Module TkZero.Combobox

Creates a themed Combobox.

"""
Creates a themed Combobox.
"""

import tkinter as tk
from tkinter import ttk
from typing import Union, Callable

from TkZero.Platform import on_aqua


class Combobox(ttk.Combobox):
    def __init__(
        self,
        parent: Union[tk.Widget, Union[tk.Tk, tk.Toplevel]],
        values: Union[list[str, ...], tuple[str, ...]] = (),
        width: int = None,
        show: str = None,
        validate: Callable = None,
        command: Callable = None,
    ):
        """
        Initiate a ttk.Combobox.

        :param parent: The parent of the combobox.
        :param values: The default values you can choose, should be a tuple or
         list of str. Defaults to ()
        :param width: The width of the combobox. Defaults to None.
        :param show: The character to show instead of the actual text.
         Defaults to None.
        :param validate: The function to use for validation. Will be passed in
         a positional argument with the text as
         a str (like `validate(contents)`) and should return a bool - True if
          passed otherwise False.
        :param command: The command to run when the value of the combobox
         changes. Defaults to None.
        """
        if not isinstance(parent, (tk.Widget, tk.Tk, tk.Toplevel)):
            raise TypeError(
                f"parent is not a "
                f"Union[tk.Widget, Union[tk.Tk, tk.Toplevel]]! "
                f"(type passed in: {repr(type(parent))})"
            )
        if not isinstance(values, (tuple, list)):
            raise TypeError(
                f"values is not a tuple or a list! "
                f"(type passed in: {repr(type(values))})"
            )
        if not isinstance(width, int) and width is not None:
            raise TypeError(
                f"width is not a int! (type passed in: {repr(type(width))})"
            )
        if not isinstance(show, str) and show is not None:
            raise TypeError(
                f"show is not a str! " f"(type passed in: {repr(type(show))})"
            )
        self._variable = tk.StringVar(value="")
        if command is not None:
            self._variable.trace_add("write", lambda *args: command())
        super().__init__(
            master=parent,
            width=width,
            textvariable=self._variable,
            show=show,
            validatecommand=(parent.register(validate), "%p")
            if validate is not None
            else None,
        )
        self._style_root = "TCombobox"
        self._enabled = True
        self._readonly = False
        self.enable_automatically = True
        if on_aqua(self):
            self.bind("<2>", lambda event: self._popup(event=event))
            self.bind("<Control-1>", lambda event: self._popup(event=event))
        else:
            self.bind("<3>", lambda event: self._popup(event=event))
        if values is not None:
            self["values"] = values
        self._make_context_menu()
        self._hovering_over = False
        self.bind("<Enter>", lambda _: self._set_hover_state(True))
        self.bind("<Leave>", lambda _: self._set_hover_state(False))

    @property
    def value(self) -> str:
        """
        Get the text in this combobox.

        :return: A str of the text in this entry.
        """
        return self.get()

    @value.setter
    def value(self, new_text: str) -> None:
        """
        Set the text on this combobox.

        :param new_text: The new text.
        :return: None.
        """
        if not isinstance(new_text, str):
            raise TypeError(
                f"new_text is not a str! " f"(type passed in: {repr(type(new_text))})"
            )
        last_states = self.state()
        if self.enable_automatically:
            self.enabled = True
        self.delete(0, tk.END)
        self.insert(0, new_text)
        if self.enable_automatically:
            self.state(last_states)

    @property
    def values(self) -> tuple[str, ...]:
        """
        Get the default options you can select.

        :return: A str of the text in this entry.
        """
        return self["values"] if self["values"] else ()

    @values.setter
    def values(self, new_values: Union[tuple[str, ...], list[str, ...]]) -> None:
        """
        Set the default options text on this combobox.

        :param new_values: The new options, as a tuple or list of str.
        :return: None.
        """
        if not isinstance(new_values, (tuple, list)):
            raise TypeError(
                f"new_values is not a tuple or a list! "
                f"(type passed in: {repr(type(new_values))})"
            )
        self["values"] = tuple([str(thing) for thing in new_values])

    @property
    def enabled(self) -> bool:
        """
        Get whether this combobox is in normal mode or disabled mode. (grayed
        out and cannot interact with)

        :return: A bool, True if normal otherwise False.
        """
        return self._enabled

    @enabled.setter
    def enabled(self, new_state: bool) -> None:
        """
        Set whether this combobox is in normal mode or disabled mode. (grayed
        out and cannot interact with)

        :param new_state: The new state (a bool) True for enabled and False
         for disabled.
        :return: None.
        """
        if not isinstance(new_state, bool):
            raise TypeError(
                f"new_state is not a bool! "
                f"(type passed in: {repr(type(new_state))})"
            )
        self._enabled = new_state
        self._readonly = False
        self.state(["!disabled" if self._enabled else "disabled"])

    @property
    def read_only(self) -> bool:
        """
        Get whether this combobox is read only mode. (cannot type in selection
        manually - must select from pre-defined values)

        :return: A bool, True if read only otherwise False.
        """
        return self._readonly

    @read_only.setter
    def read_only(self, new_state: bool) -> None:
        """
        Set whether this combobox is in read only mode (cannot type in
        selection manually - must select from pre-defined values)

        :param new_state: The new state (a bool) True for normal and False for
         read only.
        :return: None.
        """
        if not isinstance(new_state, bool):
            raise TypeError(
                f"new_state is not a bool! "
                f"(type passed in: {repr(type(new_state))})"
            )
        self._enabled = True
        self._readonly = new_state
        self.state(["readonly" if self._readonly else "!readonly"])

    @property
    def hovering_over(self) -> bool:
        """
        Get whether the cursor is hovering over this widget or not.

        :return: A bool.
        """
        return self._hovering_over

    def _set_hover_state(self, is_hovering: bool) -> None:
        """
        Set whether we are hovering over this widget or not.

        :param is_hovering: A bool.
        :return: None.
        """
        self._hovering_over = is_hovering

    def _make_context_menu(self) -> None:
        """
        Initiate the context menu.

        :return: None.
        """
        self._context_menu = tk.Menu(self, tearoff=0)
        self._context_menu.add_command(
            label="Copy",
            command=self.copy_contents,
            underline=0,
            accelerator="Command-C" if on_aqua(self) else "Control+C",
        )
        self._context_menu.add_command(
            label="Cut",
            command=self.cut_contents,
            accelerator="Command-X" if on_aqua(self) else "Control+X",
        )
        self._context_menu.add_command(
            label="Paste",
            command=self.paste_contents,
            underline=0,
            accelerator="Command-V" if on_aqua(self) else "Control+V",
        )
        self._context_menu.add_separator()
        self._context_menu.add_command(
            label="Delete", command=self.delete_contents, accelerator="Delete"
        )
        self._context_menu.add_separator()
        self._context_menu.add_command(
            label="Select all",
            command=self.select_all_contents,
            underline=7,
            accelerator="Command-A" if on_aqua(self) else "Control+A",
        )

    def _update_context_menu_states(self) -> None:
        """
        Update the context menu states, like whether to allow copying or not.

        :return: None.
        """
        if not self.enabled:
            self._context_menu.entryconfigure("Copy", state=tk.DISABLED)
            self._context_menu.entryconfigure("Cut", state=tk.DISABLED)
            self._context_menu.entryconfigure("Paste", state=tk.DISABLED)
            self._context_menu.entryconfigure("Delete", state=tk.DISABLED)
            self._context_menu.entryconfigure("Select all", state=tk.DISABLED)
            return
        if self.read_only:
            self._context_menu.entryconfigure("Copy", state=tk.NORMAL)
            self._context_menu.entryconfigure("Cut", state=tk.DISABLED)
            self._context_menu.entryconfigure("Paste", state=tk.DISABLED)
            self._context_menu.entryconfigure("Delete", state=tk.DISABLED)
            self._context_menu.entryconfigure("Select all", state=tk.NORMAL)
            return
        if self.selection_present():
            self._context_menu.entryconfigure("Copy", state=tk.NORMAL)
            self._context_menu.entryconfigure("Cut", state=tk.NORMAL)
            self._context_menu.entryconfigure("Paste", state=tk.NORMAL)
            self._context_menu.entryconfigure("Delete", state=tk.NORMAL)
            self._context_menu.entryconfigure("Select all", state=tk.DISABLED)
        else:
            self._context_menu.entryconfigure("Copy", state=tk.DISABLED)
            self._context_menu.entryconfigure("Cut", state=tk.DISABLED)
            self._context_menu.entryconfigure("Paste", state=tk.NORMAL)
            self._context_menu.entryconfigure("Delete", state=tk.DISABLED)
            self._context_menu.entryconfigure("Select all", state=tk.NORMAL)

    def _popup(self, event) -> None:
        """
        Try to pop up the context menu.

        :param event: An object that Tk passes in with information about the
         event that we need.
        :return: None.
        """
        self._update_context_menu_states()
        if self.enabled:
            try:
                self._context_menu.tk_popup(event.x_root, event.y_root, 0)
            finally:
                self._context_menu.grab_release()

    def select_all_contents(self) -> None:
        """
        Select everything.

        :return: None.
        """
        self.select_range(0, tk.END)

    def delete_contents(self) -> None:
        """
        Delete the highlighted things.

        :return: None.
        """
        if self.selection_present():
            self.delete(tk.SEL_FIRST, tk.SEL_LAST)

    def paste_contents(self) -> None:
        """
        Paste into the entry.

        :return: None.
        """
        self.delete_contents()
        self.insert(self.index(tk.INSERT), self.clipboard_get())

    def cut_contents(self) -> None:
        """
        Cut the highlighted contents.

        :return: None.
        """
        if self.selection_present():
            self.clipboard_clear()
            self.clipboard_append(self.selection_get())
            self.update()
            self.delete(tk.SEL_FIRST, tk.SEL_LAST)
            self.select_clear()

    def copy_contents(self) -> None:
        """
        Copy the highlighted contents.

        :return: None.
        """
        if self.selection_present():
            self.clipboard_clear()
            self.clipboard_append(self.selection_get())
            self.update()

    def apply_style(self, style_name: str) -> None:
        """
        Apply a theme to this combobox.

        :param style_name: The name of the theme as a str, ex. "Warning"
        :return: None.
        """
        if not isinstance(style_name, str):
            raise TypeError(
                f"style_name is not a str! "
                f"(type passed in: {repr(type(style_name))})"
            )
        self.configure(style=f"{style_name}.{self._style_root}")

Classes

class Combobox (parent: Union[tkinter.Widget, tkinter.Tk, tkinter.Toplevel], values: Union[list, tuple] = (), width: int = None, show: str = None, validate: Callable = None, command: Callable = None)

Ttk Combobox widget combines a text field with a pop-down list of values.

Initiate a ttk.Combobox.

:param parent: The parent of the combobox. :param values: The default values you can choose, should be a tuple or list of str. Defaults to () :param width: The width of the combobox. Defaults to None. :param show: The character to show instead of the actual text. Defaults to None. :param validate: The function to use for validation. Will be passed in a positional argument with the text as a str (like validate(contents)) and should return a bool - True if passed otherwise False. :param command: The command to run when the value of the combobox changes. Defaults to None.

Expand source code

class Combobox(ttk.Combobox):
    def __init__(
        self,
        parent: Union[tk.Widget, Union[tk.Tk, tk.Toplevel]],
        values: Union[list[str, ...], tuple[str, ...]] = (),
        width: int = None,
        show: str = None,
        validate: Callable = None,
        command: Callable = None,
    ):
        """
        Initiate a ttk.Combobox.

        :param parent: The parent of the combobox.
        :param values: The default values you can choose, should be a tuple or
         list of str. Defaults to ()
        :param width: The width of the combobox. Defaults to None.
        :param show: The character to show instead of the actual text.
         Defaults to None.
        :param validate: The function to use for validation. Will be passed in
         a positional argument with the text as
         a str (like `validate(contents)`) and should return a bool - True if
          passed otherwise False.
        :param command: The command to run when the value of the combobox
         changes. Defaults to None.
        """
        if not isinstance(parent, (tk.Widget, tk.Tk, tk.Toplevel)):
            raise TypeError(
                f"parent is not a "
                f"Union[tk.Widget, Union[tk.Tk, tk.Toplevel]]! "
                f"(type passed in: {repr(type(parent))})"
            )
        if not isinstance(values, (tuple, list)):
            raise TypeError(
                f"values is not a tuple or a list! "
                f"(type passed in: {repr(type(values))})"
            )
        if not isinstance(width, int) and width is not None:
            raise TypeError(
                f"width is not a int! (type passed in: {repr(type(width))})"
            )
        if not isinstance(show, str) and show is not None:
            raise TypeError(
                f"show is not a str! " f"(type passed in: {repr(type(show))})"
            )
        self._variable = tk.StringVar(value="")
        if command is not None:
            self._variable.trace_add("write", lambda *args: command())
        super().__init__(
            master=parent,
            width=width,
            textvariable=self._variable,
            show=show,
            validatecommand=(parent.register(validate), "%p")
            if validate is not None
            else None,
        )
        self._style_root = "TCombobox"
        self._enabled = True
        self._readonly = False
        self.enable_automatically = True
        if on_aqua(self):
            self.bind("<2>", lambda event: self._popup(event=event))
            self.bind("<Control-1>", lambda event: self._popup(event=event))
        else:
            self.bind("<3>", lambda event: self._popup(event=event))
        if values is not None:
            self["values"] = values
        self._make_context_menu()
        self._hovering_over = False
        self.bind("<Enter>", lambda _: self._set_hover_state(True))
        self.bind("<Leave>", lambda _: self._set_hover_state(False))

    @property
    def value(self) -> str:
        """
        Get the text in this combobox.

        :return: A str of the text in this entry.
        """
        return self.get()

    @value.setter
    def value(self, new_text: str) -> None:
        """
        Set the text on this combobox.

        :param new_text: The new text.
        :return: None.
        """
        if not isinstance(new_text, str):
            raise TypeError(
                f"new_text is not a str! " f"(type passed in: {repr(type(new_text))})"
            )
        last_states = self.state()
        if self.enable_automatically:
            self.enabled = True
        self.delete(0, tk.END)
        self.insert(0, new_text)
        if self.enable_automatically:
            self.state(last_states)

    @property
    def values(self) -> tuple[str, ...]:
        """
        Get the default options you can select.

        :return: A str of the text in this entry.
        """
        return self["values"] if self["values"] else ()

    @values.setter
    def values(self, new_values: Union[tuple[str, ...], list[str, ...]]) -> None:
        """
        Set the default options text on this combobox.

        :param new_values: The new options, as a tuple or list of str.
        :return: None.
        """
        if not isinstance(new_values, (tuple, list)):
            raise TypeError(
                f"new_values is not a tuple or a list! "
                f"(type passed in: {repr(type(new_values))})"
            )
        self["values"] = tuple([str(thing) for thing in new_values])

    @property
    def enabled(self) -> bool:
        """
        Get whether this combobox is in normal mode or disabled mode. (grayed
        out and cannot interact with)

        :return: A bool, True if normal otherwise False.
        """
        return self._enabled

    @enabled.setter
    def enabled(self, new_state: bool) -> None:
        """
        Set whether this combobox is in normal mode or disabled mode. (grayed
        out and cannot interact with)

        :param new_state: The new state (a bool) True for enabled and False
         for disabled.
        :return: None.
        """
        if not isinstance(new_state, bool):
            raise TypeError(
                f"new_state is not a bool! "
                f"(type passed in: {repr(type(new_state))})"
            )
        self._enabled = new_state
        self._readonly = False
        self.state(["!disabled" if self._enabled else "disabled"])

    @property
    def read_only(self) -> bool:
        """
        Get whether this combobox is read only mode. (cannot type in selection
        manually - must select from pre-defined values)

        :return: A bool, True if read only otherwise False.
        """
        return self._readonly

    @read_only.setter
    def read_only(self, new_state: bool) -> None:
        """
        Set whether this combobox is in read only mode (cannot type in
        selection manually - must select from pre-defined values)

        :param new_state: The new state (a bool) True for normal and False for
         read only.
        :return: None.
        """
        if not isinstance(new_state, bool):
            raise TypeError(
                f"new_state is not a bool! "
                f"(type passed in: {repr(type(new_state))})"
            )
        self._enabled = True
        self._readonly = new_state
        self.state(["readonly" if self._readonly else "!readonly"])

    @property
    def hovering_over(self) -> bool:
        """
        Get whether the cursor is hovering over this widget or not.

        :return: A bool.
        """
        return self._hovering_over

    def _set_hover_state(self, is_hovering: bool) -> None:
        """
        Set whether we are hovering over this widget or not.

        :param is_hovering: A bool.
        :return: None.
        """
        self._hovering_over = is_hovering

    def _make_context_menu(self) -> None:
        """
        Initiate the context menu.

        :return: None.
        """
        self._context_menu = tk.Menu(self, tearoff=0)
        self._context_menu.add_command(
            label="Copy",
            command=self.copy_contents,
            underline=0,
            accelerator="Command-C" if on_aqua(self) else "Control+C",
        )
        self._context_menu.add_command(
            label="Cut",
            command=self.cut_contents,
            accelerator="Command-X" if on_aqua(self) else "Control+X",
        )
        self._context_menu.add_command(
            label="Paste",
            command=self.paste_contents,
            underline=0,
            accelerator="Command-V" if on_aqua(self) else "Control+V",
        )
        self._context_menu.add_separator()
        self._context_menu.add_command(
            label="Delete", command=self.delete_contents, accelerator="Delete"
        )
        self._context_menu.add_separator()
        self._context_menu.add_command(
            label="Select all",
            command=self.select_all_contents,
            underline=7,
            accelerator="Command-A" if on_aqua(self) else "Control+A",
        )

    def _update_context_menu_states(self) -> None:
        """
        Update the context menu states, like whether to allow copying or not.

        :return: None.
        """
        if not self.enabled:
            self._context_menu.entryconfigure("Copy", state=tk.DISABLED)
            self._context_menu.entryconfigure("Cut", state=tk.DISABLED)
            self._context_menu.entryconfigure("Paste", state=tk.DISABLED)
            self._context_menu.entryconfigure("Delete", state=tk.DISABLED)
            self._context_menu.entryconfigure("Select all", state=tk.DISABLED)
            return
        if self.read_only:
            self._context_menu.entryconfigure("Copy", state=tk.NORMAL)
            self._context_menu.entryconfigure("Cut", state=tk.DISABLED)
            self._context_menu.entryconfigure("Paste", state=tk.DISABLED)
            self._context_menu.entryconfigure("Delete", state=tk.DISABLED)
            self._context_menu.entryconfigure("Select all", state=tk.NORMAL)
            return
        if self.selection_present():
            self._context_menu.entryconfigure("Copy", state=tk.NORMAL)
            self._context_menu.entryconfigure("Cut", state=tk.NORMAL)
            self._context_menu.entryconfigure("Paste", state=tk.NORMAL)
            self._context_menu.entryconfigure("Delete", state=tk.NORMAL)
            self._context_menu.entryconfigure("Select all", state=tk.DISABLED)
        else:
            self._context_menu.entryconfigure("Copy", state=tk.DISABLED)
            self._context_menu.entryconfigure("Cut", state=tk.DISABLED)
            self._context_menu.entryconfigure("Paste", state=tk.NORMAL)
            self._context_menu.entryconfigure("Delete", state=tk.DISABLED)
            self._context_menu.entryconfigure("Select all", state=tk.NORMAL)

    def _popup(self, event) -> None:
        """
        Try to pop up the context menu.

        :param event: An object that Tk passes in with information about the
         event that we need.
        :return: None.
        """
        self._update_context_menu_states()
        if self.enabled:
            try:
                self._context_menu.tk_popup(event.x_root, event.y_root, 0)
            finally:
                self._context_menu.grab_release()

    def select_all_contents(self) -> None:
        """
        Select everything.

        :return: None.
        """
        self.select_range(0, tk.END)

    def delete_contents(self) -> None:
        """
        Delete the highlighted things.

        :return: None.
        """
        if self.selection_present():
            self.delete(tk.SEL_FIRST, tk.SEL_LAST)

    def paste_contents(self) -> None:
        """
        Paste into the entry.

        :return: None.
        """
        self.delete_contents()
        self.insert(self.index(tk.INSERT), self.clipboard_get())

    def cut_contents(self) -> None:
        """
        Cut the highlighted contents.

        :return: None.
        """
        if self.selection_present():
            self.clipboard_clear()
            self.clipboard_append(self.selection_get())
            self.update()
            self.delete(tk.SEL_FIRST, tk.SEL_LAST)
            self.select_clear()

    def copy_contents(self) -> None:
        """
        Copy the highlighted contents.

        :return: None.
        """
        if self.selection_present():
            self.clipboard_clear()
            self.clipboard_append(self.selection_get())
            self.update()

    def apply_style(self, style_name: str) -> None:
        """
        Apply a theme to this combobox.

        :param style_name: The name of the theme as a str, ex. "Warning"
        :return: None.
        """
        if not isinstance(style_name, str):
            raise TypeError(
                f"style_name is not a str! "
                f"(type passed in: {repr(type(style_name))})"
            )
        self.configure(style=f"{style_name}.{self._style_root}")

Ancestors

• tkinter.ttk.Combobox
• tkinter.ttk.Entry
• tkinter.ttk.Widget
• tkinter.Entry
• tkinter.Widget
• tkinter.BaseWidget
• tkinter.Misc
• tkinter.Pack
• tkinter.Place
• tkinter.Grid
• tkinter.XView

Instance variables

var enabled : bool

Get whether this combobox is in normal mode or disabled mode. (grayed out and cannot interact with)

:return: A bool, True if normal otherwise False.

Expand source code

@property
def enabled(self) -> bool:
    """
    Get whether this combobox is in normal mode or disabled mode. (grayed
    out and cannot interact with)

    :return: A bool, True if normal otherwise False.
    """
    return self._enabled

var hovering_over : bool

Get whether the cursor is hovering over this widget or not.

:return: A bool.

Expand source code

@property
def hovering_over(self) -> bool:
    """
    Get whether the cursor is hovering over this widget or not.

    :return: A bool.
    """
    return self._hovering_over

var read_only : bool

Get whether this combobox is read only mode. (cannot type in selection manually - must select from pre-defined values)

:return: A bool, True if read only otherwise False.

Expand source code

@property
def read_only(self) -> bool:
    """
    Get whether this combobox is read only mode. (cannot type in selection
    manually - must select from pre-defined values)

    :return: A bool, True if read only otherwise False.
    """
    return self._readonly

var value : str

Get the text in this combobox.

:return: A str of the text in this entry.

Expand source code

@property
def value(self) -> str:
    """
    Get the text in this combobox.

    :return: A str of the text in this entry.
    """
    return self.get()

var values : tuple

Get the default options you can select.

:return: A str of the text in this entry.

Expand source code

@property
def values(self) -> tuple[str, ...]:
    """
    Get the default options you can select.

    :return: A str of the text in this entry.
    """
    return self["values"] if self["values"] else ()

Methods

def apply_style(self, style_name: str) ‑> NoneType

Apply a theme to this combobox.

:param style_name: The name of the theme as a str, ex. "Warning" :return: None.

Expand source code

def apply_style(self, style_name: str) -> None:
    """
    Apply a theme to this combobox.

    :param style_name: The name of the theme as a str, ex. "Warning"
    :return: None.
    """
    if not isinstance(style_name, str):
        raise TypeError(
            f"style_name is not a str! "
            f"(type passed in: {repr(type(style_name))})"
        )
    self.configure(style=f"{style_name}.{self._style_root}")

def copy_contents(self) ‑> NoneType

Copy the highlighted contents.

:return: None.

Expand source code

def copy_contents(self) -> None:
    """
    Copy the highlighted contents.

    :return: None.
    """
    if self.selection_present():
        self.clipboard_clear()
        self.clipboard_append(self.selection_get())
        self.update()

def cut_contents(self) ‑> NoneType

Cut the highlighted contents.

:return: None.

Expand source code

def cut_contents(self) -> None:
    """
    Cut the highlighted contents.

    :return: None.
    """
    if self.selection_present():
        self.clipboard_clear()
        self.clipboard_append(self.selection_get())
        self.update()
        self.delete(tk.SEL_FIRST, tk.SEL_LAST)
        self.select_clear()

def delete_contents(self) ‑> NoneType

Delete the highlighted things.

:return: None.

Expand source code

def delete_contents(self) -> None:
    """
    Delete the highlighted things.

    :return: None.
    """
    if self.selection_present():
        self.delete(tk.SEL_FIRST, tk.SEL_LAST)

def paste_contents(self) ‑> NoneType

Paste into the entry.

:return: None.

Expand source code

def paste_contents(self) -> None:
    """
    Paste into the entry.

    :return: None.
    """
    self.delete_contents()
    self.insert(self.index(tk.INSERT), self.clipboard_get())

def select_all_contents(self) ‑> NoneType

Select everything.

:return: None.

Expand source code

def select_all_contents(self) -> None:
    """
    Select everything.

    :return: None.
    """
    self.select_range(0, tk.END)