Make OnMouseXX protected internal as a quick-fix workaround that at least makes them not public, so work can continue.

Terminal.Gui/Text/Autocomplete/PopupAutocomplete.PopUp.cs

@@ -14,7 +14,7 @@ public abstract partial class PopupAutocomplete
             WantMousePositionReports = true;
         }
 
-        public override bool OnMouseEvent (MouseEvent mouseEvent) { return _autoComplete.OnMouseEvent (mouseEvent); }
+        protected internal override bool OnMouseEvent  (MouseEvent mouseEvent) { return _autoComplete.OnMouseEvent (mouseEvent); }
 
         public override void OnDrawContent (Rectangle contentArea)
         {

Terminal.Gui/View/ViewMouse.cs

@@ -37,7 +37,7 @@ public partial class View
     /// </remarks>
     /// <param name="mouseEvent"></param>
     /// <returns><see langword="true"/>, if the event was handled, <see langword="false"/> otherwise.</returns>
-    public virtual bool OnMouseEnter (MouseEvent mouseEvent)
+    protected internal virtual bool OnMouseEnter (MouseEvent mouseEvent)
     {
         if (!Enabled)
         {
@@ -65,7 +65,7 @@ public partial class View
     /// </remarks>
     /// <param name="mouseEvent"></param>
     /// <returns><see langword="true"/>, if the event was handled, <see langword="false"/> otherwise.</returns>
-    public virtual bool OnMouseLeave (MouseEvent mouseEvent)
+    protected internal virtual bool OnMouseLeave (MouseEvent mouseEvent)
     {
         if (!Enabled)
         {
@@ -92,7 +92,7 @@ public partial class View
     /// </remarks>
     /// <param name="mouseEvent"></param>
     /// <returns><see langword="true"/>, if the event was handled, <see langword="false"/> otherwise.</returns>
-    public virtual bool OnMouseEvent (MouseEvent mouseEvent)
+    protected internal virtual bool OnMouseEvent (MouseEvent mouseEvent)
     {
         if (!Enabled)
         {

Terminal.Gui/Views/ColorPicker.cs

@@ -89,7 +89,7 @@ public class ColorPicker : View
     public event EventHandler<ColorEventArgs> ColorChanged;
 
     ///<inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (!me.Flags.HasFlag (MouseFlags.Button1Clicked) || !CanFocus)
         {

Terminal.Gui/Views/ComboBox.cs

@@ -243,7 +243,7 @@ public class ComboBox : View
     public event EventHandler Expanded;
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (me.X == Bounds.Right - 1
             && me.Y == Bounds.Top
@@ -794,7 +794,7 @@ public class ComboBox : View
             set => _hideDropdownListOnClick = WantContinuousButtonPressed = value;
         }
 
-        public override bool OnMouseEvent (MouseEvent me)
+        protected internal override bool OnMouseEvent  (MouseEvent me)
         {
             var res = false;
             bool isMousePositionValid = IsMousePositionValid (me);

Terminal.Gui/Views/DateField.cs

@@ -114,7 +114,7 @@ public class DateField : TextField
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent ev)
+    protected internal override bool OnMouseEvent  (MouseEvent ev)
     {
         bool result = base.OnMouseEvent (ev);
 

Terminal.Gui/Views/HexView.cs

@@ -262,7 +262,7 @@ public class HexView : View
     public event EventHandler<HexViewEditEventArgs> Edited;
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         // BUGBUG: Test this with a border! Assumes Frame == Bounds!
 

Terminal.Gui/Views/ListView.cs

@@ -347,7 +347,7 @@ public class ListView : View
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (!me.Flags.HasFlag (MouseFlags.Button1Clicked)
             && !me.Flags.HasFlag (MouseFlags.Button1DoubleClicked)

Terminal.Gui/Views/Menu/Menu.cs

@@ -1183,7 +1183,7 @@ internal sealed class Menu : View
         _host?.SetNeedsDisplay ();
     }
 
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (!_host._handled && !_host.HandleGrabView (me, this))
         {

Terminal.Gui/Views/Menu/MenuBar.cs

@@ -1647,7 +1647,7 @@ public class MenuBar : View
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (!_handled && !HandleGrabView (me, this))
         {

Terminal.Gui/Views/RadioGroup.cs

@@ -161,7 +161,7 @@ public class RadioGroup : View
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (!me.Flags.HasFlag (MouseFlags.Button1Clicked))
         {

Terminal.Gui/Views/ScrollBarView.cs

@@ -275,7 +275,7 @@ public class ScrollBarView : View
     public event EventHandler ChangedPosition;
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent mouseEvent)
+    protected internal override bool OnMouseEvent  (MouseEvent mouseEvent)
     {
         if (mouseEvent.Flags != MouseFlags.Button1Pressed
             && mouseEvent.Flags != MouseFlags.Button1DoubleClicked

Terminal.Gui/Views/ScrollView.cs

@@ -384,7 +384,7 @@ public class ScrollView : View
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (me.Flags == MouseFlags.WheeledDown && ShowVerticalScrollIndicator)
         {

Terminal.Gui/Views/Slider.cs

@@ -1522,7 +1522,7 @@ public class Slider<T> : View
     private Point? _moveRenderPosition;
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent mouseEvent)
+    protected internal override bool OnMouseEvent  (MouseEvent mouseEvent)
     {
         // Note(jmperricone): Maybe we click to focus the cursor, and on next click we set the option.
         //                    That will makes OptionFocused Event more relevant.

Terminal.Gui/Views/StatusBar.cs

@@ -142,7 +142,7 @@ public class StatusBar : View
     }
 
     ///<inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (me.Flags != MouseFlags.Button1Clicked)
         {

Terminal.Gui/Views/TabView.cs

@@ -590,7 +590,7 @@ public class TabView : View
             Add (_rightScrollIndicator, _leftScrollIndicator);
         }
 
-        public override bool OnMouseEvent (MouseEvent me)
+        protected internal override bool OnMouseEvent  (MouseEvent me)
         {
             Tab hit = me.View is Tab ? (Tab)me.View : null;
 

Terminal.Gui/Views/TableView/TableView.cs

@@ -787,7 +787,7 @@ public class TableView : View
     }
 
     ///<inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         if (!me.Flags.HasFlag (MouseFlags.Button1Clicked)
             && !me.Flags.HasFlag (MouseFlags.Button1DoubleClicked)

Terminal.Gui/Views/TextField.cs

@@ -846,7 +846,7 @@ public class TextField : View
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent ev)
+    protected internal override bool OnMouseEvent  (MouseEvent ev)
     {
         if (!ev.Flags.HasFlag (MouseFlags.Button1Pressed)
             && !ev.Flags.HasFlag (MouseFlags.ReportMousePosition)

Terminal.Gui/Views/TextValidateField.cs

@@ -533,7 +533,7 @@ namespace Terminal.Gui
         }
 
         /// <inheritdoc/>
-        public override bool OnMouseEvent (MouseEvent mouseEvent)
+        protected internal override bool OnMouseEvent  (MouseEvent mouseEvent)
         {
             if (mouseEvent.Flags.HasFlag (MouseFlags.Button1Pressed))
             {

Terminal.Gui/Views/TextView.cs

@@ -3319,7 +3319,7 @@ public class TextView : View
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent ev)
+    protected internal override bool OnMouseEvent  (MouseEvent ev)
     {
         if (!ev.Flags.HasFlag (MouseFlags.Button1Clicked)
             && !ev.Flags.HasFlag (MouseFlags.Button1Pressed)

Terminal.Gui/Views/TileView.cs

@@ -901,7 +901,7 @@ public class TileView : View
             }
         }
 
-        public override bool OnMouseEvent (MouseEvent mouseEvent)
+        protected internal override bool OnMouseEvent  (MouseEvent mouseEvent)
         {
             if (!dragPosition.HasValue && mouseEvent.Flags == MouseFlags.Button1Pressed)
             {

Terminal.Gui/Views/TimeField.cs

@@ -163,7 +163,7 @@ public class TimeField : TextField
     }
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent ev)
+    protected internal override bool OnMouseEvent  (MouseEvent ev)
     {
         bool result = base.OnMouseEvent (ev);
 

Terminal.Gui/Views/Toplevel.cs

@@ -237,7 +237,7 @@ public partial class Toplevel : View
     public event EventHandler Loaded;
 
     /// <inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent mouseEvent)
+    protected internal override bool OnMouseEvent  (MouseEvent mouseEvent)
     {
         if (!CanFocus)
         {

Terminal.Gui/Views/TreeView/TreeView.cs

@@ -1002,7 +1002,7 @@ public class TreeView<T> : View, ITreeView where T : class
     public bool IsSelected (T model) { return Equals (SelectedObject, model) || (MultiSelect && multiSelectedRegions.Any (s => s.Contains (model))); }
 
     ///<inheritdoc/>
-    public override bool OnMouseEvent (MouseEvent me)
+    protected internal override bool OnMouseEvent  (MouseEvent me)
     {
         // If it is not an event we care about
         if (!me.Flags.HasFlag (MouseFlags.Button1Clicked)

UICatalog/Scenarios/LineDrawing.cs

@@ -84,7 +84,7 @@ public class LineDrawing : Scenario
             return false;
         }
 
-        public override bool OnMouseEvent (MouseEvent mouseEvent)
+        protected override bool OnMouseEvent (MouseEvent mouseEvent)
         {
             if (mouseEvent.Flags.HasFlag (MouseFlags.Button1Pressed))
             {