SlidingStage

Slides between selected items on a horizontal axis
Mountain lake Terraced farm Winter trees Forest river Red panda
Demo: SlidingStage is the basis of this SlidingPages component

Overview

SlidingStage displays a set of items on a horizontal axis, with a single item completely visible at a time. It shows a sliding transition when changing which item is selected.

This component provides no interaction on its own, but is the basis for carousel-like components in Elix, including Carousel and SlidingPages (shown above). Those components handle a variety of input methods to let the user navigate which item is shown in the viewport.

SlidingStage can be used as the stage in an Explorer. Here SlidingStage is used to provide a sliding transition between the pages in a Tabs instance:

home
Home
search
Search
settings
Settings
Home page
Search page
Settings page
Demo: SlidingStage used in Tabs for navigation

See also

Carousel
Carousel with a sliding effect and navigation controls
CrossfadeStage
Shows a crossfade effect when transitioning between a single selected item
Modes
Shows a single panel at a time
SlidingPages
Simple carousel with no visible UI controls

API

Class hierarchy:

This element is used as a shadow part in Carousel, CarouselWithThumbnails, PlainCarousel, and PlainCarouselWithThumbnails.

closestAvailableItemIndex(state, options) method

Look for an item which is available in the given state..

The options parameter can accept options for:

  • direction: 1 to move forward, -1 to move backward
  • index: the index to start at, defaults to state.currentIndex
  • wrap: whether to wrap around the ends of the items array, defaults to state.cursorOperationsWrap.

If an available item was found, this returns its index. If no item was found, this returns -1.

Parameters:

  • state: PlainObject
  • options: PlainObject

Returns: number

Defined by ItemsCursorMixin

contentSlot property

See contentSlot.

Defined by SlotContentMixin

currentIndex property

The index of the current item, or -1 if no item is current.

Type: number

Defined by CursorAPIMixin

currentindexchanged event

Raised when the currentIndex property changes.

Defined by CursorAPIMixin

currentItem property

The current item, or null if no item is current.

Type: Element

Defined by CursorAPIMixin

currentItemRequired property

True if the list should always have a current item (if it has items).

Type: boolean

Default: false

Defined by CursorAPIMixin

cursorOperationsWrap property

True if cursor operations wrap from last to first, and vice versa.

Type: boolean

Default: false

Defined by CursorAPIMixin

defaultState property

The default state for the component. This can be extended by mixins and classes to provide additional default state.

Type: PlainObject

Defined by ReactiveMixin

goFirst() method

Moves to the first item in the list.

Returns: Boolean True if the current item changed, false if not.

Defined by CursorAPIMixin

goLast() method

Move to the last item in the list.

Returns: Boolean True if the current item changed

Defined by CursorAPIMixin

goNext() method

Move to the next item in the list.

If the list has no current item, the first item will become current.

Returns: Boolean True if the current item changed

Defined by CursorAPIMixin

goPrevious() method

Moves to the previous item in the list.

If the list has no current item, the last item will become current.

Returns: Boolean True if the current item changed

Defined by CursorAPIMixin

ids property

A convenient shortcut for looking up an element by ID 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[ids].foo to obtain the corresponding button in the component instance's shadow tree. The ids property is simply a shorthand for getElementById, so this[ids].foo is the same as this[shadowRoot].getElementById('foo').

Type: object

Defined by ShadowTemplateMixin

[internal.goFirst]() method

Move to the first item in the set.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

[internal.goLast]() method

Move to the last item in the set.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

[internal.goNext]() method

Move to the next item in the set.

If no item is current, move to the first item.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

[internal.goPrevious]() method

Move to the previous item in the set.

If no item is current, move to the last item.

Returns: Boolean True if the current item changed, false if not.

Defined by ItemsCursorMixin

items property

The current set of items drawn from the element's current state.

Type: Array.

Defined by ItemsAPIMixin

itemschange event

Raised when the items property changes.

Defined by ItemsAPIMixin

render(changed) method

Render the indicated changes in state to the DOM.

The default implementation of this method does nothing. Override this method in your component to update your component's host element and any shadow elements to reflect the component's new state. See the rendering example.

Be sure to call super in your method implementation so that your component's base classes and mixins have a chance to perform their own render work.

Parameters:

  • changed: ChangedFlagsdictionary of flags indicating which state members have changed since the last render

Defined by ReactiveMixin

renderChanges() method

Render any pending component changes to the DOM.

This method does nothing if the state has not changed since the last render call.

ReactiveMixin will invoke this method following a setState call; you should not need to invoke this method yourself.

This method invokes the internal render method, then invokes the rendered method.

Defined by ReactiveMixin

rendered(changed) method

Perform any work that must happen after state changes have been rendered to the DOM.

The default implementation of this method does nothing. Override this method in your component to perform work that requires the component to be fully rendered, such as setting focus on a shadow element or inspecting the computed style of an element. If such work should result in a change in component state, you can safely call setState during the rendered method.

Be sure to call super in your method implementation so that your component's base classes and mixins have a chance to perform their own post-render work.

Parameters:

  • changed: ChangedFlags

Defined by ReactiveMixin

selectedIndex property

The index of the selected item, or -1 if no item is selected.

Type: number

Defined by SingleSelectAPIMixin

selectedindexchange event

Raised when the selectedIndex property changes.

Defined by SingleSelectAPIMixin

selectedItem property

The selected item, or null if no item is selected.

Type: Element

Defined by SingleSelectAPIMixin

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.

Parameters:

  • changes: PlainObjectthe changes to apply to the element's state

Returns: Promise - resolves when the new state has been rendered

Defined by ReactiveMixin

state property

The component's current state.

The returned state object is immutable. To update it, invoke internal.setState.

It's extremely useful to be able to inspect component state while debugging. If you append ?elixdebug=true to a page's URL, then ReactiveMixin will conditionally expose a public state property that returns the component's state. You can then access the state in your browser's debug console.

Type: PlainObject

Defined by ReactiveMixin

stateEffects(state, changed) method

Ask the component whether a state with a set of recently-changed fields implies that additional second-order changes should be applied to that state to make it consistent.

This method is invoked during a call to internal.setState to give all of a component's mixins and classes a chance to respond to changes in state. If one mixin/class updates state that it controls, another mixin/class may want to respond by updating some other state member that it controls.

This method should return a dictionary of changes that should be applied to the state. If the dictionary object is not empty, the internal.setState will apply the changes to the state, and invoke this stateEffects method again to determine whether there are any third-order effects that should be applied. This process repeats until all mixins/classes report that they have no additional changes to make.

See an example of how ReactiveMixin invokes the stateEffects to ensure state consistency.

Parameters:

  • state: PlainObjecta proposal for a new state
  • changed: ChangedFlagsthe set of fields changed in this latest proposal for the new state

Returns: PlainObject

Defined by ReactiveMixin