Class ScrollTrigger

ScrollTrigger allows you to run actions when the user scrolls a target element (or the main scrollable element) in a given direction, and undo those actions when they scroll in the opposite direction.

To use with auto-widgets (HTML API), see registerTrigger for the specification.

  • Arguments (optional): One or more (comma-separated) scroll directions. Note that if you do not specify any directions, then the trigger will just run once, on any scroll.
  • Additional trigger options:

Example

Show the element when the user scrolls the page up, hide when scrolling down. User scrolling left or right not trigger the action. See getOppositeXYDirections:

<div data-lisn-on-scroll="up @show"></div>

Example

As above, but using a CSS class instead of data attribute:

<div class="lisn-on-scroll--up@show"></div>

Example

Show the element 1000ms after the first time the user scrolls the page up:

<div data-lisn-on-scroll="up @show +once +delay=1000"></div>

Example

Add class scrolled the first time the user scrolls the page in any direction (note that the once option is implied here), and show the element 1000ms after each time the user scrolls the page up, hide it as soon as they scroll down:

<div data-lisn-on-scroll="@add-class=scrolled ;
                          up @show +do-delay=1000"
></div>

Example

When the user scrolls up or down the closest ancestor with class section, then add classes c1 and c2 and enable trigger my-trigger defined on this same element; undo all of that when scrolling right or left:

<div class="section">
  <div data-lisn-on-scroll="up,down @add-class=c1,c2 @enable=my-trigger +scrollable=this.section"
     data-lisn-on-run="@show +id=my-trigger"
  ></div>
</div>

Example

As above, but using data-lisn-ref attribute instead of class selector.

<div data-lisn-ref="section">
  <div data-lisn-on-scroll="up,down @add-class=c1,c2 @enable=my-trigger +scrollable=this-section"
     data-lisn-on-run="@show +id=my-trigger"
  ></div>
</div>

Hierarchy (View Summary)

Methods

get register

Constructors

constructor

Properties

destroy disable enable getActions getConfig getElement isDestroyed isDisabled onDestroy onDisable onEnable reverse run toggle toggleEnable

Methods

Staticget

Staticregister

Constructors

constructor

Properties

Readonlydestroy

destroy: () => Promise<void>

Undoes all modifications to the element and returns it to its original state.

You will need to recreate it if you want to enable its functionality again.

Readonlydisable

disable: () => Promise<void>

Disables the functionality of the widget. What this means is specific to each widget.

Readonlyenable

enable: () => Promise<void>

Re-enables the functionality of the widget. What this means is specific to each widget.

ReadonlygetActions

getActions: () => Action[]

Returns the trigger's actions.

ReadonlygetConfig

getConfig: () => ScrollTriggerConfig

Returns the trigger config.

ReadonlygetElement

getElement: () => Element

Returns the element passed to the widget constructor.

ReadonlyisDestroyed

isDestroyed: () => boolean

Returns true if the widget is destroyed.

ReadonlyisDisabled

isDisabled: () => boolean

Returns true if the widget is currently disabled.

ReadonlyonDestroy

onDestroy: (handler: WidgetHandler) => void

The given handler will be called when the widget is destroyed.

ReadonlyonDisable

onDisable: (handler: WidgetHandler) => void

The given handler will be called when the widget is disabled.

ReadonlyonEnable

onEnable: (handler: WidgetHandler) => void

The given handler will be called when the widget is enabled.

Readonlyreverse

reverse: () => Promise<void>

"Undo"es all the Actions linked to the trigger.

Readonlyrun

run: () => Promise<void>

"Do"es all the Actions linked to the trigger.

Readonlytoggle

toggle: () => Promise<void>

"Toggle"s all the Actions linked to the trigger.

ReadonlytoggleEnable

toggleEnable: () => Promise<void>

Re-enables the widget if disabled, otherwise disables it.

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Methods
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Properties