textual.screen

This module contains the Screen class and related objects.

The Screen class is a special widget which represents the content in the terminal. See Screens for details.

ScreenResultCallbackType module-attribute

ScreenResultCallbackType = Union[
    Callable[[ScreenResultType], None],
    Callable[[ScreenResultType], Awaitable[None]],
]

Type of a screen result callback function.

ScreenResultType module-attribute

ScreenResultType = TypeVar('ScreenResultType')

The result type of a screen.

ModalScreen

ModalScreen(name=None, id=None, classes=None)

Bases: Screen[ScreenResultType]

A screen with bindings that take precedence over the App's key bindings.

The default styling of a modal screen will dim the screen underneath.

ResultCallback

ResultCallback(requester, callback, future=None)

Bases: Generic[ScreenResultType]

Holds the details of a callback.

Parameters:

Name	Type	Description	Default
requester	MessagePump	The object making a request for the callback.	required
callback	ScreenResultCallbackType[ScreenResultType] | None	The callback function.	required
future	Future[ScreenResultType] | None	A Future to hold the result.	None

callback instance-attribute

callback = callback

The callback function.

future instance-attribute

future = future

A future for the result

requester instance-attribute

requester = requester

The object in the DOM that requested the callback.

Screen

Screen(name=None, id=None, classes=None)

Bases: Generic[ScreenResultType], Widget

The base class for screens.

Parameters:

Name	Type	Description	Default
name	str | None	The name of the screen.	None
id	str | None	The ID of the screen in the DOM.	None
classes	str | None	The CSS classes for the screen.	None

AUTO_FOCUS class-attribute

AUTO_FOCUS = None

A selector to determine what to focus automatically when the screen is activated.

The widget focused is the first that matches the given CSS selector. Set to None to inherit the value from the screen's app. Set to "" to disable auto focus.

COMMANDS class-attribute

COMMANDS = set()

Command providers used by the command palette, associated with the screen.

Should be a set of command.Provider classes.

CSS class-attribute

CSS = ''

Inline CSS, useful for quick scripts. Rules here take priority over CSS_PATH.

Note

This CSS applies to the whole app.

CSS_PATH class-attribute

CSS_PATH = None

File paths to load CSS from.

Note

This CSS applies to the whole app.

SUB_TITLE class-attribute

SUB_TITLE = None

A class variable to set the default sub-title for the screen.

This overrides the app sub-title. To update the sub-title while the screen is running, you can set the sub_title attribute.

TITLE class-attribute

TITLE = None

A class variable to set the default title for the screen.

This overrides the app title. To update the title while the screen is running, you can set the title attribute.

active_bindings property

active_bindings

Get currently active bindings for this screen.

If no widget is focused, then app-level bindings are returned. If a widget is focused, then any bindings present in the screen and app are merged and returned.

This property may be used to inspect current bindings.

Returns:

Type	Description
dict[str, ActiveBinding]	A map of keys to a tuple containing (namespace, binding, enabled boolean).

bindings_updated_signal instance-attribute

bindings_updated_signal = Signal(self, 'bindings_updated')

A signal published when the bindings have been updated

focus_chain property

focus_chain

A list of widgets that may receive focus, in focus order.

focused class-attribute instance-attribute

focused = Reactive(None)

The focused widget or None for no focus. To set focus, do not update this value directly. Use set_focus instead.

is_active property

is_active

Is the screen active (i.e. visible and top of the stack)?

is_current property

is_current

Is the screen current (i.e. visible to user)?

is_modal property

is_modal

Is the screen modal?

layers property

layers

Layers from parent.

Returns:

Type	Description
tuple[str, ...]	Tuple of layer names.

screen_layout_refresh_signal instance-attribute

screen_layout_refresh_signal = Signal(
    self, "layout-refresh"
)

The signal that is published when the screen's layout is refreshed.

stack_updates class-attribute instance-attribute

stack_updates = Reactive(0, repaint=False)

An integer that updates when the screen is resumed.

sub_title class-attribute instance-attribute

sub_title = SUB_TITLE

Screen sub-title to override the app sub-title.

title class-attribute instance-attribute

title = TITLE

Screen title to override the app title.

action_dismiss async

action_dismiss(result=_NoResult)

A wrapper around dismiss that can be called as an action.

Parameters:

Name	Type	Description	Default
result	ScreenResultType | Type[_NoResult]	The optional result to be passed to the result callback.	_NoResult

can_view

can_view(widget)

Check if a given widget is in the current view (scrollable area).

Note: This doesn't necessarily equate to a widget being visible. There are other reasons why a widget may not be visible.

Parameters:

Name	Type	Description	Default
widget	Widget	A widget that is a descendant of self.	required

Returns:

Type	Description
bool	True if the entire widget is in view, False if it is partially visible or not in view.

dismiss

dismiss(result=_NoResult)

Dismiss the screen, optionally with a result.

Note

Only the active screen may be dismissed. If you try to dismiss a screen that isn't active, this method will raise a ScreenError.

If result is provided and a callback was set when the screen was pushed, then the callback will be invoked with result.

Parameters:

Name	Type	Description	Default
result	ScreenResultType | Type[_NoResult]	The optional result to be passed to the result callback.	_NoResult

Raises:

Type	Description
ScreenError	If the screen being dismissed is not active.
ScreenStackError	If trying to dismiss a screen that is not at the top of the stack.

find_widget

find_widget(widget)

Get the screen region of a Widget.

Parameters:

Name	Type	Description	Default
widget	Widget	A Widget within the composition.	required

Returns:

Type	Description
MapGeometry	Region relative to screen.

Raises:

Type	Description
NoWidget	If the widget could not be found in this screen.

focus_next

focus_next(selector='*')

Focus the next widget, optionally filtered by a CSS selector.

If no widget is currently focused, this will focus the first focusable widget. If no focusable widget matches the given CSS selector, focus is set to None.

Parameters:

Name	Type	Description	Default
selector	str | type[QueryType]	CSS selector to filter what nodes can be focused.	'*'

Returns:

Type	Description
Widget | None	Newly focused widget, or None for no focus. If the return is not None, then it is guaranteed that the widget returned matches the CSS selectors given in the argument.

focus_previous

focus_previous(selector='*')

Focus the previous widget, optionally filtered by a CSS selector.

If no widget is currently focused, this will focus the first focusable widget. If no focusable widget matches the given CSS selector, focus is set to None.

Parameters:

Name	Type	Description	Default
selector	str | type[QueryType]	CSS selector to filter what nodes can be focused.	'*'

Returns:

Type	Description
Widget | None	Newly focused widget, or None for no focus. If the return is not None, then it is guaranteed that the widget returned matches the CSS selectors given in the argument.

get_focusable_widget_at

get_focusable_widget_at(x, y)

Get the focusable widget under a given coordinate.

If the widget directly under the given coordinate is not focusable, then this method will check if any of the ancestors are focusable. If no ancestors are focusable, then None will be returned.

Parameters:

Name	Type	Description	Default
x	int	X coordinate.	required
y	int	Y coordinate.	required

Returns:

Type	Description
Widget | None	A Widget, or None if there is no focusable widget underneath the coordinate.

get_offset

get_offset(widget)

Get the absolute offset of a given Widget.

Parameters:

Name	Type	Description	Default
widget	Widget	A widget	required

Returns:

Type	Description
Offset	The widget's offset relative to the top left of the terminal.

get_style_at

get_style_at(x, y)

Get the style under a given coordinate.

Parameters:

Name	Type	Description	Default
x	int	X Coordinate.	required
y	int	Y Coordinate.	required

Returns:

Type	Description
Style	Rich Style object.

get_widget_at

get_widget_at(x, y)

Get the widget at a given coordinate.

Parameters:

Name	Type	Description	Default
x	int	X Coordinate.	required
y	int	Y Coordinate.	required

Returns:

Type	Description
tuple[Widget, Region]	Widget and screen region.

Raises:

Type	Description
NoWidget	If there is no widget under the screen coordinate.

get_widgets_at

get_widgets_at(x, y)

Get all widgets under a given coordinate.

Parameters:

Name	Type	Description	Default
x	int	X coordinate.	required
y	int	Y coordinate.	required

Returns:

Type	Description
Iterable[tuple[Widget, Region]]	Sequence of (WIDGET, REGION) tuples.

refresh_bindings

refresh_bindings()

Call to request a refresh of bindings.

set_focus

set_focus(widget, scroll_visible=True)

Focus (or un-focus) a widget. A focused widget will receive key events first.

Parameters:

Name	Type	Description	Default
widget	Widget | None	Widget to focus, or None to un-focus.	required
scroll_visible	bool	Scroll widget in to view.	True

validate_sub_title

validate_sub_title(sub_title)

Ensure the sub-title is a string or None.

validate_title

validate_title(title)

Ensure the title is a string or None.

SystemModalScreen

SystemModalScreen(name=None, id=None, classes=None)

Bases: ModalScreen[ScreenResultType]

A variant of ModalScreen for internal use.

This version of ModalScreen allows us to build system-level screens; the type being used to indicate that the screen should be isolated from the main application.

Note

This screen is set to not inherit CSS.