operators.py

            for inout, soctype in (
                    ('INPUTS', 'MAIN',),
                    ('INPUTS', 'SHADER',),
                    ('INPUTS', 'RGBA',),
                    ('INPUTS', 'VECTOR',),
                    ('INPUTS', 'VALUE',),
                    ('OUTPUTS', 'MAIN',),
                    ('OUTPUTS', 'SHADER',),
                    ('OUTPUTS', 'RGBA',),
                    ('OUTPUTS', 'VECTOR',),
                    ('OUTPUTS', 'VALUE',),
            ):
                if src_sockets[inout][soctype] and dst_sockets[inout][soctype]:
                    if soctype == 'MAIN':
                        sc = src_sockets[inout][src_sockets[inout]['MAIN']]
                        dt = dst_sockets[inout][dst_sockets[inout]['MAIN']]
                    else:
                        sc = src_sockets[inout][soctype]
                        dt = dst_sockets[inout][soctype]
                    # start with 'dt' to determine number of possibilities.
                    for i, soc in enumerate(dt):
                        # if src main has enough entries - match them with dst main sockets by indexes.
                        if len(sc) > i:
                            matches[inout][soctype].append(((sc[i][1], sc[i][3]), (soc[1], soc[3])))
                        # add 'VALUE_NAME' criterion to inputs.
                        if inout == 'INPUTS' and soctype == 'VALUE':
                            for s in sc:
                                if s[2] == soc[2]:  # if names match
                                    # append src (index, dval), dst (index, dval)
                                    matches['INPUTS']['VALUE_NAME'].append(((s[1], s[3]), (soc[1], soc[3])))

            # When src ['INPUTS']['MAIN'] is 'VECTOR' replace 'MAIN' with matches VECTOR if possible.
            # This creates better links when relinking textures.
            if src_sockets['INPUTS']['MAIN'] == 'VECTOR' and matches['INPUTS']['VECTOR']:
                matches['INPUTS']['MAIN'] = matches['INPUTS']['VECTOR']

            # Pass default values and RELINK:
            for tp in ('MAIN', 'SHADER', 'RGBA', 'VECTOR', 'VALUE_NAME', 'VALUE'):
                # INPUTS: Base on matches in proper order.
                for (src_i, src_dval), (dst_i, dst_dval) in matches['INPUTS'][tp]:
                    # pass dvals
                    if src_dval and dst_dval and tp in {'RGBA', 'VALUE_NAME'}:
                        new_node.inputs[dst_i].default_value = src_dval
                    # Special case: switch to math
                    if node.type in {'MIX_RGB', 'ALPHAOVER', 'ZCOMBINE'} and\
                            new_node.type == 'MATH' and\
                            tp == 'MAIN':
                        new_dst_dval = max(src_dval[0], src_dval[1], src_dval[2])
                        new_node.inputs[dst_i].default_value = new_dst_dval
                        if node.type == 'MIX_RGB':
                            if node.blend_type in [o[0] for o in operations]:
                                new_node.operation = node.blend_type
                    # Special case: switch from math to some types
                    if node.type == 'MATH' and\
                            new_node.type in {'MIX_RGB', 'ALPHAOVER', 'ZCOMBINE'} and\
                            tp == 'MAIN':
                        for i in range(3):
                            new_node.inputs[dst_i].default_value[i] = src_dval
                        if new_node.type == 'MIX_RGB':
                            if node.operation in [t[0] for t in blend_types]:
                                new_node.blend_type = node.operation
                            # Set Fac of MIX_RGB to 1.0
                            new_node.inputs[0].default_value = 1.0
                    # make link only when dst matching input is not linked already.
                    if node.inputs[src_i].links and not new_node.inputs[dst_i].links:
                        in_src_link = node.inputs[src_i].links[0]
                        in_dst_socket = new_node.inputs[dst_i]
                        connect_sockets(in_src_link.from_socket, in_dst_socket)
                        links.remove(in_src_link)
                # OUTPUTS: Base on matches in proper order.
                for (src_i, src_dval), (dst_i, dst_dval) in matches['OUTPUTS'][tp]:
                    for out_src_link in node.outputs[src_i].links:
                        out_dst_socket = new_node.outputs[dst_i]
                        connect_sockets(out_dst_socket, out_src_link.to_socket)
            # relink rest inputs if possible, no criteria
            for src_inp in node.inputs:
                for dst_inp in new_node.inputs:
                    if src_inp.links and not dst_inp.links:
                        src_link = src_inp.links[0]
                        connect_sockets(src_link.from_socket, dst_inp)
                        links.remove(src_link)
            # relink rest outputs if possible, base on node kind if any left.
            for src_o in node.outputs:
                for out_src_link in src_o.links:
                    for dst_o in new_node.outputs:
                        if src_o.type == dst_o.type:
                            connect_sockets(dst_o, out_src_link.to_socket)
            # relink rest outputs no criteria if any left. Link all from first output.
            for src_o in node.outputs:
                for out_src_link in src_o.links:
                    if new_node.outputs:
                        connect_sockets(new_node.outputs[0], out_src_link.to_socket)
            nodes.remove(node)
        force_update(context)
        return {'FINISHED'}


class NWMergeNodes(Operator, NWBase):
    bl_idname = "node.nw_merge_nodes"
    bl_label = "Merge Nodes"
    bl_description = "Merge Selected Nodes"
    bl_options = {'REGISTER', 'UNDO'}

    mode: EnumProperty(
        name="mode",
        description="All possible blend types, boolean operations and math operations",
        items=blend_types + [op for op in geo_combine_operations if op not in blend_types] + [op for op in operations if op not in blend_types],
    )
    merge_type: EnumProperty(
        name="merge type",
        description="Type of Merge to be used",
        items=(
            ('AUTO', 'Auto', 'Automatic Output Type Detection'),
            ('SHADER', 'Shader', 'Merge using ADD or MIX Shader'),
            ('GEOMETRY', 'Geometry', 'Merge using Mesh Boolean or Join Geometry Node'),
            ('MIX', 'Mix Node', 'Merge using Mix Nodes'),
            ('MATH', 'Math Node', 'Merge using Math Nodes'),
            ('ZCOMBINE', 'Z-Combine Node', 'Merge using Z-Combine Nodes'),
            ('ALPHAOVER', 'Alpha Over Node', 'Merge using Alpha Over Nodes'),
        ),
    )

    # Check if the link connects to a node that is in selected_nodes
    # If not, then check recursively for each link in the nodes outputs.
    # If yes, return True. If the recursion stops without finding a node
    # in selected_nodes, it returns False. The depth is used to prevent
    # getting stuck in a loop because of an already present cycle.
    @staticmethod
    def link_creates_cycle(link, selected_nodes, depth=0) -> bool:
        if depth > 255:
            # We're stuck in a cycle, but that cycle was already present,
            # so we return False.
            # NOTE: The number 255 is arbitrary, but seems to work well.
            return False
        node = link.to_node
        if node in selected_nodes:
            return True
        if not node.outputs:
            return False
        for output in node.outputs:
            if output.is_linked:
                for olink in output.links:
                    if NWMergeNodes.link_creates_cycle(olink, selected_nodes, depth + 1):
                        return True
        # None of the outputs found a node in selected_nodes, so there is no cycle.
        return False

    # Merge the nodes in `nodes_list` with a node of type `node_name` that has a multi_input socket.
    # The parameters `socket_indices` gives the indices of the node sockets in the order that they should
    # be connected. The last one is assumed to be a multi input socket.
    # For convenience the node is returned.
    @staticmethod
    def merge_with_multi_input(nodes_list, merge_position, do_hide, loc_x, links, nodes, node_name, socket_indices):
        # The y-location of the last node
        loc_y = nodes_list[-1][2]
        if merge_position == 'CENTER':
            # Average the y-location
            for i in range(len(nodes_list) - 1):
                loc_y += nodes_list[i][2]
            loc_y = loc_y / len(nodes_list)
        new_node = nodes.new(node_name)
        new_node.hide = do_hide
        new_node.location.x = loc_x
        new_node.location.y = loc_y
        selected_nodes = [nodes[node_info[0]] for node_info in nodes_list]
        prev_links = []
        outputs_for_multi_input = []
        for i, node in enumerate(selected_nodes):
            node.select = False
            # Search for the first node which had output links that do not create
            # a cycle, which we can then reconnect afterwards.
            if prev_links == [] and node.outputs[0].is_linked:
                prev_links = [
                    link for link in node.outputs[0].links if not NWMergeNodes.link_creates_cycle(
                        link, selected_nodes)]
            # Get the index of the socket, the last one is a multi input, and is thus used repeatedly
            # To get the placement to look right we need to reverse the order in which we connect the
            # outputs to the multi input socket.
            if i < len(socket_indices) - 1:
                ind = socket_indices[i]
                connect_sockets(node.outputs[0], new_node.inputs[ind])
            else:
                outputs_for_multi_input.insert(0, node.outputs[0])
        if outputs_for_multi_input != []:
            ind = socket_indices[-1]
            for output in outputs_for_multi_input:
                connect_sockets(output, new_node.inputs[ind])
        if prev_links != []:
            for link in prev_links:
                connect_sockets(new_node.outputs[0], link.to_node.inputs[0])
        return new_node

    def execute(self, context):
        settings = context.preferences.addons[__package__].preferences
        merge_hide = settings.merge_hide
        merge_position = settings.merge_position  # 'center' or 'bottom'

        do_hide = False
        do_hide_shader = False
        if merge_hide == 'ALWAYS':
            do_hide = True
            do_hide_shader = True
        elif merge_hide == 'NON_SHADER':
            do_hide = True

        tree_type = context.space_data.node_tree.type
        if tree_type == 'GEOMETRY':
            node_type = 'GeometryNode'
        if tree_type == 'COMPOSITING':
            node_type = 'CompositorNode'
        elif tree_type == 'SHADER':
            node_type = 'ShaderNode'
        elif tree_type == 'TEXTURE':
            node_type = 'TextureNode'
        nodes, links = get_nodes_links(context)
        mode = self.mode
        merge_type = self.merge_type
        # Prevent trying to add Z-Combine in not 'COMPOSITING' node tree.
        # 'ZCOMBINE' works only if mode == 'MIX'
        # Setting mode to None prevents trying to add 'ZCOMBINE' node.
        if (merge_type == 'ZCOMBINE' or merge_type == 'ALPHAOVER') and tree_type != 'COMPOSITING':
            merge_type = 'MIX'
            mode = 'MIX'
        if (merge_type != 'MATH' and merge_type != 'GEOMETRY') and tree_type == 'GEOMETRY':
            merge_type = 'AUTO'
        # The Mix node and math nodes used for geometry nodes are of type 'ShaderNode'
        if (merge_type == 'MATH' or merge_type == 'MIX') and tree_type == 'GEOMETRY':
            node_type = 'ShaderNode'
        selected_mix = []  # entry = [index, loc]
        selected_shader = []  # entry = [index, loc]
        selected_geometry = []  # entry = [index, loc]
        selected_math = []  # entry = [index, loc]
        selected_vector = []  # entry = [index, loc]
        selected_z = []  # entry = [index, loc]
        selected_alphaover = []  # entry = [index, loc]

        for i, node in enumerate(nodes):
            if node.select and node.outputs:
                if merge_type == 'AUTO':
                    for (type, types_list, dst) in (
                            ('SHADER', ('MIX', 'ADD'), selected_shader),
                            ('GEOMETRY', [t[0] for t in geo_combine_operations], selected_geometry),
                            ('RGBA', [t[0] for t in blend_types], selected_mix),
                            ('VALUE', [t[0] for t in operations], selected_math),
                            ('VECTOR', [], selected_vector),
                    ):
                        output = get_first_enabled_output(node)
                        output_type = output.type
                        valid_mode = mode in types_list
                        # When mode is 'MIX' we have to cheat since the mix node is not used in
                        # geometry nodes.
                        if tree_type == 'GEOMETRY':
                            if mode == 'MIX':
                                if output_type == 'VALUE' and type == 'VALUE':
                                    valid_mode = True
                                elif output_type == 'VECTOR' and type == 'VECTOR':
                                    valid_mode = True
                                elif type == 'GEOMETRY':
                                    valid_mode = True
                        # When mode is 'MIX' use mix node for both 'RGBA' and 'VALUE' output types.
                        # Cheat that output type is 'RGBA',
                        # and that 'MIX' exists in math operations list.
                        # This way when selected_mix list is analyzed:
                        # Node data will be appended even though it doesn't meet requirements.
                        elif output_type != 'SHADER' and mode == 'MIX':
                            output_type = 'RGBA'
                            valid_mode = True
                        if output_type == type and valid_mode:
                            dst.append([i, node.location.x, node.location.y, node.dimensions.x, node.hide])
                else:
                    for (type, types_list, dst) in (
                            ('SHADER', ('MIX', 'ADD'), selected_shader),
                            ('GEOMETRY', [t[0] for t in geo_combine_operations], selected_geometry),
                            ('MIX', [t[0] for t in blend_types], selected_mix),
                            ('MATH', [t[0] for t in operations], selected_math),
                            ('ZCOMBINE', ('MIX', ), selected_z),
                            ('ALPHAOVER', ('MIX', ), selected_alphaover),
                    ):
                        if merge_type == type and mode in types_list:
                            dst.append([i, node.location.x, node.location.y, node.dimensions.x, node.hide])
        # When nodes with output kinds 'RGBA' and 'VALUE' are selected at the same time
        # use only 'Mix' nodes for merging.
        # For that we add selected_math list to selected_mix list and clear selected_math.
        if selected_mix and selected_math and merge_type == 'AUTO':
            selected_mix += selected_math
            selected_math = []
        for nodes_list in [
                selected_mix,
                selected_shader,
                selected_geometry,
                selected_math,
                selected_vector,
                selected_z,
                selected_alphaover]:
            if not nodes_list:
                continue
            count_before = len(nodes)
            # sort list by loc_x - reversed
            nodes_list.sort(key=lambda k: k[1], reverse=True)
            # get maximum loc_x
            loc_x = nodes_list[0][1] + nodes_list[0][3] + 70
            nodes_list.sort(key=lambda k: k[2], reverse=True)

            # Change the node type for math nodes in a geometry node tree.
            if tree_type == 'GEOMETRY':
                if nodes_list is selected_math or nodes_list is selected_vector or nodes_list is selected_mix:
                    node_type = 'ShaderNode'
                    if mode == 'MIX':
                        mode = 'ADD'
                else:
                    node_type = 'GeometryNode'
            if merge_position == 'CENTER':
                # average yloc of last two nodes (lowest two)
                loc_y = ((nodes_list[len(nodes_list) - 1][2]) + (nodes_list[len(nodes_list) - 2][2])) / 2
                if nodes_list[len(nodes_list) - 1][-1]:  # if last node is hidden, mix should be shifted up a bit
                    if do_hide:
                        loc_y += 40
                    else:
                        loc_y += 80
            else:
                loc_y = nodes_list[len(nodes_list) - 1][2]
            offset_y = 100
            if not do_hide:
                offset_y = 200
            if nodes_list == selected_shader and not do_hide_shader:
                offset_y = 150.0
            the_range = len(nodes_list) - 1
            if len(nodes_list) == 1:
                the_range = 1
            was_multi = False
            for i in range(the_range):
                if nodes_list == selected_mix:
                    mix_name = 'Mix'
                    if tree_type == 'COMPOSITING':
                        mix_name = 'MixRGB'
                    add_type = node_type + mix_name
                    add = nodes.new(add_type)
                    if tree_type != 'COMPOSITING':
                        add.data_type = 'RGBA'
                    add.blend_type = mode
                    if mode != 'MIX':
                        add.inputs[0].default_value = 1.0
                    add.show_preview = False
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 6
                    second = 7
                    if tree_type == 'COMPOSITING':
                        first = 1
                        second = 2
                    add.width_hidden = 100.0
                elif nodes_list == selected_math:
                    add_type = node_type + 'Math'
                    add = nodes.new(add_type)
                    add.operation = mode
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 0
                    second = 1
                    add.width_hidden = 100.0
                elif nodes_list == selected_shader:
                    if mode == 'MIX':
                        add_type = node_type + 'MixShader'
                        add = nodes.new(add_type)
                        add.hide = do_hide_shader
                        if do_hide_shader:
                            loc_y = loc_y - 50
                        first = 1
                        second = 2
                        add.width_hidden = 100.0
                    elif mode == 'ADD':
                        add_type = node_type + 'AddShader'
                        add = nodes.new(add_type)
                        add.hide = do_hide_shader
                        if do_hide_shader:
                            loc_y = loc_y - 50
                        first = 0
                        second = 1
                        add.width_hidden = 100.0
                elif nodes_list == selected_geometry:
                    if mode in ('JOIN', 'MIX'):
                        add_type = node_type + 'JoinGeometry'
                        add = self.merge_with_multi_input(
                            nodes_list, merge_position, do_hide, loc_x, links, nodes, add_type, [0])
                    else:
                        add_type = node_type + 'MeshBoolean'
                        indices = [0, 1] if mode == 'DIFFERENCE' else [1]
                        add = self.merge_with_multi_input(
                            nodes_list, merge_position, do_hide, loc_x, links, nodes, add_type, indices)
                        add.operation = mode
                    was_multi = True
                    break
                elif nodes_list == selected_vector:
                    add_type = node_type + 'VectorMath'
                    add = nodes.new(add_type)
                    add.operation = mode
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 0
                    second = 1
                    add.width_hidden = 100.0
                elif nodes_list == selected_z:
                    add = nodes.new('CompositorNodeZcombine')
                    add.show_preview = False
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 0
                    second = 2
                    add.width_hidden = 100.0
                elif nodes_list == selected_alphaover:
                    add = nodes.new('CompositorNodeAlphaOver')
                    add.show_preview = False
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 1
                    second = 2
                    add.width_hidden = 100.0
                add.location = loc_x, loc_y
                loc_y += offset_y
                add.select = True

            # This has already been handled separately
            if was_multi:
                continue
            count_adds = i + 1
            count_after = len(nodes)
            index = count_after - 1
            first_selected = nodes[nodes_list[0][0]]
            # "last" node has been added as first, so its index is count_before.
            last_add = nodes[count_before]
            # Create list of invalid indexes.
            invalid_nodes = [nodes[n[0]]
                             for n in (selected_mix + selected_math + selected_shader + selected_z + selected_geometry)]

            # Special case:
            # Two nodes were selected and first selected has no output links, second selected has output links.
            # Then add links from last add to all links 'to_socket' of out links of second selected.
            first_selected_output = get_first_enabled_output(first_selected)
            if len(nodes_list) == 2:
                if not first_selected_output.links:
                    second_selected = nodes[nodes_list[1][0]]
                    for ss_link in get_first_enabled_output(second_selected).links:
                        # Prevent cyclic dependencies when nodes to be merged are linked to one another.
                        # Link only if "to_node" index not in invalid indexes list.
                        if not self.link_creates_cycle(ss_link, invalid_nodes):
                            connect_sockets(get_first_enabled_output(last_add), ss_link.to_socket)
            # add links from last_add to all links 'to_socket' of out links of first selected.
            for fs_link in first_selected_output.links:
                # Link only if "to_node" index not in invalid indexes list.
                if not self.link_creates_cycle(fs_link, invalid_nodes):
                    connect_sockets(get_first_enabled_output(last_add), fs_link.to_socket)
            # add link from "first" selected and "first" add node
            node_to = nodes[count_after - 1]
            connect_sockets(first_selected_output, node_to.inputs[first])
            if node_to.type == 'ZCOMBINE':
                for fs_out in first_selected.outputs:
                    if fs_out != first_selected_output and fs_out.name in ('Z', 'Depth'):
                        connect_sockets(fs_out, node_to.inputs[1])
                        break
            # add links between added ADD nodes and between selected and ADD nodes
            for i in range(count_adds):
                if i < count_adds - 1:
                    node_from = nodes[index]
                    node_to = nodes[index - 1]
                    node_to_input_i = first
                    node_to_z_i = 1  # if z combine - link z to first z input
                    connect_sockets(get_first_enabled_output(node_from), node_to.inputs[node_to_input_i])
                    if node_to.type == 'ZCOMBINE':
                        for from_out in node_from.outputs:
                            if from_out != get_first_enabled_output(node_from) and from_out.name in ('Z', 'Depth'):
                                connect_sockets(from_out, node_to.inputs[node_to_z_i])
                if len(nodes_list) > 1:
                    node_from = nodes[nodes_list[i + 1][0]]
                    node_to = nodes[index]
                    node_to_input_i = second
                    node_to_z_i = 3  # if z combine - link z to second z input
                    connect_sockets(get_first_enabled_output(node_from), node_to.inputs[node_to_input_i])
                    if node_to.type == 'ZCOMBINE':
                        for from_out in node_from.outputs:
                            if from_out != get_first_enabled_output(node_from) and from_out.name in ('Z', 'Depth'):
                                connect_sockets(from_out, node_to.inputs[node_to_z_i])
                index -= 1
            # set "last" of added nodes as active
            nodes.active = last_add
            for i, x, y, dx, h in nodes_list:
                nodes[i].select = False

        return {'FINISHED'}


class NWBatchChangeNodes(Operator, NWBase):
    bl_idname = "node.nw_batch_change"
    bl_label = "Batch Change"
    bl_description = "Batch Change Blend Type and Math Operation"
    bl_options = {'REGISTER', 'UNDO'}

    blend_type: EnumProperty(
        name="Blend Type",
        items=blend_types + navs,
    )
    operation: EnumProperty(
        name="Operation",
        items=operations + navs,
    )

    def execute(self, context):
        blend_type = self.blend_type
        operation = self.operation
        for node in context.selected_nodes:
            if node.type == 'MIX_RGB' or (node.bl_idname == 'ShaderNodeMix' and node.data_type == 'RGBA'):
                if blend_type not in [nav[0] for nav in navs]:
                    node.blend_type = blend_type
                else:
                    if blend_type == 'NEXT':
                        index = [i for i, entry in enumerate(blend_types) if node.blend_type in entry][0]
                        # index = blend_types.index(node.blend_type)
                        if index == len(blend_types) - 1:
                            node.blend_type = blend_types[0][0]
                        else:
                            node.blend_type = blend_types[index + 1][0]

                    if blend_type == 'PREV':
                        index = [i for i, entry in enumerate(blend_types) if node.blend_type in entry][0]
                        if index == 0:
                            node.blend_type = blend_types[len(blend_types) - 1][0]
                        else:
                            node.blend_type = blend_types[index - 1][0]

            if node.type == 'MATH' or node.bl_idname == 'ShaderNodeMath':
                if operation not in [nav[0] for nav in navs]:
                    node.operation = operation
                else:
                    if operation == 'NEXT':
                        index = [i for i, entry in enumerate(operations) if node.operation in entry][0]
                        # index = operations.index(node.operation)
                        if index == len(operations) - 1:
                            node.operation = operations[0][0]
                        else:
                            node.operation = operations[index + 1][0]

                    if operation == 'PREV':
                        index = [i for i, entry in enumerate(operations) if node.operation in entry][0]
                        # index = operations.index(node.operation)
                        if index == 0:
                            node.operation = operations[len(operations) - 1][0]
                        else:
                            node.operation = operations[index - 1][0]

        return {'FINISHED'}


class NWChangeMixFactor(Operator, NWBase):
    bl_idname = "node.nw_factor"
    bl_label = "Change Factor"
    bl_description = "Change Factors of Mix Nodes and Mix Shader Nodes"
    bl_options = {'REGISTER', 'UNDO'}

    # option: Change factor.
    # If option is 1.0 or 0.0 - set to 1.0 or 0.0
    # Else - change factor by option value.
    option: FloatProperty()

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        option = self.option
        selected = []  # entry = index
        for si, node in enumerate(nodes):
            if node.select:
                if node.type in {'MIX_RGB', 'MIX_SHADER'} or node.bl_idname == 'ShaderNodeMix':
                    selected.append(si)

        for si in selected:
            fac = nodes[si].inputs[0]
            nodes[si].hide = False
            if option in {0.0, 1.0}:
                fac.default_value = option
            else:
                fac.default_value += option

        return {'FINISHED'}


class NWCopySettings(Operator, NWBase):
    bl_idname = "node.nw_copy_settings"
    bl_label = "Copy Settings"
    bl_description = "Copy Settings of Active Node to Selected Nodes"
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):
        valid = False
        if nw_check(context):
            if (
                    context.active_node is not None and
                    context.active_node.type != 'FRAME'
            ):
                valid = True
        return valid

    def execute(self, context):
        node_active = context.active_node
        node_selected = context.selected_nodes

        # Error handling
        if not (len(node_selected) > 1):
            self.report({'ERROR'}, "2 nodes must be selected at least")
            return {'CANCELLED'}

        # Check if active node is in the selection
        selected_node_names = [n.name for n in node_selected]
        if node_active.name not in selected_node_names:
            self.report({'ERROR'}, "No active node")
            return {'CANCELLED'}

        # Get nodes in selection by type
        valid_nodes = [n for n in node_selected if n.type == node_active.type]

        if not (len(valid_nodes) > 1) and node_active:
            self.report({'ERROR'}, "Selected nodes are not of the same type as {}".format(node_active.name))
            return {'CANCELLED'}

        if len(valid_nodes) != len(node_selected):
            # Report nodes that are not valid
            valid_node_names = [n.name for n in valid_nodes]
            not_valid_names = list(set(selected_node_names) - set(valid_node_names))
            self.report(
                {'INFO'},
                "Ignored {} (not of the same type as {})".format(
                    ", ".join(not_valid_names),
                    node_active.name))

        # Reference original
        orig = node_active
        # node_selected_names = [n.name for n in node_selected]

        # Output list
        success_names = []

        # Deselect all nodes
        for i in node_selected:
            i.select = False

        # Code by zeffii from http://blender.stackexchange.com/a/42338/3710
        # Run through all other nodes
        for node in valid_nodes[1:]:

            # Check for frame node
            parent = node.parent if node.parent else None
            node_loc = [node.location.x, node.location.y]

            # Select original to duplicate
            orig.select = True

            # Duplicate selected node
            bpy.ops.node.duplicate()
            new_node = context.selected_nodes[0]

            # Deselect copy
            new_node.select = False

            # Properties to copy
            node_tree = node.id_data
            props_to_copy = 'bl_idname name location height width'.split(' ')

            # Input and outputs
            reconnections = []
            mappings = chain.from_iterable([node.inputs, node.outputs])
            for i in (i for i in mappings if i.is_linked):
                for L in i.links:
                    reconnections.append([L.from_socket.path_from_id(), L.to_socket.path_from_id()])

            # Properties
            props = {j: getattr(node, j) for j in props_to_copy}
            props_to_copy.pop(0)

            for prop in props_to_copy:
                setattr(new_node, prop, props[prop])

            # Get the node tree to remove the old node
            nodes = node_tree.nodes
            nodes.remove(node)
            new_node.name = props['name']

            if parent:
                new_node.parent = parent
                new_node.location = node_loc

            for str_from, str_to in reconnections:
                connect_sockets(eval(str_from), eval(str_to))

            success_names.append(new_node.name)

        orig.select = True
        node_tree.nodes.active = orig
        self.report(
            {'INFO'},
            "Successfully copied attributes from {} to: {}".format(
                orig.name,
                ", ".join(success_names)))
        return {'FINISHED'}


class NWCopyLabel(Operator, NWBase):
    bl_idname = "node.nw_copy_label"
    bl_label = "Copy Label"
    bl_options = {'REGISTER', 'UNDO'}

    option: EnumProperty(
        name="option",
        description="Source of name of label",
        items=(
            ('FROM_ACTIVE', 'from active', 'from active node',),
            ('FROM_NODE', 'from node', 'from node linked to selected node'),
            ('FROM_SOCKET', 'from socket', 'from socket linked to selected node'),
        )
    )

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        option = self.option
        active = nodes.active
        if option == 'FROM_ACTIVE':
            if active:
                src_label = active.label
                for node in [n for n in nodes if n.select and nodes.active != n]:
                    node.label = src_label
        elif option == 'FROM_NODE':
            selected = [n for n in nodes if n.select]
            for node in selected:
                for input in node.inputs:
                    if input.links:
                        src = input.links[0].from_node
                        node.label = src.label
                        break
        elif option == 'FROM_SOCKET':
            selected = [n for n in nodes if n.select]
            for node in selected:
                for input in node.inputs:
                    if input.links:
                        src = input.links[0].from_socket
                        node.label = src.name
                        break

        return {'FINISHED'}


class NWClearLabel(Operator, NWBase):
    bl_idname = "node.nw_clear_label"
    bl_label = "Clear Label"
    bl_options = {'REGISTER', 'UNDO'}

    option: BoolProperty()

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        for node in [n for n in nodes if n.select]:
            node.label = ''

        return {'FINISHED'}

    def invoke(self, context, event):
        if self.option:
            return self.execute(context)
        else:
            return context.window_manager.invoke_confirm(self, event)


class NWModifyLabels(Operator, NWBase):
    """Modify Labels of all selected nodes"""
    bl_idname = "node.nw_modify_labels"
    bl_label = "Modify Labels"
    bl_options = {'REGISTER', 'UNDO'}

    prepend: StringProperty(
        name="Add to Beginning"
    )
    append: StringProperty(
        name="Add to End"
    )
    replace_from: StringProperty(
        name="Text to Replace"
    )
    replace_to: StringProperty(
        name="Replace with"
    )

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        for node in [n for n in nodes if n.select]:
            node.label = self.prepend + node.label.replace(self.replace_from, self.replace_to) + self.append

        return {'FINISHED'}

    def invoke(self, context, event):
        self.prepend = ""
        self.append = ""
        self.remove = ""
        return context.window_manager.invoke_props_dialog(self)


class NWAddTextureSetup(Operator, NWBase):
    bl_idname = "node.nw_add_texture"
    bl_label = "Texture Setup"
    bl_description = "Add Texture Node Setup to Selected Shaders"
    bl_options = {'REGISTER', 'UNDO'}

    add_mapping: BoolProperty(
        name="Add Mapping Nodes",
        description="Create coordinate and mapping nodes for the texture (ignored for selected texture nodes)",
        default=True)

    @classmethod
    def poll(cls, context):
        if nw_check(context):
            space = context.space_data
            if space.tree_type == 'ShaderNodeTree':
                return True
        return False

    def execute(self, context):
        nodes, links = get_nodes_links(context)

        texture_types = [x.nodetype for x in
                         get_nodes_from_category('Texture', context)]
        selected_nodes = [n for n in nodes if n.select]

        for node in selected_nodes:
            if not node.inputs:
                continue

            input_index = 0
            target_input = node.inputs[0]
            for input in node.inputs:
                if input.enabled:
                    input_index += 1
                    if not input.is_linked:
                        target_input = input
                        break
            else:
                self.report({'WARNING'}, "No free inputs for node: " + node.name)
                continue

            x_offset = 0
            padding = 40.0
            locx = node.location.x
            locy = node.location.y - (input_index * padding)

            is_texture_node = node.rna_type.identifier in texture_types
            use_environment_texture = node.type == 'BACKGROUND'

            # Add an image texture before normal shader nodes.
            if not is_texture_node:
                image_texture_type = 'ShaderNodeTexEnvironment' if use_environment_texture else 'ShaderNodeTexImage'
                image_texture_node = nodes.new(image_texture_type)
                x_offset = x_offset + image_texture_node.width + padding
                image_texture_node.location = [locx - x_offset, locy]
                nodes.active = image_texture_node
                connect_sockets(image_texture_node.outputs[0], target_input)

                # The mapping setup following this will connect to the first input of this image texture.
                target_input = image_texture_node.inputs[0]

            node.select = False

            if is_texture_node or self.add_mapping:
                # Add Mapping node.
                mapping_node = nodes.new('ShaderNodeMapping')
                x_offset = x_offset + mapping_node.width + padding
                mapping_node.location = [locx - x_offset, locy]
                connect_sockets(mapping_node.outputs[0], target_input)

                # Add Texture Coordinates node.
                tex_coord_node = nodes.new('ShaderNodeTexCoord')
                x_offset = x_offset + tex_coord_node.width + padding
                tex_coord_node.location = [locx - x_offset, locy]

                is_procedural_texture = is_texture_node and node.type != 'TEX_IMAGE'
                use_generated_coordinates = is_procedural_texture or use_environment_texture
                tex_coord_output = tex_coord_node.outputs[0 if use_generated_coordinates else 2]
                connect_sockets(tex_coord_output, mapping_node.inputs[0])

        return {'FINISHED'}


class NWAddPrincipledSetup(Operator, NWBase, ImportHelper):
    bl_idname = "node.nw_add_textures_for_principled"
    bl_label = "Principled Texture Setup"
    bl_description = "Add Texture Node Setup for Principled BSDF"
    bl_options = {'REGISTER', 'UNDO'}

    directory: StringProperty(
        name='Directory',
        subtype='DIR_PATH',
        default='',
        description='Folder to search in for image files'
    )
    files: CollectionProperty(
        type=bpy.types.OperatorFileListElement,
        options={'HIDDEN', 'SKIP_SAVE'}
    )

    relative_path: BoolProperty(
        name='Relative Path',
        description='Set the file path relative to the blend file, when possible',
        default=True
    )

    order = [
        "filepath",
        "files",
    ]

    def draw(self, context):
        layout = self.layout
        layout.alignment = 'LEFT'

        layout.prop(self, 'relative_path')

    @classmethod
    def poll(cls, context):
        valid = False
        if nw_check(context):
            space = context.space_data
            if space.tree_type == 'ShaderNodeTree':
                valid = True
        return valid

    def execute(self, context):
        # Check if everything is ok
        if not self.directory:
            self.report({'INFO'}, 'No Folder Selected')
            return {'CANCELLED'}
        if not self.files[:]:
            self.report({'INFO'}, 'No Files Selected')
            return {'CANCELLED'}

        nodes, links = get_nodes_links(context)
        active_node = nodes.active
        if not (active_node and active_node.bl_idname == 'ShaderNodeBsdfPrincipled'):
            self.report({'INFO'}, 'Select Principled BSDF')
            return {'CANCELLED'}

        # Filter textures names for texturetypes in filenames
        # [Socket Name, [abbreviations and keyword list], Filename placeholder]
        tags = context.preferences.addons[__package__].preferences.principled_tags
        normal_abbr = tags.normal.split(' ')
        bump_abbr = tags.bump.split(' ')
        gloss_abbr = tags.gloss.split(' ')
        rough_abbr = tags.rough.split(' ')
        socketnames = [
            ['Displacement', tags.displacement.split(' '), None],
            ['Base Color', tags.base_color.split(' '), None],
            ['Subsurface Color', tags.sss_color.split(' '), None],
            ['Metallic', tags.metallic.split(' '), None],
            ['Specular', tags.specular.split(' '), None],
            ['Roughness', rough_abbr + gloss_abbr, None],
            ['Bump', bump_abbr, None],
            ['Normal', normal_abbr, None],
            ['Transmission', tags.transmission.split(' '), None],
            ['Emission', tags.emission.split(' '), None],
            ['Alpha', tags.alpha.split(' '), None],
            ['Ambient Occlusion', tags.ambient_occlusion.split(' '), None],
        ]

        match_files_to_socket_names(self.files, socketnames)
        # Remove socketnames without found files
        socketnames = [s for s in socketnames if s[2]
                       and path.exists(self.directory + s[2])]
        if not socketnames:
            self.report({'INFO'}, 'No matching images found')
            print('No matching images found')
            return {'CANCELLED'}

        # Don't override path earlier as os.path is used to check the absolute path
        import_path = self.directory
        if self.relative_path:
            if bpy.data.filepath:
                try:
                    import_path = bpy.path.relpath(self.directory)
                except ValueError:
                    pass

        # Add found images
        print('\nMatched Textures:')
        texture_nodes = []
        disp_texture = None
        ao_texture = None
        normal_node = None
        normal_node_texture = None
        bump_node = None
        bump_node_texture = None
        roughness_node = None
        for i, sname in enumerate(socketnames):
            print(i, sname[0], sname[2])