Add add-on installation hooks (#2523)

* Add add-on installation hooks

* Fix GUI code run in background thread

deleteAddon() is run in the background in the update routine so it
shouldn't containg any GUI code.

* Add a hint to the docstrings (dae)

qt/aqt/addons.py

@@ -426,7 +426,9 @@ class AddonManager:
             conflicts = manifest.get("conflicts", [])
             found_conflicts = self._disableConflicting(package, conflicts)
             meta = self.addonMeta(package)
+            gui_hooks.addon_manager_will_install_addon(self, package)
             self._install(package, zfile)
+            gui_hooks.addon_manager_did_install_addon(self, package)
 
         schema = self._manifest_schema["properties"]
         manifest_meta = {
@@ -450,10 +452,11 @@ class AddonManager:
         base = self.addonsFolder(module)
         if os.path.exists(base):
             self.backupUserFiles(module)
-            if not self.deleteAddon(module):
+            try:
+                self.deleteAddon(module)
+            except Exception:
                 self.restoreUserFiles(module)
-                return
+                raise
-
         os.mkdir(base)
         self.restoreUserFiles(module)
 
@@ -469,17 +472,8 @@ class AddonManager:
                 continue
             zfile.extract(n, base)
 
-    # true on success
+    def deleteAddon(self, module: str) -> None:
-    def deleteAddon(self, module: str) -> bool:
+        send_to_trash(Path(self.addonsFolder(module)))
-        try:
-            send_to_trash(Path(self.addonsFolder(module)))
-            return True
-        except OSError as e:
-            showWarning(
-                tr.addons_unable_to_update_or_delete_addon(val=str(e)),
-                textFormat="plain",
-            )
-            return False
 
     # Processing local add-on files
     ######################################################################
@@ -912,12 +906,17 @@ class AddonsDialog(QDialog):
         if not askUser(tr.addons_delete_the_numd_selected_addon(count=len(selected))):
             return
         gui_hooks.addons_dialog_will_delete_addons(self, selected)
-        for module in selected:
+        try:
-            # doing this before deleting, as `enabled` is always True afterwards
+            for module in selected:
-            if self.mgr.addon_meta(module).enabled:
+                # doing this before deleting, as `enabled` is always True afterwards
-                self._require_restart = True
+                if self.mgr.addon_meta(module).enabled:
-            if not self.mgr.deleteAddon(module):
+                    self._require_restart = True
-                break
+                self.mgr.deleteAddon(module)
+        except OSError as e:
+            showWarning(
+                tr.addons_unable_to_update_or_delete_addon(val=str(e)),
+                textFormat="plain",
+            )
         self.form.addonList.clearSelection()
         self.redrawAddons()
 

qt/tools/genhooks_gui.py

@@ -1211,6 +1211,22 @@ gui_hooks.webview_did_inject_style_into_page.append(mytest)
         args=["dialog: aqt.addons.AddonsDialog", "ids: list[str]"],
         doc="""Allows doing an action before an add-on is deleted.""",
     ),
+    Hook(
+        name="addon_manager_will_install_addon",
+        args=["manager: aqt.addons.AddonManager", "module: str"],
+        doc="""Called before installing or updating an addon.
+        
+        Can be used to release DB connections or open files that
+        would prevent an update from succeeding.""",
+    ),
+    Hook(
+        name="addon_manager_did_install_addon",
+        args=["manager: aqt.addons.AddonManager", "module: str"],
+        doc="""Called after installing or updating an addon.
+        
+        Can be used to restore DB connections or open files after
+        an add-on has been updated.""",
+    ),
     # Model
     ###################
     Hook(