Differential D1255 Diff 4214 release/scripts/templates_py/ui_previews_dynamic_enum.py

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release/scripts/templates_py/ui_previews_dynamic_enum.py

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				# 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 addons, it is recommended to place the icons inside the
				# addon 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"""
				wm = context.window_manager

				enum_items = []
				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: %s" % 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.
				# Also works with previews for 'MOVIE', 'BLEND' and 'FONT'
				filepath = os.path.join(directory, name)
				thumb = pcoll.load(filepath, filepath, 'IMAGE')
				# enum item: (identifier, name, description, icon, number)
				enum_items.append((name, 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()