Initial commit. Added interface. Testing with RadioGroup

Terminal.Gui/View/Orientation/IOrientation.cs

@@ -0,0 +1,127 @@
+
+namespace Terminal.Gui;
+using System;
+
+/// <summary>
+///     Implement this interface to provide orientation support.
+/// </summary>
+public interface IOrientation
+{
+    /// <summary>
+    ///     Gets or sets the orientation of the View.
+    /// </summary>
+    Orientation Orientation { get; set; }
+
+    /// <summary>
+    ///     Raised when <see cref="Orientation"/> is changing. Can be cancelled.
+    /// </summary>
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanging;
+
+    /// <summary>
+    ///     Called when <see cref="Orientation"/> is changing.
+    /// </summary>
+    /// <param name="currentOrientation">The current orienation.</param>
+    /// <param name="newOrientation">The new orienation.</param>
+    /// <returns><see langword="true"/> to cancel the change.</returns>
+    public bool OnOrientationChanging (Orientation currentOrientation, Orientation newOrientation) { return false; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanged;
+
+    /// <summary>
+    ///     Called when <see cref="Orientation"/> has been changed.
+    /// </summary>
+    /// <param name="oldOrientation"></param>
+    /// <param name="newOrientation"></param>
+    /// <returns></returns>
+    public void OnOrientationChanged (Orientation oldOrientation, Orientation newOrientation) { return; }
+}
+
+
+/// <summary>
+///     Helper class for implementing <see cref="IOrientation"/>.
+/// </summary>
+public class OrientationHelper
+{
+    private Orientation _orientation = Orientation.Vertical;
+    private readonly IOrientation _owner;
+
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="OrientationHelper"/> class.
+    /// </summary>
+    /// <param name="owner"></param>
+    public OrientationHelper (IOrientation owner)
+    {
+        _owner = owner;
+    }
+
+    /// <summary>
+    ///     Gets or sets the orientation of the View.
+    /// </summary>
+    public Orientation Orientation
+    {
+        get => _orientation;
+        set
+        {
+            var args = new CancelEventArgs<Orientation> (in _orientation, ref value);
+            OrientationChanging?.Invoke (_owner, args);
+            if (args.Cancel)
+            {
+                return;
+            }
+
+            if (_owner?.OnOrientationChanging (value, _orientation) ?? false)
+            {
+                return;
+            }
+
+            Orientation old = _orientation;
+            if (_orientation != value)
+            {
+                _orientation = value;
+                _owner.Orientation = value;
+            }
+
+            args = new CancelEventArgs<Orientation> (in old, ref _orientation);
+            OrientationChanged?.Invoke (_owner, args);
+
+            _owner?.OnOrientationChanged (old, _orientation);
+        }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanging;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="currentOrientation"></param>
+    /// <param name="newOrientation"></param>
+    /// <returns></returns>
+    protected bool OnOrientationChanging (Orientation currentOrientation, Orientation newOrientation)
+    {
+        return _owner?.OnOrientationChanging (currentOrientation, newOrientation) ?? false;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanged;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="oldOrientation"></param>
+    /// <param name="newOrientation"></param>
+    /// <returns></returns>
+    protected void OnOrientationChanged (Orientation oldOrientation, Orientation newOrientation)
+    {
+        _owner?.OnOrientationChanged (oldOrientation, newOrientation);
+    }
+}
+
+

Terminal.Gui/Views/OrientationEventArgs.cs

@@ -1,19 +0,0 @@
-namespace Terminal.Gui;
-
-/// <summary><see cref="EventArgs"/> for <see cref="Orientation"/> events.</summary>
-public class OrientationEventArgs : EventArgs
-{
-    /// <summary>Constructs a new instance.</summary>
-    /// <param name="orientation">the new orientation</param>
-    public OrientationEventArgs (Orientation orientation)
-    {
-        Orientation = orientation;
-        Cancel = false;
-    }
-
-    /// <summary>If set to true, the orientation change operation will be canceled, if applicable.</summary>
-    public bool Cancel { get; set; }
-
-    /// <summary>The new orientation.</summary>
-    public Orientation Orientation { get; set; }
-}

Terminal.Gui/Views/RadioGroup.cs

@@ -1,14 +1,14 @@
 namespace Terminal.Gui;
 
 /// <summary>Displays a group of labels each with a selected indicator. Only one of those can be selected at a given time.</summary>
-public class RadioGroup : View, IDesignable
+public class RadioGroup : View, IDesignable, IOrientation
 {
     private int _cursor;
     private List<(int pos, int length)> _horizontal;
     private int _horizontalSpace = 2;
-    private Orientation _orientation = Orientation.Vertical;
     private List<string> _radioLabels = [];
     private int _selected;
+    private readonly OrientationHelper _orientationHelper;
 
     /// <summary>
     ///     Initializes a new instance of the <see cref="RadioGroup"/> class.
@@ -103,6 +103,13 @@ public class RadioGroup : View, IDesignable
                         return true;
                     });
 
+        _orientationHelper = new OrientationHelper (this);
+        _orientationHelper.OrientationChanging += (sender, e) => OrientationChanging?.Invoke (this, e);
+        _orientationHelper.OrientationChanged += (sender, e) => OrientationChanged?.Invoke (this, e);
+
+        //OrientationChanging += (sender, e) => OnOrientationChanging (e.CurrentValue, e.NewValue);
+        //OrientationChanged += (sender, e) => OnOrientationChanged (e.CurrentValue, e.NewValue);
+
         SetupKeyBindings ();
 
         LayoutStarted += RadioGroup_LayoutStarted;
@@ -142,15 +149,15 @@ public class RadioGroup : View, IDesignable
         int viewportX = e.MouseEvent.Position.X;
         int viewportY = e.MouseEvent.Position.Y;
 
-        int pos = _orientation == Orientation.Horizontal ? viewportX : viewportY;
+        int pos = Orientation == Orientation.Horizontal ? viewportX : viewportY;
 
-        int rCount = _orientation == Orientation.Horizontal
+        int rCount = Orientation == Orientation.Horizontal
                          ? _horizontal.Last ().pos + _horizontal.Last ().length
                          : _radioLabels.Count;
 
         if (pos < rCount)
         {
-            int c = _orientation == Orientation.Horizontal
+            int c = Orientation == Orientation.Horizontal
                         ? _horizontal.FindIndex (x => x.pos <= viewportX && x.pos + x.length - 2 >= viewportX)
                         : viewportY;
 
@@ -173,7 +180,7 @@ public class RadioGroup : View, IDesignable
         get => _horizontalSpace;
         set
         {
-            if (_horizontalSpace != value && _orientation == Orientation.Horizontal)
+            if (_horizontalSpace != value && Orientation == Orientation.Horizontal)
             {
                 _horizontalSpace = value;
                 UpdateTextFormatterText ();
@@ -182,16 +189,6 @@ public class RadioGroup : View, IDesignable
         }
     }
 
-    /// <summary>
-    ///     Gets or sets the <see cref="Orientation"/> for this <see cref="RadioGroup"/>. The default is
-    ///     <see cref="Orientation.Vertical"/>.
-    /// </summary>
-    public Orientation Orientation
-    {
-        get => _orientation;
-        set => OnOrientationChanged (value);
-    }
-
     /// <summary>
     ///     The radio labels to display. A key binding will be added for each radio enabling the user to select
     ///     and/or focus the radio label using the keyboard. See <see cref="View.HotKey"/> for details on how HotKeys work.
@@ -323,30 +320,45 @@ public class RadioGroup : View, IDesignable
         }
     }
 
-    /// <summary>Called when the view orientation has changed. Invokes the <see cref="OrientationChanged"/> event.</summary>
-    /// <param name="newOrientation"></param>
-    /// <returns>True of the event was cancelled.</returns>
-    public virtual bool OnOrientationChanged (Orientation newOrientation)
+    /// <summary>
+    ///     Gets or sets the <see cref="Orientation"/> for this <see cref="RadioGroup"/>. The default is
+    ///     <see cref="Orientation.Vertical"/>.
+    /// </summary>
+    public Orientation Orientation
     {
-        var args = new OrientationEventArgs (newOrientation);
-        OrientationChanged?.Invoke (this, args);
-
-        if (!args.Cancel)
-        {
-            _orientation = newOrientation;
-            SetupKeyBindings ();
-            SetContentSize ();
-        }
-
-        return args.Cancel;
+        get => _orientationHelper.Orientation;
+        set => _orientationHelper.Orientation = value;
     }
 
+    #region IOrientation
+    /// <inheritdoc />
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanging;
+
+    /// <inheritdoc />
+    public bool OnOrientationChanging (Orientation currentOrientation, Orientation newOrientation)
+    {
+        return false;
+    }
+
+    /// <inheritdoc />
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanged;
+
+    /// <summary>Called when <see cref="Orientation"/> has changed.</summary>
+    /// <param name="oldOrientation"></param>
+    /// <param name="newOrientation"></param>
+    public void OnOrientationChanged (Orientation oldOrientation, Orientation newOrientation)
+    {
+        SetupKeyBindings ();
+        SetContentSize ();
+    }
+    #endregion IOrientation
+
     // TODO: This should be cancelable
     /// <summary>Called whenever the current selected item changes. Invokes the <see cref="SelectedItemChanged"/> event.</summary>
     /// <param name="selectedItem"></param>
     /// <param name="previousSelectedItem"></param>
     public virtual void OnSelectedItemChanged (int selectedItem, int previousSelectedItem)
-    { 
+    {
         if (_selected == selectedItem)
         {
             return;
@@ -355,12 +367,6 @@ public class RadioGroup : View, IDesignable
         SelectedItemChanged?.Invoke (this, new (selectedItem, previousSelectedItem));
     }
 
-    /// <summary>
-    ///     Fired when the view orientation has changed. Can be cancelled by setting
-    ///     <see cref="OrientationEventArgs.Cancel"/> to true.
-    /// </summary>
-    public event EventHandler<OrientationEventArgs> OrientationChanged;
-
     /// <inheritdoc/>
     public override Point? PositionCursor ()
     {
@@ -429,7 +435,7 @@ public class RadioGroup : View, IDesignable
 
     private void SetContentSize ()
     {
-        switch (_orientation)
+        switch (Orientation)
         {
             case Orientation.Vertical:
                 var width = 0;
@@ -469,3 +475,27 @@ public class RadioGroup : View, IDesignable
         return true;
     }
 }
+
+public class RadioGroupHorizontal : RadioGroup, IOrientation
+{
+    private bool _preventOrientationChange = false;
+    public RadioGroupHorizontal () : base ()
+    {
+        Orientation = Orientation.Horizontal;
+        _preventOrientationChange = true;
+
+        OrientationChanging += RadioGroupHorizontal_OrientationChanging;
+    }
+
+    private void RadioGroupHorizontal_OrientationChanging (object sender, CancelEventArgs<Orientation> e)
+    {
+        //e.Cancel = _preventOrientationChange;
+    }
+
+    /// <inheritdoc />
+    bool IOrientation.OnOrientationChanging (Orientation currrentOrientation, Orientation newOrientation)
+    {
+        return _preventOrientationChange;
+    }
+
+}

Terminal.Gui/Views/Slider.cs

@@ -310,17 +310,16 @@ public class Slider<T> : View
     #region Events
 
     /// <summary>
-    ///     Fired when the slider orientation has changed. Can be cancelled by setting
-    ///     <see cref="OrientationEventArgs.Cancel"/> to true.
+    ///     Fired when the slider orientation has changed. Can be cancelled.
     /// </summary>
-    public event EventHandler<OrientationEventArgs> OrientationChanged;
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanged;
 
     /// <summary>Called when the slider orientation has changed. Invokes the <see cref="OrientationChanged"/> event.</summary>
     /// <param name="newOrientation"></param>
     /// <returns>True of the event was cancelled.</returns>
     public virtual bool OnOrientationChanged (Orientation newOrientation)
     {
-        var args = new OrientationEventArgs (newOrientation);
+        var args = new CancelEventArgs<Orientation> (in _config._sliderOrientation, ref newOrientation);
         OrientationChanged?.Invoke (this, args);
 
         if (!args.Cancel)

UICatalog/Scenarios/ExpanderButton.cs

@@ -74,7 +74,7 @@ public class ExpanderButton : Button
     /// <returns>True of the event was cancelled.</returns>
     protected virtual bool OnOrientationChanging (Orientation newOrientation)
     {
-        var args = new OrientationEventArgs (newOrientation);
+        var args = new CancelEventArgs<Orientation> (in _orientation, ref newOrientation);
         OrientationChanging?.Invoke (this, args);
 
         if (!args.Cancel)
@@ -105,10 +105,9 @@ public class ExpanderButton : Button
     }
 
     /// <summary>
-    ///     Fired when the orientation has changed. Can be cancelled by setting
-    ///     <see cref="OrientationEventArgs.Cancel"/> to true.
+    ///     Fired when the orientation has changed. Can be cancelled.
     /// </summary>
-    public event EventHandler<OrientationEventArgs> OrientationChanging;
+    public event EventHandler<CancelEventArgs<Orientation>> OrientationChanging;
 
     /// <summary>
     ///     The glyph to display when the view is collapsed.