Drawer
A drawer is a modal panel that slides in from the side of the page. A drawer is generally used to provide navigation in situations where: a) screen real estate is constrained and b) the navigation UI is not critical to completing the user’s primary goal (and, hence, not critical to the application’s business goal).
Drawer displays a ModalBackdrop behind the main overlay content to help the user understand the modal condition. Both the backdrop and the dialog itself can be styled.
Drawer is very similar to Dialog in construction, and provides the same level of keyboard support.
The user may dismiss the drawer by pressing Esc, or by swiping to the side with touch or the trackpad. You may also provide a UI element inside the drawer — e.g., a close box — that dismisses the drawer.
Usage
import Drawer from 'elix/src/Drawer.js';
const drawer = new Drawer(); // or
const drawer = document.createElement('elix-drawer');
In HTML:
<script type="module" src="node_modules/elix/src/Drawer.js"></script>
<elix-drawer>
<!-- Drawer contents go here -->
</elix-drawer>
API
Ancestry: Drawer → ReactiveElement → HTMLElement
Built with mixins AttributeMarshallingMixin, DialogModalityMixin, KeyboardMixin, LanguageDirectionMixin, OpenCloseMixin, OverlayMixin, ReactiveMixin, RenderUpdatesMixin, ShadowTemplateMixin, TouchSwipeMixin, TrackpadSwipeMixin, and TransitionEffectMixin.
Includes subelements ModalBackdrop and OverlayFrame.
$ property
The collection of references to the elements with IDs in the component's Shadow DOM subtree.
Example: if component's template contains a shadow element
<button id="foo">, you can use the reference this.$.foo to obtain
the corresponding button in the component instance's shadow tree.
Such references simplify a component's access to its own elements. In exchange, this mixin trades off a one-time cost of querying all elements in the shadow tree instead of paying an ongoing cost to query for an element each time the component wants to inspect or manipulate it.
These shadow element references are established the first time you read
the $ property. They are * not updated if you subsequently modify the
shadow tree yourself (to replace one item with another, to add new items
with id attributes, etc.).
Type: object
Defined by ShadowTemplateMixin inherited from ReactiveElement
close(result) method
Close the component (if not already closed).
Some components like AlertDialog want to indicate why or
how they were closed. To support such scenarios, you can supply a value
to the optional result parameter. This result will be made available
in the whenClosed promise and the state.result member.
- result:
object– an indication of how or why the element closed
Defined by OpenCloseMixin
closeFinished property
True if the element has completely closed.
For components not using asynchronous open/close effects, this property
returns the same value as the closed property. For elements that have a
true value of state.openCloseEffects (e.g., elements using
TransitionEffectMixin), this property returns
true only if state.effect is "close" and state.effectPhase is
"after".
Type: boolean
Defined by OpenCloseMixin
defaultState property
The default state for the component. This can be extended by mixins and classes to provide additional default state.
Type: object
Defined by ReactiveMixin inherited from ReactiveElement
effect-phase-changed event
Raised when state.effect or state.effectPhase changes.
Note: In general, Elix components do not raise events in response to
outside manipulation. (See
symbols.raiseChangeEvents.) However, for
a component using TransitionEffectMixin, a single invocation of the
startEffect method will cause the element to pass through multiple
visual states. This makes it hard for external hosts of this
component to know what visual state the component is in. Accordingly,
the mixin raises the effect-phase-changed event whenever the effect
or phase changes, even if symbols.raiseChangeEvents is false.
Defined by TransitionEffectMixin
opened-changed event
Raised when the opened/closed state of the component changes.
Defined by OpenCloseMixin
refineState(state) method
Apply changes to a proposed new state for the component to enforce necessary consistency between state members. See Refining state for details.
Returns: boolean - true if the state is already acceptable as it is
- state:
object– a proposed new state for the component
Defined by ReactiveMixin inherited from ReactiveElement
render() method
Render the component to the DOM.
This method does nothing if the state has not changed since the last render call.
This method invokes all internal render methods. It then invoked componentDidMount (for first render) or componentDidUpdate (for subsequent renders).
Defined by ReactiveMixin inherited from ReactiveElement
setState(changes) method
Update the component's state by merging the specified changes on top of the existing state. If the component is connected to the document, and the new state has changed, this returns a promise to asynchronously render the component. Otherwise, this returns a resolved promise.
Returns: Promise - resolves when the new state has been rendered
- changes:
object– the changes to apply to the element's state
Defined by ReactiveMixin inherited from ReactiveElement
shouldComponentUpdate(nextState) method
Return true if the component should update.
The default implementation does a shallow check of property values like React's PureComponent. This seems adequate for most web components. You can override this to always return true (like React's base Component class), or to perform more specific, deeper checks for changes in state.
Returns: boolean - true if the component should update (rerender)
- nextState:
object– the proposed new state for the element
Defined by ReactiveMixin inherited from ReactiveElement
state property
The component's current state.
The returned state object is immutable. To update it, invoke setState.
Type: object
Defined by ReactiveMixin inherited from ReactiveElement
symbols.elementsWithTransitions property
Return the elements that use CSS transitions to provide visual effects.
By default, this assumes the host element itself will have a CSS transition applied to it, and so returns an array containing the element. If you will be applying CSS transitions to other elements, override this property and return an array containing the implicated elements.
See symbols.elementsWithTransitions for details.
Type: Array.<HTMLElement>
Defined by TransitionEffectMixin
toggle(opened) method
Toggle the open/close state of the element.
- opened:
boolean– true if the element should be opened, false if closed.
Defined by OpenCloseMixin
updates property
The attributes and properies that should be applied to the component on render. By default, this is an empty plain object. Your mixin or component can extend this to identify the properties to set on the host element or elements in the shadow subtree.
Type: object
Defined by RenderUpdatesMixin inherited from ReactiveElement
whenClosed() method
This method can be used as an alternative to listening to the "opened-changed" event, particularly in situations where you want to only handle the next time the component is closed.
Returns: Promise A promise that resolves when the element has
completely closed, including the completion of any asynchronous opening
effect.
Defined by OpenCloseMixin