feat: initial draft of lifecycle events API for plugins

src/slic3r/plugin/PluginHooks.cpp

@@ -7,6 +7,7 @@
 
 #include "libslic3r/Config.hpp"
 #include "libslic3r/Exception.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 #include "libslic3r/Print.hpp"
 #include "libslic3r_version.h"
 
@@ -46,6 +47,16 @@ void install_capability_resolver()
     });
 }
 
+// Global libslic3r-side seam (Slic3r::fire_lifecycle_event, in libslic3r/LifecycleEvents.hpp):
+// broadcasts to every loaded, enabled capability regardless of type, unlike the SlicingPipeline
+// hook below which only targets picker-selected SlicingPipeline capabilities.
+void install_lifecycle_event_hook()
+{
+    set_lifecycle_hook_fn([](LifecycleEvent event, const LifecycleEventContext& ctx) {
+        PluginManager::instance().dispatch_lifecycle_event(event, ctx);
+    });
+}
+
 // Print::process() fires this hook at each pipeline seam on the slicing worker
 // thread; here we run the picker-selected SlicingPipeline capabilities. Per
 // capability we acquire the GIL, honor cancellation, and convert a plugin
@@ -122,12 +133,14 @@ void install()
 {
     install_capability_resolver();
     install_slicing_pipeline_hook();
+    install_lifecycle_event_hook();
 }
 
 void uninstall()
 {
     ConfigBase::set_resolve_capability_fn(nullptr);
     Print::set_slicing_pipeline_hook_fn(nullptr);
+    set_lifecycle_hook_fn(nullptr);
 }
 
 } // namespace Slic3r::plugin_hooks

src/slic3r/plugin/PluginManager.cpp

@@ -1,5 +1,6 @@
 #include "PluginManager.hpp"
 
+#include <exception>
 #include <libslic3r/Utils.hpp>
 #include <memory>
 #include <pybind11/embed.h>
@@ -1987,4 +1988,24 @@ ExecutionResult PluginManager::run_script_capability(const std::string& plugin_k
     return result;
 }
 
+void PluginManager::dispatch_lifecycle_event(LifecycleEvent evt, const LifecycleEventContext& ctx) {
+    for (const auto& cap : get_plugin_capabilities()) {
+        if (!cap || !cap->is_enabled()) continue;
+        try {
+            cap->on_lifecycle_event(evt, ctx);
+        } catch (const std::exception& ex) {
+            BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << ": plugin '" << cap->audit_plugin_key() << "/" << cap->name()
+                                       << "' on_lifecycle_event(" << lifecycle_event_to_string(evt) << ") threw: " << ex.what()
+                                       << " [ctx name='" << ctx.name << "', code=" << lifecycle_evt_code_to_string(ctx.code)
+                                       << ", msg='" << ctx.msg << "']";
+        } catch (...) {
+            BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << ": plugin '" << cap->audit_plugin_key() << "/" << cap->name()
+                                       << "' on_lifecycle_event(" << lifecycle_event_to_string(evt)
+                                       << ") threw a non-standard exception"
+                                       << " [ctx name='" << ctx.name << "', code=" << lifecycle_evt_code_to_string(ctx.code)
+                                       << ", msg='" << ctx.msg << "']";
+        }
+    }
+}
+
 } // namespace Slic3r

src/slic3r/plugin/PluginManager.hpp

@@ -8,6 +8,7 @@
 #include <condition_variable>
 #include <functional>
 #include <libslic3r/Config.hpp>
+#include <libslic3r/LifecycleEvents.hpp>
 #include <map>
 #include <memory>
 #include <mutex>
@@ -20,7 +21,6 @@
 #include <pybind11/embed.h>
 
 #include "CloudPluginService.hpp"
-#include "PluginFsUtils.hpp"
 #include "PluginDescriptor.hpp"
 #include "PluginLoader.hpp"
 #include "PluginConfig.hpp"
@@ -204,6 +204,8 @@ public:
 
     ExecutionResult run_script_capability(const std::string& plugin_key, const std::string& capability_name, std::string& error);
 
+    void dispatch_lifecycle_event(LifecycleEvent evt, const LifecycleEventContext& ctx);
+
 private:
     PluginManager()                                = default;
     PluginManager(const PluginManager&)            = delete;

src/slic3r/plugin/PyPluginTrampoline.hpp

@@ -129,6 +129,12 @@ public:
     {
         ORCA_PY_OVERRIDE_AUDITED(::Slic3r::PluginAuditManager::AuditMode::Loading, [] {}, PYBIND11_OVERRIDE, void, Base, on_cancelled);
     }
+
+    void on_lifecycle_event(LifecycleEvent event, const LifecycleEventContext& ctx) override
+    {
+        ORCA_PY_OVERRIDE_AUDITED(
+            ::Slic3r::PluginAuditManager::AuditMode::Loading, [] {}, PYBIND11_OVERRIDE, void, Base, on_lifecycle_event, event, ctx);
+    }
 };
 
 class PyPluginInterfaceTrampoline : public PyPluginCommonTrampoline<PluginCapabilityInterface>

src/slic3r/plugin/PythonPluginBridge.cpp

@@ -338,6 +338,44 @@ void bind_python_api(pybind11::module_& m)
         .value("FatalError", PluginResult::FatalError)
         .export_values();
 
+    py::enum_<LifecycleEvent>(m, "LifecycleEvent", "Application lifecycle moment passed to on_lifecycle_event")
+        .value("NewProject", LifecycleEvent::NewProject)
+        .value("ProjectOpened", LifecycleEvent::ProjectOpened)
+        .value("ProjectBeforeSave", LifecycleEvent::ProjectBeforeSave)
+        .value("ProjectAfterSave", LifecycleEvent::ProjectAfterSave)
+        .value("ProjectClosed", LifecycleEvent::ProjectClosed)
+        .value("SliceStarted", LifecycleEvent::SliceStarted)
+        .value("SliceGeometryFinished", LifecycleEvent::SliceGeometryFinished)
+        .value("GCodeExportStarted", LifecycleEvent::GCodeExportStarted)
+        .value("GCodeExportFinished", LifecycleEvent::GCodeExportFinished)
+        .value("SlicingJobComplete", LifecycleEvent::SlicingJobComplete)
+        .value("ObjectAdded", LifecycleEvent::ObjectAdded)
+        .value("ObjectDeleted", LifecycleEvent::ObjectDeleted)
+        .value("ObjectTransformed", LifecycleEvent::ObjectTransformed)
+        .value("PresetSelected", LifecycleEvent::PresetSelected)
+        .value("PresetSaved", LifecycleEvent::PresetSaved)
+        .value("PrintStateChanged", LifecycleEvent::PrintStateChanged)
+        .value("DeviceOnlineChanged", LifecycleEvent::DeviceOnlineChanged)
+        .value("DeviceDiscovered", LifecycleEvent::DeviceDiscovered)
+        .value("DeviceSelected", LifecycleEvent::DeviceSelected)
+        .value("DeviceConnected", LifecycleEvent::DeviceConnected)
+        .value("DeviceDisconnected", LifecycleEvent::DeviceDisconnected)
+        .value("UploadStarted", LifecycleEvent::UploadStarted)
+        .value("UploadFinished", LifecycleEvent::UploadFinished)
+        .export_values();
+
+    py::enum_<LifecycleEvtCode>(m, "LifecycleEvtCode", "Outcome code accompanying a LifecycleEventContext")
+        .value("Ok", LifecycleEvtCode::Ok)
+        .value("Error", LifecycleEvtCode::Error)
+        .value("Warn", LifecycleEvtCode::Warn)
+        .export_values();
+
+    py::class_<LifecycleEventContext>(m, "LifecycleEventContext", "Payload accompanying a LifecycleEvent")
+        .def(py::init<>())
+        .def_readonly("name", &LifecycleEventContext::name)
+        .def_readonly("code", &LifecycleEventContext::code)
+        .def_readonly("msg", &LifecycleEventContext::msg);
+
     py::class_<PluginContext>(m, "PluginContext", "Context shared with plugin entry points")
         .def(py::init<>())
         .def_readwrite("orca_version", &PluginContext::orca_version);
@@ -362,6 +400,9 @@ void bind_python_api(pybind11::module_& m)
         .def("get_type", &PluginCapabilityInterface::get_type)
         .def("on_load", &PluginCapabilityInterface::on_load)
         .def("on_unload", &PluginCapabilityInterface::on_unload)
+        .def("on_lifecycle_event", &PluginCapabilityInterface::on_lifecycle_event,
+             "Override to react to an application lifecycle moment (LifecycleEvent) and its\n"
+             "LifecycleEventContext payload. Available on every capability type.")
         .def("has_config_ui", &PluginCapabilityInterface::has_config_ui,
              "Override to return True to replace the host's default JSON editor with your own HTML\n"
              "UI, returned by get_config_ui(). Every capability is configurable and appears in the\n"

src/slic3r/plugin/PythonPluginInterface.hpp

@@ -10,6 +10,8 @@
 #include <nlohmann/json.hpp>
 #include <pybind11/embed.h>
 
+#include <libslic3r/LifecycleEvents.hpp>
+
 namespace Slic3r {
 
 enum class PluginCapabilityType { PrinterConnection = 0, Automation, Analysis, Importer, Exporter, Visualization, Script, SlicingPipeline, Unknown };
@@ -167,6 +169,8 @@ public:
     virtual void on_unload() {}
     virtual void on_cancelled() {}
 
+    virtual void on_lifecycle_event(LifecycleEvent event, const LifecycleEventContext& ctx) { (void) event; (void) ctx; }
+
     // ── C++-only host state, never exposed to Python. Set by the loader at materialization. ──
     //
     // The capability owns its own identity and enable flag: they are read once under the GIL, live