Events#

The event catalog. Every widget announces what it does as a named event; data-carrying events hand the handler a typed payload, while native events hand it a curated, toolkit-free Event. This module is the home of all of those types, so editors can autocomplete the attributes on each one.

For a task-oriented introduction — listening, reading a payload, cancelling a subscription, emitting your own — see the Events guide.

Event handling#

The curated event handed to native handlers and the cancellable handle returned by every binding.

`Event`	The object a handler receives for native and context events.
`Subscription`	Handle returned by `widget.on(...)`.

Value and input payloads#

Handed to handlers for value commits, live input, validation, and toggles.

`ChangeEvent`	Fires when a field's value is committed (on blur or Enter).
`InputEvent`	Fires on every keystroke, before the value is committed.
`ValidationEvent`	Fires after validation runs — `valid`, `invalid`, and `validate`.
`TextModifiedEvent`	Fires when a text area's modified (dirty) flag changes.
`ToggleEvent`	Fires when an expander is expanded or collapsed.

Slider payloads#

The live and committed payloads for the single- and range-value sliders.

`SliderEvent`	Fires while a slider (or gauge/meter) value moves.
`SliderCommitEvent`	Fires when a slider value is committed (drag released or stepped).
`RangeSliderEvent`	Fires while either handle of a range slider moves.
`RangeSliderCommitEvent`	Fires when a range slider's values are committed.

Date payloads#

DateSelectEvent

Fires when a date (or date range) is chosen in a calendar.

Navigation and layout payloads#

Page, nav-pane, display-mode, and accordion activity.

`PageChangeEvent`	Fires when the active page changes (mount, will-mount, change).
`WorkspaceChangeEvent`	Fires when the shell's active workspace changes (a rail switch).
`NavEvent`	Fires when a navigation item is selected.
`PaneToggleEvent`	Fires when a navigation pane opens or closes.
`DisplayModeEvent`	Fires when a navigation widget's display mode changes.
`AccordionChangeEvent`	Fires when an accordion's set of open panels changes.

Tab payloads#

The change/activate/deactivate/close payloads for a tab strip.

`TabChangeEvent`	Fires when the active tab changes.
`TabActivateEvent`	Fires when a tab becomes active.
`TabDeactivateEvent`	Fires when a tab stops being active.
`TabCloseEvent`	Fires when a tab's close button is used.

Data and selection payloads#

Row CRUD, selection, export, tree selection, button-group clicks, menu selection, and the data-source change broadcast.

`RowEvent`	Fires for a single-row action (click, double-click, right-click).
`RowsEvent`	Fires for a multi-row action (insert, update, delete, move).
`SelectionEvent`	Fires when the set of selected rows changes.
`TreeSelectionEvent`	Fires when a tree's set of selected nodes changes.
`ExportEvent`	Fires after the table's data is exported (copied or saved).
`ButtonGroupClickEvent`	Fires when a button in a button group is clicked.
`MenuSelectEvent`	Fires when a menu item is activated (`MenuButton` / `ContextMenu`).
`DataChangeEvent`	Broadcast by a data source when its data or view changes.

Picture and media payloads#

The load and error events fired by Picture as it decodes and displays an image.

`ImageLoadEvent`	Fires when a `Picture` has decoded its source and displayed it.
`ImageErrorEvent`	Fires when a `Picture` fails to load or decode its source.

Supporting types#

Value types carried inside payloads, rather than handed to a handler directly.

TabRef

Identifies a tab by key and display text.

Enumerations#

The string-literal tags carried by the change and data-change payloads.

type bootstack.events.ChangeKind#: What a data-source change describes — 'load', 'insert', 'update', 'delete', 'move', 'filter', 'sort', 'reload', 'select'.

type bootstack.events.ChangeMethod#: How a change was made — 'click', 'key', 'programmatic', 'unknown'.

type bootstack.events.ChangeReason#: Why a change event fired — 'user', 'api', 'hide', 'forget', 'unknown'.