addons: Call installer.get_addons() asynchronously to prevent lag

when viewing a flatpak with many addons.

Author: mtwebster

resources/mintinstall.glade

@@ -2120,7 +2120,23 @@
                                     <property name="can-focus">False</property>
                                     <property name="orientation">vertical</property>
                                     <child>
-                                      <object class="GtkFrame">
+                                      <object class="GtkSpinner" id="addons_spinner">
+                                        <property name="can-focus">False</property>
+                                        <property name="halign">center</property>
+                                        <property name="valign">start</property>
+                                        <property name="margin-top">24</property>
+                                        <property name="width-request">48</property>
+                                        <property name="height-request">48</property>
+                                        <property name="no-show-all">True</property>
+                                      </object>
+                                      <packing>
+                                        <property name="expand">False</property>
+                                        <property name="fill">True</property>
+                                        <property name="position">0</property>
+                                      </packing>
+                                    </child>
+                                    <child>
+                                      <object class="GtkFrame" id="addons_content_frame">
                                         <property name="visible">True</property>
                                         <property name="can-focus">False</property>
                                         <property name="label-xalign">0</property>

usr/lib/linuxmint/mintinstall/mintinstall.py

@@ -643,6 +643,7 @@ def __init__(self):
         self.installer = installer.Installer()
         self.installer.connect("appstream-changed", self.on_appstream_changed)
         self.task_cancellable = None
+        self.addons_cancellable = None
         self.current_task = None
         self.recursion_buster = False
 
@@ -946,6 +947,10 @@ def list_header_func(row, before, user_data=None):
 
         self.addons_listbox = self.builder.get_object("box_addons")
         self.addons_listbox.set_header_func(list_header_func, None)
+
+        self.addons_page = self.builder.get_object("addons_page")
+        self.addons_content = self.builder.get_object("addons_content_frame")
+        self.addons_spinner = self.builder.get_object("addons_spinner")
         self.package_details_listbox = self.builder.get_object("package_details_listbox")
 
         self.app_list_stack = self.builder.get_object("app_list_stack")
@@ -2295,6 +2300,11 @@ def go_back_action(self):
         XApp.set_window_progress(self.main_window, 0)
         self.stop_progress_pulse()
 
+        if self.addons_cancellable is not None:
+            self.addons_cancellable.cancel()
+            self.addons_cancellable = None
+            self.addons_spinner.stop()
+
         # If we're still loading details (and simulating), there's no task yet,
         # but we can cancel it via cancellable the installer gave us initially.
         if self.task_cancellable is not None:
@@ -3175,25 +3185,51 @@ def on_installer_info_ready(self, task):
             self.launch_button.hide()
 
     def populate_addons(self, pkginfo):
+        if self.addons_cancellable is not None:
+            self.addons_cancellable.cancel()
+        self.addons_cancellable = Gio.Cancellable()
+
         for row in self.addons_listbox.get_children():
             row.destroy()
 
+        self.addons_content.hide()
+        self.addons_spinner.show()
+        self.addons_spinner.start()
+        self.addons_page.show()
+
+        thread = threading.Thread(
+            target=self._populate_addons_thread,
+            args=(pkginfo, self.addons_cancellable),
+            daemon=True,
+        )
+        thread.start()
+
+    def _populate_addons_thread(self, pkginfo, cancellable):
         addons = self.installer.get_addons(pkginfo)
-        if addons is None:
-            self.builder.get_object("addons_page").hide()
-            return
+        if addons:
+            addons.sort(key=lambda a: a.get_display_name().casefold())
+        GLib.idle_add(self._populate_addons_finished, pkginfo, addons, cancellable)
+
+    def _populate_addons_finished(self, pkginfo, addons, cancellable):
+        if cancellable.is_cancelled():
+            return False
+
+        self.addons_spinner.stop()
+        self.addons_spinner.hide()
+
+        if not addons:
+            self.addons_page.hide()
+            return False
 
         name_size_group = Gtk.SizeGroup(mode=Gtk.SizeGroupMode.HORIZONTAL)
         button_size_group = Gtk.SizeGroup(mode=Gtk.SizeGroupMode.HORIZONTAL)
 
-        first = True
         for addon in addons:
-            print("Discovered addon: %s" % addon.name)
-            first = False
-
             row = FlatpakAddonRow(self, pkginfo, addon, name_size_group, button_size_group)
             self.addons_listbox.insert(row, -1)
-            self.builder.get_object("addons_page").show_all()
+
+        self.addons_content.show_all()
+        return False
 
     def on_installer_progress(self, pkginfo, progress, estimating, status_text=None):
         if self.current_pkginfo is not None and self.current_pkginfo.name == pkginfo.name: