Disables filipping the dropdowns up or dynamically repositioning
them along the y-axis to prevent them getting hidden behind the
navbar or them covering the trigger element.
The custom handling of Space and Enter for dropdowns that was added to
aria.js were not needed in the latests Bootstrap versions. So removed
them. Vanilla Bootstrap emulates click when Space or Enter keys are
pressed on a tab.
* Move the focus to the last menu item when the menu is displayed by
pressing the Up arrow key.
* When the menu is open and Tab/Shift-Tab is pressed, focus on the
next/previous focusable element on the DOM instead of focusing back on
the menu trigger.
* Combine event handling for the dropdown menu trigger.
The legacy M.core.event.FORM_SUBMIT_AJAX ecent has been replaced with a
new core_form/events::formSubmittedByJavascript native DOM event.
The new event can be listened to at any point in the DOM using the
following syntax:
```
import {eventTypes} from 'core_form/events';
document.addEventListener(eventTypes.formSubmittedByJavascript, handler);
```
A backward-compatabibility layer is included to ensure that any
legacy YUI event triggered on a form is still respected and the new
native event is also fired.
A similar handler is also included to ensure that any legacy YUI event
listener is still called with the same arguments.
These legacy bridges will be removed after Moodle 4.3.
If the drawer toggle button was clicked in quick succession to close
and then re-open, then the delayed Aria.hide method would be called
which hid the drawer content when it finished opening.
* The aria-describedby attribute can be a list of element IDs that
describe the element. On form validation, the ID of the error message
container is added to this attribute which may already be containing
another ID. So we need to properly add/remove the error message ID
so that we don't delete any existing ID(s) in the aria-describedby
attribute during form validation.
Where an element, like an `alert`, is closed it is removed from the DOM
before the event fires (this is a correct behaviour).
This means that the final event confirming that the action happened
(i.e. close => closed) fires, but does not bubble up the DOM to the
document.body.
This change moves the end event listener to only be added after a start
event has been fired, and to attach directly to the HTMLElement where it
will be fired. This means that the Event handler will still be called,
even though it has been removed from the DOM, because it does not need
to bubble up to the body.
Mihail Geshoski