Rigify: Add ability to disable installed feature sets

This patch is a continuation of D8519, was also suggested in T88711#1170152.
It adds a checkbox for each feature set in the Rigify Preferences, to disable/enable that feature set without having to completely remove it from the file system.

Challenges that were hopefully successfully tackled:
- Keep list in sync when user manually adds or removes things through the file system instead of the "add/remove feature set" buttons in the UI.
- Avoid re-building the feature set list all the time so that the checkbox states can actually be stored when the user exits Blender.
- Disabling a feature set means calling its unregister function, then rebuilding the rig types and metarigs lists/menus.
- Some renaming slipped in because I found the variable name "feature_set" a bit confusing. If needed, I could split this change into a separate patch or just forget about it, but I think the longer names help here.

Testing would be welcome, since things turned out a bit more tricky than expected.

In a follow-up patch I would like to do a code quality pass, to split the code a bit better here. There is a bit too much stuff in __init__.py in particular. I will get started on that when this gets close to being finalized.

Reviewed By: angavrilov

Differential Revision: https://developer.blender.org/D12260

4 files changed, 110 insertions, 44 deletions

diff --git a/rigify/__init__.py b/rigify/__init__.py
index 20e18a42..5d8782d4 100644
--- a/rigify/__init__.py
+++ b/rigify/__init__.py
@@ -149,6 +149,33 @@ class RigifyFeatureSets(bpy.types.PropertyGroup):
     name: bpy.props.StringProperty()
     module_name: bpy.props.StringProperty()
 
+    def toggle_featureset(self, context):
+        feature_set_list.call_register_function(self.module_name, self.enabled)
+        context.preferences.addons[__package__].preferences.update_external_rigs()
+
+    enabled: bpy.props.BoolProperty(
+        name = "Enabled", 
+        description = "Whether this feature-set is registered or not",
+        update = toggle_featureset,
+        default = True
+    )
+
+
+class RIGIFY_UL_FeatureSets(bpy.types.UIList):
+    def draw_item(self, context, layout, data, item, icon, active_data, active_propname):
+        rigify_prefs = data
+        feature_sets = rigify_prefs.rigify_feature_sets
+        active_set = feature_sets[rigify_prefs.active_feature_set_index]
+        feature_set_entry = item
+        if self.layout_type in {'DEFAULT', 'COMPACT'}:
+            row = layout.row()
+            row.prop(feature_set_entry, 'name', text="", emboss=False)
+
+            icon = 'CHECKBOX_HLT' if feature_set_entry.enabled else 'CHECKBOX_DEHLT'
+            row.enabled = feature_set_entry.enabled
+            layout.prop(feature_set_entry, 'enabled', text="", icon=icon, emboss=False)
+        elif self.layout_type in {'GRID'}:
+            pass
 
 class RigifyPreferences(AddonPreferences):
     # this must match the addon name, use '__package__'
@@ -157,32 +184,50 @@ class RigifyPreferences(AddonPreferences):
 
     def register_feature_sets(self, register):
         """Call register or unregister of external feature sets"""
-        for set_name in feature_set_list.get_installed_list():
+        for set_name in feature_set_list.get_enabled_modules_names():
             feature_set_list.call_register_function(set_name, register)
 
-    def update_external_rigs(self, force=False):
+    def refresh_installed_feature_sets(self):
+        """Synchronize preferences entries with what's actually in the file system."""
+        feature_set_prefs = self.rigify_feature_sets
+
+        module_names = feature_set_list.get_installed_modules_names()
+
+        # If there is a feature set preferences entry with no corresponding 
+        # installed module, user must've manually removed it from the filesystem,
+        # so let's remove such entries.
+        to_delete = [ i for i, fs in enumerate(feature_set_prefs) if fs.module_name not in module_names ]
+        for i in reversed(to_delete):
+            feature_set_prefs.remove(i)
+
+        # If there is an installed feature set in the file system but no corresponding
+        # entry, user must've installed it manually. Make sure it has an entry.
+        for module_name in module_names:
+            for fs in feature_set_prefs:
+                if module_name == fs.module_name:
+                    break
+            else:
+                fs = feature_set_prefs.add()
+                fs.name = feature_set_list.get_ui_name(module_name)
+                fs.module_name = module_name
+
+    def update_external_rigs(self):
         """Get external feature sets"""
-        set_list = feature_set_list.get_installed_list()
 
-        # Update feature set list
-        self.rigify_feature_sets.clear()
+        self.refresh_installed_feature_sets()
 
-        for s in set_list:
-            list_entry = self.rigify_feature_sets.add()
-            list_entry.name = feature_set_list.get_ui_name(s)
-            list_entry.module_name = s
+        set_list = feature_set_list.get_enabled_modules_names()
 
-        if force or len(set_list) > 0:
-            # Reload rigs
-            print('Reloading external rigs...')
-            rig_lists.get_external_rigs(set_list)
+        # Reload rigs
+        print('Reloading external rigs...')
+        rig_lists.get_external_rigs(set_list)
 
-            # Reload metarigs
-            print('Reloading external metarigs...')
-            metarig_menu.get_external_metarigs(set_list)
+        # Reload metarigs
+        print('Reloading external metarigs...')
+        metarig_menu.get_external_metarigs(set_list)
 
-            # Re-register rig parameters
-            register_rig_parameters()
+        # Re-register rig parameters
+        register_rig_parameters()
 
     rigify_feature_sets: bpy.props.CollectionProperty(type=RigifyFeatureSets)
     active_feature_set_index: IntProperty()
@@ -196,8 +241,8 @@ class RigifyPreferences(AddonPreferences):
 
         row = layout.row()
         row.template_list(
-            "UI_UL_list",
-            "rigify_feature_sets",
+            'RIGIFY_UL_FeatureSets',
+            '',
             self, "rigify_feature_sets",
             self, 'active_feature_set_index'
         )
@@ -259,8 +304,7 @@ def draw_feature_set_prefs(layout, context, featureset: RigifyFeatureSets):
         op = row.operator('wm.url_open', text="Report a Bug", icon='URL')
         op.url = info['tracker_url']
 
-    op = row.operator("wm.rigify_remove_feature_set", text="Remove", icon='CANCEL')
-    op.featureset = featureset.module_name
+    row.operator("wm.rigify_remove_feature_set", text="Remove", icon='CANCEL')
 
 
 class RigifyName(bpy.types.PropertyGroup):
@@ -443,6 +487,7 @@ classes = (
     RigifyColorSet,
     RigifySelectionColors,
     RigifyArmatureLayer,
+    RIGIFY_UL_FeatureSets,
     RigifyFeatureSets,
     RigifyPreferences,
 )
diff --git a/rigify/feature_set_list.py b/rigify/feature_set_list.py
index a50bd010..cb46f5c6 100644
--- a/rigify/feature_set_list.py
+++ b/rigify/feature_set_list.py
@@ -16,6 +16,8 @@
 #
 #======================= END GPL LICENSE BLOCK ========================
 
+from typing import List
+
 import bpy
 from bpy.props import StringProperty
 import os
@@ -44,7 +46,8 @@ def get_install_path(*, create=False):
     return INSTALL_PATH
 
 
-def get_installed_list():
+def get_installed_modules_names() -> List[str]:
+    """Return a list of module names of all feature sets in the file system."""
     features_path = get_install_path()
     if not features_path:
         return []
@@ -60,6 +63,17 @@ def get_installed_list():
     return sets
 
 
+def get_enabled_modules_names() -> List[str]:
+    """Return a list of module names of all enabled feature sets."""
+    rigify_prefs = bpy.context.preferences.addons[__package__].preferences
+    installed_module_names = get_installed_modules_names()
+    rigify_feature_sets = rigify_prefs.rigify_feature_sets
+
+    enabled_module_names = { fs.module_name for fs in rigify_feature_sets if fs.enabled }
+
+    return [name for name in installed_module_names if name in enabled_module_names]
+
+
 def get_module(feature_set):
     return importlib.import_module('.'.join([*NAME_PREFIX, feature_set]))
 
@@ -88,17 +102,17 @@ def get_info_dict(feature_set):
     return {}
 
 
-def call_function_safe(feature_set, name, args=[], kwargs={}):
-    module = get_module_safe(feature_set)
+def call_function_safe(module_name, func_name, args=[], kwargs={}):
+    module = get_module_safe(module_name)
 
     if module:
-        func = getattr(module, name, None)
+        func = getattr(module, func_name, None)
 
         if callable(func):
             try:
                 return func(*args, **kwargs)
             except Exception:
-                print("Rigify Error: Could not call function '%s' of feature set '%s': exception occurred.\n" % (name, feature_set))
+                print(f"Rigify Error: Could not call function '{func_name}' of feature set '{module_name}': exception occurred.\n")
                 traceback.print_exc()
                 print("")
 
@@ -128,7 +142,7 @@ def feature_set_items(scene, context):
         ('rigify', 'Rigify Built-in', 'Rigs bundled with Rigify'),
     ]
 
-    for fs in get_installed_list():
+    for fs in get_enabled_modules_names():
         ui_name = get_ui_name(fs)
         items.append((fs, ui_name, ui_name))
 
@@ -222,8 +236,7 @@ class DATA_OT_rigify_add_feature_set(bpy.types.Operator):
 
             addon_prefs.update_external_rigs()
 
-            new_index = addon_prefs.rigify_feature_sets.find(get_ui_name(fixed_dirname))
-            addon_prefs.active_feature_set_index = new_index
+            addon_prefs.active_feature_set_index = len(addon_prefs.rigify_feature_sets)-1
 
         return {'FINISHED'}
 
@@ -234,8 +247,6 @@ class DATA_OT_rigify_remove_feature_set(bpy.types.Operator):
     bl_description = "Remove external feature set (rigs, metarigs, ui templates)"
     bl_options = {"REGISTER", "UNDO", "INTERNAL"}
 
-    featureset: StringProperty(maxlen=1024, options={'HIDDEN', 'SKIP_SAVE'})
-
     @classmethod
     def poll(cls, context):
         return True
@@ -245,18 +256,29 @@ class DATA_OT_rigify_remove_feature_set(bpy.types.Operator):
 
     def execute(self, context):
         addon_prefs = context.preferences.addons[__package__].preferences
+        feature_sets = addon_prefs.rigify_feature_sets
+        active_idx = addon_prefs.active_feature_set_index
+        active_fs = feature_sets[active_idx]
 
-        # Call the unregister callback of the set being removed
-        call_register_function(self.featureset, False)
+        # Call the unregister callback of the set being removed.
+        if active_fs.enabled:
+            call_register_function(active_fs.module_name, register=False)
 
+        # Remove the feature set's folder from the file system.
         rigify_config_path = get_install_path()
         if rigify_config_path:
-            set_path = os.path.join(rigify_config_path, self.featureset)
+            set_path = os.path.join(rigify_config_path, active_fs.module_name)
             if os.path.exists(set_path):
                 rmtree(set_path)
 
-        addon_prefs.update_external_rigs(force=True)
-        addon_prefs.active_feature_set_index = 0
+        # Remove the feature set's entry from the addon preferences.
+        feature_sets.remove(active_idx)
+
+        # Remove the feature set's entries from the metarigs and rig types.
+        addon_prefs.update_external_rigs()
+
+        # Update active index.
+        addon_prefs.active_feature_set_index -= 1
 
         return {'FINISHED'}
 
diff --git a/rigify/metarig_menu.py b/rigify/metarig_menu.py
index 48da1e89..7a48df44 100644
--- a/rigify/metarig_menu.py
+++ b/rigify/metarig_menu.py
@@ -214,17 +214,16 @@ def unregister():
     for mf in menu_funcs:
         bpy.types.VIEW3D_MT_armature_add.remove(mf)
 
-def get_external_metarigs(set_list):
+def get_external_metarigs(feature_module_names):
     unregister()
 
     # Clear and fill metarigs public variables
     metarigs.clear()
     get_internal_metarigs()
 
-
-    for feature_set in set_list:
+    for module_name in feature_module_names:
         try:
-            base_dir, base_path = feature_set_list.get_dir_path(feature_set, METARIG_DIR)
+            base_dir, base_path = feature_set_list.get_dir_path(module_name, METARIG_DIR)
 
             get_metarigs(metarigs['external'], base_dir, base_path)
         except Exception:
diff --git a/rigify/ui.py b/rigify/ui.py
index 59dbf9b6..eac8b673 100644
--- a/rigify/ui.py
+++ b/rigify/ui.py
@@ -54,7 +54,7 @@ def build_type_list(context, rigify_types):
 
     for r in sorted(rig_lists.rigs):
         if (context.object.data.active_feature_set in ('all', rig_lists.rigs[r]['feature_set'])
-                or len(feature_set_list.get_installed_list()) == 0
+                or len(feature_set_list.get_enabled_modules_names()) == 0
                 ):
             a = rigify_types.add()
             a.name = r
@@ -191,7 +191,7 @@ class DATA_PT_rigify_samples(bpy.types.Panel):
             id_store.rigify_active_type = 0
 
         # Rig type list
-        if len(feature_set_list.get_installed_list()) > 0:
+        if len(feature_set_list.get_enabled_modules_names()) > 0:
             row = layout.row()
             row.prop(context.object.data, "active_feature_set")
         row = layout.row()
@@ -609,7 +609,7 @@ class BONE_PT_rigify_buttons(bpy.types.Panel):
         build_type_list(context, id_store.rigify_types)
 
         # Rig type field
-        if len(feature_set_list.get_installed_list()) > 0:
+        if len(feature_set_list.get_enabled_modules_names()) > 0:
             row = layout.row()
             row.prop(context.object.data, "active_feature_set")
         row = layout.row()