If the Work Orders list in the Help from (F1) is larger than the form and scroll bar was used to scroll down, status changes make the Work Orders tab go to the top again. Disturbing... This fix makes the form stay at the current scroll position. Also the case when switching tabs.

Author: sweiland-openrails

Source/RunActivity/Viewer3D/Popups/HelpWindow.cs

@@ -1160,6 +1160,18 @@ public override void TabAction()
 
         protected override ControlLayout Layout(ControlLayout layout)
         {
+            int scrollPosition = 0;
+            if (Tabs[ActiveTab].Vbox != null)
+            {
+                foreach (var control in Tabs[ActiveTab].Vbox.Controls)
+                {
+                    if (control is ControlLayoutScrollboxVertical controlLayoutScrollboxVertical)
+                    {
+                        scrollPosition = controlLayoutScrollboxVertical.GetScrollPosition();
+                    }
+                }
+            }
+
             var vbox = base.Layout(layout).AddLayoutVertical();
 
             if (Tabs.Count > 0)
@@ -1175,8 +1187,17 @@ protected override ControlLayout Layout(ControlLayout layout)
                 }
                 vbox.AddHorizontalSeparator();
                 Tabs[ActiveTab].Layout(vbox);
+
+                foreach (var control in vbox.Controls)
+                {
+                    if (control is ControlLayoutScrollboxVertical controlLayoutScrollboxVertical)
+                    {
+                        controlLayoutScrollboxVertical.SetScrollPosition(scrollPosition);
+                    }
+                }
             }
 
+            Tabs[ActiveTab].Vbox = vbox;
             return vbox;
         }
 
@@ -1202,12 +1223,14 @@ class TabData
             public readonly Tab Tab;
             public readonly string TabLabel;
             public readonly Action<ControlLayout> Layout;
+            public Orts.Viewer3D.Popups.ControlLayoutVertical Vbox;
 
             public TabData(Tab tab, string tabLabel, Action<ControlLayout> layout)
             {
                 Tab = tab;
                 TabLabel = tabLabel;
                 Layout = layout;
+                Vbox = null;
             }
         }
 

Source/RunActivity/Viewer3D/Popups/WindowControls.cs

@@ -587,6 +587,7 @@ protected ControlLayoutScrollbox(int width, int height)
 
         public abstract int ScrollSize { get; }
 
+        public abstract int GetScrollPosition();
         public abstract void SetScrollPosition(int position);
 
         internal RasterizerState ScissorTestEnable = new RasterizerState { ScissorTestEnable = true };
@@ -707,6 +708,11 @@ public override int ScrollSize
             }
         }
 
+        public override int GetScrollPosition()
+        {
+            return ScrollPosition;
+        }
+
         public override void SetScrollPosition(int position)
         {
             position = Math.Max(0, Math.Min(Math.Max(0, ScrollSize), position));
@@ -841,6 +847,11 @@ public override int ScrollSize
             }
         }
 
+        public override int GetScrollPosition()
+        {
+            return(ScrollPosition);
+        }
+
         public override void SetScrollPosition(int position)
         {
             position = Math.Max(0, Math.Min(Math.Max(0, ScrollSize), position));