Tkinter Color Picker Demo

This code is based on the Tcl clrpick.tcl demo.

Clicking on one of the buttons pops up the native color picker dialog, which, in Windows is

Once a color is chosen either the background or foreground color of the widgets are changed.

Note that the background Style option for ttk.Button, in Windows, only changes the buttons highlight area and not the entire button background.

# File: clrpick.py
#    http://infohost.nmt.edu/tcc/help/pubs/tkinter//dialogs.html#tkColorChooser

from tkinter import *
from tkinter import ttk
from tkinter.colorchooser import *

from demopanels import MsgPanel, SeeDismissPanel

class ColorPickDemo(ttk.Frame):
    
    def __init__(self, isapp=True, name='clrpickdemo'):
        ttk.Frame.__init__(self, name=name)
        self.pack(expand=Y, fill=BOTH)
        self.master.title('Color Picker Demo')
        self.isapp = isapp
        self._create_widgets()
        
    def _create_widgets(self):
        if self.isapp:
            MsgPanel(self, 
                     ["Press the buttons below to choose the foreground ",
                      "and background colors for the widgets in this window."])
            
            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)
        
        bgBtn = ttk.Button(demoPanel, text='Set background color...',
                           width=25, name='bgBtn',
                           command=lambda: self._set_color('background'))
        fgBtn = ttk.Button(demoPanel, text='Set foreground color...',
                           width=25, name='fgBtn',
                           command=lambda: self._set_color('foreground'))
        bgBtn.pack(side=TOP, anchor=CENTER, pady='2m')
        fgBtn.pack(side=TOP, anchor=CENTER, pady='2m')

    def _set_color(self, opt):
        
        # askcolor() returns a tuple of the form
        # ((r,g,b), hex) or (None, None) if cancelled
        color = askcolor(parent=self,
                         title='Choose a {} color'.format(opt))
        if color[1]:
            opts = {opt: color[1]}
            children = self._get_all_children(self.master.winfo_children(),
                                              self.master.winfo_children())
    
            for child in children:
                try:
                    child.config(opts)
                except TclError:    # no background/foreground attribute
                    # ttk.Button background option only changes the
                    # button highlight area, not the entire background
                    # foreground works as expected
                    ttk.Style().configure(child.winfo_class(), **opts)
        
    def _get_all_children(self, children, allChildren) :
        # recursive routine to get all of a given widgets children
        # children - list of a given widgets children
        # allchildren - list of 'all' the given widgets children
        #               including grandchildren, great-grandchildren,etc
        #               initially, should be the same as children
        for child in children :
            if child.winfo_children():
                allChildren.extend(child.winfo_children())
                self._get_all_children(child.winfo_children(), allChildren)
        
        return allChildren

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