Panel(bpy_struct)

Basic Panel Example

This script is a simple panel which will draw into the object properties section.

Notice the ‘CATEGORY_PT_name’ Panel.bl_idname, this is a naming convention for panels.

Note

Panel subclasses must be registered for blender to use them.

import bpy


class HelloWorldPanel(bpy.types.Panel):
    bl_idname = "OBJECT_PT_hello_world"
    bl_label = "Hello World"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "object"

    def draw(self, context):
        self.layout.label(text="Hello World")


bpy.utils.register_class(HelloWorldPanel)

Simple Object Panel

This panel has a Panel.poll and Panel.draw_header function, even though the contents is basic this closely resembles blenders panels.

import bpy


class ObjectSelectPanel(bpy.types.Panel):
    bl_idname = "OBJECT_PT_select"
    bl_label = "Select"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "object"
    bl_options = {'DEFAULT_CLOSED'}

    @classmethod
    def poll(cls, context):
        return (context.object is not None)

    def draw_header(self, context):
        layout = self.layout
        layout.label(text="My Select Panel")

    def draw(self, context):
        layout = self.layout

        box = layout.box()
        box.label(text="Selection Tools")
        box.operator("object.select_all").action = 'TOGGLE'
        row = box.row()
        row.operator("object.select_all").action = 'INVERT'
        row.operator("object.select_random")


bpy.utils.register_class(ObjectSelectPanel)

Mix-in Classes

A mix-in parent class can be used to share common properties and Menu.poll function.

import bpy


class View3DPanel:
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'
    bl_category = "Tool"

    @classmethod
    def poll(cls, context):
        return (context.object is not None)


class PanelOne(View3DPanel, bpy.types.Panel):
    bl_idname = "VIEW3D_PT_test_1"
    bl_label = "Panel One"

    def draw(self, context):
        self.layout.label(text="Small Class")


class PanelTwo(View3DPanel, bpy.types.Panel):
    bl_idname = "VIEW3D_PT_test_2"
    bl_label = "Panel Two"

    def draw(self, context):
        self.layout.label(text="Also Small Class")


bpy.utils.register_class(PanelOne)
bpy.utils.register_class(PanelTwo)

base class — bpy_struct

class bpy.types.Panel(bpy_struct)

Panel containing UI elements

bl_category

The category (tab) in which the panel will be displayed, when applicable

Type

string, default “”, (never None)

bl_context

The context in which the panel belongs to. (TODO: explain the possible combinations bl_context/bl_region_type/bl_space_type)

Type

string, default “”, (never None)

bl_description

The panel tooltip

Type

string, default “”

bl_idname

If this is set, the panel gets a custom ID, otherwise it takes the name of the class used to define the panel. For example, if the class name is “OBJECT_PT_hello”, and bl_idname is not set by the script, then bl_idname = “OBJECT_PT_hello”

Type

string, default “”, (never None)

bl_label

The panel label, shows up in the panel header at the right of the triangle used to collapse the panel

Type

string, default “”, (never None)

bl_options

Options for this panel type

• DEFAULT_CLOSED Default Closed – Defines if the panel has to be open or collapsed at the time of its creation.

• HIDE_HEADER Hide Header – If set to False, the panel shows a header, which contains a clickable arrow to collapse the panel and the label (see bl_label).

• INSTANCED Instanced Panel – Multiple panels with this type can be used as part of a list depending on data external to the UI. Used to create panels for the modifiers and other stacks.

• HEADER_LAYOUT_EXPAND Expand Header Layout – Allow buttons in the header to stretch and shrink to fill the entire layout width.

Type

enum set in {‘DEFAULT_CLOSED’, ‘HIDE_HEADER’, ‘INSTANCED’, ‘HEADER_LAYOUT_EXPAND’}, default {‘DEFAULT_CLOSED’}

bl_order

Panels with lower numbers are default ordered before panels with higher numbers

Type

int in [0, inf], default 0

bl_owner_id

The ID owning the data displayed in the panel, if any

Type

string, default “”, (never None)

bl_parent_id

If this is set, the panel becomes a sub-panel

Type

string, default “”, (never None)

bl_region_type

The region where the panel is going to be used in

Type

enum in [‘WINDOW’, ‘HEADER’, ‘CHANNELS’, ‘TEMPORARY’, ‘UI’, ‘TOOLS’, ‘TOOL_PROPS’, ‘PREVIEW’, ‘HUD’, ‘NAVIGATION_BAR’, ‘EXECUTE’, ‘FOOTER’, ‘TOOL_HEADER’, ‘XR’], default ‘WINDOW’

bl_space_type

The space where the panel is going to be used in

• EMPTY Empty.

• VIEW_3D 3D Viewport – Manipulate objects in a 3D environment.

• IMAGE_EDITOR UV/Image Editor – View and edit images and UV Maps.

• NODE_EDITOR Node Editor – Editor for node-based shading and compositing tools.

• SEQUENCE_EDITOR Video Sequencer – Video editing tools.

• CLIP_EDITOR Movie Clip Editor – Motion tracking tools.

• DOPESHEET_EDITOR Dope Sheet – Adjust timing of keyframes.

• GRAPH_EDITOR Graph Editor – Edit drivers and keyframe interpolation.

• NLA_EDITOR Nonlinear Animation – Combine and layer Actions.

• TEXT_EDITOR Text Editor – Edit scripts and in-file documentation.

• CONSOLE Python Console – Interactive programmatic console for advanced editing and script development.

• INFO Info – Log of operations, warnings and error messages.

• TOPBAR Top Bar – Global bar at the top of the screen for global per-window settings.

• STATUSBAR Status Bar – Global bar at the bottom of the screen for general status information.

• OUTLINER Outliner – Overview of scene graph and all available data-blocks.

• PROPERTIES Properties – Edit properties of active object and related data-blocks.

• FILE_BROWSER File Browser – Browse for files and assets.

• SPREADSHEET Spreadsheet – Explore geometry data in a table.

• PREFERENCES Preferences – Edit persistent configuration settings.

Type

enum in [‘EMPTY’, ‘VIEW_3D’, ‘IMAGE_EDITOR’, ‘NODE_EDITOR’, ‘SEQUENCE_EDITOR’, ‘CLIP_EDITOR’, ‘DOPESHEET_EDITOR’, ‘GRAPH_EDITOR’, ‘NLA_EDITOR’, ‘TEXT_EDITOR’, ‘CONSOLE’, ‘INFO’, ‘TOPBAR’, ‘STATUSBAR’, ‘OUTLINER’, ‘PROPERTIES’, ‘FILE_BROWSER’, ‘SPREADSHEET’, ‘PREFERENCES’], default ‘EMPTY’

bl_translation_context

Specific translation context, only define when the label needs to be disambiguated from others using the exact same label

Type

string, default “*”, (never None)

bl_ui_units_x

When set, defines popup panel width

Type

int in [0, inf], default 0

custom_data

Panel data

Type

Constraint, (readonly)

is_popover

Type

boolean, default False, (readonly)

layout

Defines the structure of the panel in the UI

Type

UILayout, (readonly)

text

XXX todo

Type

string, default “”, (never None)

use_pin

Show the panel on all tabs

Type

boolean, default False

classmethod poll(context)

If this method returns a non-null output, then the panel can be drawn

Return type

boolean

draw(context)

Draw UI elements into the panel UI layout

draw_header(context)

Draw UI elements into the panel’s header UI layout

draw_header_preset(context)

Draw UI elements for presets in the panel’s header

classmethod bl_rna_get_subclass(id, default=None)

Parameters

id (string) – The RNA type identifier.

Returns

The RNA type or default when not found.

Return type

bpy.types.Struct subclass

classmethod bl_rna_get_subclass_py(id, default=None)

Parameters

id (string) – The RNA type identifier.

Returns

The class or default when not found.

Return type

type

Inherited Properties

bpy_struct.id_data

Inherited Functions

bpy_struct.as_pointer bpy_struct.driver_add bpy_struct.driver_remove bpy_struct.get bpy_struct.id_properties_clear bpy_struct.id_properties_ensure bpy_struct.id_properties_ui bpy_struct.is_property_hidden bpy_struct.is_property_overridable_library bpy_struct.is_property_readonly bpy_struct.is_property_set

bpy_struct.items bpy_struct.keyframe_delete bpy_struct.keyframe_insert bpy_struct.keys bpy_struct.path_from_id bpy_struct.path_resolve bpy_struct.pop bpy_struct.property_overridable_library_set bpy_struct.property_unset bpy_struct.type_recast bpy_struct.values