source: SHX/trunk/SeismicHandler/basics/tools.py @ 531

# -*- coding: utf-8 -*-

"""
Collection of globally used helper functions.
"""
__all__ = ["Property", "Singleton"]

# property wrapper
def Property(func):
    return property(**func())


class Singleton(type):
    """
    Meta-class for singletons.
    """

    def __init__(cls, name, bases, dic):
        super(Singleton, cls).__init__(name, bases, dic)
        cls.instance = None

    def __call__(cls, *args, **kwargs):
        if cls.instance is None:
            cls.instance = super(Singleton, cls).__call__(*args, **kwargs)

        return cls.instance


def expandTraceList(trcs, selection):
    """
    Expand comma separated list of traces into sorted internal trace numbers
    (reverse order).
    """

    if not len(trcs):
        return None

    selection = [i.lower() for i in selection.split(",")]

    if "all" in selection:
        selected = range(0, len(trcs))
        selected.reverse()
        return selected

    selected = []
    for s in selection:
        # range
        if "-" in s:
            try:
                start, stop = map(int, s.split("-"))
            except:
                print "  skipping '%s'" % s
                continue

            if stop < start:
                start, stop = stop, start

            selected.extend(range(start - 1, stop))

        else:
            if s.isdigit():
                selected.append(int(s) - 1)
            else:
                print "  skipping '%s'" % s

    # unique
    selected = list(set(selected))
    selected.sort()
    selected.reverse()

    return selected