bootstack.SplitView#

class bootstack.SplitView(orient='horizontal', *, padding=None, accent=None, surface=None, sash_thickness=None, width=None, height=None, parent=None, **kwargs)#

Bases: PublicWidgetBase

A resizable split container with panes separated by draggable sashes.

Add panes with .add() and place children inside each pane using the returned SplitPane handle. Sashes between panes can be dragged at runtime to resize them. Panes are addressable by key — enumerate them with panes, look one up with item(), insert one at a position with insert(), reorder with move(), and drop one with remove().

Parameters:

  • orient (Orient) – Pane arrangement — 'horizontal' (side-by-side) or 'vertical' (stacked top-to-bottom). Defaults to 'horizontal'.

  • padding (Padding | None) – Space in pixels between the outer border and the pane area. A single value applies to all sides; (x, y) sets the horizontal and vertical amounts. Defaults to None.

  • accent (AccentToken | str | None) – Color intent token applied to the sash. When omitted, the sash uses the theme’s default color.

  • surface (SurfaceToken | str | None) – Surface token for the pane background.

  • sash_thickness (int | None) – Width (horizontal split) or height (vertical split) of the draggable sash in pixels. Defaults to the theme’s standard sash size (typically 6 px).

  • width (int | None) – Requested width in pixels.

  • height (int | None) – Requested height in pixels.

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

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

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 panes: tuple[SplitPane, ...]#

All panes in left-to-right (or top-to-bottom) order.

property sash_positions: list[int]#

Current position of every sash in pixels, in order.

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(*, key=None, weight=1, layout='vstack', padding=None, gap=0, fill_items=None, expand_items=None, anchor_items=None, columns=None, rows=None, sticky_items=None, auto_flow='row')#

Add a pane and return a handle for placing its children and controlling it.

Parameters:

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

  • weight (int) – Relative size weight when the container is resized. Panes with a higher weight take proportionally more space. Settable afterward via the pane’s weight property. Defaults to 1.

  • layout (LayoutKind) – Internal pane layout. Defaults to 'vstack'.

  • padding (Padding | None) – Space in pixels inside the pane border. Defaults to None.

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

  • fill_items (Fill | str | None) – Default fill direction applied to every child.

  • expand_items (bool | None) – Whether children expand to consume extra space.

  • anchor_items (Anchor | str | None) – Default anchor applied to every child.

  • 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']).

  • rows (int | list[int | str] | None) – Row definitions for 'grid' layout, same format as columns.

  • sticky_items (Sticky | str | None) – Default sticky value for grid children.

  • auto_flow (AutoFlow) – Grid auto-flow direction. Defaults to 'row'.

Returns:

SplitPane — use as a context manager to place children, and as a handle to read/set weight or remove() the pane.

Return type:

SplitPane

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(index, *, key=None, weight=1, layout='vstack', padding=None, gap=0, fill_items=None, expand_items=None, anchor_items=None, columns=None, rows=None, sticky_items=None, auto_flow='row')#

Add a pane at a specific position. Accepts the same options as add().

Parameters:

  • index (int) – Zero-based position to insert the new pane at. Existing panes at or after this position shift toward the end.

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

  • weight (int) – Relative size weight. Defaults to 1.

  • layout (LayoutKind) – Internal pane layout. Defaults to 'vstack'.

  • padding (Padding | None) – Space in pixels inside the pane border. Defaults to None.

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

  • fill_items (Fill | str | None) – Default fill direction applied to every child.

  • expand_items (bool | None) – Whether children expand to consume extra space.

  • anchor_items (Anchor | str | None) – Default anchor applied to every child.

  • columns (int | list[int | str] | None) – Column definitions for 'grid' layout.

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

  • sticky_items (Sticky | str | None) – Default sticky value for grid children.

  • auto_flow (AutoFlow) – Grid auto-flow direction. Defaults to 'row'.

Returns:

SplitPane — same handle returned by add().

Return type:

SplitPane

item(key)#

Return the pane handle for key.

Parameters:

key (str) – Pane key.

Returns:

The SplitPane for that key — read/set its weight or remove() it.

Return type:

SplitPane

keys()#

All pane keys in order.

move(key, index)#

Move an existing pane to a new position.

Parameters:

  • key (str) – The key of the pane to move.

  • index (int) – Zero-based target position.

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(key)#

Remove a pane and destroy its content.

Parameters:

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

sash_position(index, position=None)#

Get or set the position of a sash.

Parameters:

  • index (int) – Zero-based sash index.

  • position (int | None) – New position in pixels. If None, returns the current position.

Returns:

Current sash position in pixels when position is None.

Return type:

int | None

set_clipboard(text)#

Replace the system clipboard contents with text.

Parameters:

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