Add integration settings sections

Penumbra/UI/Integration/IntegrationSettingsRegistry.cs

@@ -0,0 +1,110 @@
+using Dalamud.Plugin;
+using OtterGui.Services;
+using OtterGui.Text;
+using Penumbra.Api.Enums;
+
+namespace Penumbra.UI.Integration;
+
+public sealed class IntegrationSettingsRegistry : IService, IDisposable
+{
+    private readonly IDalamudPluginInterface _pluginInterface;
+    
+    private readonly List<(string InternalName, string Name, Action Draw)> _sections = [];
+
+    private bool _disposed = false;
+
+    public IntegrationSettingsRegistry(IDalamudPluginInterface pluginInterface)
+    {
+        _pluginInterface = pluginInterface;
+        
+        _pluginInterface.ActivePluginsChanged += OnActivePluginsChanged;
+    }
+
+    public void Dispose()
+    {
+        _disposed = true;
+        
+        _pluginInterface.ActivePluginsChanged -= OnActivePluginsChanged;
+        
+        _sections.Clear();
+    }
+
+    public void Draw()
+    {
+        foreach (var (internalName, name, draw) in _sections)
+        {
+            if (!ImUtf8.CollapsingHeader($"Integration with {name}###IntegrationSettingsHeader.{internalName}"))
+                continue;
+
+            using var id = ImUtf8.PushId($"IntegrationSettings.{internalName}");
+            try
+            {
+                draw();
+            }
+            catch (Exception e)
+            {
+                Penumbra.Log.Error($"Error while drawing {internalName} integration settings: {e}");
+            }
+        }
+    }
+
+    public PenumbraApiEc RegisterSection(Action draw)
+    {
+        if (_disposed)
+            return PenumbraApiEc.SystemDisposed;
+        
+        var plugin = GetPlugin(draw);
+        if (plugin is null)
+            return PenumbraApiEc.InvalidArgument;
+
+        var section = (plugin.InternalName, plugin.Name, draw);
+        
+        var index = FindSectionIndex(plugin.InternalName);
+        if (index >= 0)
+        {
+            if (_sections[index] == section)
+                return PenumbraApiEc.NothingChanged;
+            _sections[index] = section;
+        }
+        else
+            _sections.Add(section);
+        _sections.Sort((lhs, rhs) => string.Compare(lhs.Name, rhs.Name, StringComparison.CurrentCultureIgnoreCase));
+
+        return PenumbraApiEc.Success;
+    }
+
+    public bool UnregisterSection(Action draw)
+    {
+        var index = FindSectionIndex(draw);
+        if (index < 0)
+            return false;
+        
+        _sections.RemoveAt(index);
+        return true;
+    }
+
+    private void OnActivePluginsChanged(IActivePluginsChangedEventArgs args)
+    {
+        if (args.Kind is PluginListInvalidationKind.Loaded)
+            return;
+
+        foreach (var internalName in args.AffectedInternalNames)
+        {
+            var index = FindSectionIndex(internalName);
+            if (index >= 0 && GetPlugin(_sections[index].Draw) is null)
+            {
+                _sections.RemoveAt(index);
+                Penumbra.Log.Warning($"Removed stale integration setting section of {internalName} (reason: {args.Kind})");
+            }
+        }
+    }
+
+    private IExposedPlugin? GetPlugin(Delegate @delegate)
+        => null; // TODO Use IDalamudPluginInterface.GetPlugin(Assembly) when it's in Dalamud stable.
+
+    private int FindSectionIndex(string internalName)
+        => _sections.FindIndex(section => section.InternalName.Equals(internalName, StringComparison.Ordinal));
+
+    private int FindSectionIndex(Action draw)
+        => _sections.FindIndex(section => section.Draw == draw);
+}