custom properties panels for most ID types. use subclassing to keep panel UI definitions minimal

release/scripts/ui/properties_data_metaball.py

@@ -18,6 +18,7 @@
 
 # <pep8 compliant>
 import bpy
+from rna_prop_ui import PropertyPanel
 
 narrowui = 180
 
@@ -58,6 +59,10 @@ class DATA_PT_context_metaball(DataButtonsPanel):
                 layout.template_ID(space, "pin_id")
 
 
+class DATA_PT_custom_props_metaball(DataButtonsPanel, PropertyPanel):
+    _context_path = "object.data"
+
+
 class DATA_PT_metaball(DataButtonsPanel):
     bl_label = "Metaball"
 
@@ -133,3 +138,7 @@ class DATA_PT_metaball_element(DataButtonsPanel):
 bpy.types.register(DATA_PT_context_metaball)
 bpy.types.register(DATA_PT_metaball)
 bpy.types.register(DATA_PT_metaball_element)
+
+bpy.types.register(DATA_PT_custom_props_metaball)
+
+