Switch

Switch is a selection control for toggling a setting on or off, rendered with a distinctive switch/slider appearance.

Use Switch when the control represents a single binary setting that takes effect immediately, such as enabling a feature, turning on notifications, or activating a mode.

Quick start

import bootstack as bs

app = bs.App()

bs.Switch(app, text="Enable dark mode", value=True).pack(padx=20, pady=6)
bs.Switch(app, text="Send notifications", value=False).pack(padx=20, pady=6)

app.mainloop()

When to use

Use Switch when:

• the setting is binary (on/off)
• the change takes effect immediately
• you want a clear visual toggle indicator

Consider a different control when...

• you need tri-state (indeterminate) support -> use CheckButton
• multiple related options can be enabled -> use CheckButton for each
• you want a compact button-like toggle -> use CheckToggle
• only one choice is allowed in a group -> use RadioButton

Appearance

Colors and styling

Use semantic color tokens with the accent parameter.

bs.Switch(app, text="Primary", accent="primary")
bs.Switch(app, text="Secondary", accent="secondary")
bs.Switch(app, text="Success", accent="success")
bs.Switch(app, text="Warning", accent="warning")
bs.Switch(app, text="Danger", accent="danger")

Examples & patterns

How the value works

Switch uses a boolean value model:

• True -> on (switch is toggled)
• False -> off (switch is not toggled)

The value option sets the initial state. Once bound, the signal or variable becomes the source of truth.

Common options

text

Label shown next to the switch.

bs.Switch(app, text="Auto-save")

command

Run a callback when the switch toggles.

enabled = bs.BooleanVar(value=True)

def on_toggle():
    print("now:", enabled.get())

bs.Switch(app, text="Enable feature", variable=enabled, command=on_toggle).pack(padx=20, pady=20)

state

Disable or enable the widget.

sw = bs.Switch(app, text="Locked", state="disabled")
sw.pack()

sw.configure(state="normal")

padding, width, underline

bs.Switch(app, text="Wider", padding=(10, 6), width=18).pack(pady=6)
bs.Switch(app, text="E_xport", underline=1).pack(pady=6)

Reacting to changes

Use command for immediate callbacks, or subscribe to the signal/variable for reactive updates.

# Using command callback
def on_toggle():
    print("toggled!")

sw = bs.Switch(app, text="Feature", command=on_toggle)

# Using signal subscription
enabled = bs.Signal(False)
sw = bs.Switch(app, text="Feature", signal=enabled)
enabled.subscribe(lambda v: print(f"Value: {v}"))

Behavior

• Click toggles between on and off states.
• Unlike CheckButton, Switch does not support an indeterminate state.
• Keyboard navigation follows standard ttk checkbutton behavior (focus + Space to toggle).
• The visual design clearly communicates whether the setting is active.

Localization

By default, widgets use localize="auto":

• if a translation key exists, it is used
• otherwise, the label is treated as a literal string

bs.Switch(app, text="settings.dark_mode")
bs.Switch(app, text="settings.dark_mode", localize=True)
bs.Switch(app, text="Dark Mode", localize=False)

Reactivity

Prefer a reactive signal=... in v2 apps:

import bootstack as bs

app = bs.App()

dark_mode = bs.Signal(False)

sw = bs.Switch(
    app,
    text="Dark mode",
    signal=dark_mode,
)
sw.pack(padx=20, pady=20)

# React to changes
dark_mode.subscribe(lambda v: print(f"Dark mode: {v}"))

app.mainloop()

You can also bind a Tk variable with variable=....

Switch vs CheckButton vs CheckToggle

Choose based on the visual context and whether you need tri-state support.

Additional resources

Related widgets

• CheckButton - classic checkbox with tri-state support
• CheckToggle - button-like toggle presentation
• RadioButton - choose one option from a group
• Form - use editor='switch' or editor='toggle' for switch fields

Framework concepts

• Signals - reactive state management
• Localization - text translation
• Design System - color tokens and variants

API reference

• bootstack.Switch