def __init__(self,scr, title = "Prompt", prompt = "Enter something : ", width= -1, name = "value"):
    """ takes window to pop up over, title of dialog, prompt string, and width of input field,
        if width is -1 it'll auto fit remaining space in the prompt window, otherwise
        the width of the input will be set to that number of characters
        the dialog will fit the parent window """
    max_y, max_x = scr.getmaxyx()
    if width == -1:
        width = (max_x - 8) - len(prompt)
    dw = max_x - 4
    self.prompt = dialog.Prompt(name,1,2,2,prompt,width)
    dialog.Dialog.__init__(self,scr,"PromptDialog",5,dw, [ dialog.Frame(title),
                                      self.prompt])

def btab(self):
    if self.focus_list:
        self.push_history(self.focus_list[self.current][1])
        self.current -= 1
        if self.current < 0:
            self.current = len(self.focus_list)-1

def focus(self):
    self.focus_list = []
    for c in self.children:
        self.pop_history(c)
        if c.getorder() > 0:
            self.focus_list.append((c.getorder(),c))
    if not self.focus_list:
        self.current = 0
        return
    self.focus_list.sort(key=lambda x: x[0])
    self.current = 0

def getname(self):
    """ get the name of this component """
    return self.name

def getorder(self):
    """ get this component's tab order number """
    return self.order

def getparent(self):
    """ get this component's curses target window """
    return self.parent

def getvalue(self):
    value = {}
    for c in self.children:
        if c.getname():
            value[c.getname()] = c.getvalue()
    return value

def goto(self, component):
    """ move focus to this component """
    for i in range(0,len(self.focus_list)):
        if self.focus_list[i][1] == component:
            self.current = i
            return True
    return False

def handle(self,ch):
    """ override the dialog handling to allow enter to do ok and esc to do cancel since we have no buttons """
    ret_ch = dialog.Dialog.handle(self,ch)
    if ch == keytab.KEYTAB_CR: # enter
        return dialog.Component.CMP_KEY_OK
    elif ch == keytab.KEYTAB_ESC: # esc
        return dialog.Component.CMP_KEY_CANCEL
    else:
        return ret_ch

def handle_mouse(self):
    if self.focus_list and self.win:
        try:
            mid, mx, my, mz, mtype = curses.getmouse()
            by,bx = self.win.getbegyx()
            oy = my - by
            ox = mx - bx
            for i in range(0,len(self.focus_list)):
                c = self.focus_list[i][1]
                ret = c.mouse_event(ox,oy,mtype)
                if ret >= 0:
                    self.current = i
                    return ret
            else:
                return -1
        except:
            return -1

def isempty(self):
    """ test if the component entry is empty """
    return False

def main(self,blocking = True,force=False,ch_in = None):
    curses.mousemask( curses.BUTTON1_PRESSED| curses.BUTTON1_RELEASED| curses.BUTTON1_CLICKED)
    self.win.nodelay(1)
    self.win.notimeout(0)
    self.win.timeout(0)
    old_cursor = curses.curs_set(1)
    while (1):
        if (not keymap.keypending(self.win)) or force:
            self.render()
        if not ch_in:
            ch = self.handle(keymap.get_keyseq(self.win,keymap.getch(self.win)))
        else:
            ch = self.handle(ch_in)
        if blocking:
            if ch == Component.CMP_KEY_CANCEL:
                curses.curs_set(old_cursor)
                return {}
            elif ch == Component.CMP_KEY_OK:
                curses.curs_set(old_cursor)
                return self.getvalue()
        else:
            if ch == Component.CMP_KEY_CANCEL:
                curses.curs_set(old_cursor)
                return (ch, {})
            else:
                curses.curs_set(old_cursor)
                return (ch, self.getvalue())

def mouse_event(self, ox, oy, mtype):
    """ handle mouse events return key value or -1 for not handled """
    return -1

def pop_history( self, child ):
    if not self.enable_history:
        return
    if not issubclass(child.__class__, Prompt):
        return
    if self.getname() and child.getname() and child.getorder() >= 0:
        key = (self.getname(), child.getname())
        if key in Dialog.history:
            hist = Dialog.history[key]
            self.hist_idx += 1
            if self.hist_idx > len(hist):
                self.hist_idx = 0
            child.setvalue(hist[-self.hist_idx])

def push_history( self, child ):
    if not self.enable_history:
        return
    if not issubclass(child.__class__, Prompt):
        return
    if self.getname() and child.getname() and child.getorder() >= 0 and not child.isempty():
        key = (self.getname(), child.getname())
        if key in Dialog.history:
            if Dialog.history[key][-1] != child.getvalue():
                Dialog.history[key].append(child.getvalue())
        else:
            Dialog.history[key] = [child.getvalue()]

def render(self):
    self.win.leaveok(1)
    for c in self.children:
        if not self.focus_list or self.focus_list[self.current][1] != c:
            c.render()
    self.win.leaveok(0)
    if self.focus_list:
        self.focus_list[self.current][1].focus()
        self.focus_list[self.current][1].render()
    self.win.refresh()

def resize(self):
    pass

def set_history( self, state ):
    self.enable_history = state

def setparent(self,parent):
    """ set the parent curses target window """
    self.parent = parent

def setpos(self, x, y ):
    """ set the position of this component """
    self.x = x
    self.y = y

def setsize(self, height, width ):
    """ set the width of this component """
    self.height = height
    self.width = width

def setvalue(self, value):
    for c in self.children:
        if c.getname() in value:
            c.setvalue(value[c.getname()])
            self.push_history(c)

def tab(self):
    if self.focus_list:
        self.push_history(self.focus_list[self.current][1])
        self.current += 1
        if self.current >= len(self.focus_list):
            self.current = 0