Keep active session in sync with active window

gaphor/application.py

@@ -9,9 +9,11 @@ All important services are present in the application object:
  - action sets
 """
 
+from __future__ import annotations
+
 import inspect
 import logging
-from typing import Dict, Type
+from typing import Dict, Optional, Set, Type
 
 import importlib_metadata
 
@@ -41,8 +43,8 @@ class _Application:
     """
 
     def __init__(self):
-        self.active_session = None
-        self.sessions = set()
+        self.active_session: Optional[Session] = None
+        self.sessions: Set[Session] = set()
 
     def init(self):
         uninitialized_services = load_services("gaphor.appservices")

gaphor/services/helpservice/__init__.py

@@ -11,12 +11,16 @@ from gaphor.core import action
 
 
 class HelpService(Service, ActionProvider):
-    # def __init__(self, main_window):
-    #     self.main_window = main_window
+    def __init__(self, session):
+        self.session = session
 
     def shutdown(self):
         pass
 
+    @property
+    def window(self):
+        return self.session.get_service("main_window").window
+
     @action(name="app.about")
     def about(self):
         builder = Gtk.Builder()
@@ -29,7 +33,7 @@ class HelpService(Service, ActionProvider):
 
         about.set_version(str(__version__))
 
-        # about.set_transient_for(self.main_window.window)
+        about.set_transient_for(self.window)
 
         about.show_all()
         about.run()
@@ -45,7 +49,7 @@ class HelpService(Service, ActionProvider):
 
         shortcuts = builder.get_object("shortcuts-gaphor")
         shortcuts.set_modal(True)
-        # shortcuts.set_transient_for(self.main_window.window)
+        shortcuts.set_transient_for(self.window)
 
         shortcuts.show_all()
         return shortcuts

gaphor/services/session.py

@@ -0,0 +1,15 @@
+from gaphor.abc import Service
+from gaphor.application import Application
+
+
+class Session(Service):
+    """
+    Application service. Get the active session.
+    """
+
+    def shutdown(self):
+        pass
+
+    def get_service(self, name):
+        assert Application.active_session
+        return Application.active_session.get_service(name)

gaphor/ui/__init__.py

@@ -65,28 +65,29 @@ def main(argv=sys.argv):
 
 
 def run(args):
+    def on_active_window(window, prop, session):
+        Application.active_session = session
+
+    def new_session(app):
+        session = Application.new_session()
+
+        main_window = session.get_service("main_window")
+        main_window.open(app)
+        app.add_window(main_window.window)
+        main_window.window.connect("notify::is-active", on_active_window, session)
+        return session
+
     def app_startup(app):
-        Application.init()
-        apply_application_actions(Application, app)
+        try:
+            Application.init()
+            apply_application_actions(Application, app)
+        except Exception:
+            app.quit()
+            raise
 
     def app_activate(app):
-        # Make sure gui is loaded ASAP.
-        # This prevents menu items from appearing at unwanted places.
-        # main_window = application.get_service("main_window")
-        # main_window.open(app)
-        # app.add_window(main_window.window)
-
         if not Application.has_sessions():
-            session = Application.new_session()
-
-            # Only at application level (startup())?
-            # component_registry = session.get_service("component_registry")
-            # apply_application_actions(component_registry, app)
-
-            main_window = session.get_service("main_window")
-            main_window.open(app)
-            app.add_window(main_window.window)
-
+            session = new_session(app)
             file_manager = session.get_service("file_manager")
             file_manager.action_new()
 
@@ -94,14 +95,7 @@ def run(args):
         print(f"Open files {files} with '{hint}'.")
         assert n_files == 1
         for file in files:
-            session = Application.new_session()
-            # component_registry = session.get_service("component_registry")
-            # apply_application_actions(component_registry, app)
-
-            main_window = session.get_service("main_window")
-            main_window.open(app)
-            app.add_window(main_window.window)
-
+            session = new_session(app)
             file_manager = Application.get_service("file_manager")
             file_manager.load(file.get_path())
 
@@ -120,7 +114,12 @@ def run(args):
 
 
 def quit():
-    Gtk.Application.get_default().quit()
+    session = Application.active_session
+    assert session
+    session.shutdown()
+    Application.sessions.discard(session)
+    if not Application.sessions:
+        Gtk.Application.get_default().quit()
 
 
 def add_main_options(gtk_app):

gaphor/ui/filemanager.py

@@ -337,7 +337,7 @@ class FileManager(Service, ActionProvider):
 
         return False
 
-    @action(name="app.quit", shortcut="<Primary>q")
+    @action(name="quit", shortcut="<Primary>q")
     def file_quit(self):
         """
         Ask user to close window if the model has changed.

pyproject.toml

@@ -62,6 +62,7 @@ gaphor = 'gaphor.ui:main'
 gaphorconvert = 'gaphor.tools.gaphorconvert:main'
 
 [tool.poetry.plugins."gaphor.appservices"]
+"session" = "gaphor.services.session:Session"
 "help" = "gaphor.services.helpservice:HelpService"
 
 [tool.poetry.plugins."gaphor.services"]