node_wrangler.py

                # 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)
                if merge_position == 'CENTER':
                    loc_y = ((nodes_list[len(nodes_list) - 1][2]) + (nodes_list[len(nodes_list) - 2][2])) / 2  # average yloc of last two nodes (lowest two)
                    if nodes_list[len(nodes_list) - 1][-1] == True:  # 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
                for i in range(the_range):
                    if nodes_list == selected_mix:
                        add_type = node_type + 'MixRGB'
                        add = nodes.new(add_type)
                        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 = 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_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
                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]
                # 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.
                if len(nodes_list) == 2:
                    if not first_selected.outputs[0].links:
                        second_selected = nodes[nodes_list[1][0]]
                        for ss_link in second_selected.outputs[0].links:
                            # Prevent cyclic dependencies when nodes to be marged are linked to one another.
                            # Create list of invalid indexes.
                            invalid_i = [n[0] for n in (selected_mix + selected_math + selected_shader + selected_z)]
                            # Link only if "to_node" index not in invalid indexes list.
                            if ss_link.to_node not in [nodes[i] for i in invalid_i]:
                                links.new(last_add.outputs[0], 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.outputs[0].links:
                    # Prevent cyclic dependencies when nodes to be marged are linked to one another.
                    # Create list of invalid indexes.
                    invalid_i = [n[0] for n in (selected_mix + selected_math + selected_shader + selected_z)]
                    # Link only if "to_node" index not in invalid indexes list.
                    if fs_link.to_node not in [nodes[i] for i in invalid_i]:
                        links.new(last_add.outputs[0], fs_link.to_socket)
                # add link from "first" selected and "first" add node
                node_to = nodes[count_after - 1]
                links.new(first_selected.outputs[0], node_to.inputs[first])
                if node_to.type == 'ZCOMBINE':
                    for fs_out in first_selected.outputs:
                        if fs_out != first_selected.outputs[0] and fs_out.name in ('Z', 'Depth'):
                            links.new(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
                        links.new(node_from.outputs[0], node_to.inputs[node_to_input_i])
                        if node_to.type == 'ZCOMBINE':
                            for from_out in node_from.outputs:
                                if from_out != node_from.outputs[0] and from_out.name in ('Z', 'Depth'):
                                    links.new(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
                        links.new(node_from.outputs[0], node_to.inputs[node_to_input_i])
                        if node_to.type == 'ZCOMBINE':
                            for from_out in node_from.outputs:
                                if from_out != node_from.outputs[0] and from_out.name in ('Z', 'Depth'):
                                    links.new(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):

        nodes, links = get_nodes_links(context)
        blend_type = self.blend_type
        operation = self.operation
        for node in context.selected_nodes:
            if node.type == 'MIX_RGB':
                if not blend_type 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':
                if not operation 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'}:
                    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 is not 'FRAME':
                valid = True
        return valid

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        selected = [n for n in nodes if n.select]
        reselect = []  # duplicated nodes will be selected after execution
        active = nodes.active
        if active.select:
            reselect.append(active)

        for node in selected:
            if node.type == active.type and node != active:
                # duplicate active, relink links as in 'node', append copy to 'reselect', delete node
                bpy.ops.node.select_all(action='DESELECT')
                nodes.active = active
                active.select = True
                bpy.ops.node.duplicate()
                copied = nodes.active
                # Copied active should however inherit some properties from 'node'
                attributes = (
                    'hide', 'show_preview', 'mute', 'label',
                    'use_custom_color', 'color', 'width', 'width_hidden',
                )
                for attr in attributes:
                    setattr(copied, attr, getattr(node, attr))
                # Handle scenario when 'node' is in frame. 'copied' is in same frame then.
                if copied.parent:
                    bpy.ops.node.parent_clear()
                locx = node.location.x
                locy = node.location.y
                # get absolute node location
                parent = node.parent
                while parent:
                    locx += parent.location.x
                    locy += parent.location.y
                    parent = parent.parent
                copied.location = [locx, locy]
                # reconnect links from node to copied
                for i, input in enumerate(node.inputs):
                    if input.links:
                        link = input.links[0]
                        links.new(link.from_socket, copied.inputs[i])
                for out, output in enumerate(node.outputs):
                    if output.links:
                        out_links = output.links
                        for link in out_links:
                            links.new(copied.outputs[out], link.to_socket)
                bpy.ops.node.select_all(action='DESELECT')
                node.select = True
                bpy.ops.node.delete()
                reselect.append(copied)
            else:  # If selected wasn't copied, need to reselect it afterwards.
                reselect.append(node)
        # clean up
        bpy.ops.node.select_all(action='DESELECT')
        for node in reselect:
            node.select = True
        nodes.active = active

        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'}

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

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        active = nodes.active
        shader_types = [x[1] for x in shaders_shader_nodes_props if x[1] not in {'MIX_SHADER', 'ADD_SHADER'}]
        texture_types = [x[1] for x in shaders_texture_nodes_props]
        valid = False
        if active:
            if active.select:
                if active.type in shader_types or active.type in texture_types:
                    if not active.inputs[0].is_linked:
                        valid = True
        if valid:
            locx = active.location.x
            locy = active.location.y

            xoffset = [500.0, 700.0]
            isshader = True
            if active.type not in shader_types:
                xoffset = [290.0, 500.0]
                isshader = False

            coordout = 2
            image_type = 'ShaderNodeTexImage'

            if (active.type in texture_types and active.type != 'TEX_IMAGE') or (active.type == 'BACKGROUND'):
                coordout = 0  # image texture uses UVs, procedural textures and Background shader use Generated
                if active.type == 'BACKGROUND':
                    image_type = 'ShaderNodeTexEnvironment'

            if isshader:
                tex = nodes.new(image_type)
                tex.location = [locx - 200.0, locy + 28.0]

            map = nodes.new('ShaderNodeMapping')
            map.location = [locx - xoffset[0], locy + 80.0]
            map.width = 240
            coord = nodes.new('ShaderNodeTexCoord')
            coord.location = [locx - xoffset[1], locy + 40.0]
            active.select = False

            if isshader:
                nodes.active = tex
                links.new(tex.outputs[0], active.inputs[0])
                links.new(map.outputs[0], tex.inputs[0])
                links.new(coord.outputs[coordout], map.inputs[0])

            else:
                nodes.active = map
                links.new(map.outputs[0], active.inputs[0])
                links.new(coord.outputs[coordout], map.inputs[0])

        return {'FINISHED'}


class NWAddReroutes(Operator, NWBase):
    """Add Reroute Nodes and link them to outputs of selected nodes"""
    bl_idname = "node.nw_add_reroutes"
    bl_label = "Add Reroutes"
    bl_description = "Add Reroutes to Outputs"
    bl_options = {'REGISTER', 'UNDO'}

    option = EnumProperty(
        name="option",
        items=[
            ('ALL', 'to all', 'Add to all outputs'),
            ('LOOSE', 'to loose', 'Add only to loose outputs'),
            ('LINKED', 'to linked', 'Add only to linked outputs'),
        ]
    )

    def execute(self, context):
        tree_type = context.space_data.node_tree.type
        option = self.option
        nodes, links = get_nodes_links(context)
        # output valid when option is 'all' or when 'loose' output has no links
        valid = False
        post_select = []  # nodes to be selected after execution
        # create reroutes and recreate links
        for node in [n for n in nodes if n.select]:
            if node.outputs:
                x = node.location.x
                y = node.location.y
                width = node.width
                # unhide 'REROUTE' nodes to avoid issues with location.y
                if node.type == 'REROUTE':
                    node.hide = False
                # When node is hidden - width_hidden not usable.
                # Hack needed to calculate real width
                if node.hide:
                    bpy.ops.node.select_all(action='DESELECT')
                    helper = nodes.new('NodeReroute')
                    helper.select = True
                    node.select = True
                    # resize node and helper to zero. Then check locations to calculate width
                    bpy.ops.transform.resize(value=(0.0, 0.0, 0.0))
                    width = 2.0 * (helper.location.x - node.location.x)
                    # restore node location
                    node.location = x, y
                    # delete helper
                    node.select = False
                    # only helper is selected now
                    bpy.ops.node.delete()
                x = node.location.x + width + 20.0
                if node.type != 'REROUTE':
                    y -= 35.0
                y_offset = -22.0
                loc = x, y
            reroutes_count = 0  # will be used when aligning reroutes added to hidden nodes
            for out_i, output in enumerate(node.outputs):
                pass_used = False  # initial value to be analyzed if 'R_LAYERS'
                # if node is not 'R_LAYERS' - "pass_used" not needed, so set it to True
                if node.type != 'R_LAYERS':
                    pass_used = True
                else:  # if 'R_LAYERS' check if output represent used render pass
                    node_scene = node.scene
                    node_layer = node.layer
                    # If output - "Alpha" is analyzed - assume it's used. Not represented in passes.
                    if output.name == 'Alpha':
                        pass_used = True
                    else:
                        # check entries in global 'rl_outputs' variable
                        for render_pass, out_name, exr_name, in_internal, in_cycles in rl_outputs:
                            if output.name == out_name:
                                pass_used = getattr(node_scene.render.layers[node_layer], render_pass)
                                break
                if pass_used:
                    valid = ((option == 'ALL') or
                             (option == 'LOOSE' and not output.links) or
                             (option == 'LINKED' and output.links))
                    # Add reroutes only if valid, but offset location in all cases.
                    if valid:
                        n = nodes.new('NodeReroute')
                        nodes.active = n
                        for link in output.links:
                            links.new(n.outputs[0], link.to_socket)
                        links.new(output, n.inputs[0])
                        n.location = loc
                        post_select.append(n)
                    reroutes_count += 1
                    y += y_offset
                    loc = x, y
            # disselect the node so that after execution of script only newly created nodes are selected
            node.select = False
            # nicer reroutes distribution along y when node.hide
            if node.hide:
                y_translate = reroutes_count * y_offset / 2.0 - y_offset - 35.0
                for reroute in [r for r in nodes if r.select]:
                    reroute.location.y -= y_translate
            for node in post_select:
                node.select = True

        return {'FINISHED'}


class NWLinkActiveToSelected(Operator, NWBase):
    """Link active node to selected nodes basing on various criteria"""
    bl_idname = "node.nw_link_active_to_selected"
    bl_label = "Link Active Node to Selected"
    bl_options = {'REGISTER', 'UNDO'}

    replace = BoolProperty()
    use_node_name = BoolProperty()
    use_outputs_names = BoolProperty()

    @classmethod
    def poll(cls, context):
        valid = False
        if nw_check(context):
            if context.active_node is not None:
                if context.active_node.select:
                    valid = True
        return valid

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        replace = self.replace
        use_node_name = self.use_node_name
        use_outputs_names = self.use_outputs_names
        active = nodes.active
        selected = [node for node in nodes if node.select and node != active]
        outputs = []  # Only usable outputs of active nodes will be stored here.
        for out in active.outputs:
            if active.type != 'R_LAYERS':
                outputs.append(out)
            else:
                # 'R_LAYERS' node type needs special handling.
                # outputs of 'R_LAYERS' are callable even if not seen in UI.
                # Only outputs that represent used passes should be taken into account
                # Check if pass represented by output is used.
                # global 'rl_outputs' list will be used for that
                for render_pass, out_name, exr_name, in_internal, in_cycles in rl_outputs:
                    pass_used = False  # initial value. Will be set to True if pass is used
                    if out.name == 'Alpha':
                        # Alpha output is always present. Doesn't have representation in render pass. Assume it's used.
                        pass_used = True
                    elif out.name == out_name:
                        # example 'render_pass' entry: 'use_pass_uv' Check if True in scene render layers
                        pass_used = getattr(active.scene.render.layers[active.layer], render_pass)
                        break
                if pass_used:
                    outputs.append(out)
        doit = True  # Will be changed to False when links successfully added to previous output.
        for out in outputs:
            if doit:
                for node in selected:
                    dst_name = node.name  # Will be compared with src_name if needed.
                    # When node has label - use it as dst_name
                    if node.label:
                        dst_name = node.label
                    valid = True  # Initial value. Will be changed to False if names don't match.
                    src_name = dst_name  # If names not used - this asignment will keep valid = True.
                    if use_node_name:
                        # Set src_name to source node name or label
                        src_name = active.name
                        if active.label:
                            src_name = active.label
                    elif use_outputs_names:
                        src_name = (out.name, )
                        for render_pass, out_name, exr_name, in_internal, in_cycles in rl_outputs:
                            if out.name in {out_name, exr_name}:
                                src_name = (out_name, exr_name)
                    if dst_name not in src_name:
                        valid = False
                    if valid:
                        for input in node.inputs:
                            if input.type == out.type or node.type == 'REROUTE':
                                if replace or not input.is_linked:
                                    links.new(out, input)
                                    if not use_node_name and not use_outputs_names:
                                        doit = False
                                    break

        return {'FINISHED'}


class NWAlignNodes(Operator, NWBase):
    '''Align the selected nodes neatly in a row/column'''
    bl_idname = "node.nw_align_nodes"
    bl_label = "Align Nodes"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context):
        # TODO prop: lock active (arrange everything without moving active node)
        nodes, links = get_nodes_links(context)
        margin = 80
        
        selection = []
        for node in nodes:
            if node.select and node.type != 'FRAME':
                selection.append(node)

        # If no nodes are selected, align all nodes
        if not selection:
            selection = nodes

        # Check if nodes should be layed out horizontally or vertically
        x_locs = [n.location.x + (n.dimensions.x / 2) for n in selection]  # use dimension to get center of node, not corner
        y_locs = [n.location.y - (n.dimensions.y / 2) for n in selection]
        x_range = max(x_locs) - min(x_locs)
        y_range = max(y_locs) - min(y_locs)
        mid_x = (max(x_locs) + min(x_locs)) / 2
        mid_y = (max(y_locs) + min(y_locs)) / 2
        horizontal = x_range > y_range

        # Sort selection by location of node mid-point
        if horizontal:
            selection = sorted(selection, key=lambda n: n.location.x + (n.dimensions.x / 2))
        else:
            selection = sorted(selection, key=lambda n: n.location.y - (n.dimensions.y / 2), reverse=True)

        # Alignment
        current_pos = 0
        for node in selection:
            current_margin = margin
            current_margin = current_margin / 2 if node.hide else current_margin  # use a smaller margin for hidden nodes

            if horizontal:
                node.location.x = current_pos
                current_pos += current_margin + node.dimensions.x
                node.location.y = mid_y + (node.dimensions.y / 2)
            else:
                node.location.y = current_pos
                current_pos -= (current_margin / 2) + node.dimensions.y  # use half-margin for vertical alignment
                node.location.x = mid_x - (node.dimensions.x / 2)

        # Position nodes centered around where they used to be
        locs = ([n.location.x + (n.dimensions.x / 2) for n in selection]) if horizontal else ([n.location.y - (n.dimensions.y / 2) for n in selection])
        new_mid = (max(locs) + min(locs)) / 2
        for node in selection:
            if horizontal:
                node.location.x += (mid_x - new_mid)
            else:
                node.location.y += (mid_y - new_mid)

        return {'FINISHED'}


class NWSelectParentChildren(Operator, NWBase):
    bl_idname = "node.nw_select_parent_child"
    bl_label = "Select Parent or Children"
    bl_options = {'REGISTER', 'UNDO'}

    option = EnumProperty(
        name="option",
        items=(
            ('PARENT', 'Select Parent', 'Select Parent Frame'),
            ('CHILD', 'Select Children', 'Select members of selected frame'),
        )
    )

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        option = self.option
        selected = [node for node in nodes if node.select]
        if option == 'PARENT':
            for sel in selected:
                parent = sel.parent
                if parent:
                    parent.select = True
        else:  # option == 'CHILD'
            for sel in selected:
                children = [node for node in nodes if node.parent == sel]
                for kid in children:
                    kid.select = True

        return {'FINISHED'}


class NWDetachOutputs(Operator, NWBase):
    """Detach outputs of selected node leaving inluts liked"""
    bl_idname = "node.nw_detach_outputs"
    bl_label = "Detach Outputs"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        selected = context.selected_nodes
        bpy.ops.node.duplicate_move_keep_inputs()
        new_nodes = context.selected_nodes
        bpy.ops.node.select_all(action="DESELECT")
        for node in selected:
            node.select = True
        bpy.ops.node.delete_reconnect()
        for new_node in new_nodes:
            new_node.select = True
        bpy.ops.transform.translate('INVOKE_DEFAULT')

        return {'FINISHED'}


class NWLinkToOutputNode(Operator, NWBase):
    """Link to Composite node or Material Output node"""
    bl_idname = "node.nw_link_out"
    bl_label = "Connect to Output"
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):
        valid = False
        if nw_check(context):
            if context.active_node is not None:
                for out in context.active_node.outputs:
                    if not out.hide:
                        valid = True
                        break
        return valid

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        active = nodes.active
        output_node = None
        output_index = None
        tree_type = context.space_data.tree_type
        output_types_shaders = [x[1] for x in shaders_output_nodes_props]
        output_types_compo = ['COMPOSITE']
        output_types_blender_mat = ['OUTPUT']
        output_types_textures = ['OUTPUT']
        output_types = output_types_shaders + output_types_compo + output_types_blender_mat
        for node in nodes:
            if node.type in output_types:
                output_node = node
                break
        if not output_node:
            bpy.ops.node.select_all(action="DESELECT")
            if tree_type == 'ShaderNodeTree':
                if context.scene.render.engine == 'CYCLES':
                    output_node = nodes.new('ShaderNodeOutputMaterial')
                else:
                    output_node = nodes.new('ShaderNodeOutput')
            elif tree_type == 'CompositorNodeTree':
                output_node = nodes.new('CompositorNodeComposite')
            elif tree_type == 'TextureNodeTree':
                output_node = nodes.new('TextureNodeOutput')
            output_node.location.x = active.location.x + active.dimensions.x + 80
            output_node.location.y = active.location.y
        if (output_node and active.outputs):
            for i, output in enumerate(active.outputs):
                if not output.hide:
                    output_index = i
                    break
            for i, output in enumerate(active.outputs):
                if output.type == output_node.inputs[0].type and not output.hide:
                    output_index = i
                    break

            out_input_index = 0
            if tree_type == 'ShaderNodeTree' and context.scene.render.engine == 'CYCLES':
                if active.outputs[output_index].name == 'Volume':
                    out_input_index = 1
                elif active.outputs[output_index].type != 'SHADER':  # connect to displacement if not a shader
                    out_input_index = 2
            links.new(active.outputs[output_index], output_node.inputs[out_input_index])

        hack_force_update(context, nodes)  # viewport render does not update

        return {'FINISHED'}


class NWMakeLink(Operator, NWBase):
    """Make a link from one socket to another"""
    bl_idname = 'node.nw_make_link'
    bl_label = 'Make Link'
    bl_options = {'REGISTER', 'UNDO'}
    from_socket = IntProperty()
    to_socket = IntProperty()

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

        n1 = nodes[context.scene.NWLazySource]
        n2 = nodes[context.scene.NWLazyTarget]

        links.new(n1.outputs[self.from_socket], n2.inputs[self.to_socket])

        hack_force_update(context, nodes)

        return {'FINISHED'}


class NWCallInputsMenu(Operator, NWBase):
    """Link from this output"""
    bl_idname = 'node.nw_call_inputs_menu'
    bl_label = 'Make Link'
    bl_options = {'REGISTER', 'UNDO'}
    from_socket = IntProperty()

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

        context.scene.NWSourceSocket = self.from_socket

        n1 = nodes[context.scene.NWLazySource]
        n2 = nodes[context.scene.NWLazyTarget]
        if len(n2.inputs) > 1:
            bpy.ops.wm.call_menu("INVOKE_DEFAULT", name=NWConnectionListInputs.bl_idname)
        elif len(n2.inputs) == 1:
            links.new(n1.outputs[self.from_socket], n2.inputs[0])
        return {'FINISHED'}


class NWAddSequence(Operator, ImportHelper):
    """Add an Image Sequence"""
    bl_idname = 'node.nw_add_sequence'
    bl_label = 'Import Image Sequence'
    bl_options = {'REGISTER', 'UNDO'}
    directory = StringProperty(subtype="DIR_PATH")
    filename = StringProperty(subtype="FILE_NAME")

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


        if context.space_data.node_tree.type == 'SHADER':
            node_type = "ShaderNodeTexImage"
        elif context.space_data.node_tree.type == 'COMPOSITING':
            node_type = "CompositorNodeImage"
        else:
            self.report({'ERROR'}, "Unsupported Node Tree type!")
            return {'CANCELLED'}

        without_ext = '.'.join(filename.split('.')[:-1])

        # if last digit isn't a number, it's not a sequence
        if without_ext[-1].isdigit():
            without_ext = without_ext[:-1] + '1'
        else:
            self.report({'ERROR'}, filename+" does not seem to be part of a sequence")
            return {'CANCELLED'}


        extension = filename.split('.')[-1]
        reverse = without_ext[::-1] # reverse string

        count_numbers = 0
        for char in reverse:
            if char.isdigit():
                count_numbers += 1
            else:
                break

        without_num = without_ext[:count_numbers*-1]

        files = sorted(glob(directory + without_num + "[0-9]"*count_numbers + "." + extension))

        num_frames = len(files)

        nodes_list = [node for node in nodes]
        if nodes_list:
            nodes_list.sort(key=lambda k: k.location.x)
            xloc = nodes_list[0].location.x - 220  # place new nodes at far left
            yloc = 0
            for node in nodes:
                node.select = False
                yloc += node_mid_pt(node, 'y')
            yloc = yloc/len(nodes)
        else:
            xloc = 0
            yloc = 0

        name_with_hashes = without_num + "#"*count_numbers + '.' + extension

        node = nodes.new(node_type)
        node.location.x = xloc
        node.location.y = yloc + 110
        node.label = name_with_hashes

        img = bpy.data.images.load(directory+(without_ext+'.'+extension))
        img.source = 'SEQUENCE'
        img.name = name_with_hashes
        node.image = img
        node.frame_offset = int(files[0][len(without_num)+len(directory):-1*(len(extension)+1)]) - 1  # separate the number from the file name of the first  file
        if context.space_data.node_tree.type == 'SHADER':
            node.image_user.frame_duration = num_frames
        else:
            node.frame_duration = num_frames

        return {'FINISHED'}


class NWAddMultipleImages(Operator, ImportHelper):
    """Add multiple images at once"""
    bl_idname = 'node.nw_add_multiple_images'
    bl_label = 'Open Selected Images'
    bl_options = {'REGISTER', 'UNDO'}
    directory = StringProperty(subtype="DIR_PATH")
    files = CollectionProperty(type=bpy.types.OperatorFileListElement, options={'HIDDEN', 'SKIP_SAVE'})

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        nodes_list = [node for node in nodes]
        if nodes_list:
            nodes_list.sort(key=lambda k: k.location.x)
            xloc = nodes_list[0].location.x - 220  # place new nodes at far left
            yloc = 0
            for node in nodes:
                node.select = False
                yloc += node_mid_pt(node, 'y')
            yloc = yloc/len(nodes)
        else:
            xloc = 0
            yloc = 0

        if context.space_data.node_tree.type == 'SHADER':
            node_type = "ShaderNodeTexImage"
        elif context.space_data.node_tree.type == 'COMPOSITING':