Switch

Examples#

Basic Example#

import flet as ft


def main(page: ft.Page):
    def handle_button_click(e: ft.Event[ft.ElevatedButton]):
        message.value = (
            f"Switch values are:  {c1.value}, {c2.value}, {c3.value}, {c4.value}."
        )
        page.update()

    page.add(
        c1 := ft.Switch(label="Unchecked switch", value=False),
        c2 := ft.Switch(label="Checked switch", value=True),
        c3 := ft.Switch(label="Disabled switch", disabled=True),
        c4 := ft.Switch(
            label="Switch with rendered label_position='left'",
            label_position=ft.LabelPosition.LEFT,
        ),
        ft.ElevatedButton(content="Submit", on_click=handle_button_click),
        message := ft.Text(),
    )


ft.run(main)

Handling change events#

import flet as ft


def main(page: ft.Page):
    def handle_switch_change(e: ft.Event[ft.Switch]):
        page.theme_mode = (
            ft.ThemeMode.DARK
            if page.theme_mode == ft.ThemeMode.LIGHT
            else ft.ThemeMode.LIGHT
        )
        e.control.label = (
            "Light ThemeMode"
            if page.theme_mode == ft.ThemeMode.LIGHT
            else "Dark ThemeMode"
        )
        page.update()

    page.theme_mode = ft.ThemeMode.LIGHT
    page.add(ft.Switch(label="Light ThemeMode", on_change=handle_switch_change))


ft.run(main)

Switch #

Bases: ConstrainedControl, AdaptiveControl

A toggle represents a physical switch that allows someone to choose between two mutually exclusive options.

For example, "On/Off", "Show/Hide".

RAISES	DESCRIPTION
`AssertionError`	If `splash_radius` is negative.

active_color #

active_color: ColorValue | None = None

The color to use when this switch is on.

active_track_color #

active_track_color: ColorValue | None = None

The color to use on the track when this switch is on.

If track_color returns a non-none color in the ControlState.SELECTED state, it will be used instead of this color.

adaptive #

adaptive: bool | None = None

Whether an adaptive Switch should be created based on the target platform.

On iOS and macOS, a CupertinoSwitch is created, which has matching functionality and presentation as Switch, and the graphics as expected on iOS. On other platforms, a Material Switch is created.

Defaults to False. See the example of usage here.

animate_offset #

animate_offset: AnimationValue | None = None

Enables implicit animation of the offset property.

More information here.

animate_opacity #

animate_opacity: AnimationValue | None = None

Enables implicit animation of the opacity property.

More information here.

animate_position #

animate_position: AnimationValue | None = None

Enables implicit animation of the positioning properties (left, right, top and bottom).

More information here.

animate_rotation #

animate_rotation: AnimationValue | None = None

Enables implicit animation of the rotate property.

More information here.

animate_scale #

animate_scale: AnimationValue | None = None

Enables implicit animation of the scale property.

More information here.

animate_size #

animate_size: AnimationValue | None = None

TBD

aspect_ratio #

aspect_ratio: Number | None = None

TBD

autofocus #

autofocus: bool = False

Whether this switch will be selected as the initial focus. If there is more than one control on a page with autofocus set, then the first one added to the page will get focus.

badge #

badge: BadgeValue | None = None

A badge to show on top of this control.

bottom #

bottom: Number | None = None

The distance that the child's bottom edge is inset from the bottom of the stack.

Note

Effective only if this control is a descendant of one of the following: Stack control, Page.overlay list.

col #

col: ResponsiveNumber = 12

If a parent of this control is a ResponsiveRow, this property is used to determine how many virtual columns of a screen this control will span.

Can be a number or a dictionary configured to have a different value for specific breakpoints, for example col={"sm": 6}.

This control spans the 12 virtual columns by default.

Dimensions

Breakpoint	Dimension
xs	<576px
sm	≥576px
md	≥768px
lg	≥992px
xl	≥1200px
xxl	≥1400px

data #

data: Any = skip_field()

Arbitrary data of any type.

disabled #

disabled: bool = False

Every control has disabled property which is False by default - control and all its children are enabled.

Note

The value of this property will be propagated down to all children controls recursively.

Example

For example, if you have a form with multiple entry controls you can disable them all together by disabling container:

ft.Column(
    disabled = True,
    controls=[
        ft.TextField(),
        ft.TextField()
    ]
)

expand #

expand: bool | int | None = None

Specifies whether/how this control should expand to fill available space in its parent layout.

More information here.

Note

Has effect only if the direct parent of this control is one of the following controls, or their subclasses: Column, Row, View, Page.

expand_loose #

expand_loose: bool = False

Allows the control to expand along the main axis if space is available, but does not require it to fill all available space.

More information here.

Note

If expand_loose is True, it will have effect only if:

expand is not None and
the direct parent of this control is one of the following controls, or their subclasses: Column, Row, View, Page.

focus_color #

focus_color: ColorValue | None = None

The color to use for the focus highlight for keyboard interactions.

height #

height: Number | None = None

Imposed Control height in virtual pixels.

hover_color #

hover_color: ColorValue | None = None

The color to be used when it is being hovered over by the mouse pointer.

inactive_thumb_color #

inactive_thumb_color: ColorValue | None = None

The color to use on the thumb when this switch is off.

Defaults to colors defined in the material design specification.

If thumb_color returns a non-none color in the ControlState.DEFAULT state, it will be used instead of this color.

inactive_track_color #

inactive_track_color: ColorValue | None = None

The color to use on the track when this switch is off.

Defaults to colors defined in the material design specification.

If track_color returns a non-none color in the ControlState.DEFAULT state, it will be used instead of this color.

key #

key: (
    str | int | float | bool | ValueKey | ScrollKey | None
) = None

label #

label: StrOrControl | None = None

The clickable label to display on the right of this switch.

label_position #

label_position: LabelPosition = RIGHT

The position of the label, if provided.

label_text_style #

label_text_style: TextStyle | None = None

The label's text style, when it is a string.

left #

left: Number | None = None

The distance that the child's left edge is inset from the left of the stack.

Note

Effective only if this control is a descendant of one of the following: Stack control, Page.overlay list.

mouse_cursor #

mouse_cursor: MouseCursor | None = None

The cursor to be displayed when a mouse pointer enters or is hovering over this control.

offset #

offset: OffsetValue | None = None

Applies a translation transformation before painting the control.

The translation is expressed as an Offset scaled to the control's size. So, Offset(x=0.25, y=0), for example, will result in a horizontal translation of one quarter the width of this control.

Example

The following example displays container at 0, 0 top left corner of a stack as transform applies -1 * 100, -1 * 100 (offset * control's size) horizontal and vertical translations to the control:

import flet as ft

def main(page: ft.Page):
    page.add(
        ft.Stack(
            width=1000,
            height=1000,
            controls=[
                ft.Container(
                    bgcolor="red",
                    width=100,
                    height=100,
                    left=100,
                    top=100,
                    offset=ft.Offset(-1, -1),
                )
            ],
        )
    )

ft.run(main)

on_animation_end #

on_animation_end: (
    ControlEventHandler[ConstrainedControl] | None
) = None

Called when animation completes.

Can be used to chain multiple animations.

The data property of the event handler argument contains the name of the animation.

More information here.

on_blur #

on_blur: ControlEventHandler[Switch] | None = None

Called when the control has lost focus.

on_change #

on_change: ControlEventHandler[Switch] | None = None

Called when the state of the Switch is changed.

on_focus #

on_focus: ControlEventHandler[Switch] | None = None

Called when the control has received focus.

opacity #

opacity: Number = 1.0

Defines the transparency of the control.

Value ranges from 0.0 (completely transparent) to 1.0 (completely opaque without any transparency).

overlay_color #

overlay_color: ControlStateValue[ColorValue] | None = None

The color for the switch's Material in various ControlState states.

The following states are supported: ControlState.PRESSED, ControlState.SELECTED, ControlState.HOVERED, ControlState.FOCUSED and ControlState.DEFAULT.

padding #

padding: PaddingValue | None = None

The amount of space to surround the child inside the bounds of the Switch.

Defaults to horizontal padding of 4 pixels. If Theme.use_material3 is false, then there is no padding by default.

page #

page: Page | PageView | None

The page (of type Page or PageView) to which this control belongs to.

parent #

parent: BaseControl | None

The direct ancestor(parent) of this control.

It defaults to None and will only have a value when this control is mounted (added to the page tree).

The Page control (which is the root of the tree) is an exception - it always has parent=None.

right #

right: Number | None = None

The distance that the child's right edge is inset from the right of the stack.

Note

Effective only if this control is a descendant of one of the following: Stack control, Page.overlay list.

rotate #

rotate: RotateValue | None = None

Transforms this control using a rotation around its center.

The value of rotate property could be one of the following types:

number - a rotation in clockwise radians. Full circle 360° is math.pi * 2 radians, 90° is pi / 2, 45° is pi / 4, etc.
Rotate - allows to specify rotation angle as well as alignment - the location of rotation center.

Example

For example:

ft.Image(
    src="https://picsum.photos/100/100",
    width=100,
    height=100,
    border_radius=5,
    rotate=Rotate(angle=0.25 * pi, alignment=ft.Alignment.CENTER_LEFT)
)

rtl #

rtl: bool = False

Whether the text direction of the control should be right-to-left (RTL).

scale #

scale: ScaleValue | None = None

Scales this control along the 2D plane. Default scale factor is 1.0, meaning no-scale.

Setting this property to 0.5, for example, makes this control twice smaller, while 2.0 makes it twice larger.

Different scale multipliers can be specified for x and y axis, by setting Control.scale property to an instance of Scale class. Either scale or scale_x and scale_y could be specified, but not all of them.

Example

ft.Image(
    src="https://picsum.photos/100/100",
    width=100,
    height=100,
    border_radius=5,
    scale=ft.Scale(scale_x=2, scale_y=0.5)
)

splash_radius #

splash_radius: Number | None = None

The radius of the splash effect when the switch is pressed.

thumb_color #

thumb_color: ControlStateValue[ColorValue] | None = None

The color of this switch's thumb in various ControlState states.

The following states are supported: ControlState.SELECTED, ControlState.HOVERED, ControlState.DISABLED, ControlState.FOCUSED and ControlState.DEFAULT (fallback).

thumb_icon #

thumb_icon: ControlStateValue[IconValue] | None = None

The icon of this Switch's thumb in various ControlState states.

The following states are supported: ControlState.SELECTED, ControlState.HOVERED, ControlState.DISABLED, ControlState.FOCUSED and ControlState.DEFAULT (fallback).

tooltip #

tooltip: TooltipValue | None = None

The tooltip ot show when this control is hovered over.

top #

top: Number | None = None

The distance that the child's top edge is inset from the top of the stack.

Note

Effective only if this control is a descendant of one of the following: Stack control, Page.overlay list.

track_color #

track_color: ControlStateValue[ColorValue] | None = None

The color of this switch's track in various ControlState states.

The following states are supported: ControlState.SELECTED, ControlState.HOVERED, ControlState.DISABLED, ControlState.FOCUSED and ControlState.DEFAULT (fallback).

track_outline_color #

track_outline_color: (
    ControlStateValue[ColorValue] | None
) = None

The outline color of this switch's track in various ControlState states.

The following states are supported: ControlState.SELECTED, ControlState.HOVERED, ControlState.DISABLED, ControlState.FOCUSED and ControlState.DEFAULT (fallback).

track_outline_width #

track_outline_width: (
    ControlStateValue[Number | None] | None
) = None

The outline width of this switch's track in all or specific ControlState states.

The following states are supported: ControlState.SELECTED, ControlState.HOVERED, ControlState.DISABLED, ControlState.FOCUSED and ControlState.DEFAULT (fallback).

value #

value: bool = False

Current value of this switch.

visible #

visible: bool = True

Every control has visible property which is True by default - control is rendered on the page. Setting visible to False completely prevents control (and all its children if any) from rendering on a page canvas. Hidden controls cannot be focused or selected with a keyboard or mouse and they do not emit any events.

width #

width: Number | None = None

Imposed Control width in virtual pixels.

before_event #

before_event(e: ControlEvent)

before_update #

before_update()

clean #

clean() -> None

did_mount #

did_mount()

init #

init()

is_isolated #

is_isolated()

update #

update() -> None

will_unmount #

will_unmount()