'Initialize data attributes and bind event methods.
.text - Idle wrapper of tk Text widget, with .bell().
.history - source statements, possibly with multiple lines.
.prefix - source already entered at prompt; filters history list.
.pointer - index into history.
.cyclic - wrap around history list (or not).'

def __init__(self, text):

    self.text = text
    self.history = []
    self.prefix = None
    self.pointer = None
    self.cyclic = idleConf.GetOption('main', 'History', 'cyclic', 1, 'bool')
    text.bind('<<history-previous>>', self.history_prev)
    text.bind('<<history-next>>', self.history_next)
