textual.events

Builtin events sent by Textual.

Events may be marked as "Bubbles" and "Verbose". See the events guide for an explanation of bubbling. Verbose events are excluded from the textual console, unless you explicitly request them with the -v switch as follows:

textual console -v

AppBlur

AppBlur()

Bases: Event

Sent when the app loses focus.

• Bubbles
• Verbose

Note

Only available when running within a terminal that supports FocusOut, or when running via textual-web.

AppFocus

AppFocus()

Bases: Event

Sent when the app has focus.

• Bubbles
• Verbose

Note

Only available when running within a terminal that supports FocusIn, or when running via textual-web.

Blur

Blur()

Bases: Event

Sent when a widget is blurred (un-focussed).

• Bubbles
• Verbose

Callback

Callback(callback)

Bases: Event

Sent by Textual to invoke a callback (see call_next and call_later).

Click

Click(
    widget,
    x,
    y,
    delta_x,
    delta_y,
    button,
    shift,
    meta,
    ctrl,
    screen_x=None,
    screen_y=None,
    style=None,
)

Bases: MouseEvent

Sent when a widget is clicked.

• Bubbles
• Verbose

Compose

Compose()

Bases: Event

Sent to a widget to request it to compose and mount children.

This event is used internally by Textual. You won't typically need to explicitly handle it,

• Bubbles
• Verbose

CursorPosition dataclass

CursorPosition(x, y)

Bases: Event

Internal event used to retrieve the terminal's cursor position.

DeliveryComplete dataclass

DeliveryComplete(key, path=None, name=None)

Bases: Event

Sent to App when a file has been delivered.

key instance-attribute

key

The delivery key associated with the delivery.

This is the same key that was returned by App.deliver_text/App.deliver_binary.

name class-attribute instance-attribute

name = None

Optional name returned to the app to identify the download.

path class-attribute instance-attribute

path = None

The path where the file was saved, or None if the path is not available, for example if the file was delivered via web browser.

DeliveryFailed dataclass

DeliveryFailed(key, exception, name=None)

Bases: Event

Sent to App when a file delivery fails.

exception instance-attribute

exception

The exception that was raised during the delivery.

key instance-attribute

key

The delivery key associated with the delivery.

name class-attribute instance-attribute

name = None

Optional name returned to the app to identify the download.

DescendantBlur dataclass

DescendantBlur(widget)

Bases: Event

Sent when a child widget is blurred.

• Bubbles
• Verbose

control property

control

The widget that was blurred (alias of widget).

widget instance-attribute

widget

The widget that was blurred.

DescendantFocus dataclass

DescendantFocus(widget)

Bases: Event

Sent when a child widget is focussed.

• Bubbles
• Verbose

control property

control

The widget that was focused (alias of widget).

widget instance-attribute

widget

The widget that was focused.

Enter

Enter(node)

Bases: Event

Sent when the mouse is moved over a widget.

Note that this event bubbles, so a widget may receive this event when the mouse moves over a child widget. Check the node attribute for the widget directly under the mouse.

• Bubbles
• Verbose

control property

control

Alias for the node under the mouse.

node instance-attribute

node = node

The node directly under the mouse.

Event

Event()

Bases: Message

The base class for all events.

Focus

Focus()

Bases: Event

Sent when a widget is focussed.

• Bubbles
• Verbose

Hide

Hide()

Bases: Event

Sent when a widget has been hidden.

• Bubbles
• Verbose

Sent when any of the following conditions apply:

• The widget is removed from the DOM.
• The widget is no longer displayed because it has been scrolled or clipped from the terminal or its container.
• The widget has its display attribute set to False.
• The widget's display style is set to "none".

Idle

Idle()

Bases: Event

Sent when there are no more items in the message queue.

This is a pseudo-event in that it is created by the Textual system and doesn't go through the usual message queue.

• Bubbles
• Verbose

InputEvent

InputEvent()

Bases: Event

Base class for input events.

Key

Key(key, character)

Bases: InputEvent

Sent when the user hits a key on the keyboard.

• Bubbles
• Verbose

Parameters:

Name	Type	Description	Default
key	str	The key that was pressed.	required
character	str | None	A printable character or None if it is not printable.	required

aliases instance-attribute

aliases = _get_key_aliases(key)

The aliases for the key, including the key itself.

character instance-attribute

character = (
    key
    if len(key) == 1
    else None if character is None else character
)

A printable character or None if it is not printable.

is_printable property

is_printable

Check if the key is printable (produces a unicode character).

Returns:

Type	Description
bool	True if the key is printable.

key instance-attribute

key = key

The key that was pressed.

name property

name

Name of a key suitable for use as a Python identifier.

name_aliases property

name_aliases

The corresponding name for every alias in aliases list.

Leave

Leave(node)

Bases: Event

Sent when the mouse is moved away from a widget, or if a widget is programmatically disabled while hovered.

Note that this widget bubbles, so a widget may receive Leave events for any child widgets. Check the node parameter for the original widget that was previously under the mouse.

• Bubbles
• Verbose

control property

control

Alias for the node that was previously under the mouse.

node instance-attribute

node = node

The node that was previously directly under the mouse.

Load

Load()

Bases: Event

Sent when the App is running but before the terminal is in application mode.

Use this event to run any setup that doesn't require any visuals such as loading configuration and binding keys.

• Bubbles
• Verbose

Mount

Mount()

Bases: Event

Sent when a widget is mounted and may receive messages.

• Bubbles
• Verbose

MouseCapture

MouseCapture(mouse_position)

Bases: Event

Sent when the mouse has been captured.

• Bubbles
• Verbose

When a mouse has been captured, all further mouse events will be sent to the capturing widget.

Parameters:

Name	Type	Description	Default
mouse_position	Offset	The position of the mouse when captured.	required

mouse_position instance-attribute

mouse_position = mouse_position

The position of the mouse when captured.

MouseDown

MouseDown(
    widget,
    x,
    y,
    delta_x,
    delta_y,
    button,
    shift,
    meta,
    ctrl,
    screen_x=None,
    screen_y=None,
    style=None,
)

Bases: MouseEvent

Sent when a mouse button is pressed.

• Bubbles
• Verbose

MouseEvent

MouseEvent(
    widget,
    x,
    y,
    delta_x,
    delta_y,
    button,
    shift,
    meta,
    ctrl,
    screen_x=None,
    screen_y=None,
    style=None,
)

Bases: InputEvent

Sent in response to a mouse event.

• Bubbles
• Verbose

Parameters:

Name	Type	Description	Default
widget	Widget | None	The widget under the mouse.	required
x	int	The relative x coordinate.	required
y	int	The relative y coordinate.	required
delta_x	int	Change in x since the last message.	required
delta_y	int	Change in y since the last message.	required
button	int	Indexed of the pressed button.	required
shift	bool	True if the shift key is pressed.	required
meta	bool	True if the meta key is pressed.	required
ctrl	bool	True if the ctrl key is pressed.	required
screen_x	int | None	The absolute x coordinate.	None
screen_y	int | None	The absolute y coordinate.	None
style	Style | None	The Rich Style under the mouse cursor.	None

button instance-attribute

button = button

Indexed of the pressed button.

ctrl instance-attribute

ctrl = ctrl

True if the ctrl key is pressed.

delta property

delta

Mouse coordinate delta (change since last event).

delta_x instance-attribute

delta_x = delta_x

Change in x since the last message.

delta_y instance-attribute

delta_y = delta_y

Change in y since the last message.

meta instance-attribute

meta = meta

True if the meta key is pressed.

offset property

offset

The mouse coordinate as an offset.

Returns:

Type	Description
Offset	Mouse coordinate.

screen_offset property

screen_offset

Mouse coordinate relative to the screen.

screen_x instance-attribute

screen_x = x if screen_x is None else screen_x

The absolute x coordinate.

screen_y instance-attribute

screen_y = y if screen_y is None else screen_y

The absolute y coordinate.

shift instance-attribute

shift = shift

True if the shift key is pressed.

style property writable

style

The (Rich) Style under the cursor.

widget instance-attribute

widget = widget

The widget under the mouse at the time of a click.

x instance-attribute

x = x

The relative x coordinate.

y instance-attribute

y = y

The relative y coordinate.

get_content_offset

get_content_offset(widget)

Get offset within a widget's content area, or None if offset is not in content (i.e. padding or border).

Parameters:

Name	Type	Description	Default
widget	Widget	Widget receiving the event.	required

Returns:

Type	Description
Offset | None	An offset where the origin is at the top left of the content area.

get_content_offset_capture

get_content_offset_capture(widget)

Get offset from a widget's content area.

This method works even if the offset is outside the widget content region.

Parameters:

Name	Type	Description	Default
widget	Widget	Widget receiving the event.	required

Returns:

Type	Description
Offset	An offset where the origin is at the top left of the content area.

MouseMove

MouseMove(
    widget,
    x,
    y,
    delta_x,
    delta_y,
    button,
    shift,
    meta,
    ctrl,
    screen_x=None,
    screen_y=None,
    style=None,
)

Bases: MouseEvent

Sent when the mouse cursor moves.

• Bubbles
• Verbose

MouseRelease

MouseRelease(mouse_position)

Bases: Event

Mouse has been released.

• Bubbles
• Verbose

Parameters:

Name	Type	Description	Default
mouse_position	Offset	The position of the mouse when released.	required

mouse_position instance-attribute

mouse_position = mouse_position

The position of the mouse when released.

MouseScrollDown

MouseScrollDown(
    widget,
    x,
    y,
    delta_x,
    delta_y,
    button,
    shift,
    meta,
    ctrl,
    screen_x=None,
    screen_y=None,
    style=None,
)

Bases: MouseEvent

Sent when the mouse wheel is scrolled down.

• Bubbles
• Verbose

MouseScrollUp

MouseScrollUp(
    widget,
    x,
    y,
    delta_x,
    delta_y,
    button,
    shift,
    meta,
    ctrl,
    screen_x=None,
    screen_y=None,
    style=None,
)

Bases: MouseEvent

Sent when the mouse wheel is scrolled up.

• Bubbles
• Verbose

MouseUp

MouseUp(
    widget,
    x,
    y,
    delta_x,
    delta_y,
    button,
    shift,
    meta,
    ctrl,
    screen_x=None,
    screen_y=None,
    style=None,
)

Bases: MouseEvent

Sent when a mouse button is released.

• Bubbles
• Verbose

Paste

Paste(text)

Bases: Event

Event containing text that was pasted into the Textual application. This event will only appear when running in a terminal emulator that supports bracketed paste mode. Textual will enable bracketed pastes when an app starts, and disable it when the app shuts down.

• Bubbles
• Verbose

Parameters:

Name	Type	Description	Default
text	str	The text that has been pasted.	required

text instance-attribute

text = text

The text that was pasted.

Print

Print(text, stderr=False)

Bases: Event

Sent to a widget that is capturing print.

• Bubbles
• Verbose

Parameters:

Name	Type	Description	Default
text	str	Text that was printed.	required
stderr	bool	True if the print was to stderr, or False for stdout.	False

Note

Python's print output can be captured with App.begin_capture_print.

stderr instance-attribute

stderr = stderr

True if the print was to stderr, or False for stdout.

text instance-attribute

text = text

The text that was printed.

Ready

Ready()

Bases: Event

Sent to the App when the DOM is ready and the first frame has been displayed.

• Bubbles
• Verbose

Resize

Resize(
    size, virtual_size, container_size=None, pixel_size=None
)

Bases: Event

Sent when the app or widget has been resized.

• Bubbles
• Verbose

Parameters:

Name	Type	Description	Default
size	Size	The new size of the Widget.	required
virtual_size	Size	The virtual size (scrollable size) of the Widget.	required
container_size	Size | None	The size of the Widget's container widget.	None

container_size instance-attribute

container_size = (
    size if container_size is None else container_size
)

The size of the Widget's container widget.

pixel_size instance-attribute

pixel_size = pixel_size

Size of terminal window in pixels if known, or None if not known.

size instance-attribute

size = size

The new size of the Widget.

virtual_size instance-attribute

virtual_size = virtual_size

The virtual size (scrollable size) of the Widget.

from_dimensions classmethod

from_dimensions(cells, pixels)

Construct from basic dimensions.

Parameters:

Name	Type	Description	Default
cells	tuple[int, int]	tuple of (, ) in cells.	required
pixels	tuple[int, int] | None	tuple of (, ) in pixels if known, or None if not known.	required

ScreenResume

ScreenResume()

Bases: Event

Sent to screen that has been made active.

• Bubbles
• Verbose

ScreenSuspend

ScreenSuspend()

Bases: Event

Sent to screen when it is no longer active.

• Bubbles
• Verbose

Show

Show()

Bases: Event

Sent when a widget is first displayed.

• Bubbles
• Verbose

Timer

Timer(timer, time, count=0, callback=None)

Bases: Event

Sent in response to a timer.

• Bubbles
• Verbose

Unmount

Unmount()

Bases: Event

Sent when a widget is unmounted and may no longer receive messages.

• Bubbles
• Verbose