"""This program demonstrates a tkinter custom dialog box.
Input:
None
Output:
Window with a custom dialog box
References:
https://www.geeksforgeeks.org/python-tkinter-toplevel-widget/
http://effbot.org/tkinterbook/tkinter-events-and-bindings.htm
https://www.tutorialspoint.com/python/python_gui_programming.htm
https://www.python-course.eu/python_tkinter.php
"""
import tkinter
class Root(tkinter.Tk):
"""Creates root window."""
_main_menu = None
_label = None
def __init__(self, *args, **kwargs):
tkinter.Tk.__init__(self, *args, **kwargs)
self.title("tkinter Custom Dialog Example")
self.geometry("%dx%d+0+0" % self.maxsize())
self._main_menu = MainMenu(self)
# center the label in a grid
self.grid_rowconfigure(0, weight=1)
self.grid_columnconfigure(0, weight=1)
self._label = tkinter.Label(self,
text="Use Tools / Settings to change this label")
self._label.grid(row=0, column=0)
def show_dialog(self):
dialog = CustomDialog(self)
if dialog.result:
self._label.config(text=dialog.text)
class MainMenu(tkinter.Menu):
"""Creates Main menu."""
@property
def root(self):
return self._root
def __init__(self, root, *args, **kwargs):
tkinter.Menu.__init__(self, root, *args, **kwargs)
self._root = root
file_menu = ToolsMenu(self, tearoff=0)
self.add_cascade(label="Tools", menu=file_menu)
root.config(menu=self)
class ToolsMenu(tkinter.Menu):
"""Creates Tools menu."""
def __init__(self, *args, **kwargs):
tkinter.Menu.__init__(self, *args, **kwargs)
self.add_command(
label="Settings...",
command=self.master.root.show_dialog)
class CustomDialog(tkinter.Toplevel):
"""Creates custom dialog box."""
_entry = None
_result = None
_text = None
@property
def result(self):
return self._result
@property
def text(self):
return self._text
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs,
padx=10,
pady=10)
self._set_properties()
self._add_widgets()
self._entry.focus_set()
self.wait_window()
def _add_widgets(self):
label = tkinter.Label(self,
text="Label Value:")
label.grid(row=0, column=0)
self._entry = tkinter.Entry(self, width=20)
self._entry.grid(row=1, column=0)
ok_button = tkinter.Button(self,
text="OK",
command=self._ok_click)
ok_button.grid(row=0, column=1)
cancel_button = tkinter.Button(self,
text="Cancel",
command=self._cancel_click)
cancel_button.grid(row=1, column=1)
self.bind("<Return>", self._ok_click)
self.bind("<Escape>", self._cancel_click)
def _cancel_click(self, event=None):
self._text = None
self._result = False
self.destroy()
def _ok_click(self, event=None):
self._text = self._entry.get()
self._result = True
self.destroy()
def _set_properties(self):
width = 300
height = 100
self.title("Change Label")
x = (self.master.winfo_screenwidth() - width) // 2
y = (self.master.winfo_screenheight() - height) // 2
self.geometry(f"{width}x{height}+{x}+{y}")
self.resizable(False, False)
if __name__ == "__main__":
root = Root()
root.mainloop()
