bootstack.Accordion#

class bootstack.Accordion(*, allow_multiple=False, allow_collapse_all=True, show_separators=True, show_border=True, variant=None, accent=None, padding=None, parent=None, **kwargs)#

Bases: PublicWidgetBase

A list of collapsible sections, optionally limited to one open at a time.

Each section is added with add(), which returns an AccordionSection context manager for placing child widgets inside that section.

Parameters:

  • allow_multiple (bool) – If True, multiple sections can be expanded at once. Defaults to False (only one section open at a time).

  • allow_collapse_all (bool) – If True (default), every section can be collapsed. If False, at least one section stays open.

  • show_separators (bool) – If True, draws a separator line between sections. Defaults to True.

  • show_border (bool) – If True, wraps the accordion in a bordered frame. Defaults to True.

  • variant (AccordionVariant | None) – Style variant applied to each section header. Defaults to None (the default header reads as a ghost/transparent bar).

  • accent (AccentToken | str | None) – Color intent token applied to all section headers. Defaults to None (theme default).

  • padding (Padding | None) – Space between the outer border and the sections, in pixels. Defaults to None.

  • parent (Any) – Explicit parent container. Omit to use the current context.

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

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 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()
add(title, *, key=None, layout='column', padding=16, gap=0, horizontal_items=None, vertical_items=None, grow_items=False, columns=None, rows=None, auto_flow='row', expanded=None, icon=None)#

Add a section and return a context manager for placing its children.

Parameters:

  • title (str) – Section header text.

  • key (str | None) – Unique identifier used with item(), expand(), collapse(), and remove(). Auto-generated if omitted.

  • layout (LayoutKind) – Body layout. Defaults to 'column'.

  • padding (Padding | None) – Space between the section border and its body, in pixels. Defaults to 16.

  • gap (int) – Space between body children in pixels. Defaults to 0.

  • horizontal_items (str | None) – How body children sit on the horizontal axis — edge values 'left'/'center'/'right'/'stretch', plus 'space-*' when horizontal is the stacking axis. Defaults to 'stretch' in grid mode, 'center' in a column and 'left' in a row.

  • vertical_items (str | None) – How body children sit on the vertical axis — edge values 'top'/'center'/'bottom'/'stretch', plus 'space-*' when vertical is the stacking axis. Defaults to 'stretch' in grid mode, 'center' in a row and 'top' in a column.

  • grow_items (bool) – For 'column'/'row', when True every body child grows equally to share the main axis. Defaults to False.

  • columns (int | list[int | str] | None) – Column definitions for 'grid' layout. An integer sets the number of equal-weight columns; a list sets per-column weights or sizes (e.g. [1, 2, 'auto', '120px']). Defaults to None.

  • rows (int | list[int | str] | None) – Row definitions for 'grid' layout. Defaults to None.

  • auto_flow (AutoFlow) – Grid placement direction. Defaults to 'row'.

  • expanded (bool | None) – Whether the section starts expanded. Defaults to the accordion’s own default (collapsed when allow_multiple=False).

  • icon (str | None) – Icon name or spec displayed in the section header.

Returns:

AccordionSection — use as a context manager to place children.

Return type:

AccordionSection

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.

collapse(key)#

Collapse the section identified by key.

Parameters:

key (str) – Section key.

collapse_all()#

Collapse all sections.

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))
expand(key)#

Expand the section identified by key.

Parameters:

key (str) – Section key.

expand_all()#

Expand all sections.

item(key)#

Return the section handle for key.

Parameters:

key (str) – Section key.

Returns:

The AccordionSection for that key — read expanded/title or call expand()/collapse()/toggle() to drive it.

Return type:

AccordionSection

items(expanded=None)#

Return all section handles in insertion order, optionally filtered.

Parameters:

expanded (bool | None) – If True, return only expanded sections. If False, only collapsed. If None (default), return all.

Returns:

A tuple of AccordionSection handles.

Return type:

tuple[AccordionSection, …]

keys()#

Return all section keys in insertion order.

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_change() → Stream#
on_change(handler: Callable[[AccordionChangeEvent], Any]) → Subscription

Register a callback fired when any section expands or collapses.

The handler receives an AccordionChangeEvent; e.expanded is the tuple of currently expanded sections.

Returns:

Subscription (with handler) or Stream (without handler).

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

remove(key)#

Remove a section by key.

Parameters:

key (str) – The key assigned when the section was added.