def onAutoIndentTriggered(self):
        """Indent current line or selected lines
        """
        cursor = self._qpart.textCursor()

        startBlock = self._qpart.document().findBlock(cursor.selectionStart())
        endBlock = self._qpart.document().findBlock(cursor.selectionEnd())

        if startBlock != endBlock:  # indent multiply lines
            stopBlock = endBlock.next()

            block = startBlock

            with self._qpart:
                while block != stopBlock:
                    self.autoIndentBlock(block, '')
                    block = block.next()
        else:  # indent 1 line
            self.autoIndentBlock(startBlock, '')
def union(matches, root, cwd):
    """Union a list of matchers.

    If the list is empty, return nevermatcher.
    If the list only contains one non-None value, return that matcher.
    Otherwise return a union matcher.
    """
    matches = list(filter(None, matches))
    if len(matches) == 0:
        return nevermatcher(root, cwd)
    elif len(matches) == 1:
        return matches[0]
    else:
        return unionmatcher(matches)