bootstack.Calendar#

class bootstack.Calendar(*, value=None, start_date=None, end_date=None, disabled_dates=None, selection_mode='single', max_date=None, min_date=None, show_outside_days=None, show_week_numbers=False, first_weekday=None, accent=None, padding=None, parent=None, **kwargs)#

Bases: PublicWidgetBase

An inline calendar for single-date or date-range selection.

Always visible — not a popup. Displays one month in 'single' mode and two months side-by-side in 'range' mode.

Dates can be passed as datetime.date objects, datetime.datetime objects, or ISO strings ("2026-05-31").

Parameters:

  • value (date | datetime | str | None) – Initially selected date (single mode only).

  • start_date (date | datetime | str | None) – Initially selected range start date (range mode).

  • end_date (date | datetime | str | None) – Initially selected range end date (range mode).

  • disabled_dates (Iterable[date | datetime | str] | None) – Dates that cannot be selected. Displayed with a strikethrough style.

  • selection_mode (Literal['single', 'range']) – 'single' (default) for one date; 'range' for a start–end span.

  • min_date (date | datetime | str | None) – Earliest selectable date. Earlier dates are disabled and month navigation is blocked before this point.

  • max_date (date | datetime | str | None) – Latest selectable date. Later dates are disabled and month navigation is blocked past this point.

  • show_outside_days (bool | None) – Show days from adjacent months in the grid. Defaults to True in single mode and False in range mode.

  • show_week_numbers (bool) – Display ISO 8601 week numbers in the leftmost column. Defaults to False.

  • first_weekday (int | None) – First day of the week as an integer (0=Monday, 6=Sunday). If omitted, the locale default is used.

  • accent (AccentToken | str | None) – Accent token applied to selected dates and highlights. Defaults to 'primary'.

  • padding (Padding | None) – Space in pixels around the calendar grid.

  • parent (Any) – Explicit parent widget. If omitted, the current context-stack container is used.

  • **kwargs (Any) – Layout placement options applied by the parent container — fill, expand, anchor, margin, row, column, sticky. See Arranging Widgets.

property disabled_dates: tuple[date, ...]#

The non-selectable dates. Assigning a new iterable updates the calendar immediately.

property is_attached: bool#

Whether the widget is currently placed in its layout.

True while the widget occupies space in its parent; False after detach (or before it has ever been placed). A detached widget keeps its state and can be returned to the layout with attach.

property max_date: date | None#

Latest selectable date. Assigning updates the calendar immediately; None clears the bound.

property min_date: date | None#

Earliest selectable date. Assigning updates the calendar immediately; None clears the bound.

property range: tuple[date | None, date | None]#

The selected date range as (start, end).

property schedule: Schedule#

Scheduler tied to this widget’s lifetime.

All jobs are automatically cancelled when the widget is destroyed. First access creates the Schedule instance; subsequent accesses return the same instance.

Usage:

self.schedule.delay(500, callback)
self.schedule.every(1000, tick)
job = self.schedule.idle(refresh)
job.cancel()
property value: date | None#

The currently selected date.

attach(**kwargs)#

Return a detached widget to its layout, optionally moving it.

With no arguments, restores the widget to exactly where detach took it from. Any layout kwargs accepted by the original placement (e.g. fill, expand, anchor, sticky, margin) override the stored options. For stacked widgets, index= sets the position among the currently attached siblings (or pass an explicit before=/after= sibling); without one, the snapshotted position is used.

Calling attach on a widget that is already attached moves it (the kwargs are re-applied). Fires on_attach.

Parameters:

**kwargs (Any) – Layout placement options to override for this placement.

Raises:

ParentResolutionError – If the widget was never placed in a layout.

capture(path, *, inset=0, settle=0.1)#

Save a picture of this widget to an image file.

Captures the area this widget occupies on screen — one widget, a whole window, or the entire application, depending on what you call it on. The file extension selects the format, so .png, .jpg, and .pdf all work.

The widget has to be visible. A capture reads pixels from the display, so the window is brought to the front first and a hidden or detached widget cannot be captured at all. Any always-on-top setting the window already had is left as it was found.

Pair it with a save dialog to let the user choose where it goes:

import bootstack as bs

def on_export():
    chosen = bs.ask_save_file(initial_file="dashboard.png")
    if chosen:
        app.capture(chosen)
Parameters:

  • path (str | Path) – Where to write the image. Missing parent folders are created, and the extension chooses the format.

  • inset (int) – Pixels to trim from every edge, zero or more. Use 2 on a whole window to drop the native border artifact.

  • settle (float) – Seconds to let the desktop finish repainting before the pixels are read. The default covers the common case of a dialog closing just beforehand. The interface pauses for this long, so a second click on the control that started the capture waits its turn rather than starting an overlapping one.

Returns:

The path that was written.

Raises:

BootstackError – If the widget is not visible on screen or has been scrolled out of view, if inset is negative, if no capture backend is available, or if the file cannot be written.

Return type:

Path

Added in version 0.3.0.

destroy()#

Destroy the widget and release the resources it holds.

Removes the widget from its parent, destroys its children, and cancels any pending or repeating jobs on its schedule. After this the widget must not be used again. Destroying a container destroys everything inside it.

detach()#

Remove the widget from its layout without destroying it.

The widget stops occupying space but keeps its state, children, and event bindings, ready to be returned with attach. The current position is snapshotted so a plain attach() restores it exactly — for stacked siblings this is the index among the currently attached siblings, so detaching other siblings first shifts that index.

Calling detach on a widget that is already detached, or one that was never placed in a layout, does nothing. Fires on_detach.

emit(event, *, data=None)#

Fire a named event on this widget, as if it produced the event itself.

This is how a composite widget surfaces high-level activity to its listeners, and the generic counterpart to the on_*() shorthands for firing events that have no dedicated method.

It is meant for the framework’s own events — 'change', 'select', 'input' and the rest of the data-carrying names. A handler registered through on() or an on_<event>() shorthand receives what is emitted.

Names that map onto a native event instead ('click', 'focus', 'blur', 'submit', …) are a different matter: emitting one asks the toolkit to deliver a real input event, which carries no payload and can reach handlers the widget installed for its own use. Emitting those is not a way to notify listeners, and a listener bound through on() may not see it. Drive the widget through its properties and methods instead.

Parameters:

  • event (str) – The event name, unprefixed — the same name you pass to on() or an on_<event>() shorthand (e.g. 'change', 'select').

  • data (Any) – The payload delivered to handlers. Pass the matching payload dataclass from bootstack.events — the same object an on_<event>() handler receives.

Example

from bootstack.events import ChangeEvent

field.emit("change", data=ChangeEvent(value=new_value))
get()#

Return the currently selected date.

get_range()#

Return the selected date range.

on(event, handler=None)#

Bind handler to event, or return a composable Stream.

With a handler — binds immediately and returns a Subscription:

sub = widget.on("change", handler)
sub.cancel()

Without a handler — returns a Stream for operator chaining. The Tk binding is created lazily when .listen() is called:

sub = widget.on("change").debounce(300).listen(handler)
sub.cancel()
Parameters:

  • event (str) – Event name (e.g. "change", "click").

  • handler (Callable[[Any], Any] | None) – Optional callback. If omitted, a Stream is returned.

Returns:

Subscription when a handler is provided; Stream otherwise.

Return type:

Stream | Subscription

on_attach(handler=None)#

Register a callback fired when the widget enters the layout.

Fires each time the widget becomes visible in its parent — on initial placement and on every attach. Pair it with on_detach to keep per-visibility resources (timers, observers) tied to the widget’s presence on screen. The handler receives a curated Event.

Parameters:

handler (Callable[[Event], Any] | None) – Called when the widget is attached. Omit to get a composable Stream.

Returns:

A cancellable Subscription when a handler is given, otherwise a Stream.

Return type:

Stream | Subscription

on_destroy(handler=None)#

Register a callback fired when the widget is destroyed.

Fires once, as the widget is torn down — the place to release resources the widget owns that aren’t cleaned up automatically (file handles, observers, external subscriptions). The handler receives a curated Event.

Parameters:

handler (Callable[[Event], Any] | None) – Called as the widget is destroyed. Omit to get a composable Stream.

Returns:

A cancellable Subscription when a handler is given, otherwise a Stream.

Return type:

Stream | Subscription

on_detach(handler=None)#

Register a callback fired when the widget leaves the layout.

Fires each time the widget stops occupying space in its parent — on detach and when an ancestor hides it. Pair it with on_attach to release per-visibility resources. The handler receives a curated Event.

Parameters:

handler (Callable[[Event], Any] | None) – Called when the widget is detached. Omit to get a composable Stream.

Returns:

A cancellable Subscription when a handler is given, otherwise a Stream.

Return type:

Stream | Subscription

on_select() → Stream#
on_select(handler: Callable[[DateSelectEvent], Any]) → Subscription

Register a callback fired when a date or range is selected.

In single mode the handler fires on every date click. In range mode it fires after each click — check calendar.range to see whether a complete range has been set (end is None while the second date is still pending).

Parameters:

handler (Callable[[DateSelectEvent], Any] | None) – Called with a DateSelectEvent. Omit to get a composable Stream instead.

Returns:

A cancellable Subscription when a handler is given, otherwise a Stream.

Return type:

Stream | Subscription

set(value)#

Set the selected date without emitting <<DateSelect>>.

set_range(start, end=None)#

Set the selected date range without emitting <<DateSelect>>.