Page

Page is a container for View controls.

A page instance and the root view are automatically created when a new user session started.

Properties

`auto_scroll`

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

`appbar`

An AppBar control to display at the top of the Page.

`banner`

A Banner control to display at the top of the Page.

`bgcolor`

Background color of the Page.

A color value could be a hex value in #ARGB format (e.g. #FFCC0000), #RGB format (e.g. #CC0000) or a named color from flet.colors module.

`bottom_appbar`

BottomAppBar control to display at the bottom of the Page. If both bottom_appbar and navigation_bar properties are provided, NavigationBar will be displayed.

`bottom_sheet`

BottomSheet control to display.

`client_ip`

🌎 Web only. IP address of the connected user.

`client_user_agent`

🌎 Web only. Browser details of the connected user.

`controls`

A list of Controls to display on the Page.

For example, to add a new control to a page:

Python

page.controls.append(ft.Text("Hello!"))
page.update()

or to get the same result as above using page.add() shortcut method:

Python

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

To remove the top most control on the page:

Python

page.controls.pop()
page.update()

`dark_theme`

Set this property to an instance of Theme to customize dark theme.

`debug`

True if Flutter client of Flet app is running in debug mode.

`design`

Reserved for future use.

`dialog`

An AlertDialog control to display.

`drawer`

A NavigationDrawer control to display as a panel sliding from the start edge of the page.

`end_drawer`

A NavigationDrawer control to display as a panel sliding from the end edge of the page.

`floating_action_button`

A FloatingActionButton control to display on top of Page content.

`floating_action_button_location`

Defines a position for the FloatingActionButton.

Property value is FloatingActionButtonLocation enum with the following values (diagrams here):

CENTER_DOCKED
CENTER_FLOAT
CENTER_TOP
END_CONTAINED
END_DOCKED
END_FLOAT (default)
END_TOP
MINI_CENTER_DOCKED
MINI_CENTER_FLOAT
MINI_CENTER_TOP
MINI_END_DOCKED
MINI_END_FLOAT
MINI_END_TOP
MINI_START_DOCKED
MINI_START_FLOAT
MINI_START_TOP
START_DOCKED
START_FLOAT

`fonts`

Allows importing custom fonts and use them with Text.font_family or apply to the entire app via theme.font_family.

The following font formats can be used with Flet:

.ttc
.ttf
.otf

The value of fonts property is a dictionary where key is the font family name to refer that font and the value is the URL of the font file to import.

Font can be imported from external resource by providing an absolute URL or from application assets by providing relative URL and assets_dir.

Specify assets_dir in flet.app() call to set the location of assets that should be available to the application. assets_dir could be a relative to your main.py directory or an absolute path. For example, consider the following program structure:

/assets
   /fonts
       /OpenSans-Regular.ttf
main.py

Now, the following program loads "Kanit" font from GitHub and "Open Sans" from the assets. "Kanit" is set as a default app font and "Open Sans" is used for a specific Text control:

import flet as ft

def main(page: ft.Page):
    page.fonts = {
        "Kanit": "https://raw.githubusercontent.com/google/fonts/master/ofl/kanit/Kanit-Bold.ttf",
        "Open Sans": "/fonts/OpenSans-Regular.ttf"
    }

    page.theme = Theme(font_family="Kanit")

    page.add(
      ft.Text("This is rendered with Kanit font"),
      ft.Text("This is Open Sans font example", font_family="Open Sans")
    )

ft.app(target=main, assets_dir="assets")

note

At the moment only static fonts are supported, i.e. fonts containing only one spacific width/weight/style combination, for example "Open Sans Regular" or "Roboto Bold Italic".

Variable fonts support is still work in progress.

However, if you need to use a variable font in your app you can create static "instantiations" at specific weights using fonttools, then use those:

fonttools varLib.mutator ./YourVariableFont-VF.ttf wght=140 wdth=85

To explore available font features (e.g. possible options for wght) use Wakamai Fondue online tool.

`height`

A height of a web page or content area of a native OS window containing Flet app. This property is read-only. It's usually being used inside page.on_resize handler.

`horizontal_alignment`

How the child Controls should be placed horizontally.

Default value is CrossAxisAlignment.START which means on the left side of the Page.

Property value is CrossAxisAlignment enum with the following values:

START (default)
CENTER
END
STRETCH
BASELINE

`locale_configuration`

A locale configuration for the app. Value is an instance of LocaleConfiguration class which has the following properties:

supported_locales - a list of Locales that the app plans to support. If the provided value is None or list is empty, this property internally defaults to [Locale("en", "US")] (American English locale) by default.
current_locale - the current Locale of the app. If the provided locale is not present in supported_locales, then this property will be set to supported_locales[0] (the first item of the list).

Locale class has the following properties:

language_code - the language code of the locale.
country_code - the country code of the locale.
script_code - the script code of the locale.

`media`

Provides details about app media (screen, window). See MediaQueryData in Flutter docs for more info.

The value of this property is an instance of PageMediaData class with the following fields:

padding (of Padding type) - The parts of the display that are partially obscured by system UI, typically by the hardware display "notches" or the system status bar.
view_padding (of Padding type) - The parts of the display that are partially obscured by system UI, typically by the hardware display "notches" or the system status bar.
view_insets (of Padding type) - The parts of the display that are completely obscured by system UI, typically by the device's keyboard.

note

In the most cases you should be fine by wrapping your content into SafeArea control.

🎬 Watch this video explaining padding, view_padding and view_insets.

`name`

Page name as specified in ft.app() call. Page name is set when Flet app is running as web app. This is a portion of the URL after host name.

`navigation_bar`

NavigationBar control to display at the bottom of the page. If both bottom_appbar and navigation_bar properties are provided, NavigationBar will be displayed.

`on_scroll_interval`

Throttling in milliseconds for on_scroll event. Default is 10.

`overlay`

A list of Controls displayed as a stack on top of main page contents.

`padding`

A space between page contents and its edges. Default value is 10 pixels from each side. To set zero padding:

Python

page.padding = 0
page.update()

See Container.padding for more information and possible values.

`platform`

Operating system the application is running on.

Property value is PagePlatform enum with the following values:

IOS
ANDROID
MACOS
WINDOWS
LINUX

This property can be used to create adaptive UI with different controls depending on the operating system:

def main(page: ft.Page):
    if page.platform == ft.PagePlatform.MACOS:
        page.add(ft.CupertinoDialogAction("Cupertino Button"))
    else:
        page.add(ft.TextButton("Material Button"))

You can also set this property for testing purposes:

import flet as ft


def main(page):
    def set_android(e):
        page.platform = ft.PagePlatform.ANDROID
        page.update()
        print("New platform:", page.platform)

    def set_ios(e):
        page.platform = "ios"
        page.update()
        print("New platform:", page.platform)

    page.add(
        ft.Switch(label="Switch A", adaptive=True),
        ft.ElevatedButton("Set Android", on_click=set_android),
        ft.ElevatedButton("Set iOS", on_click=set_ios),
    )

    print("Default platform:", page.platform)


ft.app(target=main)

`platform_brightness`

The current brightness mode of the host platform: ft.ThemeMode.LIGHT or ft.ThemeMode.DARK.

`pubsub`

A simple PubSub implementation for passing messages between app sessions.

`subscribe(handler)`

Subscribe current app session for broadcast (no topic) messages. handler is a function or method with a single message argument, for example:

def main(page: ft.Page):

    def on_broadcast_message(message):
        print(message)

    page.pubsub.subscribe(on_broadcast_message)

`subscribe_topic(topic, handler)`

Subscribe current app session to a specific topic. handler is a function or method with two arguments: topic and message, for example:

def main(page: ft.Page):

    def on_message(topic, message):
        print(topic, message)

    page.pubsub.subscribe_topic("general", on_message)

`send_all(message)`

Broadcast message to all subscribers. message could be anything: a simple literal or a class instance, for example:

@dataclass
class Message:
    user: str
    text: str

def main(page: ft.Page):

    def on_broadcast_message(message):
        page.add(ft.Text(f"{message.user}: {message.text}"))

    page.pubsub.subscribe(on_broadcast_message)

    def on_send_click(e):
        page.pubsub.send_all(Message("John", "Hello, all!"))

    page.add(ft.ElevatedButton(text="Send message", on_click=on_send_click))

`send_all_on_topic(topic, message)`

Send message to all subscribers on specific topic.

`send_others(message)`

Broadcast message to all subscribers except sender.

`send_others_on_topic(topic, message)`

Send message to all subscribers on specific topic except sender.

`unsubscribe()`

Unsubscribe current app session from broadcast messages, for example:

@dataclass
class Message:
    user: str
    text: str

def main(page: ft.Page):

    def on_leave_click(e):
        page.pubsub.unsubscribe()

    page.add(ft.ElevatedButton(text="Leave chat", on_click=on_leave_click))

`unsubscribe_topic(topic)`

Unsubscribe current app session from specific topic.

`unsubscribe_all()`

Unsubscribe current app session from broadcast messages and all topics, for example:

def main(page: ft.Page):
    def client_exited(e):
        page.pubsub.unsubscribe_all()

    page.on_close = client_exited

`pwa`

True if the application is running as Progressive Web App (PWA). Read-only.

`query`

A part of app URL after ?. The value is an instance of QueryString with helper methods for fetching query parameters.

`route`

Get or sets page's navigation route. See Navigation and routing section for more information and examples.

`rtl`

True to set text direction to right-to-left. Default is False.

`scroll`

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

Property value is an optional ScrollMode enum with None as default.

Supported values:

None (default) - the Row is non-scrollable and its content could overflow.
AUTO - scrolling is enabled and scroll bar is only shown when scrolling occurs.
ADAPTIVE - scrolling is enabled and scroll bar is always shown when running app as web or desktop.
ALWAYS - scrolling is enabled and scroll bar is always shown.
HIDDEN - scrolling is enabled, but scroll bar is always hidden.

`session`

A simple KV storage for session data.

`session_id`

A unique ID of user's session. This property is read-only.

`spacing`

Vertical spacing between controls on the Page. Default value is 10 virtual pixels. Spacing is applied only when alignment is set to start, end or center.

`splash`

A Control that will be displayed on top of Page contents. ProgressBar or ProgressRing could be used as an indicator for some lengthy operation, for example:

Python

from time import sleep
import flet as ft

def main(page: ft.Page):
    def button_click(e):
        page.splash = ft.ProgressBar()
        btn.disabled = True
        page.update()
        sleep(3)
        page.splash = None
        btn.disabled = False
        page.update()

    btn = ft.ElevatedButton("Do some lengthy task!", on_click=button_click)
    page.add(btn)

ft.app(target=main)

`show_semantics_debugger`

True turns on an overlay that shows the accessibility information reported by the framework.

`theme`

Set this property to an instance of theme.Theme to customize light theme. Currently, a theme can only be automatically generated from a "seed" color. For example, to generate light theme from a green color:

Python

page.theme = theme.Theme(color_scheme_seed="green")
page.update()

Theme class has the following properties:

color_scheme_seed - a seed color to algorithmically derive the rest of theme colors from.
color_scheme - an instance of ft.ColorScheme class that allows to customize Material colors scheme derived from color_scheme_seed.
text_theme - an instance of ft.TextTheme class to customize text styles that contrasts with the card and canvas colors.
primary_text_theme - an instance of ft.TextTheme class describing a text theme that contrasts with the primary color.
scrollbar_theme - an instance of ft.ScrollbarTheme class customizing the appearance of scrollbars across the app.
tabs_theme - an instance of ft.TabsTheme class customizing the appearance of Tabs control across the app.
font_family - the base font for all UI elements.
use_material3 - True (default) to use Material 3 design; otherwise Material 2.
visual_density - ThemeVisualDensity enum: STANDARD (default), COMPACT, COMFORTABLE, ADAPTIVE_PLATFORM_DENSITY.
page_transitions - an instance of PageTransitionsTheme that allows customizing navigation page transitions for different platforms. See section below.
system_overlay_style - an instance of SystemOverlayStyle that allows customizing the appearance of system overlays like the status bar and system navigation bar.

SystemOverlayStyle class has the following properties:

system_navigation_bar_color - the color of the system navigation bar.
system_navigation_bar_divider_color - the color of the divider between the system navigation bar and the app content.
enforce_system_navigation_bar_contrast - indicates whether the system should enforce contrast for the status bar when setting a transparent status bar.
enforce_system_status_bar_contrast - indicates whether the system should enforce contrast for the navigation bar when setting a transparent navigation bar.
system_navigation_bar_icon_brightness - the Brightness of the system navigation bar icons. Either Brightness.DARK or Brightness.LIGHT.
status_bar_brightness - the Brightness of the status bar. Either Brightness.DARK or Brightness.LIGHT.
status_bar_icon_brightness - the Brightness of the status bar icons. Either Brightness.DARK or Brightness.LIGHT.

note

Read this note about system fonts if you like to use them in font_family of your theme.

`ColorScheme` class

A set of 30 colors based on the Material spec that can be used to configure the color properties of most components. Read more about ColorScheme in Flutter docs.

ColorScheme class has the following properties:

primary - The color displayed most frequently across your app’s screens and components.
on_primary - A color that's clearly legible when drawn on primary.
primary_container - A color used for elements needing less emphasis than primary.
on_primary_container - A color that's clearly legible when drawn on primary_container.
secondary - An accent color used for less prominent components in the UI, such as filter chips, while expanding the opportunity for color expression.
on_secondary - A color that's clearly legible when drawn on secondary.
secondary_container - A color used for elements needing less emphasis than secondary.
on_secondary_container - A color that's clearly legible when drawn on secondary_container.
tertiary - A color used as a contrasting accent that can balance primary and secondary colors or bring heightened attention to an element, such as an input field.
on_tertiary - A color that's clearly legible when drawn on tertiary.
tertiary_container - A color used for elements needing less emphasis than tertiary.
on_tertiary_container - A color that's clearly legible when drawn on tertiary_container.
error - The color to use for input validation errors, e.g. for TextField.error_text.
on_error - A color that's clearly legible when drawn on error.
error_container - A color used for error elements needing less emphasis than error.
on_error_container - A color that's clearly legible when drawn on error_container.
background - A color that typically appears behind scrollable content.
on_background - A color that's clearly legible when drawn on background.
surface - The background color for widgets like Card.
on_surface - A color that's clearly legible when drawn on surface.
surface_variant - A color variant of surface that can be used for differentiation against a component using surface.
on_surface_variant - A color that's clearly legible when drawn on surface_variant.
outline - A utility color that creates boundaries and emphasis to improve usability.
outline_variant - A utility color that creates boundaries for decorative elements when a 3:1 contrast isn’t required, such as for dividers or decorative elements.
shadow - A color use to paint the drop shadows of elevated components.
scrim - A color use to paint the scrim around of modal components.
inverse_surface - A surface color used for displaying the reverse of what’s seen in the surrounding UI, for example in a SnackBar to bring attention to an alert.
on_inverse_surface - A color that's clearly legible when drawn on inverse_surface.
inverse_primary - An accent color used for displaying a highlight color on inverse_surface backgrounds, like button text in a SnackBar.
surface_tint - A color used as an overlay on a surface color to indicate a component's elevation.

`TextTheme` class

Customizes text styles.

TextTheme class has the following properties of ft.TextStyle type:

body_large - Largest of the body styles. Body styles are used for longer passages of text.
body_medium - Middle size of the body styles. Body styles are used for longer passages of text. The default text style for Material.
body_small - Smallest of the body styles.
display_large - Largest of the display styles. As the largest text on the screen, display styles are reserved for short, important text or numerals. They work best on large screens.
display_medium - Middle size of the display styles.
display_small - Smallest of the display styles.
headline_large - Largest of the headline styles. Headline styles are smaller than display styles. They're best-suited for short, high-emphasis text on smaller screens.
headline_medium - Middle size of the headline styles.
headline_small - Smallest of the headline styles.
label_large - Largest of the label styles. Label styles are smaller, utilitarian styles, used for areas of the UI such as text inside of components or very small supporting text in the content body, like captions. Used for text on ElevatedButton, TextButton and OutlinedButton.
label_medium - Middle size of the label styles.
label_small - Smallest of the label styles.
title_large - Largest of the title styles. Titles are smaller than headline styles and should be used for shorter, medium-emphasis text.
title_medium - Middle size of the title styles.
title_small - Smallest of the title styles.

`ScrollbarTheme` class

Customizes the colors, thickness, and shape of scrollbars across the app.

ScrollbarTheme class has the following properties:

thumb_visibility - Indicates that the scrollbar thumb should be visible, even when a scroll is not underway. When False, the scrollbar will be shown during scrolling and will fade out otherwise. When True, the scrollbar will always be visible and never fade out. Property value could be either a single boolean value or a dictionary with ft.MaterialState as keys and boolean as values.
thickness - the thickness of the scrollbar in the cross axis of the scrollable. Property value could be either a single float value or a dictionary with ft.MaterialState as keys and float as values.
track_visibility - Indicates that the scrollbar track should be visible. When True, the scrollbar track will always be visible so long as the thumb is visible. If the scrollbar thumb is not visible, the track will not be visible either. Defaults to False when None. If this property is None, then ScrollbarTheme.track_visibility of Theme.scrollbar_theme is used. If that is also None, the default value is False. Property value could be either a single boolean value or a dictionary with ft.MaterialState as keys and boolean as values.
radius - The Radius of the scrollbar thumb's rounded rectangle corners.
thumb_color - Overrides the default Color of the Scrollbar thumb. The value is either a single color string or ft.MaterialState dictionary.
track_color - Overrides the default Color of the Scrollbar track. The value is either a single color string or ft.MaterialState dictionary.
track_border_color - Overrides the default Color of the Scrollbar track border. The value is either a single color string or ft.MaterialState dictionary.
cross_axis_margin - Distance from the scrollbar thumb to the nearest cross axis edge in logical pixels. The scrollbar track consumes this space. Must not be null and defaults to 0.
main_axis_margin - Distance from the scrollbar thumb's start and end to the edge of the viewport in logical pixels. It affects the amount of available paint area. The scrollbar track consumes this space. Mustn't be null and defaults to 0.
min_thumb_length - The preferred smallest size the scrollbar thumb can shrink to when the total scrollable extent is large, the current visible viewport is small, and the viewport is not overscrolled.
interactive - Whether the Scrollbar should be interactive and respond to dragging on the thumb, or tapping in the track area. When False, the scrollbar will not respond to gesture or hover events, and will allow to click through it. Defaults to True when None, unless on Android, which will default to False when None.

`TabsTheme` class

Customizes the appearance of Tabs control across the app.

TabsTheme class has the following properties:

divider_color - The color of the divider.
indicator_border_radius - The radius of the indicator's corners.
indicator_border_side - The color and weight of the horizontal line drawn below the selected tab.
indicator_padding - Locates the selected tab's underline relative to the tab's boundary. The indicator_tab_size property can be used to define the tab indicator's bounds in terms of its (centered) tab widget with False, or the entire tab with True.
indicator_color - The color of the line that appears below the selected tab.
indicator_tab_size - True for indicator to take entire tab.
label_color - The color of selected tab labels.
unselected_label_color - The color of unselected tab labels.
overlay_color - Defines the ink response focus, hover, and splash colors. If specified, it is resolved against one of MaterialState.FOCUSED, MaterialState.HOVERED, and MaterialState.PRESSED.

theme.page_transitions allows customizing navigation page transitions for different platforms. The value is an instance of PageTransitionsTheme class with the following optional properties:

android (default value is FADE_UPWARDS)
ios (default value is CUPERTINO)
macos (default value is ZOOM)
linux (default value is ZOOM)
windows (default value is ZOOM)

Supported transitions is ft.PageTransitionTheme enum: NONE (zero delay transition without any animation), FADE_UPWARDS, OPEN_UPWARDS, ZOOM, CUPERTINO.

An simple example:

theme = ft.Theme()
theme.page_transitions.android = ft.PageTransitionTheme.OPEN_UPWARDS
theme.page_transitions.ios = ft.PageTransitionTheme.CUPERTINO
theme.page_transitions.macos = ft.PageTransitionTheme.FADE_UPWARDS
theme.page_transitions.linux = ft.PageTransitionTheme.ZOOM
theme.page_transitions.windows = ft.PageTransitionTheme.NONE
page.theme = theme
page.update()

`theme_mode`

Page theme.

Property value is an optional ThemeMode enum with SYSTEM as default.

Supported values: SYSTEM (default), LIGHT or DARK.

`title`

A title of browser or native OS window, for example:

Python

page.title = "My awesome app"
page.update()

`url`

The complete web app's URL.

`vertical_alignment`

How the child Controls should be placed vertically.

For example, MainAxisAlignment.START, the default, places the children at the top of a Page.

Property value is MainAxisAlignment enum with the following values:

START (default)
END
CENTER
SPACE_BETWEEN
SPACE_AROUND
SPACE_EVENLY

`views`

A list of View controls to build navigation history.

The last view in the list is the one displayed on a page.

The first view is a "root" view which cannot be popped.

`web`

True if the application is running in the web browser.

`width`

A width of a web page or content area of a native OS window containing Flet app. This property is read-only. It's usually being used inside page.on_resize handler.

`window_always_on_top`

🖥️ Desktop only. Sets whether the window should show always on top of other windows. Default is False.

`window_bgcolor`

🖥️ Desktop only. Sets background color of an application window.

Use together with page.bgcolor to make a window transparent:

import flet as ft

def main(page: ft.Page):
    page.window_bgcolor = ft.colors.TRANSPARENT
    page.bgcolor = ft.colors.TRANSPARENT
    page.window_title_bar_hidden = True
    page.window_frameless = True
    page.window_left = 400
    page.window_top = 200
    page.add(ft.ElevatedButton("I'm a floating button!"))

ft.app(target=main)

`window_focused`

🖥️ Desktop only. Set to True to focus a native OS window with a Flet app.

`window_frameless`

🖥️ Desktop only. Set to True to make app window frameless.

`window_full_screen`

🖥️ Desktop only. Set to True to switch app's native OS window to a fullscreen mode. Default is False.

`window_height`

🖥️ Desktop only. Get or set the height of a native OS window containing Flet app.

`window_left`

🖥️ Desktop only. Get or set a horizontal position of a native OS window - a distance in virtual pixels from the left edge of the screen.

`window_maximizable`

🖥️ Desktop only. Set to False to hide/disable native OS window's "Maximize" button. Default is True.

`window_maximized`

🖥️ Desktop only. True if a native OS window containing Flet app is maximized; otherwise False. Set this property to True to programmatically maximize the window and set it to False to unmaximize it.

`window_max_height`

🖥️ Desktop only. Get or set the maximum height of a native OS window containing Flet app.

`window_max_width`

🖥️ Desktop only. Get or set the maximum width of a native OS window containing Flet app.

`window_minimizable`

🖥️ Desktop only. Set to False to hide/disable native OS window's "Minimize" button. Default is True.

`window_minimized`

🖥️ Desktop only. True if a native OS window containing Flet app is minimized; otherwise False. Set this property to True to programmatically minimize the window and set it to False to restore it.

`window_min_height`

🖥️ Desktop only. Get or set the minimum height of a native OS window containing Flet app.

`window_min_width`

🖥️ Desktop only. Get or set the minimum width of a native OS window containing Flet app.

`window_movable`

🖥️ Desktop only. macOS only. Set to False to prevent user from changing a position of a native OS window containing Flet app. Default is True.

`window_opacity`

🖥️ Desktop only. Sets the opacity of a native OS window. The value must be between 0.0 (fully transparent) and 1.0 (fully opaque).

`window_resizable`

🖥️ Desktop only. Set to False to prevent user from resizing a native OS window containing Flet app. Default is True.

`window_title_bar_hidden`

🖥️ Desktop only. Set to True to hide window title bar. See WindowDragArea control that allows moving an app window with hidden title bar.

`window_title_bar_buttons_hidden`

🖥️ Desktop only. Set to True to hide window action buttons when a title bar is hidden. macOS only.

`window_top`

🖥️ Desktop only. Get or set a vertical position of a native OS window - a distance in virtual pixels from the top edge of the screen.

`window_prevent_close`

🖥️ Desktop only. Set to True to intercept the native close signal. Could be used together with page.on_window_event (close) event handler and page.window_destroy() to implement app exit confirmation logic - see page.window_destroy() for code example.

`window_progress_bar`

🖥️ Desktop only. The value from 0.0 to 1.0 to display a progress bar on Task Bar (Windows) or Dock (macOS) application button.

`window_skip_task_bar`

🖥️ Desktop only. Set to True to hide application from the Task Bar (Windows) or Dock (macOS).

`window_visible`

🖥️ Desktop only. Set to True to make application window visible. Used when the app is starting with a hidden window.

The following program starts with a hidden window and makes it visible in 3 seconds:

from time import sleep

import flet as ft


def main(page: ft.Page):

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

    sleep(3)
    page.window_visible = True
    page.update()  

ft.app(target=main, view=ft.AppView.FLET_APP_HIDDEN)

Note view=ft.AppView.FLET_APP_HIDDEN which hides app window on start.

`window_width`

🖥️ Desktop only. Get or set the width of a native OS window containing Flet app.

Methods

`can_launch_url(url)`

Checks whether the specified URL can be handled by some app installed on the device.

Returns True if it is possible to verify that there is a handler available. A False return value can indicate either that there is no handler available, or that the application does not have permission to check. For example:

On recent versions of Android and iOS, this will always return False unless the application has been configuration to allow querying the system for launch support.
On web, this will always return False except for a few specific schemes that are always assumed to be supported (such as http(s)), as web pages are never allowed to query installed applications.

`close_banner()`

Closes active banner.

`close_bottom_sheet()`

Closes active bottom sheet.

`close_dialog()`

Closes active dialog.

`close_drawer()`

Closes active drawer.

`close_end_drawer()`

Closes active end drawer.

`close_in_app_web_view()`

📱 Mobile only. Closes in-app web view opened with launch_url().

`error(message)`

`fetch_page_details()`

`get_clipboard()`

Get the last text value saved to a clipboard on a client side.

`get_control(id)`

`get_upload_url(file_name, expires)`

Generates presigned upload URL for built-in upload storage:

file_name - a relative to upload storage path.
expires - a URL time-to-live in seconds.

For example:

upload_url = page.get_upload_url("dir/filename.ext", 60)

To enable built-in upload storage provide upload_dir argument to flet.app() call:

ft.app(target=main, upload_dir="uploads")

`go(route)`

A helper method that updates page.route, calls page.on_route_change event handler to update views and finally calls page.update().

`insert(at, *controls)`

Inserts controls at specific index of page.controls list.

`launch_url(url)`

Opens url in a new browser window.

Optional method arguments:

web_window_name - window tab/name to open URL in: _self - the same browser tab, _blank - a new browser tab (or in external application on mobile device) or <your name> - a named tab.
web_popup_window - set to True to display a URL in a browser popup window. Default is False.
window_width - optional, popup window width.
window_height - optional, popup window height.

`login(provider, fetch_user, fetch_groups, scope, saved_token, on_open_authorization_url, complete_page_html, redirect_to_page, authorization)`

Starts OAuth flow. See Authentication guide for more information and examples.

`logout()`

Clears current authentication context. See Authentication guide for more information and examples.

`remove(*controls)`

Removes specific controls from page.controls list.

`remove_at(index)`

Remove controls from page.controls list at specific index.

`run_task(handler, *args, **kwargs)`

Run handler coroutine as a new Task in the event loop associated with the current page.

`run_thread(handler, *args)`

Run handler function as a new Thread in the executor associated with the current page.

`scroll_to(offset, delta, key, duration, curve)`

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

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

`set_clipboard(data)`

Set clipboard data on a client side (user's web browser or a desktop), for example:

Python

page.set_clipboard("This value comes from Flet app")

`show_banner(banner: Banner)`

Displays the banner at the top of the page.

`show_bottom_sheet(bottom_sheet: BottomSheet)`

Displays bottom sheet at the bottom of the page.

`show_dialog(dialog: AlertDialog)`

Displays dialog.

`show_drawer(drawer: NavigationDialog)`

Displays drawer.

`show_end_drawer(drawer: NavigationDialog)`

Displays end_drawer.

`show_snack_bar(snack_bar: SnackBar)`

Displays SnackBar at the bottom of the page.

snack_bar - A SnackBar control to display at the bottom of the Page.

`window_center()`

🖥️ Desktop only. Move app's native OS window to a center of the screen.

`window_close()`

🖥️ Desktop only. Closes application window.

`window_destroy()`

🖥️ Desktop only. Forces closing app's native OS window. This method could be used with page.window_prevent_close = True to implement app exit confirmation:

import flet as ft

def main(page: ft.Page):
    page.title = "MyApp"

    def window_event(e):
        if e.data == "close":
            page.dialog = confirm_dialog
            confirm_dialog.open = True
            page.update()

    page.window_prevent_close = True
    page.on_window_event = window_event

    def yes_click(e):
        page.window_destroy()

    def no_click(e):
        confirm_dialog.open = False
        page.update()

    confirm_dialog = ft.AlertDialog(
        modal=True,
        title=ft.Text("Please confirm"),
        content=ft.Text("Do you really want to exit this app?"),
        actions=[
            ft.ElevatedButton("Yes", on_click=yes_click),
            ft.OutlinedButton("No", on_click=no_click),
        ],
        actions_alignment=ft.MainAxisAlignment.END,
    )

    page.add(ft.Text('Try exiting this app by clicking window\'s "Close" button!'))

ft.app(target=main)

`window_to_front()`

🖥️ Desktop only. Brings application window to a foreground.

Events

`on_app_lifecycle_state_change`

Triggers when app lifecycle state changes.

You can use this event to know when the app becomes active (brought to the front) to update UI with the latest information. This event works on iOS, Android, all desktop platforms and web.

Event details is an object of ft.AppLifecycleStateChangeEvent type. It contains state field of AppLifecycleState enum type which could have one of the following values:

`AppLifecycleState.SHOW`

The application is shown.

On mobile platforms, this is usually just before the application replaces another application in the foreground.

On desktop platforms, this is just before the application is shown after being minimized or otherwise made to show at least one view of the application.

On the web, this is just before a window (or tab) is shown.

`AppLifecycleState.RESUME`

The application gains input focus. Indicates that the application is entering a state where it is visible, active, and accepting user input.

`AppLifecycleState.HIDE`

The application is hidden.

On mobile platforms, this is usually just before the application is replaced by another application in the foreground.

On desktop platforms, this is just before the application is hidden by being minimized or otherwise hiding all views of the application.

On the web, this is just before a window (or tab) is hidden.

`AppLifecycleState.INACTIVE`

The application loses input focus.

On mobile platforms, this can be during a phone call or when a system dialog is visible.

On desktop platforms, this is when all views in an application have lost input focus but at least one view of the application is still visible.

On the web, this is when the window (or tab) has lost input focus.

`AppLifecycleState.PAUSE`

The application is paused.

On mobile platforms, this happens right before the application is replaced by another application.

On desktop platforms and the web, this function is not called.

`AppLifecycleState.DETACH`

The application has exited, and detached all host views from the engine.

This callback is only called on iOS and Android.

`AppLifecycleState.RESTART`

The application is resumed after being paused.

On mobile platforms, this happens just before this application takes over as the active application.

On desktop platforms and the web, this function is not called.

`on_close`

Fires when a session has expired after configured amount of time (60 minutes by default).

`on_connect`

Fires when a web user (re-)connects to a page session. It is not triggered when an app page is first opened, but is triggered when the page is refreshed, or Flet web client has re-connected after computer was unlocked. This event could be used to detect when a web user becomes "online".

`on_disconnect`

Fires when a web user disconnects from a page session, i.e. closes browser tab/window.

`on_error`

Fires when unhandled exception occurs.

`on_keyboard_event`

Fires when a keyboard key is pressed. Event object e is an instance of KeyboardEvent class:

@dataclass
class ft.KeyboardEvent:
    key: str
    shift: bool
    ctrl: bool
    alt: bool
    meta: bool

Check a simple usage example.

`on_login`

Fires upon successful or failed OAuth authorization flow. See Authentication guide for more information and examples.

`on_logout`

Fires after page.logout() call.

`on_media_change`

Fires when page.media has changed. Event object is an instance of PageMediaData class described in page.media section.

`on_platform_brigthness_change`

Fires when brightness of app host platform has changed.

`on_resize`

Fires when a browser or native OS window containing Flet app is resized by a user, for example:

Python

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

page.on_resize = page_resize

`on_route_change`

Fires when page route changes either programmatically, by editing application URL or using browser Back/Forward buttons.

Event object e is an instance of RouteChangeEvent class:

class RouteChangeEvent(ft.ControlEvent):
    route: str     # a new page root

`on_scroll`

Fires when page's scroll position is changed by a user.

See Column.on_scroll for event details and examples.

`on_view_pop`

Fires when the user clicks automatic "Back" button in AppBar control.

Event object e is an instance of ViewPopEvent class:

class ViewPopEvent(ft.ControlEvent):
    view: ft.View

where view is an instance of View control that contains the AppBar.

`on_window_event`

Fires when an application's native OS window changes its state: position, size, maximized, minimized, etc.

data contains window's event name:

close
focus
blur
maximize
unmaximize
minimize
restore
resize
resized (macOS and Windows only)
move
moved (macOS and Windows only)
enterFullScreen
leaveFullScreen

Properties
Methods
Events

Properties​

auto_scroll​

appbar​

banner​

bgcolor​

bottom_appbar​

bottom_sheet​

client_ip​

client_user_agent​

controls​

dark_theme​

debug​

design​

dialog​

drawer​

end_drawer​

floating_action_button​

floating_action_button_location​

fonts​

height​

horizontal_alignment​

locale_configuration​

media​

name​

navigation_bar​

on_scroll_interval​

overlay​

padding​

platform​

platform_brightness​

pubsub​

subscribe(handler)​

subscribe_topic(topic, handler)​

send_all(message)​

send_all_on_topic(topic, message)​

send_others(message)​

send_others_on_topic(topic, message)​

unsubscribe()​

unsubscribe_topic(topic)​

unsubscribe_all()​

pwa​

query​

route​

rtl​

scroll​

session​

session_id​

spacing​

splash​

show_semantics_debugger​

theme​

ColorScheme class​

TextTheme class​

ScrollbarTheme class​

TabsTheme class​

Navigation transitions​

theme_mode​

title​

url​

vertical_alignment​

views​

web​

width​

window_always_on_top​

window_bgcolor​

window_focused​

window_frameless​

window_full_screen​

window_height​

window_left​

window_maximizable​

window_maximized​

window_max_height​

window_max_width​

window_minimizable​

window_minimized​

window_min_height​

window_min_width​

window_movable​

window_opacity​

Properties

`auto_scroll`

`appbar`

`banner`

`bgcolor`

`bottom_appbar`

`bottom_sheet`

`client_ip`

`client_user_agent`

`controls`

`dark_theme`

`debug`

`design`

`dialog`

`drawer`

`end_drawer`

`floating_action_button`

`floating_action_button_location`

`fonts`

`height`

`horizontal_alignment`

`locale_configuration`

`media`

`name`

`navigation_bar`

`on_scroll_interval`

`overlay`

`padding`

`platform`

`platform_brightness`

`pubsub`

`subscribe(handler)`

`subscribe_topic(topic, handler)`

`send_all(message)`

`send_all_on_topic(topic, message)`

`send_others(message)`

`send_others_on_topic(topic, message)`

`unsubscribe()`

`unsubscribe_topic(topic)`

`unsubscribe_all()`

`pwa`

`query`

`route`

`rtl`

`scroll`

`session`

`session_id`

`spacing`

`splash`

`show_semantics_debugger`

`theme`

`ColorScheme` class

`TextTheme` class

`ScrollbarTheme` class

`TabsTheme` class

Navigation transitions

`theme_mode`

`title`

`url`

`vertical_alignment`

`views`

`web`

`width`

`window_always_on_top`

`window_bgcolor`

`window_focused`

`window_frameless`

`window_full_screen`

`window_height`

`window_left`

`window_maximizable`

`window_maximized`

`window_max_height`

`window_max_width`

`window_minimizable`

`window_minimized`

`window_min_height`

`window_min_width`

`window_movable`

`window_opacity`