clear ();
 #if DEBUG_IDISPOSABLE
 

Terminal.Gui/Application/ApplicationNavigation.cs

@@ -104,6 +104,10 @@ internal void SetFocused (View? value)
     /// </returns>
     public bool AdvanceFocus (NavigationDirection direction, TabBehavior? behavior)
     {
+        if (Application.PopoverHost is { Visible: true })
+        {
+            return Application.PopoverHost.AdvanceFocus (direction, behavior);
+        }
         return Application.Top is { } && Application.Top.AdvanceFocus (direction, behavior);
     }
 }

Terminal.Gui/Application/PopoverHost.cs

@@ -0,0 +1,106 @@
+#nullable enable
+using System.Diagnostics;
+using System.Net.Mime;
+using static System.Net.Mime.MediaTypeNames;
+
+namespace Terminal.Gui;
+
+/// <summary>
+///     Singleton View that hosts Views to be shown as Popovers. The host covers the whole screen and is transparent both
+///     visually and to the mouse. Set <see cref="View.Visible"/> to show or hide the Popovers.
+/// </summary>
+/// <remarks>
+///     <para>
+///         If the user clicks anywhere not occulded by a SubView of the PopoverHost, the PopoverHost will be hidden.
+///     </para>
+/// </remarks>
+public sealed class PopoverHost : View
+{
+    /// <summary>
+    ///     Initializes <see cref="Application.PopoverHost"/>.
+    /// </summary>
+    internal static void Init ()
+    {
+        // Setup PopoverHost
+        if (Application.PopoverHost is { })
+        {
+            throw new InvalidOperationException (@"PopoverHost is a singleton; Init and Cleanup must be balanced.");
+        }
+
+        Application.PopoverHost = new PopoverHost ();
+
+        // TODO: Add a diagnostic setting for this?
+        Application.PopoverHost.TextFormatter.VerticalAlignment = Alignment.End;
+        Application.PopoverHost.TextFormatter.Alignment = Alignment.End;
+        Application.PopoverHost.Text = "popoverHost";
+
+        Application.PopoverHost.BeginInit ();
+        Application.PopoverHost.EndInit ();
+    }
+
+    /// <summary>
+    ///     Cleans up <see cref="Application.PopoverHost"/>.
+    /// </summary>
+    internal static void Cleanup ()
+    {
+        Application.PopoverHost?.Dispose ();
+        Application.PopoverHost = null;
+    }
+
+
+    /// <summary>
+    ///     Creates a new instance.
+    /// </summary>
+    public PopoverHost ()
+    {
+        Id = "popoverHost";
+        CanFocus = true;
+        ViewportSettings = ViewportSettings.Transparent | ViewportSettings.TransparentMouse;
+        Width = Dim.Fill ();
+        Height = Dim.Fill ();
+        base.Visible = false;
+
+
+        AddCommand (Command.Quit, Quit);
+
+        bool? Quit (ICommandContext? ctx)
+        {
+            if (Visible)
+            {
+                Visible = false;
+
+                return true;
+            }
+
+            return null;
+        }
+
+        KeyBindings.Add (Application.QuitKey, Command.Quit);
+    }
+
+    /// <inheritdoc />
+    protected override bool OnClearingViewport () { return true; }
+
+    /// <inheritdoc />
+    protected override bool OnVisibleChanging ()
+    {
+        if (!Visible)
+        {
+            //ColorScheme ??= Application.Top?.ColorScheme;
+            //Frame = Application.Screen;
+
+            SetRelativeLayout (Application.Screen.Size);
+        }
+
+        return false;
+    }
+
+    /// <inheritdoc />
+    protected override void OnVisibleChanged ()
+    {
+        if (Visible)
+        {
+            SetFocus ();
+        }
+    }
+}

Terminal.Gui/ConsoleDrivers/AnsiResponseParser/AnsiMouseParser.cs

@@ -52,7 +52,7 @@ public bool IsMouse (string? cur)
                 Flags = GetFlags (buttonCode, terminator)
             };
 
-            Logging.Trace ($"{nameof (AnsiMouseParser)} handled as {input} mouse {m.Flags} at {m.Position}");
+            //Logging.Trace ($"{nameof (AnsiMouseParser)} handled as {input} mouse {m.Flags} at {m.Position}");
 
             return m;
         }

Terminal.Gui/ConsoleDrivers/V2/InputProcessor.cs

@@ -79,7 +79,7 @@ public void OnMouseEvent (MouseEventArgs a)
 
         foreach (MouseEventArgs e in _mouseInterpreter.Process (a))
         {
-            Logging.Trace ($"Mouse Interpreter raising {e.Flags}");
+           // Logging.Trace ($"Mouse Interpreter raising {e.Flags}");
 
             // Pass on
             MouseEvent?.Invoke (this, e);

Terminal.Gui/Input/Command.cs

@@ -14,6 +14,11 @@ namespace Terminal.Gui;
 /// </remarks>
 public enum Command
 {
+    /// <summary>
+    ///     Indicates the command is not bound or invalid. Will call <see cref="View.RaiseCommandNotBound"/>.
+    /// </summary>
+    NotBound = 0,
+
     #region Base View Commands
 
     /// <summary>

Terminal.Gui/View/View.Command.cs

@@ -14,6 +14,9 @@ public partial class View // Command APIs
     /// </summary>
     private void SetupCommands ()
     {
+        // NotBound - Invoked if no handler is bound
+        AddCommand (Command.NotBound, RaiseCommandNotBound);
+
         // Enter - Raise Accepted
         AddCommand (Command.Accept, RaiseAccepting);
 
@@ -50,6 +53,45 @@ private void SetupCommands ()
                                     });
     }
 
+    /// <summary>
+    ///     Called when a command that has not been bound is invoked.
+    /// </summary>
+    /// <returns>
+    ///     <see langword="null"/> if no event was raised; input processing should continue.
+    ///     <see langword="false"/> if the event was raised and was not handled (or cancelled); input processing should continue.
+    ///     <see langword="true"/> if the event was raised and handled (or cancelled); input processing should stop.
+    /// </returns>
+    protected bool? RaiseCommandNotBound (ICommandContext? ctx)
+    {
+        CommandEventArgs args = new () { Context = ctx };
+
+        // Best practice is to invoke the virtual method first.
+        // This allows derived classes to handle the event and potentially cancel it.
+        if (OnCommandNotBound (args) || args.Cancel)
+        {
+            return true;
+        }
+
+        // If the event is not canceled by the virtual method, raise the event to notify any external subscribers.
+        CommandNotBound?.Invoke (this, args);
+
+        return CommandNotBound is null ? null : args.Cancel;
+    }
+
+    /// <summary>
+    ///      Called when a command that has not been bound is invoked.
+    ///     Set CommandEventArgs.Cancel to
+    ///     <see langword="true"/> and return <see langword="true"/> to cancel the event. The default implementation does nothing.
+    /// </summary>
+    /// <param name="args">The event arguments.</param>
+    /// <returns><see langword="true"/> to stop processing.</returns>
+    protected virtual bool OnCommandNotBound (CommandEventArgs args) { return false; }
+
+    /// <summary>
+    ///     Cancelable event raised when a command that has not been bound is invoked.
+    /// </summary>
+    public event EventHandler<CommandEventArgs>? CommandNotBound;
+
     /// <summary>
     ///     Called when the user is accepting the state of the View and the <see cref="Command.Accept"/> has been invoked. Calls <see cref="OnAccepting"/> which can be cancelled; if not cancelled raises <see cref="Accepting"/>.
     ///     event. The default <see cref="Command.Accept"/> handler calls this method.
@@ -294,9 +336,7 @@ private void SetupCommands ()
         {
             if (!_commandImplementations.ContainsKey (command))
             {
-                throw new NotSupportedException (
-                                                 @$"A Binding was set up for the command {command} ({binding}) but that command is not supported by this View ({GetType ().Name})"
-                                                );
+                Logging.Warning (@$"{command} is not supported by this View ({GetType ().Name}). Binding: {binding}.");
             }
 
             // each command has its own return value
@@ -327,16 +367,15 @@ private void SetupCommands ()
     /// </returns>
     public bool? InvokeCommand<TBindingType> (Command command, TBindingType binding)
     {
-        if (_commandImplementations.TryGetValue (command, out CommandImplementation? implementation))
+        if (!_commandImplementations.TryGetValue (command, out CommandImplementation? implementation))
         {
-            return implementation (new CommandContext<TBindingType> ()
-            {
-                Command = command,
-                Binding = binding,
-            });
+            _commandImplementations.TryGetValue (Command.NotBound, out implementation);
         }
-
-        return null;
+        return implementation! (new CommandContext<TBindingType> ()
+        {
+            Command = command,
+            Binding = binding,
+        });
     }
 
     /// <summary>
@@ -350,11 +389,12 @@ private void SetupCommands ()
     /// </returns>
     public bool? InvokeCommand (Command command)
     {
-        if (_commandImplementations.TryGetValue (command, out CommandImplementation? implementation))
+        if (!_commandImplementations.TryGetValue (command, out CommandImplementation? implementation))
         {
-            return implementation (null);
+            _commandImplementations.TryGetValue (Command.NotBound, out implementation);
         }
 
-        return null;
+        return implementation! (null);
+
     }
 }