bl_pkg/bl_extension_ui.py

@@ -17,6 +17,7 @@ import bpy
 
 from bpy.types import (
     Menu,
+    Operator,
     Panel,
 )
 
@@ -415,7 +416,7 @@ def extensions_panel_draw_impl(
                     )
             else:
                 # Not installed, always placeholder.
-                row.label(text="", icon='CHECKBOX_DEHLT')
+                row.operator("preferences.extensions_enable_not_installed", text="", icon='CHECKBOX_DEHLT', emboss=False)
 
             if show_development:
                 if mark:
@@ -661,10 +662,26 @@ def extensions_panel_draw(panel, context):
     )
 
 
+class USERPREF_OT_extensions_enable_not_installed(Operator):
+    """Extension needs to be installed before it can be enabled"""
+    bl_idname = "preferences.extensions_enable_not_installed"
+    bl_label = "Enable Extension"
+
+    @classmethod
+    def poll(cls, context):
+        return False
+
+    def execute(self, context):
+        # This operator only exists to be able to show disabled checkboxes for extensions
+        # while giving users a reasonable explanation on why is that.
+        return {'CANCELLED'}
+
+
 classes = (
     # Pop-overs.
     USERPREF_PT_extensions_bl_pkg_filter,
     USERPREF_MT_extensions_bl_pkg_settings,
+    USERPREF_OT_extensions_enable_not_installed,
 )