ListView

Examples

Live example

Auto-scrolling and dynamical items addition

import asyncio

import flet as ft


async def main(page: ft.Page):
    def handle_switch_change(e: ft.Event[ft.Switch]):
        lv.auto_scroll = not lv.auto_scroll
        page.update()

    lv = ft.ListView(
        spacing=10,
        padding=20,
        width=150,
        auto_scroll=True,
        controls=[
            ft.Text(f"Line {i}", color=ft.Colors.ON_SECONDARY) for i in range(0, 60)
        ],
    )

    page.add(
        ft.Row(
            expand=True,
            vertical_alignment=ft.CrossAxisAlignment.START,
            controls=[
                ft.Container(
                    content=lv,
                    bgcolor=ft.Colors.GREY_500,
                ),
                ft.Switch(
                    thumb_icon=ft.Icons.LIST_OUTLINED,
                    value=True,
                    label="Auto-scroll",
                    label_position=ft.LabelPosition.RIGHT,
                    on_change=handle_switch_change,
                ),
            ],
        )
    )

    # add a new item to the ListView every 1 second
    for i in range(len(lv.controls), 120):
        await asyncio.sleep(1)
        lv.controls.append(ft.Text(f"Line {i}", color=ft.Colors.ON_SECONDARY))
        page.update()


ft.run(main)

ListView

Bases: ConstrainedControl, ScrollableControl, AdaptiveControl

A scrollable list of controls arranged linearly.

ListView is the most commonly used scrolling control. It displays its children one after another in the scroll direction. In the cross axis, the children are required to fill the ListView.

adaptive

adaptive: bool | None = None

Enables platform-specific rendering or inheritance of adaptiveness from parent controls.

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

auto_scroll

auto_scroll: bool = False

True if scrollbar should automatically move its position to the end when children updated. Must be False for scroll_to() method to work.

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.

build_controls_on_demand

build_controls_on_demand: bool = True

Whether the controls should be built lazily/on-demand.

This is particularly useful when dealing with a large number of controls.

cache_extent

cache_extent: Number | None = None

Items that fall in the cache area (before or after the visible area that are about to become visible when the user scrolls) are laid out even though they are not yet visible on screen.

The cache_extent describes how many pixels the cache area extends before the leading edge and after the trailing edge of the viewport.

The total extent covered is: cache_extent before + main axis extent + cache_extent after.

clip_behavior

clip_behavior: ClipBehavior = HARD_EDGE

How to clip the controls

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

controls

controls: list[Control] = field(default_factory=list)

A list of Controls to display inside ListView.

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()
    ]
)

divider_thickness

divider_thickness: Number = 0

If greater than 0 then Divider is used as a spacing between list view items.

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.

first_item_prototype

first_item_prototype: bool = False

Whether the dimensions of the first item of controls should be used as a "prototype" for all other items, i.e. their height or width will be the same as the first item.

height

height: Number | None = None

Imposed Control height in virtual pixels.

horizontal

horizontal: bool = False

Whether to layout the controls horizontally.

item_extent

item_extent: Number | None = None

A fixed height or width (when horizontal is True) of an item to optimize rendering.

key

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

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.

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_scroll

on_scroll: EventHandler[OnScrollEvent] | None = None

Called when scroll position is changed by a user. class.

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).

padding

padding: PaddingValue | None = None

The amount of space by which to inset the children.

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.

reverse

reverse: bool = False

Whether the scroll view scrolls in the reading direction.

For example, if the reading direction is left-to-right and horizontal is True, then the scroll view scrolls from left to right when reverse is False and from right to left when reverse is True.

Similarly, if horizontal is False, then the scroll view scrolls from top to bottom when reverse is False and from bottom to top when reverse is True.

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)
)

scroll

scroll: ScrollMode | None = None

Enables a vertical scrolling for the Column to prevent its content overflow.

Defaults to ScrollMode.None.

scroll_interval

scroll_interval: Number = 10

Throttling in milliseconds for on_scroll event.

semantic_child_count

semantic_child_count: int | None = None

The number of children that will contribute semantic information.

spacing

spacing: Number = 0

The height of divider between the controls.

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.

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()

scroll_to

scroll_to(
    offset: Number | None = None,
    delta: Number | None = None,
    scroll_key: str
    | int
    | float
    | bool
    | ScrollKey
    | None = None,
    duration: DurationValue | None = None,
    curve: AnimationCurve | None = None,
)

Moves scroll position to either absolute offset, relative delta or jump to the control with specified key.

offset is an absolute value between minimum and maximum extents of a scrollable control, for example:

products.scroll_to(offset=100, duration=1000)

offset could be a negative to scroll from the end of a scrollable. For example, to scroll to the very end:

products.scroll_to(offset=-1, duration=1000)

delta allows moving scroll relatively to the current position. Use positive delta to scroll forward and negative delta to scroll backward. For example, to move scroll on 50 pixels forward:

products.scroll_to(delta=50)

key allows moving scroll position to a control with specified key. Most of Flet controls have key property which is translated to Flutter as "global key". key must be unique for the entire page/view. For example:

import flet as ft

def main(page: ft.Page):
    cl = ft.Column(
        spacing=10,
        height=200,
        width=200,
        scroll=ft.ScrollMode.ALWAYS,
    )
    for i in range(0, 50):
        cl.controls.append(ft.Text(f"Text line {i}", key=str(i)))

    def scroll_to_key(e):
        cl.scroll_to(key="20", duration=1000)

    page.add(
        ft.Container(cl, border=ft.border.all(1)),
        ft.ElevatedButton("Scroll to key '20'", on_click=scroll_to_key),
    )

ft.run(main)

Note

scroll_to() method won't work with ListView and GridView controls building their items dynamically.

duration is scrolling animation duration in milliseconds. Defaults to 0 - no animation.

curve configures animation curve. Property value is AnimationCurve enum. Defaults to AnimationCurve.EASE.

scroll_to_async

scroll_to_async(
    offset: float | None = None,
    delta: float | None = None,
    scroll_key: str
    | int
    | float
    | bool
    | ScrollKey
    | None = None,
    duration: DurationValue | None = None,
    curve: AnimationCurve | None = None,
)

Moves scroll position to either absolute offset, relative delta or jump to the control with specified key.

offset is an absolute value between minimum and maximum extents of a scrollable control, for example:

products.scroll_to(offset=100, duration=1000)

offset could be a negative to scroll from the end of a scrollable. For example, to scroll to the very end:

products.scroll_to(offset=-1, duration=1000)

delta allows moving scroll relatively to the current position. Use positive delta to scroll forward and negative delta to scroll backward. For example, to move scroll on 50 pixels forward:

products.scroll_to(delta=50)

key allows moving scroll position to a control with specified key. Most of Flet controls have key property which is translated to Flutter as "global key". key must be unique for the entire page/view. For example:

import flet as ft

def main(page: ft.Page):
    cl = ft.Column(
        spacing=10,
        height=200,
        width=200,
        scroll=ft.ScrollMode.ALWAYS,
    )
    for i in range(0, 50):
        cl.controls.append(ft.Text(f"Text line {i}", key=str(i)))

    def scroll_to_key(e):
        cl.scroll_to(key="20", duration=1000)

    page.add(
        ft.Container(cl, border=ft.border.all(1)),
        ft.ElevatedButton("Scroll to key '20'", on_click=scroll_to_key),
    )

ft.run(main)

Note

scroll_to() method won't work with ListView and GridView controls building their items dynamically.

duration is scrolling animation duration in milliseconds. Defaults to 0 - no animation.

curve configures animation curve. Property value is AnimationCurve enum. Defaults to AnimationCurve.EASE.

update

update() -> None

will_unmount

will_unmount()