Add main_window_did_init hook and clarify difference to profile_did_open

qt/aqt/gui_hooks.py

@@ -1475,6 +1475,38 @@ class _EmptyCardsWillShowHook:
 empty_cards_will_show = _EmptyCardsWillShowHook()
 
 
+class _MainWindowDidInitHook:
+    """Executed after the main window is fully initialized
+        
+        A sample use case for this hook would be to delay actions until Anki objects
+        like the profile or collection are fully initialized. In contrast to
+        `profile_did_open`, this hook will only fire once per Anki session and
+        is thus suitable for single-shot subscribers.
+        """
+
+    _hooks: List[Callable[[], None]] = []
+
+    def append(self, cb: Callable[[], None]) -> None:
+        """()"""
+        self._hooks.append(cb)
+
+    def remove(self, cb: Callable[[], None]) -> None:
+        if cb in self._hooks:
+            self._hooks.remove(cb)
+
+    def __call__(self) -> None:
+        for hook in self._hooks:
+            try:
+                hook()
+            except:
+                # if the hook fails, remove it
+                self._hooks.remove(hook)
+                raise
+
+
+main_window_did_init = _MainWindowDidInitHook()
+
+
 class _MediaSyncDidProgressHook:
     _hooks: List[Callable[["aqt.mediasync.LogEntryWithTime"], None]] = []
 
@@ -1624,6 +1656,13 @@ overview_will_render_content = _OverviewWillRenderContentHook()
 
 
 class _ProfileDidOpenHook:
+    """Executed whenever a user profile has been opened
+        
+        Please note that this hook will also be called on profile switches, so if you
+        are looking to simply delay an add-on action in a single-shot manner,
+        `main_window_did_init` is likely the more suitable choice.
+        """
+
     _hooks: List[Callable[[], None]] = []
 
     def append(self, cb: Callable[[], None]) -> None:

qt/aqt/main.py

@@ -118,7 +118,12 @@ class AnkiQt(QMainWindow):
             fn = self.setupProfileAfterWebviewsLoaded
         else:
             fn = self.setupProfile
-        self.progress.timer(10, fn, False, requiresCollection=False)
+
+        def on_window_init():
+            fn()
+            gui_hooks.main_window_did_init()
+
+        self.progress.timer(10, on_window_init, False, requiresCollection=False)
 
     def setupUI(self) -> None:
         self.col = None

qt/tools/genhooks_gui.py

@@ -400,8 +400,27 @@ hooks = [
     ),
     # Main
     ###################
+    Hook(
+        name="main_window_did_init",
+        doc="""Executed after the main window is fully initialized
+        
+        A sample use case for this hook would be to delay actions until Anki objects
+        like the profile or collection are fully initialized. In contrast to
+        `profile_did_open`, this hook will only fire once per Anki session and
+        is thus suitable for single-shot subscribers.
+        """,
+    ),
     Hook(name="backup_did_complete"),
-    Hook(name="profile_did_open", legacy_hook="profileLoaded"),
+    Hook(
+        name="profile_did_open",
+        legacy_hook="profileLoaded",
+        doc="""Executed whenever a user profile has been opened
+        
+        Please note that this hook will also be called on profile switches, so if you
+        are looking to simply delay an add-on action in a single-shot manner,
+        `main_window_did_init` is likely the more suitable choice.
+        """,
+    ),
     Hook(name="profile_will_close", legacy_hook="unloadProfile"),
     Hook(
         name="collection_did_load",