operators.py

# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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# ##### END GPL LICENSE BLOCK #####

# Copyright 2011, Ryan Inch

import bpy

from copy import deepcopy

from bpy.types import (
    Operator,
)

from bpy.props import (
    BoolProperty,
    StringProperty,
    IntProperty
)

from .internals import (
    expanded,
    layer_collections,
    qcd_slots,
    update_property_group,
    get_modifiers,
    send_report,
)

rto_history = {
    "exclude": {},
    "exclude_all": {},
    "select": {},
    "select_all": {},
    "hide": {},
    "hide_all": {},
    "disable": {},
    "disable_all": {},
    "render": {},
    "render_all": {}
}

copy_buffer = {"RTO": "", "values": []}
swap_buffer = {"A": {"RTO": "", "values": []}, "B": {"RTO": "", "values": []}}

class ExpandAllOperator(Operator):
    '''Expand/Collapse all collections'''
    bl_label = "Expand All Items"
    bl_idname = "view3d.expand_all_items"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context):
        if len(expanded) > 0:
            expanded.clear()
        else:
            for laycol in layer_collections.values():
                if laycol["ptr"].children:
                    expanded.append(laycol["name"])

        # update tree view
        update_property_group(context)

        return {'FINISHED'}


expand_history = {"target": "", "history": []}
class ExpandSublevelOperator(Operator):
    '''  * Ctrl-Click to expand/collapse all sublevels\n  * Shift-Click to isolate/restore tree\n  * Alt-Click to discard history'''
    bl_label = "Expand Sublevel Items"
    bl_idname = "view3d.expand_sublevel"
    bl_options = {'REGISTER', 'UNDO'}

    expand: BoolProperty()
    name: StringProperty()
    index: IntProperty()

    # static class var
    isolated = False

    def invoke(self, context, event):
        global expand_history
        cls = ExpandSublevelOperator

        modifiers = get_modifiers(event)

        if modifiers == {"alt"}:
            expand_history["target"] = ""
            expand_history["history"].clear()
            cls.isolated = False

        elif modifiers == {"ctrl"}:
            # expand/collapse all subcollections
            expand = None

            # check whether to expand or collapse
            if self.name in expanded:
                expanded.remove(self.name)
                expand = False
            else:
                expanded.append(self.name)
                expand = True

            # do expanding/collapsing
            def loop(laycol):
                for item in laycol.children:
                    if expand:
                        if not item.name in expanded:
                            expanded.append(item.name)
                    else:
                        if item.name in expanded:
                            expanded.remove(item.name)

                    if len(item.children) > 0:
                        loop(item)

            loop(layer_collections[self.name]["ptr"])

            expand_history["target"] = ""
            expand_history["history"].clear()
            cls.isolated = False

        elif modifiers == {"shift"}:
            def isolate_tree(current_laycol):
                parent = current_laycol["parent"]

                for laycol in parent["children"]:
                    if laycol["name"] != current_laycol["name"] and laycol["name"] in expanded:
                        expanded.remove(laycol["name"])
                        expand_history["history"].append(laycol["name"])

                if parent["parent"]:
                    isolate_tree(parent)

            if cls.isolated:
                for item in expand_history["history"]:
                    expanded.append(item)

                expand_history["target"] = ""
                expand_history["history"].clear()
                cls.isolated = False

            else:
                isolate_tree(layer_collections[self.name])
                expand_history["target"] = self.name
                cls.isolated = True

        else:
            # expand/collapse collection
            if self.expand:
                expanded.append(self.name)
            else:
                expanded.remove(self.name)

            expand_history["target"] = ""
            expand_history["history"].clear()
            cls.isolated = False


        # set selected row to the collection you're expanding/collapsing and update tree view
        context.scene.collection_manager.cm_list_index = self.index
        update_property_group(context)

        return {'FINISHED'}


class CMSetCollectionOperator(Operator):
    '''  * Click to move object to collection.\n  * Shift-Click to add/remove object from collection'''
    bl_label = "Set Object Collection"
    bl_idname = "view3d.set_collection"
    bl_options = {'REGISTER', 'UNDO'}

    collection_index: IntProperty()
    collection_name: StringProperty()

    def invoke(self, context, event):
        collection = layer_collections[self.collection_name]["ptr"].collection

        if event.shift:
            # add object to collection

            # check if in collection
            if context.active_object.name not in collection.objects:
                # add to collection
                bpy.ops.object.link_to_collection(collection_index=self.collection_index)

            else:
                # check and disallow removing from all collections
                for obj in context.selected_objects:
                    if len(obj.users_collection) == 1:
                        send_report("Error removing 1 or more objects from this collection.\nObjects would be left without a collection")

                        return {'FINISHED'}

                # remove from collection
                bpy.ops.collection.objects_remove(collection=collection.name)

        else:
            # move object to collection
            bpy.ops.object.move_to_collection(collection_index=self.collection_index)

        return {'FINISHED'}


class CMExcludeOperator(Operator):
    '''  * Shift-Click to isolate/restore previous state\n  * Ctrl-Click to toggle children\n  * Shift-Ctrl-Click to toggle nested isolation\n  * Alt-Click to discard history'''
    bl_label = "Exclude Collection from View Layer"
    bl_idname = "view3d.exclude_collection"
    bl_options = {'REGISTER', 'UNDO'}

    name: StringProperty()

    # static class var
    isolated = False

    def invoke(self, context, event):
        global rto_history
        cls = CMExcludeOperator

        modifiers = get_modifiers(event)
        view_layer = context.view_layer.name
        laycol_ptr = layer_collections[self.name]["ptr"]

        if not view_layer in rto_history["exclude"]:
            rto_history["exclude"][view_layer] = {"target": "", "history": []}

        target = rto_history["exclude"][view_layer]["target"]
        exclude_history = rto_history["exclude"][view_layer]["history"]

        if modifiers == {"alt"}:
            del rto_history["exclude"][view_layer]
            cls.isolated = False

        elif modifiers == {"shift"}:
            # isolate/de-isolate exclusion of collections

            active_layer_collections = [x["ptr"] for x in layer_collections.values()
                                        if not x["ptr"].exclude]

            # check if previous state should be restored
            if cls.isolated and self.name == target:
                # restore previous state
                for x, item in enumerate(layer_collections.values()):
                    item["ptr"].exclude = exclude_history[x]

                # reset exclude history
                del rto_history["exclude"][view_layer]

                cls.isolated = False

            # check if all collections should be enabled
            elif (len(active_layer_collections) == 1 and
                  active_layer_collections[0].name == self.name):
                # enable all collections
                for item in layer_collections.values():
                    item["ptr"].exclude = False

                # reset exclude history
                del rto_history["exclude"][view_layer]

                cls.isolated = False

            else:
                # isolate collection

                rto_history["exclude"][view_layer]["target"] = self.name

                # reset exclude history
                exclude_history.clear()

                # save state
                for item in layer_collections.values():
                    exclude_history.append(item["ptr"].exclude)

                # isolate collection
                for item in layer_collections.values():
                    if item["name"] != laycol_ptr.name:
                        item["ptr"].exclude = True

                laycol_ptr.exclude = False

                # exclude all children
                laycol_iter_list = [laycol_ptr.children]
                while len(laycol_iter_list) > 0:
                    new_laycol_iter_list = []
                    for laycol_iter in laycol_iter_list:
                        for layer_collection in laycol_iter:
                            layer_collection.exclude = True
                            if len(layer_collection.children) > 0:
                                new_laycol_iter_list.append(layer_collection.children)

                    laycol_iter_list = new_laycol_iter_list

                cls.isolated = True


        elif modifiers == {"ctrl"}:
            # toggle children

            # reset exclude history
            del rto_history["exclude"][view_layer]

            # toggle exclusion of collection (this propagates to children)
            laycol_ptr.exclude = not laycol_ptr.exclude

            cls.isolated = False

        elif modifiers == {"ctrl", "shift"}:
            # toggle nested isolation

            rto_history["exclude"][view_layer]["target"] = self.name

            if cls.isolated and self.name == target:
                # restore previous state
                for x, item in enumerate(layer_collections.values()):
                    item["ptr"].exclude = exclude_history[x]

                # reset exclude history
                del rto_history["exclude"][view_layer]

                cls.isolated = False

            else:
                # isolate nested collections

                # reset exclude history
                exclude_history.clear()

                # save state
                for item in layer_collections.values():
                    exclude_history.append(item["ptr"].exclude)

                # get child states
                child_states = {}
                laycol_iter_list = [laycol_ptr.children]
                while len(laycol_iter_list) > 0:
                    new_laycol_iter_list = []
                    for laycol_iter in laycol_iter_list:
                        for layer_collection in laycol_iter:
                            child_states[layer_collection.name] = layer_collection.exclude
                            if len(layer_collection.children) > 0:
                                new_laycol_iter_list.append(layer_collection.children)

                    laycol_iter_list = new_laycol_iter_list

                # isolate collection
                for item in layer_collections.values():
                    if item["name"] != laycol_ptr.name:
                        item["ptr"].exclude = True

                laycol_ptr.exclude = False

                # restore child states
                laycol_iter_list = [laycol_ptr.children]
                while len(laycol_iter_list) > 0:
                    new_laycol_iter_list = []
                    for laycol_iter in laycol_iter_list:
                        for layer_collection in laycol_iter:
                            layer_collection.exclude = child_states[layer_collection.name]
                            if len(layer_collection.children) > 0:
                                new_laycol_iter_list.append(layer_collection.children)

                    laycol_iter_list = new_laycol_iter_list

                cls.isolated = True

        else:
            # toggle exclusion

            # reset exclude history
            del rto_history["exclude"][view_layer]


            # get current child exclusion state
            child_exclusion = []

            laycol_iter_list = [laycol_ptr.children]
            while len(laycol_iter_list) > 0:
                new_laycol_iter_list = []
                for laycol_iter in laycol_iter_list:
                    for layer_collection in laycol_iter:
                        child_exclusion.append([layer_collection, layer_collection.exclude])
                        if len(layer_collection.children) > 0:
                            new_laycol_iter_list.append(layer_collection.children)

                laycol_iter_list = new_laycol_iter_list


            # toggle exclusion of collection
            laycol_ptr.exclude = not laycol_ptr.exclude


            # set correct state for all children
            for laycol in child_exclusion:
                laycol[0].exclude = laycol[1]

            cls.isolated = False

        # reset exclude all history
        if view_layer in rto_history["exclude_all"]:
            del rto_history["exclude_all"][view_layer]

        return {'FINISHED'}


class CMUnExcludeAllOperator(Operator):
    '''  * Click to toggle between current excluded state and all included.\n  * Shift-Click to invert excluded status of all collections\n  * Ctrl-Click to Copy/Paste RTOs\n  * Ctrl-Alt-Click to swap RTOs\n  * Alt-Click to discard history and copy/swap actions'''
    bl_label = "Toggle Excluded Status Of All Collections"
    bl_idname = "view3d.un_exclude_all_collections"
    bl_options = {'REGISTER', 'UNDO'}

    def invoke(self, context, event):
        global rto_history
        global copy_buffer
        global swap_buffer

        view_layer = context.view_layer.name
        modifiers = get_modifiers(event)

        if not view_layer in rto_history["exclude_all"]:
            rto_history["exclude_all"][view_layer] = []

        exclude_all_history = rto_history["exclude_all"][view_layer]

        if modifiers == {"alt"}:
            # clear RTO history
            del rto_history["exclude_all"][view_layer]

            # clear copy buffer
            if copy_buffer["RTO"] == "exclude":
                copy_buffer["RTO"] = ""
                copy_buffer["values"].clear()

            # clear swap buffer
            if swap_buffer["A"]["RTO"] == "exclude":
                swap_buffer["A"]["RTO"] = ""
                swap_buffer["A"]["values"].clear()
                swap_buffer["B"]["RTO"] = ""
                swap_buffer["B"]["values"].clear()

            return {'FINISHED'}

        if modifiers == {"ctrl"}:
            if not copy_buffer["values"]:
                # copy
                copy_buffer["RTO"] = "exclude"
                for laycol in layer_collections.values():
                    copy_buffer["values"].append(laycol["ptr"].exclude)

            else:
                # paste
                for x, laycol in enumerate(layer_collections.values()):
                    laycol["ptr"].exclude = copy_buffer["values"][x]

                # clear copy buffer
                copy_buffer["RTO"] = ""
                copy_buffer["values"].clear()

            return {'FINISHED'}

        if modifiers == {"ctrl", "alt"}:
            if not swap_buffer["A"]["values"]:
                # get A
                swap_buffer["A"]["RTO"] = "exclude"
                for laycol in layer_collections.values():
                    swap_buffer["A"]["values"].append(laycol["ptr"].exclude)

            else:
                # get B
                swap_buffer["B"]["RTO"] = "exclude"
                for laycol in layer_collections.values():
                    swap_buffer["B"]["values"].append(laycol["ptr"].exclude)

                # swap A with B
                for x, laycol in enumerate(layer_collections.values()):
                    attr_A = attr_B = laycol["ptr"]

                    # get attributes
                    RTO_A = swap_buffer["A"]["RTO"].split(".")
                    RTO_B = swap_buffer["B"]["RTO"].split(".")

                    if RTO_A[0] == "collection":
                        attr_A = getattr(attr_A, RTO_A[0])

                    if RTO_B[0] == "collection":
                        attr_B = getattr(attr_B, RTO_B[0])


                    # swap values
                    setattr(attr_A, RTO_A[-1], swap_buffer["B"]["values"][x])
                    setattr(attr_B, RTO_B[-1], swap_buffer["A"]["values"][x])

                # clear swap buffer
                swap_buffer["A"]["RTO"] = ""
                swap_buffer["A"]["values"].clear()
                swap_buffer["B"]["RTO"] = ""
                swap_buffer["B"]["values"].clear()

            return {'FINISHED'}

        if len(exclude_all_history) == 0:
            exclude_all_history.clear()
            keep_history = False

            if event.shift:
                for item in layer_collections.values():
                    keep_history = True
                    exclude_all_history.append(item["ptr"].exclude)

                for x, item in enumerate(layer_collections.values()):
                    item["ptr"].exclude = not exclude_all_history[x]

            else:
                for item in reversed(list(layer_collections.values())):
                    if item["ptr"].exclude:
                        keep_history = True

                    exclude_all_history.append(item["ptr"].exclude)

                    item["ptr"].exclude = False

                exclude_all_history.reverse()

            if not keep_history:
                del rto_history["exclude_all"][view_layer]

        else:
            for x, item in enumerate(layer_collections.values()):
                item["ptr"].exclude = exclude_all_history[x]

            del rto_history["exclude_all"][view_layer]

        return {'FINISHED'}


class CMRestrictSelectOperator(Operator):
    '''  * Shift-Click to isolate/restore previous state\n  * Ctrl-Click to toggle children\n  * Shift-Ctrl-Click to toggle nested isolation\n  * Alt-Click to discard history'''
    bl_label = "Disable Selection of Collection"
    bl_idname = "view3d.restrict_select_collection"
    bl_options = {'REGISTER', 'UNDO'}

    name: StringProperty()

    # static class var
    isolated = False

    def invoke(self, context, event):
        global rto_history
        cls = CMRestrictSelectOperator

        modifiers = get_modifiers(event)
        view_layer = context.view_layer.name
        laycol_ptr = layer_collections[self.name]["ptr"]

        if not view_layer in rto_history["select"]:
            rto_history["select"][view_layer] = {"target": "", "history": []}

        target = rto_history["select"][view_layer]["target"]
        select_history = rto_history["select"][view_layer]["history"]

        if modifiers == {"alt"}:
            del rto_history["select"][view_layer]
            cls.isolated = False

        elif modifiers == {"shift"}:
            # isolate/de-isolate selectability of collections

            laycol = layer_collections[self.name]

            # get active collections
            active_layer_collections = [x["ptr"] for x in layer_collections.values()
                                        if x["ptr"].collection.hide_select == False]

            # check if previous state should be restored
            if cls.isolated and self.name == target:
                # restore previous state
                for x, item in enumerate(layer_collections.values()):
                    item["ptr"].collection.hide_select = select_history[x]

                # reset select history
                del rto_history["select"][view_layer]

                cls.isolated = False

            # check if all collections should be enabled
            elif (len(active_layer_collections) == 1 and
                  active_layer_collections[0].name == self.name):
                # make all collections selectable
                for item in layer_collections.values():
                    item["ptr"].collection.hide_select = False

                # reset select history
                del rto_history["select"][view_layer]

                cls.isolated = False

            else:
                # isolate selectability

                rto_history["select"][view_layer]["target"] = self.name

                # reset select history
                select_history.clear()

                # save state
                for item in layer_collections.values():
                    select_history.append(item["ptr"].collection.hide_select)

                # make all collections unselectable
                for item in layer_collections.values():
                    item["ptr"].collection.hide_select = True

                # allow selection of active collection plus parents
                laycol_ptr.collection.hide_select = False

                laycol = layer_collections[self.name]
                while laycol["id"] != 0:
                    laycol["ptr"].collection.hide_select = False
                    laycol = laycol["parent"]

                cls.isolated = True

        elif modifiers == {"ctrl"}:
            # toggle children

            # reset select history
            del rto_history["select"][view_layer]

            # toggle selectability of collection
            state = not laycol_ptr.collection.hide_select
            laycol_ptr.collection.hide_select = state

            # pass state to children
            laycol_iter_list = [laycol_ptr.children]
            while len(laycol_iter_list) > 0:
                new_laycol_iter_list = []
                for laycol_iter in laycol_iter_list:
                    for layer_collection in laycol_iter:
                        layer_collection.collection.hide_select = state
                        if len(layer_collection.children) > 0:
                            new_laycol_iter_list.append(layer_collection.children)

                laycol_iter_list = new_laycol_iter_list

            cls.isolated = False

        elif modifiers == {"ctrl", "shift"}:
            # isolate nested collections

            laycol = layer_collections[self.name]

            # check if previous state should be restored
            if cls.isolated and self.name == target:
                # restore previous state
                for x, item in enumerate(layer_collections.values()):
                    item["ptr"].collection.hide_select = select_history[x]

                # reset select history
                del rto_history["select"][view_layer]

                cls.isolated = False

            else:
                # isolate nested selectability

                rto_history["select"][view_layer]["target"] = self.name

                # reset select history
                select_history.clear()

                # save state
                for item in layer_collections.values():
                    select_history.append(item["ptr"].collection.hide_select)

                # get child states
                child_states = {}
                laycol_iter_list = [laycol_ptr.children]
                while len(laycol_iter_list) > 0:
                    new_laycol_iter_list = []
                    for laycol_iter in laycol_iter_list:
                        for layer_collection in laycol_iter:
                            child_states[layer_collection.name] = layer_collection.collection.hide_select
                            if len(layer_collection.children) > 0:
                                new_laycol_iter_list.append(layer_collection.children)

                    laycol_iter_list = new_laycol_iter_list

                # make all collections unselectable
                for item in layer_collections.values():
                    item["ptr"].collection.hide_select = True

                # allow selection of active collection plus parents
                laycol_ptr.collection.hide_select = False

                laycol = layer_collections[self.name]
                while laycol["id"] != 0:
                    laycol["ptr"].collection.hide_select = False
                    laycol = laycol["parent"]

                # restore child states
                laycol_iter_list = [laycol_ptr.children]
                while len(laycol_iter_list) > 0:
                    new_laycol_iter_list = []
                    for laycol_iter in laycol_iter_list:
                        for layer_collection in laycol_iter:
                            layer_collection.collection.hide_select = child_states[layer_collection.name]
                            if len(layer_collection.children) > 0:
                                new_laycol_iter_list.append(layer_collection.children)

                    laycol_iter_list = new_laycol_iter_list

                cls.isolated = True

        else:
            # toggle selectable

            # reset select history
            del rto_history["select"][view_layer]

            # toggle selectability of collection
            laycol_ptr.collection.hide_select = not laycol_ptr.collection.hide_select

            cls.isolated = False

        # reset select all history
        if view_layer in rto_history["select_all"]:
            del rto_history["select_all"][view_layer]

        return {'FINISHED'}


class CMUnRestrictSelectAllOperator(Operator):
    '''  * Click to toggle between current selectable state and all selectable.\n  * Shift-Click to invert selectable status of all collections\n  * Ctrl-Click to Copy/Paste RTOs\n  * Ctrl-Alt-Click to swap RTOs\n  * Alt-Click to discard history and copy/swap actions'''
    bl_label = "Toggle Selectable Status Of All Collections"
    bl_idname = "view3d.un_restrict_select_all_collections"
    bl_options = {'REGISTER', 'UNDO'}

    def invoke(self, context, event):
        global rto_history
        global copy_buffer
        global swap_buffer

        view_layer = context.view_layer.name
        modifiers = get_modifiers(event)

        if not view_layer in rto_history["select_all"]:
            rto_history["select_all"][view_layer] = []

        select_all_history = rto_history["select_all"][view_layer]

        if modifiers == {"alt"}:
            # clear RTO history
            del rto_history["select_all"][view_layer]

            # clear copy buffer
            if copy_buffer["RTO"] == "collection.hide_select":
                copy_buffer["RTO"] = ""
                copy_buffer["values"].clear()

            # clear swap buffer
            if swap_buffer["A"]["RTO"] == "collection.hide_select":
                swap_buffer["A"]["RTO"] = ""
                swap_buffer["A"]["values"].clear()
                swap_buffer["B"]["RTO"] = ""
                swap_buffer["B"]["values"].clear()

            return {'FINISHED'}

        if modifiers == {"ctrl"}:
            if not copy_buffer["values"]:
                # copy
                copy_buffer["RTO"] = "collection.hide_select"
                for laycol in layer_collections.values():
                    copy_buffer["values"].append(laycol["ptr"].collection.hide_select)

            else:
                # paste
                for x, laycol in enumerate(layer_collections.values()):
                    laycol["ptr"].collection.hide_select = copy_buffer["values"][x]

                # clear copy buffer
                copy_buffer["RTO"] = ""
                copy_buffer["values"].clear()

            return {'FINISHED'}

        if modifiers == {"ctrl", "alt"}:
            if not swap_buffer["A"]["values"]:
                # get A
                swap_buffer["A"]["RTO"] = "collection.hide_select"
                for laycol in layer_collections.values():
                    swap_buffer["A"]["values"].append(laycol["ptr"].collection.hide_select)

            else:
                # get B
                swap_buffer["B"]["RTO"] = "collection.hide_select"
                for laycol in layer_collections.values():
                    swap_buffer["B"]["values"].append(laycol["ptr"].collection.hide_select)

                # swap A with B
                for x, laycol in enumerate(layer_collections.values()):
                    attr_A = attr_B = laycol["ptr"]

                    # get attributes
                    RTO_A = swap_buffer["A"]["RTO"].split(".")
                    RTO_B = swap_buffer["B"]["RTO"].split(".")

                    if RTO_A[0] == "collection":
                        attr_A = getattr(attr_A, RTO_A[0])

                    if RTO_B[0] == "collection":
                        attr_B = getattr(attr_B, RTO_B[0])


                    # swap values
                    setattr(attr_A, RTO_A[-1], swap_buffer["B"]["values"][x])
                    setattr(attr_B, RTO_B[-1], swap_buffer["A"]["values"][x])

                # clear swap buffer
                swap_buffer["A"]["RTO"] = ""
                swap_buffer["A"]["values"].clear()
                swap_buffer["B"]["RTO"] = ""
                swap_buffer["B"]["values"].clear()

            return {'FINISHED'}

        if len(select_all_history) == 0:
            select_all_history.clear()
            keep_history = False

            for item in layer_collections.values():
                collection = item["ptr"].collection

                if event.shift:
                    keep_history = True
                    select_all_history.append(collection.hide_select)
                    collection.hide_select = not collection.hide_select

                else:
                    if collection.hide_select:
                        keep_history = True

                    select_all_history.append(collection.hide_select)
                    collection.hide_select = False

            if not keep_history:
                del rto_history["select_all"][view_layer]

        else:
            for x, item in enumerate(layer_collections.values()):
                item["ptr"].collection.hide_select = select_all_history[x]

            del rto_history["select_all"][view_layer]

        return {'FINISHED'}


class CMHideOperator(Operator):
    '''  * Shift-Click to isolate/restore previous state\n  * Ctrl-Click to toggle children\n  * Shift-Ctrl-Click to toggle nested isolation\n  * Alt-Click to discard history'''
    bl_label = "Hide Collection"
    bl_idname = "view3d.hide_collection"
    bl_options = {'REGISTER', 'UNDO'}

    name: StringProperty()

    # static class var
    isolated = False

    def invoke(self, context, event):
        global rto_history
        cls = CMHideOperator

        modifiers = get_modifiers(event)
        view_layer = context.view_layer.name
        laycol_ptr = layer_collections[self.name]["ptr"]

        if not view_layer in rto_history["hide"]:
            rto_history["hide"][view_layer] = {"target": "", "history": []}

        target = rto_history["hide"][view_layer]["target"]
        hide_history = rto_history["hide"][view_layer]["history"]

        if modifiers == {"alt"}:
            del rto_history["hide"][view_layer]
            cls.isolated = False

        elif modifiers == {"shift"}:
            # isolate/de-isolate view of collections

            laycol = layer_collections[self.name]

            # get active collections
            active_layer_collections = [x["ptr"] for x in layer_collections.values()
                                        if x["ptr"].hide_viewport == False]

            # check if previous state should be restored
            if cls.isolated and self.name == target:
                # restore previous state
                for x, item in enumerate(layer_collections.values()):
                    item["ptr"].hide_viewport = hide_history[x]

                # reset hide history
                del rto_history["hide"][view_layer]

                cls.isolated = False

            # check if all collections should be enabled
            elif (len(active_layer_collections) == 1 and
                  active_layer_collections[0].name == self.name):
                # show all collections
                for laycol in layer_collections.values():
                    laycol["ptr"].hide_viewport = False

            # reset hide history
                del rto_history["hide"][view_layer]

                cls.isolated = False

            else:
                # isolate visibility

                rto_history["hide"][view_layer]["target"] = self.name

                # reset hide history
                hide_history.clear()

                # save state
                for item in layer_collections.values():
                    hide_history.append(item["ptr"].hide_viewport)

                # hide all collections
                for laycol in layer_collections.values():
                    laycol["ptr"].hide_viewport = True

                # show active collection plus parents
                laycol_ptr.hide_viewport = False

                laycol = layer_collections[self.name]
                while laycol["id"] != 0:
                    laycol["ptr"].hide_viewport = False
                    laycol = laycol["parent"]

                cls.isolated = True

        elif modifiers == {"ctrl"}:
            # toggle children

            # reset hide history
            del rto_history["hide"][view_layer]

            # toggle view of collection
            state = not laycol_ptr.hide_viewport
            laycol_ptr.hide_viewport = state

            # pass state to children
            laycol_iter_list = [laycol_ptr.children]
            while len(laycol_iter_list) > 0:
                new_laycol_iter_list = []
                for laycol_iter in laycol_iter_list:
                    for layer_collection in laycol_iter:
                        layer_collection.hide_viewport = state
                        if len(layer_collection.children) > 0:
                            new_laycol_iter_list.append(layer_collection.children)

                laycol_iter_list = new_laycol_iter_list

            cls.isolated = False

        elif modifiers == {"ctrl", "shift"}:
            # isolate nested collections

            laycol = layer_collections[self.name]

            # check if previous state should be restored
            if cls.isolated and self.name == target:
                # restore previous state
                for x, item in enumerate(layer_collections.values()):
                    item["ptr"].hide_viewport = hide_history[x]

                # reset hide history
                del rto_history["hide"][view_layer]

                cls.isolated = False

            else:
                # isolate nested visibility