blender/scripts/templates_py/ui_previews_dynamic_enum.py
Campbell Barton 98986c6562 Python: replace '%' with str.format for examples & templates
Use modern/preferred string formatting for user facing scripts.
2024-04-12 15:33:40 +10:00

142 lines
4.1 KiB
Python

# This sample script demonstrates a dynamic EnumProperty with custom icons.
# The EnumProperty is populated dynamically with thumbnails of the contents of
# a chosen directory in 'enum_previews_from_directory_items'.
# Then, the same enum is displayed with different interfaces. Note that the
# generated icon previews do not have Blender IDs, which means that they can
# not be used with UILayout templates that require IDs,
# such as template_list and template_ID_preview.
#
# Other use cases:
# - make a fixed list of enum_items instead of calculating them in a function
# - generate isolated thumbnails to use as custom icons in buttons
# and menu items
#
# For custom icons, see the template "ui_previews_custom_icon.py".
#
# For distributable scripts, it is recommended to place the icons inside the
# script directory and access it relative to the py script file for portability:
#
# os.path.join(os.path.dirname(__file__), "images")
import os
import bpy
def enum_previews_from_directory_items(self, context):
"""EnumProperty callback"""
enum_items = []
if context is None:
return enum_items
wm = context.window_manager
directory = wm.my_previews_dir
# Get the preview collection (defined in register func).
pcoll = preview_collections["main"]
if directory == pcoll.my_previews_dir:
return pcoll.my_previews
print("Scanning directory:", directory)
if directory and os.path.exists(directory):
# Scan the directory for `*.png` files
image_paths = []
for fn in os.listdir(directory):
if fn.lower().endswith(".png"):
image_paths.append(fn)
for i, name in enumerate(image_paths):
# generates a thumbnail preview for a file.
filepath = os.path.join(directory, name)
icon = pcoll.get(name)
if not icon:
thumb = pcoll.load(name, filepath, 'IMAGE')
else:
thumb = pcoll[name]
enum_items.append((name, name, "", thumb.icon_id, i))
pcoll.my_previews = enum_items
pcoll.my_previews_dir = directory
return pcoll.my_previews
class PreviewsExamplePanel(bpy.types.Panel):
"""Creates a Panel in the Object properties window"""
bl_label = "Previews Example Panel"
bl_idname = "OBJECT_PT_previews"
bl_space_type = 'PROPERTIES'
bl_region_type = 'WINDOW'
bl_context = "object"
def draw(self, context):
layout = self.layout
wm = context.window_manager
row = layout.row()
row.prop(wm, "my_previews_dir")
row = layout.row()
row.template_icon_view(wm, "my_previews")
row = layout.row()
row.prop(wm, "my_previews")
# We can store multiple preview collections here,
# however in this example we only store "main"
preview_collections = {}
def register():
from bpy.types import WindowManager
from bpy.props import (
StringProperty,
EnumProperty,
)
WindowManager.my_previews_dir = StringProperty(
name="Folder Path",
subtype='DIR_PATH',
default=""
)
WindowManager.my_previews = EnumProperty(
items=enum_previews_from_directory_items,
)
# Note that preview collections returned by bpy.utils.previews
# are regular Python objects - you can use them to store custom data.
#
# This is especially useful here, since:
# - It avoids us regenerating the whole enum over and over.
# - It can store enum_items' strings
# (remember you have to keep those strings somewhere in py,
# else they get freed and Blender references invalid memory!).
import bpy.utils.previews
pcoll = bpy.utils.previews.new()
pcoll.my_previews_dir = ""
pcoll.my_previews = ()
preview_collections["main"] = pcoll
bpy.utils.register_class(PreviewsExamplePanel)
def unregister():
from bpy.types import WindowManager
del WindowManager.my_previews
for pcoll in preview_collections.values():
bpy.utils.previews.remove(pcoll)
preview_collections.clear()
bpy.utils.unregister_class(PreviewsExamplePanel)
if __name__ == "__main__":
register()