#!/usr/bin/python

import sys
from xml.dom import minidom
import Tkinter

def attr_to_dict(attr):
    ''' convert (widget or grid_location) attributes into a dict '''
    dict = {}
    for a in attr.values():
        if a.name == 'image':
            dict[a.name] = Tkinter.PhotoImage(file=a.value)
        elif a.name == 'command':
            module = sys.modules[__name__]
            dict[a.name] = getattr(module, a.value)
        else:
            dict[a.name] = a.value
    return dict

def construct_widget_dict():
    ''' Go through all widget xml nodes on first level, I mean, those widgets defined
inside other widget will not be checked. If the widget has a name, it will
be recorded in the widget_dict.'''
    widgets = [e for e in xmldoc.firstChild.childNodes
               if e.nodeType == e.ELEMENT_NODE and e.nodeName == "widget"]
    for w in widgets:
        if "name" in w.attributes.keys():
            widget_dict[w.attributes["name"].value] = w
            
def widget(w_xml, p_win):
    ''' create a widget. 
 w_xml is a xml node describing the widget. 
 p_win is the parent widget.'''
    func = getattr(Tkinter, w_xml.attributes["type"].value)
    # convert attributes into dictionary
    wa_list = [wa for wa in w_xml.childNodes
               if wa.nodeType == wa.ELEMENT_NODE and wa.nodeName =="widget_attribute"]
    if wa_list:
        # only process the first element, and there should be only one element.
        attr_dict = attr_to_dict(wa_list[0].attributes)
        w_win = func(p_win, attr_dict)
    else:
        w_win = func(p_win)

    gm_list = [m for m in w_xml.childNodes 
               if m.nodeType == m.ELEMENT_NODE and m.nodeName == "grid_management"]
    gl_list = [l for l in w_xml.childNodes 
               if l.nodeType == l.ELEMENT_NODE and l.nodeName == "grid_location"]
    w_list = [ w for w in w_xml.childNodes 
               if w.nodeType == w.ELEMENT_NODE and w.nodeName == "widget" ]

    for w in w_list:
        widget(w, w_win)

    for m in gm_list:
        for cf in m.childNodes:
            if cf.nodeType != m.ELEMENT_NODE or cf.nodeName != "configure":
                continue
            if "row" in cf.attributes.keys():
                cf_func = getattr(w_win, "rowconfigure")
                n = cf.attributes["row"].value
            elif "column" in cf.attributes.keys():
                cf_func = getattr(w_win, "columnconfigure")
                n = cf.attributes["column"].value
            else:
                continue
            cf_func(n, weight=cf.attributes["weight"].value)
        # only process the first item
        break

    for l in gl_list:
        ld = attr_to_dict(l.attributes)
        w_win.grid(ld)
        # only process the first item
        break

def display():
    ''' Display a series of widgets '''
    root_window = Tkinter.Tk()

    # first display the main frame
    widget(widget_dict["main"], root_window)
    root_window.columnconfigure(0, weight=1)
    root_window.rowconfigure(0, weight=1)
    root_window.geometry('800x600+0+0')
    root_window.mainloop()

# commands for buttons
def quit():
    print "quit"

def previous_step():
    print "previous step"

def next_step():
    
    print "next step"

xmldoc = minidom.parse("../../xml/interface_t.xml")

widget_dict={}
construct_widget_dict()

sequence_dict={}
construct_sequence_dict()

display()