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BasePage

BasePage #

Bases: AdaptiveControl

A visual container representing a top-level view in a Flet application.

BasePage serves as the base class for Page and MultiView, and provides a unified surface for rendering application content, app bars, navigation elements, dialogs, overlays, and more. It manages one or more View instances and exposes high-level layout, scrolling, and theming properties.

Unlike lower-level layout controls (e.g., Column, Container), BasePage represents an entire logical view or screen of the app. It provides direct access to view-level controls such as AppBar, NavigationBar, FloatingActionButton, and supports system-level events like window resizing and media changes.

This class is not intended to be used directly in most apps; instead, use Page or MultiView, which extend this base functionality.

adaptive #

adaptive: bool | None = None

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

appbar #

appbar: AppBar | CupertinoAppBar | None

Gets or sets the top application bar (AppBar or CupertinoAppBar) for the view.

The app bar typically displays the page title and optional actions such as navigation icons, menus, or other interactive elements.

auto_scroll #

auto_scroll: bool

badge #

badge: BadgeValue | None = None

A badge to show on top of this control.

bgcolor #

bgcolor: ColorValue | None

bottom_appbar #

bottom_appbar: BottomAppBar | None

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[BaseControl]

dark_theme #

dark_theme: Theme | None = None

Customizes the theme of the application when in dark theme mode.

data #

data: Any = skip_field()

Arbitrary data of any type.

decoration #

decoration: BoxDecoration | None

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()
    ]
)

drawer #

drawer: NavigationDrawer | None

enable_screenshots #

enable_screenshots: bool = False

Enable taking screenshots of the entire page with take_screenshot method.

end_drawer #

end_drawer: NavigationDrawer | None

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.

floating_action_button #

floating_action_button: FloatingActionButton | None

floating_action_button_location #

floating_action_button_location: (
    FloatingActionButtonLocation | OffsetValue | None
)

foreground_decoration #

foreground_decoration: BoxDecoration | None

height #

height: Number | None = None

Page height in logical pixels.

Note
  • This property is read-only.
  • To get or set the full window height including window chrome (e.g., title bar and borders) when running a Flet app on desktop, use the height property of Page.window instead.

horizontal_alignment #

horizontal_alignment: CrossAxisAlignment | None

key #

key: KeyValue | None = None

locale_configuration #

locale_configuration: LocaleConfiguration | None = None

Configures supported locales and the current locale.

media #

media: PageMediaData = field(
    default_factory=lambda: PageMediaData(
        padding=zero(),
        view_padding=zero(),
        view_insets=zero(),
        device_pixel_ratio=0,
    )
)

Represents the environmental metrics of a page or window.

navigation_bar #

navigation_bar: (
    NavigationBar | CupertinoNavigationBar | None
)

on_media_change #

on_media_change: EventHandler[PageMediaData] | None = None

Called when media has changed.

on_resize #

on_resize: EventHandler[PageResizeEvent] | None = None

Called when a user resizes a browser or native OS window containing Flet app, for example:

def page_resize(e):
    print("New page size:", page.window.width, page.window_height)

page.on_resize = page_resize

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 #

overlay: list[BaseControl]

padding #

padding: PaddingValue | None

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.

rtl #

rtl: bool = False

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

scroll #

scroll: ScrollMode | None

show_semantics_debugger #

show_semantics_debugger: bool | None = None

Whether to turn on an overlay that shows the accessibility information reported by the framework.

spacing #

spacing: Number | None

theme #

theme: Theme | None = None

Customizes the theme of the application when in light theme mode. Currently, a theme can only be automatically generated from a "seed" color. For example, to generate light theme from a green color.

theme_mode #

theme_mode: ThemeMode | None = SYSTEM

The page's theme mode.

title #

title: str | None = None

Page or window title.

tooltip #

tooltip: TooltipValue | None = None

The tooltip ot show when this control is hovered over.

vertical_alignment #

vertical_alignment: MainAxisAlignment | None

views #

views: list[View] = field(default_factory=lambda: [View()])

A list of views managed by the page.

Each View represents a distinct navigation state or screen in the application.

The first view in the list is considered the active one by default.

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

Page width in logical pixels.

Note
  • This property is read-only.
  • To get or set the full window height including window chrome (e.g., title bar and borders) when running a Flet app on desktop, use the width property of Page.window instead.

add #

add(*controls: Control) -> None

Adds controls to the page.

page.add(ft.Text("Hello!"), ft.FilledButton("Button"))

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()

insert #

insert(at: int, *controls: Control) -> None

Inserts controls at specific index of page.controls list.

is_isolated #

is_isolated()

pop_dialog #

pop_dialog() -> DialogControl | None

Closes the most recently opened dialog.

This method searches the active dialog stack for the topmost dialog that is currently open, marks it as closed, updates its state, and returns the closed dialog.

RETURNS DESCRIPTION
DialogControl | None

The closed dialog instance if one was found, otherwise None.

remove #

remove(*controls: Control) -> None

Removes specific controls from page.controls list.

remove_at #

remove_at(index: int) -> None

Remove controls from page.controls list at specific index.

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,
) -> None

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

See Column.scroll_to() for method details and examples.

show_dialog #

show_dialog(dialog: DialogControl) -> None

Displays a dialog and manages its dismissal lifecycle.

This method adds the specified dialog to the active dialog stack and renders it on the page. If the dialog is already open, an exception is raised. The on_dismiss handler of the dialog is temporarily wrapped to ensure the dialog is removed from the stack and its dismissal event is triggered appropriately.

PARAMETER DESCRIPTION
dialog

The dialog instance to display. Must not already be open.

TYPE: DialogControl

RAISES DESCRIPTION
Exception

If the specified dialog is already open.

take_screenshot #

take_screenshot(
    pixel_ratio: Number | None = None,
    delay: DurationValue | None = None,
) -> bytes

Captures a screenshot of the entire page with overlays.

PARAMETER DESCRIPTION
pixel_ratio

A pixel ratio of the captured screenshot. If None, device-specific pixel ratio will be used.

TYPE: Number | None DEFAULT: None

delay

A delay before taking a screenshot. The delay will be 20 milliseconds if not specified.

TYPE: DurationValue | None DEFAULT: None

RETURNS DESCRIPTION
bytes

Screenshot in PNG format.

update #

update(*controls) -> None

will_unmount #

will_unmount()