SlideshowWithPlayControls

Slideshow with buttons for controlling playback
Mountain lake Terraced farm Winter trees Forest river Red panda
Demo: Play controls let the user go back, pause/resume, or forward

Overview

This component is simply a Slideshow that uses PlayControlsMixin to add buttons for controlling slideshow playback.

For a variation that uses standard carousel controls (arrows and page dots), see CarouselSlideshow. For a more basic variation with no controls, see Slideshow.

API

Class hierarchy:

The element defines the following shadow parts:

  • control-button: any of the buttons that control playback, default type is Button
  • next-button: the button that navigates to the next item
  • play-button: the button that starts or pauses playback
  • previous-button: the button that navigates to the previous item

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

controlButtonPartType property

The class or tag used to create the control-button parts – the play control buttons.

Type: (component class constructor)|HTMLTemplateElement|string

Default: Button

Defined by PlayControlsMixin

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

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

cursorTimerDuration property

The time in milliseconds that will elapse after the cursor advances before the cursor will be advanced to the next item in the list.

Type: number

Default: 1000 (1 second)

Defined by TimerCursorMixin

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

effectEndTarget 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 effectEndTarget for details.

Type: HTMLElement

Defined by TransitionEffectMixin

effectphasechange event

Raised when state.effect or state.effectPhase changes.

Note: In general, Elix components do not raise events in response to outside manipulation. (See 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 effectphasechange event whenever the effect or phase changes, even if internal.raiseChangeEvents is false.

Defined by TransitionEffectMixin

goDown() method

Interprets goDown to mean "move to the next item".

Defined by DirectionCursorMixin

goEnd() method

Interprets goEnd to mean "move to the last item".

Defined by DirectionCursorMixin

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

goLeft() method

Interprets goLeft to mean "move to the previous item".

If the element has a rightToLeft property and it is true, then this moves to the next item.

Defined by DirectionCursorMixin

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

goRight() method

Interprets goRight to mean "move to the next item".

If the element has a rightToLeft property and it is true, then this moves to the previous item.

Defined by DirectionCursorMixin

goStart() method

Interprets goStart to mean "move to the first item".

Defined by DirectionCursorMixin

goUp() method

Interprets goUp to mean "move to the previous item".

Defined by DirectionCursorMixin

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

itemschange event

Raised when the items property changes.

Defined by ItemsAPIMixin

keydown() method

See the symbols documentation for details.

Defined by KeyboardMixin

pause() method

Pause automatic progression of the cursor.

Defined by TimerCursorMixin

play() method

Begin automatic progression of the cursor.

Defined by TimerCursorMixin

playing property

True if the element is playing.

Type: boolean

Default: false

Defined by TimerCursorMixin

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

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

selectioneffectfinish event

This event is raised when changing the selection and the selection effect has completed.

The order of events when the currentIndex property changes is therefore: selectedindexchange (occurs immediately when the index changes), followed by selectioneffectend (occurs some time later).

Defined by CrossfadeStage

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

startEffect(effect) method

See startEffect.

Parameters:

  • effect: string

Defined by TransitionEffectMixin

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 method 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

swipeDown() method

Invokes the goUp method.

Defined by SwipeDirectionMixin

swipeLeft() method

Invokes the goRight method.

Defined by SwipeDirectionMixin

swipeRight() method

Invokes the goLeft method.

Defined by SwipeDirectionMixin

swipeTarget property

See swipeTarget.

Type: HTMLElement

Defined by TouchSwipeMixin

swipeUp() method

Invokes the goDown method.

Defined by SwipeDirectionMixin

wrap(target) method

Destructively wrap a node with elements for play controls.

Parameters:

  • target: Elementthe element that should be wrapped by play controls

Defined by PlayControlsMixin