bootstack.MenuButton#

class bootstack.MenuButton(text='', *, items=None, on_select=None, icon=None, icon_only=False, show_arrow=True, menu_options=None, disabled=False, accent=None, variant='default', density=None, textsignal=None, localize=None, parent=None, **kwargs)#

Bases: IconProperty, PublicWidgetBase

A button that opens a dropdown menu when clicked.

Items are added at construction via items= or dynamically with add_item(). The on_select callback fires for every item click, receiving a dict with type, text, and value keys.

Parameters:

  • text (str) – Button text. Defaults to an empty string.

  • items (list[Any] | None) – Initial list of item dicts. Each dict must have a type key ('command', 'check', 'radio', or 'separator') plus item-specific keys such as text, icon, value, and on_click (the per-item callback).

  • on_select (Callable[[MenuSelectEvent], Any] | None) – Callback fired when any menu item is activated. Called with a MenuSelectEvent (type, text, value of the activated item).

  • icon (str | IconSpec | None) – Icon name shown on the button face.

  • icon_only (bool) – If True, hides the label and shows only the icon. Inferred automatically when icon= is set and label is empty. Defaults to False.

  • show_arrow (bool) – If True (default), shows the dropdown chevron arrow. Pass False to hide it (useful when the icon implies the action).

  • menu_options (dict[str, Any] | None) – Extra options forwarded to the underlying ContextMenu at construction (e.g. {'anchor': 'se', 'offset': 4}).

  • disabled (bool) – If True, button is shown but non-interactive. Defaults to False.

  • accent (AccentToken | str | None) – Color intent token. Defaults to the theme default.

  • variant (ButtonVariant) – Style variant. Default 'ghost'.

  • density (WidgetDensity | None) – Layout density.

  • textsignal (Signal[str] | None) – Signal[str] bound to the button label text.

  • localize (LocalizeMode | None) – Whether the button text is translated through the catalog — True, False, or 'auto'. Defaults to the app’s localize_mode.

  • parent (Any) – Override the context-stack parent widget.

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

property disabled: bool#

Whether the button is non-interactive.

property icon: str | IconSpec | None#

The icon shown on the widget, or None if none is set.

A Bootstrap Icons name, or an IconSpec mapping ({'name', 'size', 'color'}) for control over size and color.

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 items: list[Any]#

All menu items in insertion order.

property keys: tuple[str, ...]#

Keys of all menu items in insertion order.

property menu: Any#

The underlying ContextMenu — for advanced programmatic access.

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_check_item(label, *, value=False, on_click=None, key=None)#

Add a checkbutton item to the dropdown.

Parameters:

  • label (str) – Item label text.

  • value (bool) – Initial checked state.

  • on_click (Callable[[], Any] | None) – Callback fired on toggle.

  • key (str | None) – Unique string key. Auto-generated if omitted.

Returns:

The key assigned to this item.

Return type:

str

add_item(label, *, on_click=None, icon=None, shortcut=None, disabled=False, key=None)#

Add a command item to the dropdown.

Parameters:

  • label (str) – Item label text.

  • on_click (Callable[[], Any] | None) – Callback fired when the item is clicked.

  • icon (str | None) – Icon name shown beside the label.

  • shortcut (str | None) – Keyboard shortcut hint displayed on the right. Accepts a modifier pattern ("Mod+S" → "Ctrl+S" / "⌘S"), a registered shortcut key name, or a literal display string.

  • disabled (bool) – If True, item is shown but non-interactive.

  • key (str | None) – Unique string key. Auto-generated if omitted.

Returns:

The key assigned to this item.

Return type:

str

add_items(items)#

Add multiple items at once from a list of item dicts.

Each dict must have a type key plus item-specific keys:

mb.add_items([
    {"type": "command", "text": "Edit",   "icon": "pencil", "on_click": edit},
    {"type": "command", "text": "Delete", "icon": "trash",  "on_click": delete},
    {"type": "separator"},
    {"type": "check",   "text": "Pinned", "value": True},
    {"type": "radio",   "text": "Small",  "value": "sm"},
])
Parameters:

items (list[Any]) – List of item dicts. type accepts 'command', 'check', 'radio', or 'separator'; an item’s on_click key sets its per-item callback.

add_radio_item(label, *, value=None, selected=False, on_click=None, key=None)#

Add a radio-button item to the dropdown.

All radio items in a MenuButton share one group variable automatically. Pass selected=True on the item that should be pre-selected on first open.

Note

Values are stored as strings internally. Pass string values (e.g. value="100%") for predictable comparisons when reading the group selection via menu.

Parameters:

  • label (str) – Item label text.

  • value (Any) – Value associated with this radio item. Stored as a string internally; defaults to label when omitted.

  • selected (bool) – If True, this item is the initial selection. Defaults to False.

  • on_click (Callable[[], Any] | None) – Callback fired on selection.

  • key (str | None) – Unique string key. Auto-generated if omitted.

Returns:

The key assigned to this item.

Return type:

str

add_separator(*, key=None)#

Add a horizontal separator to the dropdown.

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.

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.

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. For a data-carrying event, pass the matching payload dataclass from bootstack.events — the same object an on_<event>() handler receives. Leave as None for native events (click, hover, focus, …), which carry no payload.

Example

widget.emit("change", data=bs.events.ChangeEvent(value=new_value))
get_clipboard()#

Return the current text contents of the system clipboard.

Returns:

The clipboard text, or an empty string when the clipboard is empty or holds non-text data.

Return type:

str

insert_item(index, type, **kwargs)#

Insert a new item at a specific position.

Parameters:

  • index (int) – Zero-based position to insert at.

  • type (str) – Item type — 'command', 'check', 'radio', or 'separator'.

  • **kwargs (Any) – Forwarded to the matching add_* method.

Returns:

The key assigned to the new item.

Return type:

str

item(key)#

Return the item object for key.

Parameters:

key (str) – Key returned by an add_* method.

move_item(key, to_index)#

Move an existing item to a new position.

Parameters:

  • key (str) – Key of the item to move.

  • to_index (int) – Target zero-based index.

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

remove_item(key)#

Remove a dropdown item by key.

Parameters:

key (str) – Key returned by an add_* method.

set_clipboard(text)#

Replace the system clipboard contents with text.

Parameters:

text (str) – The text to place on the clipboard.

show_menu()#

Open the dropdown menu programmatically.

Has no effect if the button is disabled or read-only.

update_item(key, **kwargs)#

Reconfigure a dropdown item after creation.

Parameters:

  • key (str) – Key returned by an add_* method.

  • **kwargs (Any) – Options forwarded to the item’s configure method.