CupertinoAppBar

Examples#

Basic Example#

import flet as ft


def main(page: ft.Page):
    page.theme_mode = ft.ThemeMode.LIGHT

    page.appbar = ft.CupertinoAppBar(
        leading=ft.Icon(ft.Icons.PALETTE, color=ft.Colors.ON_SECONDARY),
        title=ft.Text("CupertinoAppBar Example"),
        trailing=ft.Icon(ft.Icons.WB_SUNNY_OUTLINED, color=ft.Colors.ON_SECONDARY),
        automatic_background_visibility=False,
        bgcolor=ft.Colors.SECONDARY,
        brightness=ft.Brightness.LIGHT,
    )

    page.add(ft.Text("Body!"))


ft.run(main)

App bar with theme mode toggle#

import flet as ft


def main(page: ft.Page):
    page.theme_mode = ft.ThemeMode.LIGHT

    def handle_theme_mode_toggle(e: ft.Event[ft.IconButton]):
        page.theme_mode = (
            ft.ThemeMode.DARK
            if page.theme_mode == ft.ThemeMode.LIGHT
            else ft.ThemeMode.LIGHT
        )
        theme_mode_button.icon = (
            ft.Icons.WB_SUNNY_OUTLINED
            if page.theme_mode == ft.ThemeMode.LIGHT
            else ft.Icons.WB_SUNNY
        )
        page.update()

    theme_mode_button = ft.IconButton(
        icon=(
            ft.Icons.WB_SUNNY_OUTLINED
            if page.theme_mode == ft.ThemeMode.LIGHT
            else ft.Icons.WB_SUNNY
        ),
        icon_color=ft.Colors.ON_INVERSE_SURFACE,
        on_click=handle_theme_mode_toggle,
    )

    page.appbar = ft.CupertinoAppBar(
        automatic_background_visibility=False,
        leading=ft.Icon(ft.Icons.PALETTE, color=ft.Colors.ON_INVERSE_SURFACE),
        bgcolor=ft.Colors.INVERSE_SURFACE,
        trailing=theme_mode_button,
        title=ft.Text("CupertinoAppBar Example", color=ft.Colors.ON_INVERSE_SURFACE),
    )

    page.add(ft.Text("Body!"))


ft.run(main)

CupertinoAppBar #

Bases: Control

An iOS-styled app bar.

Note

The alignment of the title depends on whether this app bar is large or not. If it is True, the title is left-aligned and if it is False (the default), the title is centered.

automatic_background_visibility #

automatic_background_visibility: bool | None = None

Whether the navigation bar should appear transparent when content is scrolled under it.

If False, the navigation bar will display its bgcolor.

automatically_imply_leading #

automatically_imply_leading: bool | None = None

Whether we should try to imply the leading control if None.

If True and leading is None, the app bar will automatically determine an appropriate leading control.
If False and leading is None, the space is allocated to the title.
If a leading control is provided, this parameter has no effect.

automatically_imply_title #

automatically_imply_title: bool | None = None

Whether we should try to imply the title control if None.

If True and title is None, a Text control containing the current route's title will be automatically filled in.
If the title is not None, this parameter has no effect.

badge #

badge: BadgeValue | None = None

A badge to show on top of this control.

bgcolor #

bgcolor: ColorValue | None = None

The fill color to use for this app bar.

Default color is defined by current theme.

border #

border: Border | None = None

The border of the app bar. By default, a single pixel bottom border side is rendered.

brightness #

brightness: Brightness | None = None

The brightness of the specified bgcolor.

Setting this value changes the style of the system status bar. It is typically used to increase the contrast ratio of the system status bar over bgcolor.

If None (the default), its value will be inferred from the relative luminance of the bgcolor.

col #

col: ResponsiveNumber = 12

If a parent of this control is a [ResponsiveRow][flet.], 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()
    ]
)

enable_background_filter_blur #

enable_background_filter_blur: bool | None = None

Whether to have a blur effect when a non-opaque bgcolor is used.

This will only be respected when automatic_background_visibility is False or until content scrolls under the navigation bar.

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][flet.], [Row][flet.], [View][flet.], [Page][flet.].

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][flet.], [Row][flet.], [View][flet.], [Page][flet.].

key #

key: KeyValue | None = None

large #

large: bool = False

Whether to use a large app bar layout.

If True, the title is left-aligned; if False, the title is centered.

leading #

leading: Control | None = None

A control to display at the start of this app bar.

Typically the leading control is an Icon or an IconButton .

If it is None and automatically_imply_leading is True, an appropriate button will be automatically created.

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

Defines the padding for the contents of the app bar.

If None, the app bar will adopt the following defaults:

vertically, contents will be sized to the same height as the app bar itself minus the status bar.
horizontally, padding will be 16 pixels according to iOS specifications unless the leading widget is an automatically inserted back button, in which case the padding will be 0.

Note

Vertical padding (top and bottom) won't change the height of this app bar.

page #

page: Page | BasePage | None

The page 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.

previous_page_title #

previous_page_title: str | None = None

Manually specify the previous route's title when automatically implying the leading back button.

Overrides the text shown with the back chevron instead of automatically showing the previous route's title when automatically_imply_leading is True.

Note

Has no effect if leading is not None or if automatically_imply_leading is False.

rtl #

rtl: bool = False

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

title #

title: StrOrControl | None = None

A string or a control to display in the middle of this app bar.

Typically a Text.

tooltip #

tooltip: TooltipValue | None = None

The tooltip ot show when this control is hovered over.

trailing #

trailing: Control | None = None

A Control to place at the end of the app bar.

Typically used for actions such as searching or editing.

transition_between_routes #

transition_between_routes: bool = True

Determines whether the app bar transitions between routes.

If True, this app bar will animate on top of route transitions when the destination route also contains a CupertinoAppBar or CupertinoSliverAppBar with transition_between_routes set to True.

This transition also occurs during edge back swipe gestures, mimicking native iOS behavior.

Note

When enabled, only one app bar can be present per route unless a hero_tag is specified.

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.

before_event #

before_event(e: ControlEvent)

before_update #

before_update()

build #

build()

Called once during control initialization to define its child controls. self.page is available in this method.

clean #

clean() -> None

did_mount #

did_mount()

init #

init()

is_isolated #

is_isolated()

update #

update() -> None

will_unmount #

will_unmount()