ui.py

        layout = self.layout

        layout.operator("view3d.create_all_qcd_slots")

        layout.separator()

        layout.operator("view3d.enable_all_qcd_slots")
        layout.operator("view3d.enable_all_qcd_slots_isolated")

        layout.separator()

        layout.operator("view3d.isolate_selected_objects_collections")
        if context.mode == 'OBJECT':
            layout.operator("view3d.disable_selected_objects_collections")

        layout.separator()

        layout.operator("view3d.disable_all_non_qcd_slots")
        layout.operator("view3d.disable_all_collections")

        if context.mode == 'OBJECT':
            layout.separator()
            layout.operator("view3d.select_all_qcd_objects")

        layout.separator()

        layout.operator("view3d.discard_qcd_history")


def view3d_header_qcd_slots(self, context):
    update_collection_tree(context)

    view_layer = context.view_layer
    layout = self.layout
    idx = 1

    check_state(context, qcd=True)


    main_row = layout.row(align=True)
    current_qcd_history = internals.qcd_history.get(context.view_layer.name, [])

    main_row.operator_menu_hold("view3d.enable_all_qcd_slots_meta",
                                text="",
                                icon='HIDE_OFF',
                                depress=bool(current_qcd_history),
                                menu="VIEW3D_MT_CM_qcd_enable_all_menu")


    split = main_row.split()
    col = split.column(align=True)
    row = col.row(align=True)
    row.scale_y = 0.5

    selected_objects = get_move_selection()
    active_object = get_move_active()

    for x in range(20):
        qcd_slot_name = internals.qcd_slots.get_name(str(x+1))

        if qcd_slot_name:
            qcd_laycol = internals.layer_collections[qcd_slot_name]["ptr"]
            collection_objects = qcd_laycol.collection.objects

            icon_value = 0

            # if the active object is in the current collection use a custom icon
            if (active_object and active_object in selected_objects and
                active_object.name in collection_objects):
                icon = 'LAYER_ACTIVE'

            # if there are selected objects use LAYER_ACTIVE
            elif not selected_objects.isdisjoint(collection_objects):
                icon = 'LAYER_USED'

            # If there are objects use LAYER_USED
            elif collection_objects:
                icon = 'NONE'
                active_icon = get_active_icon(context, qcd_laycol)
                icon_value = active_icon.icon_id

            else:
                icon = 'BLANK1'


            prop = row.operator("view3d.view_move_qcd_slot", text="", icon=icon,
                                icon_value=icon_value, depress=not qcd_laycol.exclude)
            prop.slot = str(x+1)

        else:
            prop = row.operator("view3d.unassigned_qcd_slot", text="", icon='X', emboss=False)
            prop.slot = str(x+1)


        if idx%5==0:
            row.separator()

        if idx == 10:
            row = col.row(align=True)
            row.scale_y = 0.5

        idx += 1


def view_layer_update(self, context):
    if context.view_layer.name != CollectionManager.last_view_layer:
        bpy.app.timers.register(update_qcd_header)
        CollectionManager.last_view_layer = context.view_layer.name


def get_active_icon(context, qcd_laycol):
    global last_icon_theme_text
    global last_icon_theme_text_sel

    tool_theme = context.preferences.themes[0].user_interface.wcol_tool
    pcoll = preview_collections["icons"]

    if qcd_laycol.exclude:
        theme_color = tool_theme.text
        last_theme_color = last_icon_theme_text
        icon = pcoll["active_icon_text"]

    else:
        theme_color = tool_theme.text_sel
        last_theme_color = last_icon_theme_text_sel
        icon = pcoll["active_icon_text_sel"]

    if last_theme_color == None or theme_color.hsv != last_theme_color:
        update_icon(pcoll["active_icon_base"], icon, theme_color)

        if qcd_laycol.exclude:
            last_icon_theme_text = theme_color.hsv

        else:
            last_icon_theme_text_sel = theme_color.hsv

    return icon


def update_icon(base, icon, theme_color):
    icon.icon_pixels = base.icon_pixels
    colored_icon = []

    for offset in range(len(icon.icon_pixels)):
        idx = offset * 4

        r = icon.icon_pixels_float[idx]
        g = icon.icon_pixels_float[idx+1]
        b = icon.icon_pixels_float[idx+2]
        a = icon.icon_pixels_float[idx+3]

        # add back some brightness and opacity blender takes away from the custom icon
        r = min(r+r*0.2,1)
        g = min(g+g*0.2,1)
        b = min(b+b*0.2,1)
        a = min(a+a*0.2,1)

        # make the icon follow the theme color (assuming the icon is white)
        r *= theme_color.r
        g *= theme_color.g
        b *= theme_color.b

        colored_icon.append(r)
        colored_icon.append(g)
        colored_icon.append(b)
        colored_icon.append(a)

    icon.icon_pixels_float = colored_icon


def filter_items_by_name_custom(pattern, bitflag, items, propname="name", flags=None, reverse=False):
        """
        Set FILTER_ITEM for items which name matches filter_name one (case-insensitive).
        pattern is the filtering pattern.
        propname is the name of the string property to use for filtering.
        flags must be a list of integers the same length as items, or None!
        return a list of flags (based on given flags if not None),
        or an empty list if no flags were given and no filtering has been done.
        """
        import fnmatch

        if not pattern or not items:  # Empty pattern or list = no filtering!
            return flags or []

        if flags is None:
            flags = [0] * len(items)

        # Make pattern case-insensitive
        pattern = pattern.lower()

        # Implicitly add heading/trailing wildcards.
        pattern = "*" + pattern + "*"

        for i, item in enumerate(items):
            name = getattr(item, propname, None)

            # Make name case-insensitive
            name = name.lower()

            # This is similar to a logical xor
            if bool(name and fnmatch.fnmatch(name, pattern)) is not bool(reverse):
                flags[i] |= bitflag

            # add in any recently created collections
            if item.name in CM_UL_items.new_collections:
                flags[i] |= bitflag

        return flags

def merge_flt_flags(l1, l2):
    for idx, _ in enumerate(l1):
        l1[idx] &= l2.pop(0)

    return l1 + l2