Try to make GUI work

addons/io_scene_gltf2/__init__.py

@@ -329,26 +329,14 @@ def __init__(self):
         for user_extension in gltf2_io_user_extensions.UserExtensionLoader().extensions
         if 'name' in user_extension.meta
     }
-    # Generate properties for each extension
-    user_extension_settings_defaults = {}
+
     for extension_name, user_extension in user_extensions.items():
-        meta = user_extension.meta
-        if 'settings' in meta:
-            property_name = 'settings_' + meta['name']
-            property_group = type(property_name, (bpy.types.PropertyGroup,), meta['settings'])
-            bpy.utils.register_class(property_group)
-            # Dynamically add user extension settings as class attribute
-            locals()[property_name] = PointerProperty(type=property_group)
-            # Store defaults
-            user_extension_settings_defaults[extension_name] = {}
-            for key, prop_def in meta['settings'].items():
-                user_extension_settings_defaults[extension_name][prop_def[1]['name']] = prop_def[1]['default']
-
-    export_user_extensions = CollectionProperty(
-        name='User Extensions',
-        type=UserExtensionPropertyGroup,
-        description='Select extensions to enable'
-    )
+        if hasattr(user_extension, 'settings'):
+            print(user_extension.settings())
+            for property_name, user_extension_property in user_extension.settings().items():
+                print(extension_name)
+                print(property_name)
+                setattr(ExportGLTF2_Base, extension_name + "_property_" + property_name,  user_extension_property)
 
     # Custom scene property for saving settings
     scene_key = "glTF2ExportSettings"
@@ -484,8 +472,8 @@ def draw(self, context):
                 self.draw_material_settings()
             elif self.ui_tab == 'ANIMATION':
                 self.draw_animation_settings()
-        elif self.ui_tab == 'EXTENSIONS':
-            self.draw_user_extensions()
+            elif self.ui_tab == 'EXTENSIONS':
+                self.draw_user_extensions()
 
         def draw_general_settings(self):
             col = self.layout.box().column()
@@ -825,57 +813,27 @@ def draw(self, context):
         layout.active = operator.export_skins
         layout.prop(operator, 'export_all_influences')
 
-    def draw_user_extensions(self):
-        # Ensure we have built the user extension properties
-        self.generate_user_extensions_properties()
-
-        # Draw entries for each user extension
-        col = self.layout.box().column()
-        col.label(text='User Extensions:', icon='PLUGIN')
-
-        for user_extension_property in self.export_user_extensions:
-            user_extension = self.user_extensions[user_extension_property.name]
-            row = col.row()
-
-            row.prop(user_extension_property, 'enable', text=user_extension_property.name)
-
-            if user_extension.meta.get('isDraft', False):
-                 row.prop(self, 'draft_prop', icon='ERROR', emboss=False)
-
-            info_op = row.operator('wm.url_open', icon='INFO', emboss=False)
-            info_op.url = user_extension.meta.get('url', '')
-
-            if user_extension_property.enable:
-                settings = getattr(self, 'settings_' + user_extension_property.name, None)
-                has_custom_draw_function = hasattr(user_extension, 'draw_settings')
-                if settings or has_custom_draw_function:
-                    box = col.box()
-                    if has_custom_draw_function:
-                        user_extension.draw_settings(box, settings)
-                    else:
-                        setting_props = [
-                            name for name in dir(settings)
-                            if not name.startswith('_')
-                            and name not in ('bl_rna', 'name', 'rna_type')
-                        ]
-                        for setting_prop in setting_props:
-                            box.prop(settings, setting_prop)
-
-
-    def generate_user_extensions_properties(self):
-        # Iterate over collection of properties
-        for user_extension_property in self.export_user_extensions:
-            # Update the enable state of the user_extension matching the property
-            user_extension = self.user_extensions[user_extension_property.name];
-            user_extension.meta['enable'] = user_extension_property.enable
-
-        # Clear Collection and re-add entries for all user extensions
-        self.export_user_extensions.clear()
-        for user_extension_name, user_extension in self.user_extensions.items():
-            prop = self.export_user_extensions.add()
-            prop.name = user_extension_name
-            prop.enable = user_extension.meta['enable']
+class GLTF_PT_export_user_extensions(bpy.types.Panel):
+    bl_space_type = 'FILE_BROWSER'
+    bl_region_type = 'TOOL_PROPS'
+    bl_label = "Extensions"
+    bl_parent_id = "FILE_PT_operator"
+    bl_options = {'DEFAULT_CLOSED'}
+
+    @classmethod
+    def poll(cls, context):
+        sfile = context.space_data
+        operator = sfile.active_operator
 
+        return operator.bl_idname == "EXPORT_SCENE_OT_gltf"
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False  # No animation.
+
+        sfile = context.space_data
+        operator = sfile.active_operator
 
 class ExportGLTF2(bpy.types.Operator, ExportGLTF2_Base, ExportHelper):
     """Export scene as glTF 2.0 file"""
@@ -987,14 +945,25 @@ def menu_func_import(self, context):
         GLTF_PT_export_animation_export,
         GLTF_PT_export_animation_shapekeys,
         GLTF_PT_export_animation_skinning,
+        GLTF_PT_export_user_extensions,
         ImportGLTF2
     )
 
 
 def register():
     for c in classes:
         bpy.utils.register_class(c)
-    # bpy.utils.register_module(__name__)
+
+
+    user_extensions = {
+        # Record name and new instance for each extension
+        user_extension.meta['name'] : user_extension()
+        for user_extension in gltf2_io_user_extensions.UserExtensionLoader().extensions
+        if 'name' in user_extension.meta
+    }   # bpy.utils.register_module(__name__)
+
+    for name, user_extension in user_extensions.items():
+        user_extension.registerExtension()
 
     # add to the export / import menu
     if bpy.app.version < (2, 80, 0):

addons/io_scene_gltf2/io/exp/extensions/example_extension.py

@@ -2,6 +2,36 @@
 from io_scene_gltf2.io.exp.gltf2_io_user_extensions import UserExtensionBase
 from io_scene_gltf2.io.com.gltf2_io_extensions import Extension
 
+
+
+class GLTF_PT_export_example_extension(bpy.types.Panel):
+    bl_space_type = 'FILE_BROWSER'
+    bl_region_type = 'TOOL_PROPS'
+    bl_label = "Example Extension"
+    bl_parent_id = "GLTF_PT_export_user_extensions"
+    bl_options = {'DEFAULT_CLOSED'}
+
+    def __init__(self):
+        from io_scene_gltf2.io.exp import gltf2_io_draco_compression_extension
+        self.is_draco_available = gltf2_io_draco_compression_extension.dll_exists()
+
+    @classmethod
+    def poll(cls, context):
+        sfile = context.space_data
+        operator = sfile.active_operator
+        if operator.is_draco_available:
+            return operator.bl_idname == "EXPORT_SCENE_OT_gltf"
+
+    def draw_header(self, context):
+        sfile = context.space_data
+        operator = sfile.active_operator
+        #self.layout.prop(operator, "ExampleExtension_property_ExampleExtension_enabled", text="")
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False  # No animation.
+
 class ExampleExtension (UserExtensionBase):
 
     # As this user extension lives in the 'user_extensions/extensions' folder it is dynamically loaded.
@@ -14,19 +44,19 @@ class ExampleExtension (UserExtensionBase):
         'isDraft': False,
         'enable': True,
         'url': 'https://www.kdab.com',
-        'settings': {
-            "ExampleBoolProperty": bpy.props.BoolProperty(
-                name='ExampleBoolProperty',
-                description='This is an example of a BoolProperty used by a UserExtension.',
-                default=True
-            ),
-            "ExampleStringProperty": bpy.props.StringProperty(
-                name='ExampleStringProperty',
-                description='This is an example of a StringProperty used by a UserExtension.',
-                default="My String"
-            )
-        }
     }
 
+    export_ExampleExtension_enabled = bpy.props.BoolProperty(
+        name='ExampleExtension_enabled',
+        description='This is an example of a BoolProperty used by a UserExtension.',
+        default=True
+        )
+
     def export(self, blender_object, export_settings) -> Extension:
         return None
+
+    def registerExtension(self):
+        bpy.utils.register_class(GLTF_PT_export_example_extension)
+
+    def settings(self):
+        return {"ExampleExtension_enabled": self.export_ExampleExtension_enabled}

addons/io_scene_gltf2/io/exp/gltf2_io_user_extensions.py

@@ -16,6 +16,7 @@
 import imp
 import importlib
 import os.path
+import bpy
 from io_scene_gltf2.io.com.gltf2_io_extensions import Extension
 
 class GLTF2ExtensionMesh: