Files
test2/scripts/startup/bl_ui/generic_ui_list.py
2023-06-20 12:15:57 +10:00

263 lines
7.3 KiB
Python

# SPDX-FileCopyrightText: 2023 Blender Foundation
#
# SPDX-License-Identifier: GPL-2.0-or-later
"""
This module (in particular the draw_ui_list function) lets you draw the commonly
used UIList layout, seen all over Blender.
This includes the list itself, and a column of buttons to the right of it, which
contains buttons to add, remove, and move entries up or down, as well as a
drop-down menu.
You can get an example of how to use this via the Blender Text Editor->
Templates->Ui List Generic.
"""
import bpy
from bpy.types import Operator
from bpy.props import (
EnumProperty,
StringProperty,
)
__all__ = (
"draw_ui_list",
)
def draw_ui_list(
layout,
context,
class_name="UI_UL_list",
*,
unique_id,
list_path,
active_index_path,
insertion_operators=True,
move_operators=True,
menu_class_name="",
**kwargs,
):
"""
Draw a UIList with Add/Remove/Move buttons and a menu.
:arg layout: UILayout to draw the list in.
:type layout: :class:`UILayout`
:arg context: Blender context to get the list data from.
:type context: :class:`Context`
:arg class_name: Name of the UIList class to draw. The default is the UIList class that ships with Blender.
:type class_name: str
:arg unique_id: Unique identifier to differentiate this from other UI lists.
:type unique_id: str
:arg list_path: Data path of the list relative to context, eg. "object.vertex_groups".
:type list_path: str
:arg active_index_path: Data path of the list active index integer relative to context,
eg. "object.vertex_groups.active_index".
:type active_index_path: str
:arg insertion_operators: Whether to draw Add/Remove buttons.
:type insertion_operators: bool
:arg move_operators: Whether to draw Move Up/Down buttons.
:type move_operators: str
:arg menu_class_name: Identifier of a Menu that should be drawn as a drop-down.
:type menu_class_name: str
:returns: The right side column.
:rtype: :class:`UILayout`.
Additional keyword arguments are passed to :class:`UIList.template_list`.
"""
row = layout.row()
list_owner_path, list_prop_name = list_path.rsplit('.', 1)
list_owner = _get_context_attr(context, list_owner_path)
index_owner_path, index_prop_name = active_index_path.rsplit('.', 1)
index_owner = _get_context_attr(context, index_owner_path)
list_to_draw = _get_context_attr(context, list_path)
row.template_list(
class_name,
unique_id,
list_owner, list_prop_name,
index_owner, index_prop_name,
rows=4 if list_to_draw else 1,
**kwargs
)
col = row.column()
if insertion_operators:
_draw_add_remove_buttons(
layout=col,
list_path=list_path,
active_index_path=active_index_path,
list_length=len(list_to_draw)
)
layout.separator()
if menu_class_name:
col.menu(menu_class_name, icon='DOWNARROW_HLT', text="")
col.separator()
if move_operators and list_to_draw:
_draw_move_buttons(
layout=col,
list_path=list_path,
active_index_path=active_index_path,
list_length=len(list_to_draw)
)
# Return the right-side column.
return col
def _draw_add_remove_buttons(
*,
layout,
list_path,
active_index_path,
list_length,
):
"""Draw the +/- buttons to add and remove list entries."""
props = layout.operator(UILIST_OT_entry_add.bl_idname, text="", icon='ADD')
props.list_path = list_path
props.active_index_path = active_index_path
row = layout.row()
row.enabled = list_length > 0
props = row.operator(UILIST_OT_entry_remove.bl_idname, text="", icon='REMOVE')
props.list_path = list_path
props.active_index_path = active_index_path
def _draw_move_buttons(
*,
layout,
list_path,
active_index_path,
list_length,
):
"""Draw the up/down arrows to move elements in the list."""
col = layout.column()
col.enabled = list_length > 1
props = layout.operator(UILIST_OT_entry_move.bl_idname, text="", icon='TRIA_UP')
props.direction = 'UP'
props.list_path = list_path
props.active_index_path = active_index_path
props = layout.operator(UILIST_OT_entry_move.bl_idname, text="", icon='TRIA_DOWN')
props.direction = 'DOWN'
props.list_path = list_path
props.active_index_path = active_index_path
def _get_context_attr(context, data_path):
"""Return the value of a context member based on its data path."""
return context.path_resolve(data_path)
def _set_context_attr(context, data_path, value):
"""Set the value of a context member based on its data path."""
owner_path, attr_name = data_path.rsplit('.', 1)
owner = context.path_resolve(owner_path)
setattr(owner, attr_name, value)
class GenericUIListOperator:
"""Mix-in class containing functionality shared by operators
that deal with managing Blender list entries."""
bl_options = {'REGISTER', 'UNDO', 'INTERNAL'}
list_path: StringProperty()
active_index_path: StringProperty()
def get_list(self, context):
return _get_context_attr(context, self.list_path)
def get_active_index(self, context):
return _get_context_attr(context, self.active_index_path)
def set_active_index(self, context, index):
_set_context_attr(context, self.active_index_path, index)
class UILIST_OT_entry_remove(GenericUIListOperator, Operator):
"""Remove the selected entry from the list"""
bl_idname = "uilist.entry_remove"
bl_label = "Remove Selected Entry"
def execute(self, context):
my_list = self.get_list(context)
active_index = self.get_active_index(context)
my_list.remove(active_index)
to_index = min(active_index, len(my_list) - 1)
self.set_active_index(context, to_index)
return {'FINISHED'}
class UILIST_OT_entry_add(GenericUIListOperator, Operator):
"""Add an entry to the list after the current active item"""
bl_idname = "uilist.entry_add"
bl_label = "Add Entry"
def execute(self, context):
my_list = self.get_list(context)
active_index = self.get_active_index(context)
to_index = min(len(my_list), active_index + 1)
my_list.add()
my_list.move(len(my_list) - 1, to_index)
self.set_active_index(context, to_index)
return {'FINISHED'}
class UILIST_OT_entry_move(GenericUIListOperator, Operator):
"""Move an entry in the list up or down"""
bl_idname = "uilist.entry_move"
bl_label = "Move Entry"
direction: EnumProperty(
name="Direction",
items=(
('UP', 'UP', 'UP'),
('DOWN', 'DOWN', 'DOWN'),
),
default='UP',
)
def execute(self, context):
my_list = self.get_list(context)
active_index = self.get_active_index(context)
delta = {
'DOWN': 1,
'UP': -1,
}[self.direction]
to_index = (active_index + delta) % len(my_list)
my_list.move(active_index, to_index)
self.set_active_index(context, to_index)
return {'FINISHED'}
# Registration.
classes = (
UILIST_OT_entry_remove,
UILIST_OT_entry_add,
UILIST_OT_entry_move,
)
register, unregister = bpy.utils.register_classes_factory(classes)