Hook models_advanced_will_show

This will be useful for add-on 1863928230. I want to let users change
the LaTeX footer/header everywhere.

qt/aqt/gui_hooks.py

@@ -1206,6 +1206,30 @@ class _MediaSyncDidStartOrStopHook:
 media_sync_did_start_or_stop = _MediaSyncDidStartOrStopHook()
 
 
+class _ModelsAdvancedWillShowHook:
+    _hooks: List[Callable[[QDialog], None]] = []
+
+    def append(self, cb: Callable[[QDialog], None]) -> None:
+        """(advanced: QDialog)"""
+        self._hooks.append(cb)
+
+    def remove(self, cb: Callable[[QDialog], None]) -> None:
+        if cb in self._hooks:
+            self._hooks.remove(cb)
+
+    def __call__(self, advanced: QDialog) -> None:
+        for hook in self._hooks:
+            try:
+                hook(advanced)
+            except:
+                # if the hook fails, remove it
+                self._hooks.remove(hook)
+                raise
+
+
+models_advanced_will_show = _ModelsAdvancedWillShowHook()
+
+
 class _OverviewDidRefreshHook:
     """Allow to update the overview window. E.g. add the deck name in the
         title."""

qt/aqt/models.py

@@ -6,7 +6,7 @@ from operator import itemgetter
 import aqt.clayout
 from anki import stdmodels
 from anki.lang import _, ngettext
-from aqt import AnkiQt
+from aqt import AnkiQt, gui_hooks
 from aqt.qt import *
 from aqt.utils import (
     askUser,
@@ -124,6 +124,7 @@ class Models(QDialog):
         d.setWindowTitle(_("Options for %s") % self.model["name"])
         frm.buttonBox.helpRequested.connect(lambda: openHelp("latex"))
         restoreGeom(d, "modelopts")
+        gui_hooks.models_advanced_will_show(d)
         d.exec_()
         saveGeom(d, "modelopts")
         self.model["latexsvg"] = frm.latexsvg.isChecked()

qt/tools/genhooks_gui.py

@@ -503,6 +503,9 @@ def emptyNewCard():
         args=["dialog: aqt.addons.AddonsDialog", "add_on: aqt.addons.AddonMeta"],
         doc="""Allows doing an action when a single add-on is selected.""",
     ),
+    # Model
+    ###################
+    Hook(name="models_advanced_will_show", args=["advanced: QDialog"],),
     # Other
     ###################
     Hook(