Two themes, and one place that decides what colour a station is

Colours came from static brushes scattered over the windows. They now come
from a Theme, and everything that paints a station, a spot or a log row
asks Themes.Current as it paints, so changing the theme changes every
window without reopening it.

light is N1MM's own palette, read out of ApplicationStyles: the pale blue
behind a window, ivory on a button, white boxes, and the four colours a
station is painted in. dark is the same states in colours for a dark
screen, which is roughly what the program looked like before.

Config > Manage Skins, Colors and Fonts picks one, under N1MM's name for
the same dialog, and shows what each theme paints a callsign. The choice
is kept in settings.json as Theme, and light is the default.

The window chrome follows through resources the Fluent controls read, so a
text box and a button take the theme's colours in every state. Fonts and
skins are not part of it.

Looked at under Xvfb in both themes: the entry window, the theme dialog,
and the log window with its rows still coloured by what each contact was
worth.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

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

@@ -3,6 +3,7 @@ using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Media;
 using Avalonia.Platform.Storage;
+using Nonemm.App.Theming;
 using Nonemm.Core;
 using Nonemm.Session;
 
@@ -22,13 +23,13 @@ public sealed partial class MessagesDialog : Window
 
     /// The three banks of function keys, coloured so the editor shows which
     /// line is which key.
-    private static readonly IBrush Blue = new SolidColorBrush(Color.FromRgb(0x29, 0x80, 0xB9));
+    private static IBrush Blue => Themes.Brush(Themes.Current.Worth);
 
-    private static readonly IBrush Green = new SolidColorBrush(Color.FromRgb(0x27, 0xAE, 0x60));
+    private static IBrush Green => Themes.Brush(Themes.Current.Multipliers);
 
-    private static readonly IBrush Red = new SolidColorBrush(Color.FromRgb(0xC0, 0x39, 0x2B));
+    private static IBrush Red => Themes.Brush(Themes.Current.Multiplier);
 
-    private static readonly IBrush Grey = new SolidColorBrush(Color.FromRgb(0x7F, 0x8C, 0x8D));
+    private static IBrush Grey => Themes.Brush(Themes.Current.Dupe);
 
     private readonly ModeCategory mode;
 

src/Nonemm.App/Dialogs/ThemeDialog.axaml

@@ -0,0 +1,27 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:Class="Nonemm.App.Dialogs.ThemeDialog"
+        Title="Colors" Width="360" SizeToContent="Height"
+        WindowStartupLocation="CenterOwner" CanResize="False">
+  <DockPanel Margin="14">
+    <StackPanel DockPanel.Dock="Bottom" Orientation="Horizontal" HorizontalAlignment="Center"
+                Spacing="30" Margin="0,14,0,0">
+      <Button Content="Ok" Width="85" HorizontalContentAlignment="Center"
+              Click="OnOk" IsDefault="True" />
+      <Button Content="Cancel" Width="85" HorizontalContentAlignment="Center"
+              Click="OnCancel" IsCancel="True" />
+    </StackPanel>
+    <StackPanel Spacing="8">
+      <TextBlock Text="Colors" FontSize="11" />
+      <ComboBox Name="ThemeBox" HorizontalAlignment="Stretch" SelectionChanged="OnPicked" />
+      <TextBlock Name="AboutText" FontSize="11" TextWrapping="Wrap" />
+      <ItemsControl Name="Swatches" Margin="0,4,0,0">
+        <ItemsControl.ItemsPanel>
+          <ItemsPanelTemplate>
+            <WrapPanel />
+          </ItemsPanelTemplate>
+        </ItemsControl.ItemsPanel>
+      </ItemsControl>
+    </StackPanel>
+  </DockPanel>
+</Window>

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

@@ -0,0 +1,65 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using Avalonia.Layout;
+using Avalonia.Media;
+using Nonemm.App.Theming;
+
+namespace Nonemm.App.Dialogs;
+
+/// Which colours the program paints with. N1MM keeps skins, colours and fonts
+/// in one place; this picks between the themes that ship with the program and
+/// shows what each one paints a station.
+public sealed partial class ThemeDialog : Window
+{
+    public ThemeDialog(string current)
+    {
+        InitializeComponent();
+        ThemeBox.ItemsSource = Themes.All.Select(Label).ToList();
+        ThemeBox.SelectedIndex = Math.Max(0, Themes.All.ToList().FindIndex(t => t.Name == Themes.Find(current).Name));
+    }
+
+    private Theme Picked => Themes.All[Math.Max(0, ThemeBox.SelectedIndex)];
+
+    private static string Label(Theme theme) => theme.Name switch
+    {
+        "light" => "Light — N1MM's own colours",
+        "dark" => "Dark — for operating at night",
+        _ => theme.Name,
+    };
+
+    private void OnPicked(object? sender, SelectionChangedEventArgs e) => ShowSwatches();
+
+    private void ShowSwatches()
+    {
+        Theme theme = Picked;
+        AboutText.Text = "What a station is painted in the callsign box, left to right: worth " +
+                         "working, one new multiplier, more than one, a dupe.";
+        Swatches.ItemsSource = new[]
+        {
+            Swatch(theme.Worth, theme.FieldBackground),
+            Swatch(theme.Multiplier, theme.FieldBackground),
+            Swatch(theme.Multipliers, theme.FieldBackground),
+            Swatch(theme.Dupe, theme.FieldBackground),
+        };
+    }
+
+    private static Border Swatch(Color text, Color background) => new()
+    {
+        Background = new SolidColorBrush(background),
+        Width = 66,
+        Height = 26,
+        Margin = new Avalonia.Thickness(0, 0, 6, 6),
+        Child = new TextBlock
+        {
+            Text = "OM3KFF",
+            FontSize = 11,
+            Foreground = new SolidColorBrush(text),
+            HorizontalAlignment = HorizontalAlignment.Center,
+            VerticalAlignment = VerticalAlignment.Center,
+        },
+    };
+
+    private void OnOk(object? sender, RoutedEventArgs e) => Close(Picked.Name);
+
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(null);
+}