Tkinter Nested Paned Windows Demo

This code is based on the Tcl ttkpane.tcl demo. A number of nested paned windows are created to which widgets are added. Draggable sashes exist between each of the nested panes i.e. between the Button and Clocks, Progress and Text and between the two panes holding the foregoing. The code makes use of the Tcl/Tk clock command to update the clock labels every 1000ms.

# File: hpane.py
#    http://www.tcl.tk/man/tcl8.5/TkCmd/ttk_panedwindow.htm#M-orient
#    http://www.tcl.tk/man/tcl/TclCmd/clock.htm

from tkinter import *
from tkinter import ttk
from tkinter.messagebox import *

from demopanels import MsgPanel, SeeDismissPanel

class NestedPanesDemo(ttk.Frame):
    
    def __init__(self, isapp=True, name='nestedpanesdemo'):
        ttk.Frame.__init__(self, name=name)
        self.pack(expand=Y, fill=BOTH)
        self.master.title('Nested Panes Demo')
        self.isapp = isapp
        self._create_widgets()
        
    def _create_widgets(self):
        if self.isapp:
            MsgPanel(self, 
                     ["This demonstration shows off a nested set of themed paned ",
                      "windows. Their sizes can be changed by grabbing the area ",
                      "between each contained pane and dragging the divider."])
            
            SeeDismissPanel(self)
        
        self._create_demo_panel()
        
    def _create_demo_panel(self):
        demoPanel = ttk.Frame(self, name='demo')
        demoPanel.pack(side=TOP, fill=BOTH, expand=Y)
        
        self._create_wnd_struct(demoPanel)
        self._fill_button_pane()
        self._fill_clock_pane()
        self._fill_progress_pane()
        self._fill_text_pane()
        
    def _create_wnd_struct(self, parent):
        outer = ttk.PanedWindow(parent, orient=HORIZONTAL, name='outer')
        outer.pack(expand=Y, fill=BOTH, padx=10, pady=(6,10))
        
        left = ttk.PanedWindow(outer, orient=VERTICAL, name='left')
        right = ttk.PanedWindow(outer, orient=VERTICAL, name='right')
        outer.add(left)
        outer.add(right)
        
        ltop = ttk.LabelFrame(left, text='Button', padding=3, name='ltop')
        lbot = ttk.LabelFrame(left, text='Clocks', padding=3, name='lbot')
        left.add(ltop)
        left.add(lbot)
        
        rtop = ttk.LabelFrame(right, text='Progress', padding=3, name='rtop')
        rbot = ttk.LabelFrame(right, text='Text', padding=3, name='rbot')
        right.add(rtop)
        right.add(rbot)

    def _fill_button_pane(self):
        # create and add button
        ltop = self.nametowidget('demo.outer.left.ltop')
        b = ttk.Button(ltop, text='Press Me', command=self._say_ouch)
        b.pack(padx=2, pady=3)
        
    def _say_ouch(self):
        # triggered when the button is pressed
        showinfo(title='Button Pressed', message='Ouch!',
                 detail='That hurt...', parent=self)
        
    def _fill_progress_pane(self):
        # create and add progress bar
        rtop = self.nametowidget('demo.outer.right.rtop')
        pb = ttk.Progressbar(rtop, mode='indeterminate')
        pb.pack(fill=BOTH, expand=Y, padx=2, pady=5)
        pb.start()
        
    def _fill_text_pane(self):
        # create and add text widget
        rbot = self.nametowidget('demo.outer.right.rbot')
        f = ttk.Frame(rbot)
        f.pack(expand=Y, fill=BOTH)
        
        txt = Text(f, wrap=WORD, width=30, bd=0)
        vscroll = ttk.Scrollbar(f, orient=VERTICAL, command=txt.yview)
        txt['yscroll'] = vscroll.set
        vscroll.pack(side=RIGHT, fill=Y)
        txt.pack(fill=BOTH, expand=Y)
                
    def _fill_clock_pane(self):
        # create and add clock labels
        # makes use of the Tcl/Tk 'clock' functions
        zones = (':Europe/Berlin',
                 ':America/Argentina/Buenos_Aires',
                 ':Africa/Johannesburg',
                 ':Europe/London',
                 ':America/Los_Angeles',
                 ':Europe/Moscow',
                 ':America/New_York',
                 ':Asia/Singapore',
                 ':Australia/Sydney',
                 ':Asia/Tokyo')

        # Force a pre-load of all the timezones 
        # needed to avoid sync problems
        for z in zones:
            c = self.tk.call('clock', 'format', 0, '-timezone', z)

        lbot = self.nametowidget('demo.outer.left.lbot')            
        for z in zones:
            # extract and format city name
            city = z.split('/')[-1] 
            city = [c if c != '_' else ' ' for c in city] 
            
            # create two labels for each city; one with the name
            # the other to hold the city's time
            lbl = ttk.Label(lbot, text=''.join(city), anchor=W)
            time = ttk.Label(lbot,  textvariable=StringVar(), anchor=W)
            lbl.pack(fill=X)
            time.pack(fill=X)
            ttk.Separator(lbot).pack(fill=X)

            # set the current time for the indicated zone        
            self._tick(time, z)
            
    def _tick(self, time, zone):
            # clock label helper function
            # sets the time immediately and updates it every 1000ms
            # (makes use of Tcl/Tk time handling routines)
            #
            # time - one of the 'clock' labels
            # zone - the associated timezone
                    
            cs = self.tk.call('clock', 'seconds')   # current clock time in seconds
            c = self.tk.call('clock', 'format', cs, '-timezone', zone, '-format', '%T')

            varname = time.cget('textvariable')
            time.setvar(varname, c)
            
            self.after(1000, self._tick, *(time, zone))
            

if __name__ == '__main__':
    NestedPanesDemo().mainloop()