Show scroll bars at full width, drop the log status bar

- Turn off scroll bar auto-hide for ScrollViewer and DataGrid.
- Make the splitter between the two log grids 5 px, in the grid line color.
- Remove the log window status bar. The stats are in the entry window.
- Show a refused log edit in an alert dialog.
- Keep the log grid's rows in an ObservableCollection, so a new contact
  does not rebuild the list and move the view.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Nonemm.App/App.axaml

@@ -16,6 +16,17 @@
         <FluentTheme />
         <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Fluent.xaml" />
 
+        <!-- the Fluent scroll bar shrinks to a thin line until the pointer is
+             over it -->
+        <Style Selector="ScrollBar">
+            <Setter Property="AllowAutoHide" Value="False" />
+        </Style>
+        <Style Selector="ScrollViewer">
+            <Setter Property="AllowAutoHide" Value="False" />
+        </Style>
+        <Style Selector="DataGrid">
+            <Setter Property="ScrollViewer.AllowAutoHide" Value="False" />
+        </Style>
         <Style Selector="Window">
             <Setter Property="Background" Value="{DynamicResource FormBackground}" />
             <Setter Property="Foreground" Value="{DynamicResource FormForeground}" />

src/Nonemm.App/Dialogs/AlertDialog.axaml

@@ -0,0 +1,11 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:Class="Nonemm.App.Dialogs.AlertDialog"
+        Width="380" SizeToContent="Height"
+        WindowStartupLocation="CenterOwner" CanResize="False">
+  <DockPanel Margin="14">
+    <Button DockPanel.Dock="Bottom" Content="OK" HorizontalAlignment="Right" Margin="0,12,0,0"
+            Click="OnClose" IsDefault="True" IsCancel="True" />
+    <TextBlock Name="MessageText" TextWrapping="Wrap" />
+  </DockPanel>
+</Window>

src/Nonemm.App/Dialogs/AlertDialog.axaml.cs

@@ -0,0 +1,16 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+
+namespace Nonemm.App.Dialogs;
+
+public sealed partial class AlertDialog : Window
+{
+    public AlertDialog(string title, string message)
+    {
+        InitializeComponent();
+        Title = title;
+        MessageText.Text = message;
+    }
+
+    private void OnClose(object? sender, RoutedEventArgs e) => Close();
+}

src/Nonemm.App/Windows/LogWindow.Columns.cs

@@ -91,8 +91,6 @@ public sealed partial class LogWindow
         }
         else if (next.Count == 0)
         {
-            message = "the log needs at least one column";
-            Refresh();
             return;
         }
         Store(LogColumns.Store(next));

src/Nonemm.App/Windows/LogWindow.axaml

@@ -5,7 +5,6 @@
         x:Class="Nonemm.App.Windows.LogWindow"
         Title="Log" Width="1000" Height="420">
   <DockPanel>
-    <TextBlock DockPanel.Dock="Bottom" Name="SummaryText" Margin="8,4" FontSize="11" Opacity="0.75" />
     <Grid RowDefinitions="2*,Auto,*">
       <Grid.Styles>
         <!-- the DataGrid's own font settings do not reach the cells, and the
@@ -55,7 +54,7 @@
       </Grid.Styles>
       <DataGrid Name="Rows" Grid.Row="0" GridLinesVisibility="Horizontal" CanUserSortColumns="True"
                 CanUserReorderColumns="True" FontSize="12" FontFamily="{x:Static theming:Fonts.Mono}" />
-      <GridSplitter Grid.Row="1" Height="3" ResizeDirection="Rows" />
+      <GridSplitter Grid.Row="1" Height="5" ResizeDirection="Rows" Background="{DynamicResource DataGridGridLinesBrush}" />
       <DataGrid Name="Earlier" Grid.Row="2" IsReadOnly="True" GridLinesVisibility="Horizontal"
                 CanUserSortColumns="False" HeadersVisibility="None"
                 FontSize="12" FontFamily="{x:Static theming:Fonts.Mono}" />

src/Nonemm.App/Windows/LogWindow.axaml.cs

@@ -1,6 +1,8 @@
+using System.Collections.ObjectModel;
 using Avalonia;
 using Avalonia.Collections;
 using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Threading;
@@ -19,11 +21,10 @@ namespace Nonemm.App.Windows;
 public sealed partial class LogWindow : RefreshableWindow
 {
     private readonly AppSession session;
-    private string message = "";
     /// The lines the grid is showing. They are kept and given the contact again
     /// when only the values changed, so that an edit does not rebuild the list
     /// and move the view.
-    private List<LogRow> shownRows = [];
+    private ObservableCollection<LogRow> shownRows = [];
     /// The contacts the operator picked, by id. The grid is told to show them
     /// as picked only while this window is in front: a marked line in a window
     /// behind says nothing about where the keyboard is.
@@ -190,33 +191,42 @@ public sealed partial class LogWindow : RefreshableWindow
         {
             Rows.ItemsSource = Array.Empty<LogRow>();
             Earlier.ItemsSource = Array.Empty<LogRow>();
-            SummaryText.Text = "no contest is open";
             return;
         }
         BuildColumns(session.Logging.Editor);
         IReadOnlyList<Qso> qsos = session.Logging.Log.Qsos;
-        if (SameContacts(qsos))
+        if (Rows.ItemsSource is DataGridCollectionView shown && shown.SourceCollection == shownRows && StartsWithShown(qsos))
         {
-            for (int at = 0; at < qsos.Count; at++)
+            // an edit, or contacts added at the end: the grid keeps its list, so
+            // the view stays where it is and an open editing box stays open
+            bool atBottom = ScrolledToBottom();
+            for (int at = 0; at < shownRows.Count; at++)
             {
                 shownRows[at].Show(qsos[at], VerdictFor(qsos[at]));
             }
-            Recolour(Rows);
-        }
-        else
-        {
             bool grown = qsos.Count > shownRows.Count;
-            Qso? bottom = BottomOfView();
+            for (int at = shownRows.Count; at < qsos.Count; at++)
-            shownRows = qsos.Select(q => new LogRow(q, VerdictFor(q))).ToList();
-            Rows.ItemsSource = Sorted(shownRows);
-            if (grown && shownRows.Count > 0)
             {
-                Rows.ScrollIntoView(shownRows[^1], null);
+                // the grid puts the row where the sort says
+                shownRows.Add(new LogRow(qsos[at], VerdictFor(qsos[at])));
+            }
+            Recolour(Rows);
+            // the view follows a new contact only when it was at the foot of
+            // the list; at the top the new row appears without a scroll
+            if (grown && atBottom && Rows.ItemsSource is DataGridCollectionView view && view.Count > 0)
+            {
+                object last = view.GetItemAt(view.Count - 1);
+                Dispatcher.UIThread.Post(() => Rows.ScrollIntoView(last, null), DispatcherPriority.Loaded);
+            }
         }
         else
         {
+            // a contact was deleted or moved: the list is built again, which
+            // puts the view at the top, so it is wound back
+            Qso? bottom = BottomOfView();
+            shownRows = new ObservableCollection<LogRow>(qsos.Select(q => new LogRow(q, VerdictFor(q))));
+            Rows.ItemsSource = Sorted(shownRows);
             ShowAgain(bottom, shownRows);
-            }
             // the new list comes with nothing picked
             if (IsActive)
             {
@@ -225,20 +235,18 @@ public sealed partial class LogWindow : RefreshableWindow
         }
         FollowQuickEdit();
         ShowEarlier();
-        SummaryText.Text = message.Length > 0 ? message : Summary(session.Logging);
-        message = "";
     }
 
-    /// True when the log holds the same contacts, in the same order, as the
+    /// True when the grid's lines are the first contacts of the log, in the
-    /// grid is showing. An edit leaves the list itself alone; logging or
+    /// same order. An edit leaves the list itself alone and logging a contact
-    /// deleting a contact does not.
+    /// adds one at the end; deleting a contact does neither.
-    private bool SameContacts(IReadOnlyList<Qso> qsos)
+    private bool StartsWithShown(IReadOnlyList<Qso> qsos)
     {
-        if (qsos.Count != shownRows.Count)
+        if (qsos.Count < shownRows.Count)
         {
             return false;
         }
-        for (int at = 0; at < qsos.Count; at++)
+        for (int at = 0; at < shownRows.Count; at++)
         {
             if (qsos[at].Id != shownRows[at].Qso.Id)
             {
@@ -262,6 +270,13 @@ public sealed partial class LogWindow : RefreshableWindow
         }
     }
 
+    private ScrollBar? VerticalBar =>
+        Rows.GetVisualDescendants().OfType<ScrollBar>()
+            .FirstOrDefault(b => b.Orientation == Avalonia.Layout.Orientation.Vertical);
+
+    /// True when the view is at the foot of the list, or when the list fits.
+    private bool ScrolledToBottom() => VerticalBar is not { } bar || bar.Value >= bar.Maximum - 0.5;
+
     /// The contact drawn at the foot of the view, or null when the log is empty
     /// or has not been drawn yet. Setting `ItemsSource` puts the view back at
     /// the top, so this is what the view is wound back to afterwards.
@@ -330,10 +345,6 @@ public sealed partial class LogWindow : RefreshableWindow
             }
         };
 
-    private static string Summary(ContestSession logging) =>
-        $"{logging.Log.Tally.Qsos} contacts · {logging.Log.Tally.Points} points · " +
-        $"{logging.Log.Tally.TotalMultipliers} multipliers · score {logging.Log.TotalScore:N0}";
-
     /// N1MM's Ctrl+F: shows the next contact with this call and selects it,
     /// starting again from the top once the last one has been shown. Null when
     /// the call is not in the log.
@@ -380,9 +391,8 @@ public sealed partial class LogWindow : RefreshableWindow
         Dispatcher.UIThread.Post(() => Edit(row.Qso, column.Field, text));
     }
 
-    /// A refused edit puts the reason in the summary line and the cell falls
+    /// A refused edit leaves the cell as it was and shows the reason.
-    /// back to what it held before.
+    private async void Edit(Qso qso, QsoField field, string text)
-    private void Edit(Qso qso, QsoField field, string text)
     {
         if (session.Logging is null)
         {
@@ -391,7 +401,7 @@ public sealed partial class LogWindow : RefreshableWindow
         QsoEdit edit = session.Logging.Edit(qso.Id, field, text);
         if (!edit.IsAccepted)
         {
-            SummaryText.Text = edit.Error;
+            await new AlertDialog("Edit refused", edit.Error).ShowDialog(this);
         }
     }
 
@@ -436,8 +446,6 @@ public sealed partial class LogWindow : RefreshableWindow
         List<Qso> picked = [.. Rows.SelectedItems.OfType<LogRow>().Select(r => r.Qso)];
         if (picked.Count == 0)
         {
-            message = "pick the contacts to change first";
-            Refresh();
             return;
         }
         string was = picked[0].Operator.Length > 0 ? picked[0].Operator : session.Settings.CurrentOperator;
@@ -450,9 +458,6 @@ public sealed partial class LogWindow : RefreshableWindow
         {
             session.Logging.Edit(qso.Id, QsoField.Operator, callsign);
         }
-        message = picked.Count == 1
-            ? $"1 contact logged by {callsign}"
-            : $"{picked.Count} contacts logged by {callsign}";
         Refresh();
     }
 
@@ -470,7 +475,6 @@ public sealed partial class LogWindow : RefreshableWindow
         if (await dialog.ShowDialog<bool>(this))
         {
             session.Logging.Delete(row.Qso.Id);
-            message = $"{row.Qso.Call.Text} deleted";
             Refresh();
         }
     }