Switch

An on/off toggle in the theme’s accent color. on_toggle receives the new bool.

ui.switch · Category: Forms · Full reference →

Preview
Code

pz.column([
    ui.switch(True, on_toggle, label="Autosave"),
    ui.switch(False, on_toggle, label="Vim mode"),
], spacing=12)

When to use

For settings that take effect immediately (Wi-Fi, autosave, dark mode).
Put it on the right of a Field to build settings screens.

Usage

import pyzed as pz
from pyzed import ui

class Settings(pz.App):
    def __init__(self):
        self.autosave = True

    def view(self):
        return ui.switch(self.autosave, lambda on: setattr(self, "autosave", on), label="Autosave")

Variants

State

Switch: Read-only (no on_toggle) — Read-only (no on_toggle)

States and events

The pz.* widget underneath: no theme, every color and size is yours.

Events

Switch has 1 event of its own, listed below. Like every widget it also has the 18 common events (click, double_click, right_click, mouse_enter, drag, key_down, resize…), attached with .on(...): see Events and Events of every component.

Event	Of	Handler gets	When
`on_toggle`	`ui.switch`, `pz.toggler`	`(checked)`	Callable that receives the new `bool` (or a message to send).

Handler gets is what Pyzed passes to your callable: () means nothing. Any handler can also be a message (a value that is not callable), which goes to update().

Handling the events

The same events written three ways. Imperative: methods of the app change self. Declarative: the handlers produce messages and one update() decides. Functional: a pure function draws an immutable state and asks for changes with set_state(...). See Imperative, declarative and functional.

class Settings(pz.App):
    def __init__(self):
        self.autosave = True

    def set_autosave(self, on):          # on_toggle: the new state
        self.autosave = on

    def view(self):
        return pz.column([
            ui.switch(self.autosave, self.set_autosave, label="Autosave"),
            ui.label("Saving as you type" if self.autosave else "Save with Ctrl+S"),
        ], spacing=8)

from dataclasses import dataclass


@dataclass
class SetAutosave:
    on: bool


class Settings(pz.App):
    autosave = True

    def update(self, message):
        match message:
            case SetAutosave(on):
                self.autosave = on

    def view(self):
        return ui.switch(self.autosave, SetAutosave, label="Autosave")

from dataclasses import dataclass


@dataclass(frozen=True)
class State:
    autosave: bool = True


def view(state, set_state):
    return ui.switch(state.autosave, lambda on: set_state(autosave=on), label="Autosave")

Tips

Properties and API

`ui.switch`

switch(
    checked,
    on_toggle=None,
    *,
    label=None,
    size='md',
    disabled=False,
    id=None,
    theme=None,
)

An on/off switch.

Property	Default	Description
`checked`	required	Current state.
`label`	`None`	Label text.
`size`	`"md"`	`"sm"`, `"md"` or `"lg"`.
`disabled`	`False`	Greys it out and ignores clicks.
`id`	`None`	Stable identifier used to focus or scroll it with a `Command`.
`theme`	`None`	Theme to use instead of the current one (`pyzed.theme.current()`).

Events: on_toggle (events).

Full reference →

`pz.toggler`

toggler(
    checked,
    label=None,
    *,
    on_toggle=None,
    size=None,
    text_size=None,
    accent=None,
    bg=None,
    border_color=None,
    knob_color=None,
    color=None,
)