feat: add ActivePluginsChanged event to DPI (closes #1192)

Dalamud/Game/ChatHandlers.cs

@@ -294,7 +294,7 @@ public class ChatHandlers : IServiceType
 
         this.hasAutoUpdatedPlugins = true;
 
-        Task.Run(() => pluginManager.UpdatePluginsAsync(true, !this.configuration.AutoUpdatePlugins)).ContinueWith(task =>
+        Task.Run(() => pluginManager.UpdatePluginsAsync(true, !this.configuration.AutoUpdatePlugins, true)).ContinueWith(task =>
         {
             if (task.IsFaulted)
             {

Dalamud/Plugin/DalamudPluginInterface.cs

@@ -88,11 +88,23 @@ public sealed class DalamudPluginInterface : IDisposable
     /// <param name="langCode">The new language code.</param>
     public delegate void LanguageChangedDelegate(string langCode);
 
+    /// <summary>
+    /// Delegate for events that listen to changes to the list of active plugins.
+    /// </summary>
+    /// <param name="kind">What action caused this event to be fired.</param>
+    /// <param name="affectedThisPlugin">If this plugin was affected by the change.</param>
+    public delegate void ActivePluginsChangedDelegate(PluginListInvalidationKind kind, bool affectedThisPlugin);
+
     /// <summary>
     /// Event that gets fired when loc is changed
     /// </summary>
     public event LanguageChangedDelegate LanguageChanged;
 
+    /// <summary>
+    /// Event that is fired when the active list of plugins is changed.
+    /// </summary>
+    public event ActivePluginsChangedDelegate ActivePluginsChanged;
+
     /// <summary>
     /// Gets the reason this plugin was loaded.
     /// </summary>
@@ -472,6 +484,16 @@ public sealed class DalamudPluginInterface : IDisposable
         // ignored
     }
 
+    /// <summary>
+    /// Dispatch the active plugins changed event.
+    /// </summary>
+    /// <param name="kind">What action caused this event to be fired.</param>
+    /// <param name="affectedThisPlugin">If this plugin was affected by the change.</param>
+    internal void NotifyActivePluginsChanged(PluginListInvalidationKind kind, bool affectedThisPlugin)
+    {
+        this.ActivePluginsChanged.Invoke(kind, affectedThisPlugin);
+    }
+
     private void OnLocalizationChanged(string langCode)
     {
         this.UiLanguage = langCode;

Dalamud/Plugin/Internal/PluginManager.cs

@@ -1063,8 +1063,9 @@ Thanks and have fun!";
     /// </summary>
     /// <param name="ignoreDisabled">Ignore disabled plugins.</param>
     /// <param name="dryRun">Perform a dry run, don't install anything.</param>
+    /// <param name="autoUpdate">If this action was performed as part of an auto-update.</param>
     /// <returns>Success or failure and a list of updated plugin metadata.</returns>
-    public async Task<List<PluginUpdateStatus>> UpdatePluginsAsync(bool ignoreDisabled, bool dryRun)
+    public async Task<List<PluginUpdateStatus>> UpdatePluginsAsync(bool ignoreDisabled, bool dryRun, bool autoUpdate = false)
     {
         Log.Information("Starting plugin update");
 
@@ -1089,6 +1090,9 @@ Thanks and have fun!";
         }
 
         this.NotifyInstalledPluginsChanged();
+        this.NotifyPluginsForStateChange(
+            autoUpdate ? PluginListInvalidationKind.AutoUpdate : PluginListInvalidationKind.Update,
+            updatedList.Select(x => x.InternalName));
 
         Log.Information("Plugin update OK.");
 
@@ -1391,6 +1395,20 @@ Thanks and have fun!";
         this.OnInstalledPluginsChanged?.InvokeSafely();
     }
 
+    private void NotifyPluginsForStateChange(PluginListInvalidationKind kind, IEnumerable<string> affectedInternalNames)
+    {
+        foreach (var installedPlugin in this.InstalledPlugins)
+        {
+            if (!installedPlugin.IsLoaded || installedPlugin.DalamudInterface == null)
+                continue;
+
+            installedPlugin.DalamudInterface.NotifyActivePluginsChanged(
+                kind,
+                // ReSharper disable once PossibleMultipleEnumeration
+                affectedInternalNames.Contains(installedPlugin.Manifest.InternalName));
+        }
+    }
+
     private static class Locs
     {
         public static string DalamudPluginUpdateSuccessful(string name, Version version) => Loc.Localize("DalamudPluginUpdateSuccessful", "    》 {0} updated to v{1}.").Format(name, version);

Dalamud/Plugin/PluginListInvalidationKind.cs

@@ -0,0 +1,17 @@
+namespace Dalamud.Plugin;
+
+/// <summary>
+/// Causes for a change to the plugin list.
+/// </summary>
+public enum PluginListInvalidationKind
+{
+    /// <summary>
+    /// An installer-initiated update reloaded plugins.
+    /// </summary>
+    Update,
+
+    /// <summary>
+    /// An auto-update reloaded plugins.
+    /// </summary>
+    AutoUpdate,
+}