Adding some example for new UIList...

doc/python_api/examples/bpy.types.UIList.py

@@ -0,0 +1,89 @@
+"""
+Basic UIList Example
++++++++++++++++++++
+This script is the UIList subclass used to show material slots, with a bunch of additional commentaries.
+
+Notice the name of the class, this naming convention is similar as the one for panels or menus.
+
+.. note::
+
+   UIList subclasses must be registered for blender to use them.
+"""
+import bpy
+
+
+class MATERIAL_UL_matslots_example(bpy.types.UIList):
+    # The draw_item function is called for each item of the collection that is visible in the list.
+    #   data is the RNA object containing the collection,
+    #   item is the current drawn item of the collection,
+    #   icon is the "computed" icon for the item (as an integer, because some objects like materials or textures
+    #   have custom icons ID, which are not available as enum items).
+    #   active_data is the RNA object containing the active property for the collection (i.e. integer pointing to the
+    #   active item of the collection).
+    #   active_propname is the name of the active property (use 'getattr(active_data, active_propname)').
+    #   index is index of the current item in the collection.
+    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
+        ob = data
+        slot = item
+        ma = slot.material
+        # draw_item must handle the three layout types... Usually 'DEFAULT' and 'COMPACT' can share the same code.
+        if self.layout_type in {'DEFAULT', 'COMPACT'}:
+            # You should always start your row layout by a label (icon + text), this will also make the row easily
+            # selectable in the list!
+            # We use icon_value of label, as our given icon is an integer value, not an enum ID.
+            layout.label(ma.name if ma else "", icon_value=icon)
+            # And now we can add other UI stuff...
+            # Here, we add nodes info if this material uses (old!) shading nodes.
+            if ma and not context.scene.render.use_shading_nodes:
+                manode = ma.active_node_material
+                if manode:
+                    # The static method UILayout.icon returns the integer value of the icon ID "computed" for the given
+                    # RNA object.
+                    layout.label("Node %s" % manode.name, icon_value=layout.icon(manode))
+                elif ma.use_nodes:
+                    layout.label("Node <none>")
+                else:
+                    layout.label("")
+        # 'GRID' layout type should be as compact as possible (typically a single icon!).
+        elif self.layout_type in {'GRID'}:
+            layout.alignment = 'CENTER'
+            layout.label("", icon_value=icon)
+
+
+# And now we can use this list everywhere in Blender. Here is a small example panel.
+class UIListPanelExample(bpy.types.Panel):
+    """Creates a Panel in the Object properties window"""
+    bl_label = "UIList Panel"
+    bl_idname = "OBJECT_PT_ui_list_example"
+    bl_space_type = 'PROPERTIES'
+    bl_region_type = 'WINDOW'
+    bl_context = "object"
+
+    def draw(self, context):
+        layout = self.layout
+
+        obj = context.object
+
+        # template_list now takes two new args.
+        # The first one is the identifier of the registered UIList to use (if you want only the default list,
+        # with no custom draw code, use "UI_UL_list").
+        layout.template_list("MATERIAL_UL_matslots_example", "", obj, "material_slots", obj, "active_material_index")
+
+        # The second one can usually be left as an empty string. It's an additional ID used to distinguish lists in case you
+        # use the same list several times in a given area.
+        layout.template_list("MATERIAL_UL_matslots_example", "compact", obj, "material_slots",
+                             obj, "active_material_index", type='COMPACT')
+
+
+def register():
+    bpy.utils.register_class(MATERIAL_UL_matslots_example)
+    bpy.utils.register_class(UIListPanelExample)
+
+
+def unregister():
+    bpy.utils.unregister_class(MATERIAL_UL_matslots_example)
+    bpy.utils.unregister_class(UIListPanelExample)
+
+
+if __name__ == "__main__":
+    register()