Declarative plugin management (#2180)

* Declarative plugin management

Allow declaring `plugin` entries in the hyprland configuration.

Plugins will be loaded if an entry is added and unloaded if that entry
is removed.

* Replace pointers with copying in updateconfigPlugins

* Include which plugin was declared twice in error

2 files changed, 39 insertions, 7 deletions

diff --git a/src/plugins/PluginSystem.cpp b/src/plugins/PluginSystem.cpp
index 73de9bf5..040cfcf1 100644
--- a/src/plugins/PluginSystem.cpp
+++ b/src/plugins/PluginSystem.cpp
@@ -119,6 +119,35 @@ void CPluginSystem::unloadAllPlugins() {
         unloadPlugin(p.get(), false); // Unload remaining plugins gracefully
 }
 
+std::vector<std::string> CPluginSystem::updateConfigPlugins(const std::vector<std::string>& plugins, bool& changed) {
+    std::vector<std::string> failures;
+
+    // unload all plugins that are no longer present
+    for (auto& p : m_vLoadedPlugins | std::views::reverse) {
+        if (p->m_bLoadedWithConfig && std::find(plugins.begin(), plugins.end(), p->path) == plugins.end()) {
+            Debug::log(LOG, "Unloading plugin %s which is no longer present in config", p->path.c_str());
+            unloadPlugin(p.get(), false);
+            changed = true;
+        }
+    }
+
+    // load all new plugins
+    for (auto& path : plugins) {
+        if (std::find_if(m_vLoadedPlugins.begin(), m_vLoadedPlugins.end(), [&](const auto& other) { return other->path == path; }) == m_vLoadedPlugins.end()) {
+            Debug::log(LOG, "Loading plugin %s which is now present in config", path.c_str());
+            const auto plugin = loadPlugin(path);
+
+            if (plugin) {
+                plugin->m_bLoadedWithConfig = true;
+                changed                     = true;
+            } else
+                failures.push_back(path);
+        }
+    }
+
+    return failures;
+}
+
 CPlugin* CPluginSystem::getPluginByPath(const std::string& path) {
     for (auto& p : m_vLoadedPlugins) {
         if (p->path == path)
diff --git a/src/plugins/PluginSystem.hpp b/src/plugins/PluginSystem.hpp
index 5d1a1532..0ef30bab 100644
--- a/src/plugins/PluginSystem.hpp
+++ b/src/plugins/PluginSystem.hpp
@@ -15,6 +15,8 @@ class CPlugin {
 
     std::string                                            path = "";
 
+    bool                                                   m_bLoadedWithConfig = false;
+
     HANDLE                                                 m_pHandle = nullptr;
 
     std::vector<IHyprLayout*>                              registeredLayouts;
@@ -27,14 +29,15 @@ class CPluginSystem {
   public:
     CPluginSystem();
 
-    CPlugin*              loadPlugin(const std::string& path);
-    void                  unloadPlugin(const CPlugin* plugin, bool eject = false);
-    void                  unloadAllPlugins();
-    CPlugin*              getPluginByPath(const std::string& path);
-    CPlugin*              getPluginByHandle(HANDLE handle);
-    std::vector<CPlugin*> getAllPlugins();
+    CPlugin*                 loadPlugin(const std::string& path);
+    void                     unloadPlugin(const CPlugin* plugin, bool eject = false);
+    void                     unloadAllPlugins();
+    std::vector<std::string> updateConfigPlugins(const std::vector<std::string>& plugins, bool& changed);
+    CPlugin*                 getPluginByPath(const std::string& path);
+    CPlugin*                 getPluginByHandle(HANDLE handle);
+    std::vector<CPlugin*>    getAllPlugins();
 
-    bool                  m_bAllowConfigVars = false;
+    bool                     m_bAllowConfigVars = false;
 
   private:
     std::vector<std::unique_ptr<CPlugin>> m_vLoadedPlugins;