4. tk Checkbutton

See: https://docs.python.org/3/library/tkinter.html#tkinter.Checkbutton
See: https://www.geeksforgeeks.org/python-tkinter-checkbutton-widget/

4.1. Usage

The tkinter.Checkbutton widget provides a checkbutton (checkbox).
To create a checkbutton widget, the general syntax is (assuming import via "import tkinter as tk"):
checkbutton_widget = tk.Checkbutton(parent, option=value)
parent is the window or frame object.
Options can be passed as parameters separated by commas.
Each checkbutton has its own IntVar because every checkbox stores its own checked state independently.
Unlike radio buttons, checkbuttons should not share the same control variable.

4.2. Using check buttons

../_images/checkboxes.png 
import tkinter as tk

# Create the main window
root = tk.Tk()
root.title("Checkbutton Example")

# Create a frame with a background color
frame1 = tk.Frame(root, bg="light blue")
frame1.pack(anchor="nw", padx=10, pady=10)

# Define a font style
font_style = ("Lucida Grande", 18)

# Define the options for group 1
options_grp1 = ["Checkbox 1", "Checkbox 2", "Checkbox 3"]
# Store each checkbox's IntVar using its label as the key.
variables = {}

for option in options_grp1:
    # Each checkbutton has its own IntVar.
    # IntVar() defaults to 0 (unchecked).
    variables[option] = tk.IntVar()

    # Make the first checkbutton checked initially.
    if option == "Checkbox 1":
        variables[option].set(1)

    button = tk.Checkbutton(
        frame1, text=option, variable=variables[option], indicatoron=1,
        bg="white", fg="black", font=font_style, padx=10, pady=5
    )
    button.pack(anchor="nw", padx=5, pady=5)

# Run the main event loop
root.mainloop()

Tasks

  1. Modify the code so that it displays four checkbuttons arranged vertically.

Modify the code so that it displays four checkbuttons arranged vertically.

import tkinter as tk

# Create the main window
root = tk.Tk()
root.title("Checkbutton Question")
# Set the size of the window
root.geometry("350x300")

# Create a frame with a background color
frame1 = tk.Frame(root, bg="light blue")
frame1.pack(anchor="nw", padx=10, pady=10)

# Define a font style
font_style = ("Lucida Grande", 18)

# Define the options for group 1
options_grp1 = ["Checkbox 1", "Checkbox 2", "Checkbox 3", "Checkbox 4"]
# Store each checkbox's IntVar using its label as the key.
variables = {}

for option in options_grp1:
    # Each checkbutton has its own IntVar.
    # IntVar() defaults to 0 (unchecked).
    variables[option] = tk.IntVar()

    # Make the first checkbutton checked initially.
    if option == "Checkbox 1":
        variables[option].set(1)

    button = tk.Checkbutton(
        frame1, text=option, variable=variables[option], indicatoron=1,
        bg="white", fg="black", font=font_style, padx=10, pady=5
    )
    button.pack(anchor="w", padx=5, pady=5)    # defaults to side="top"


# Run the main event loop
root.mainloop()

4.3. Methods

checkbutton_widget.select()
Selects the checkbutton.
Sets the associated control variable to the onvalue.
checkbutton_widget.deselect()
Deselects the checkbutton.
Sets the associated control variable to the offvalue.
checkbutton_widget.toggle()
Toggles the state of the checkbutton.
If the checkbutton is selected it becomes deselected, and vice versa.
checkbutton_widget.flash()
Briefly flashes the checkbutton several times.
Useful for drawing the user's attention to the widget.
checkbutton_widget.invoke()
Simulates the user clicking the checkbutton.
Toggles the state and calls the function specified by the command option, if one exists.
Returns the value returned by the callback function.

4.4. Control variable methods

variable.get()
Returns the current value of the associated control variable.
variable.set(value)
Sets the value of the associated control variable.
If value equals the onvalue, the checkbutton becomes selected.
If value equals the offvalue, the checkbutton becomes deselected.

4.5. Parameter syntax

checkbutton_widget = tk.Checkbutton(parent, option=value)
parent is the window or frame object.
Options can be passed as parameters separated by commas.

Parameters:

activebackground
Syntax: checkbutton_widget = tk.Checkbutton(parent, activebackground="color")
Description: Sets the background color of the checkbutton when it is active.
Default: SystemButtonFace
Example: checkbutton_widget = tk.Checkbutton(root, activebackground="lightblue")
activeforeground
Syntax: checkbutton_widget = tk.Checkbutton(parent, activeforeground="color")
Description: Sets the foreground color of the checkbutton when it is active.
Default: SystemWindowText
Example: checkbutton_widget = tk.Checkbutton(root, activeforeground="blue")
anchor
Syntax: checkbutton_widget = tk.Checkbutton(parent, anchor="position")
Description: Sets the anchor position for the text and indicator.
Default: center
Example: checkbutton_widget = tk.Checkbutton(root, anchor="w")
background
bg
Syntax: checkbutton_widget = tk.Checkbutton(parent, background="color")
Description: Sets the background color of the checkbutton.
Default: SystemButtonFace
Example: checkbutton_widget = tk.Checkbutton(root, background="lightyellow")
bd
Syntax: checkbutton_widget = tk.Checkbutton(parent, bd=border_width)
Description: Sets the border width of the checkbutton.
Default: 2
Example: checkbutton_widget = tk.Checkbutton(root, bd=5)
bitmap
Syntax: checkbutton_widget = tk.Checkbutton(parent, bitmap="bitmap_name")
Description: Sets a bitmap image to be displayed on the checkbutton.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, bitmap="error")
borderwidth
Syntax: checkbutton_widget = tk.Checkbutton(parent, borderwidth=width)
Description: Sets the width of the border around the checkbutton.
Default: 2
Example: checkbutton_widget = tk.Checkbutton(root, borderwidth=3)
command
Syntax: checkbutton_widget = tk.Checkbutton(parent, command=function)
Description: Specifies a function to be called when the checkbutton is toggled.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, command=my_function)
compound
Syntax: checkbutton_widget = tk.Checkbutton(parent, compound="position")
Description: Specifies how to display the image and text (if both are set).
Default: none
Example: checkbutton_widget = tk.Checkbutton(root, compound="left")
cursor
Syntax: checkbutton_widget = tk.Checkbutton(parent, cursor="cursor_type")
Description: Sets the mouse cursor when hovering over the checkbutton.
Default: arrow
Example: checkbutton_widget = tk.Checkbutton(root, cursor="hand2")
disabledforeground
Syntax: checkbutton_widget = tk.Checkbutton(parent, disabledforeground="color")
Description: Sets the foreground color when the checkbutton is disabled.
Default: SystemDisabledText
Example: checkbutton_widget = tk.Checkbutton(root, disabledforeground="gray")
foreground
fg
Syntax: checkbutton_widget = tk.Checkbutton(parent, fg="color")
Description: Sets the foreground color of the checkbutton (text color).
Default: SystemWindowText
Example: checkbutton_widget = tk.Checkbutton(root, fg="black")
font
Syntax: checkbutton_widget = tk.Checkbutton(parent, font=("font_name", size, "style"))
Description: Specifies the font type, size, and style for the text of the checkbutton.
Default: TkDefaultFont
Example: checkbutton_widget = tk.Checkbutton(root, font=("Arial", 12, "bold"))
height
Syntax: checkbutton_widget = tk.Checkbutton(parent, height=value)
Description: Sets the height of the checkbutton.
Default: 0 (automatically determined)
Example: checkbutton_widget = tk.Checkbutton(root, height=2)
highlightbackground
Syntax: checkbutton_widget = tk.Checkbutton(parent, highlightbackground="color")
Description: Sets the background color of the checkbutton when it does not have focus.
Default: SystemButtonFace
Example: checkbutton_widget = tk.Checkbutton(root, highlightbackground="gray")
highlightcolor
Syntax: checkbutton_widget = tk.Checkbutton(parent, highlightcolor="color")
Description: Sets the color of the highlight when the checkbutton has focus.
Default: SystemWindowFrame
Example: checkbutton_widget = tk.Checkbutton(root, highlightcolor="blue")
highlightthickness
Syntax: checkbutton_widget = tk.Checkbutton(parent, highlightthickness=thickness)
Description: Sets the thickness of the highlight border.
Default: 1
Example: checkbutton_widget = tk.Checkbutton(root, highlightthickness=2)
image
Syntax: checkbutton_widget = tk.Checkbutton(parent, image="image_name")
Description: Sets an image to be displayed on the checkbutton.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, image=my_image)
indicatoron
Syntax: checkbutton_widget = tk.Checkbutton(parent, indicatoron=1)
Description: Displays a traditional checkbox when set to 1. Set to 0 to display the widget as a regular toggle button.
Set indicatoron=1 to display a traditional checkbox.
Set indicatoron=0 to make the checkbutton appear as a regular button that stays pressed when selected.
Default: 1
Example: checkbutton_widget = tk.Checkbutton(root, indicatoron=0)
justify
Syntax: checkbutton_widget = tk.Checkbutton(parent, justify="position")
Description: Sets the justification of the text (left, center, right).
Default: center
Example: checkbutton_widget = tk.Checkbutton(root, justify="right")
offrelief
Syntax: checkbutton_widget = tk.Checkbutton(parent, offrelief="style")
Description: Sets the relief style for the indicator when off.
Default: raised
Example: checkbutton_widget = tk.Checkbutton(root, offrelief="flat")
offvalue
Syntax: checkbutton_widget = tk.Checkbutton(parent, offvalue=value)
Description: Sets the value associated with the checkbutton when it is not checked.
Default: 0
Example: checkbutton_widget = tk.Checkbutton(root, offvalue=0)
onvalue
Syntax: checkbutton_widget = tk.Checkbutton(parent, onvalue=value)
Description: Sets the value associated with the checkbutton when it is checked.
Default: 1
Example: checkbutton_widget = tk.Checkbutton(root, onvalue=1)
overrelief
Syntax: checkbutton_widget = tk.Checkbutton(parent, overrelief="style")
Description: Sets the relief style for the indicator when hovered over.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, overrelief="sunken")
padx
Syntax: checkbutton_widget = tk.Checkbutton(parent, padx=padding_value)
Description: Sets the horizontal padding within the checkbutton.
Default: 1
Example: checkbutton_widget = tk.Checkbutton(root, padx=10)
pady
Syntax: checkbutton_widget = tk.Checkbutton(parent, pady=padding_value)
Description: Sets the vertical padding within the checkbutton.
Default: 1
Example: checkbutton_widget = tk.Checkbutton(root, pady=10)
relief
Syntax: checkbutton_widget = tk.Checkbutton(parent, relief="style")
Description: Sets the border style of the checkbutton. Options include flat, raised, sunken, groove, ridge.
Default: flat
Example: checkbutton_widget = tk.Checkbutton(root, relief="raised")
selectcolor
Syntax: checkbutton_widget = tk.Checkbutton(parent, selectcolor="color")
Description: Sets the color of the indicator when the checkbutton is selected.
Default: SystemWindow
Example: checkbutton_widget = tk.Checkbutton(root, selectcolor="lightgreen")
selectimage
Syntax: checkbutton_widget = tk.Checkbutton(parent, selectimage="image_name")
Description: Sets an image to be displayed when the checkbutton is selected.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, selectimage=my_selected_image)
state
Syntax: checkbutton_widget = tk.Checkbutton(parent, state="state_type")
Description: Sets the state of the checkbutton. Options include normal or disabled.
Default: normal
Example: checkbutton_widget = tk.Checkbutton(root, state="disabled")
takefocus
Syntax: checkbutton_widget = tk.Checkbutton(parent, takefocus=1)
Description: Allows the checkbutton to receive keyboard focus using the Tab key.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, takefocus=1)
text
Syntax: checkbutton_widget = tk.Checkbutton(parent, text="label")
Description: Sets the text label for the checkbutton.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, text="Option 1")
textvariable
Syntax: checkbutton_widget = tk.Checkbutton(parent, textvariable=variable)
Description: Associates a variable with the text of the checkbutton.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, textvariable=my_text_var)
tristateimage
Syntax: checkbutton_widget = tk.Checkbutton(parent, tristateimage="image_name")
Description: Sets an image to be displayed when the checkbutton is in a tri-state mode.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, tristateimage=my_tristate_image)
tristatevalue
Syntax: checkbutton_widget = tk.Checkbutton(parent, tristatevalue=value)
Description: Sets the value associated with the checkbutton in a tri-state mode.
Default: None
Example: checkbutton_widget = tk.Checkbutton(root, tristatevalue=2)
underline
Syntax: checkbutton_widget = tk.Checkbutton(parent, underline=index)
Description: Specifies the index of the character to underline in the text.
Default: -1 (no underline)
Example: checkbutton_widget = tk.Checkbutton(root, underline=0)
variable
Syntax: checkbutton_widget = tk.Checkbutton(parent, variable=control_variable)
Description: Associates the checkbutton with a control variable (e.g., IntVar, StringVar).
Default: An internal Tcl variable created automatically.
Example: checkbutton_widget = tk.Checkbutton(root, variable=my_var)
width
Syntax: checkbutton_widget = tk.Checkbutton(parent, width=width_value)
Description: Sets the width of the checkbutton.
Default: 0 (automatically determined)
Example: checkbutton_widget = tk.Checkbutton(root, width=30)
wraplength
Syntax: checkbutton_widget = tk.Checkbutton(parent, wraplength=length)
Description: Sets the line length for text wrapping in the checkbutton.
Default: 0 (no wrapping)
Example: checkbutton_widget = tk.Checkbutton(root, wraplength=100)

4.6. Default options

Code to display the default value for each Checkbutton option is shown below.
import tkinter as tk

root = tk.Tk()

widget = tk.Checkbutton(root)
widget_options = widget.keys()

for option in widget_options:
    print(f"{option}: {widget.cget(option)}")  # cget retrieves the current value of the option