Mirror Engine
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Mirror Engine API


Mirror Engine API / ScrollViewComponent

Class: ScrollViewComponent

A ScrollViewComponent enables a group of entities to behave like a masked scrolling area, with optional horizontal and vertical scroll bars.

Extends

  • Component

Properties

entity

entity: Entity

The Entity that this Component is attached to.

Inherited from

Component.entity

system

system: ComponentSystem

The ComponentSystem used to create this Component.

Inherited from

Component.system

bounceAmount

Get Signature

get bounceAmount(): number

Gets how far the content should move before bouncing back.

Returns

number

Set Signature

set bounceAmount(arg: number): void

Sets how far the content should move before bouncing back.

Parameters
arg

number

Returns

void


contentEntity

Get Signature

get contentEntity(): null | Entity

Gets the entity which contains the scrolling content itself.

Returns

null | Entity

Set Signature

set contentEntity(arg: null | Entity): void

Sets the entity which contains the scrolling content itself. This entity must have an ElementComponent.

Parameters
arg

null | Entity

Returns

void


enabled

Get Signature

get enabled(): boolean

Gets the enabled state of the component.

Returns

boolean

Set Signature

set enabled(arg: boolean): void

Sets the enabled state of the component.

Parameters
arg

boolean

Returns

void

Overrides

Component.enabled

friction

Get Signature

get friction(): number

Gets how freely the content should move if thrown.

Returns

number

Set Signature

set friction(arg: number): void

Sets how freely the content should move if thrown, i.e. By flicking on a phone or by flinging the scroll wheel on a mouse. A value of 1 means that content will stop immediately; 0 means that content will continue moving forever (or until the bounds of the content are reached, depending on the scrollMode).

Parameters
arg

number

Returns

void


horizontal

Get Signature

get horizontal(): boolean

Gets whether horizontal scrolling is enabled.

Returns

boolean

Set Signature

set horizontal(arg: boolean): void

Sets whether horizontal scrolling is enabled.

Parameters
arg

boolean

Returns

void


horizontalScrollbarEntity

Get Signature

get horizontalScrollbarEntity(): null | Entity

Gets the entity to be used as the horizontal scrollbar.

Returns

null | Entity

Set Signature

set horizontalScrollbarEntity(arg: null | Entity): void

Sets the entity to be used as the horizontal scrollbar. This entity must have a ScrollbarComponent.

Parameters
arg

null | Entity

Returns

void


horizontalScrollbarVisibility

Get Signature

get horizontalScrollbarVisibility(): number

Gets whether the horizontal scrollbar should be visible all the time, or only visible when the content exceeds the size of the viewport.

Returns

number

Set Signature

set horizontalScrollbarVisibility(arg: number): void

Sets whether the horizontal scrollbar should be visible all the time, or only visible when the content exceeds the size of the viewport.

Parameters
arg

number

Returns

void


mouseWheelSensitivity

Get Signature

get mouseWheelSensitivity(): Vec2

Gets the mouse wheel horizontal and vertical sensitivity.

Returns

Vec2

Set Signature

set mouseWheelSensitivity(arg: Vec2): void

Sets the mouse wheel horizontal and vertical sensitivity. Only used if useMouseWheel is set. Setting a direction to 0 will disable mouse wheel scrolling in that direction. 1 is a default sensitivity that is considered to feel good. The values can be set higher or lower than 1 to tune the sensitivity. Defaults to [1, 1].

Parameters
arg

Vec2

Returns

void


scroll

Get Signature

get scroll(): Vec2

Gets the scroll value.

Returns

Vec2

Set Signature

set scroll(value: Vec2): void

Sets the scroll value.

Parameters
value

Vec2

Returns

void


scrollMode

Get Signature

get scrollMode(): number

Gets the scroll mode of the scroll viewer.

Returns

number

Set Signature

set scrollMode(arg: number): void

Sets the scroll mode of the scroll viewer. Specifies how the scroll view should behave when the user scrolls past the end of the content. Modes are defined as follows:

Parameters
arg

number

Returns

void


useMouseWheel

Get Signature

get useMouseWheel(): boolean

Gets whether to use mouse wheel for scrolling (horizontally and vertically).

Returns

boolean

Set Signature

set useMouseWheel(arg: boolean): void

Sets whether to use mouse wheel for scrolling (horizontally and vertically).

Parameters
arg

boolean

Returns

void


vertical

Get Signature

get vertical(): boolean

Gets whether vertical scrolling is enabled.

Returns

boolean

Set Signature

set vertical(arg: boolean): void

Sets whether vertical scrolling is enabled.

Parameters
arg

boolean

Returns

void


verticalScrollbarEntity

Get Signature

get verticalScrollbarEntity(): null | Entity

Gets the entity to be used as the vertical scrollbar.

Returns

null | Entity

Set Signature

set verticalScrollbarEntity(arg: null | Entity): void

Sets the entity to be used as the vertical scrollbar. This entity must have a ScrollbarComponent.

Parameters
arg

null | Entity

Returns

void


verticalScrollbarVisibility

Get Signature

get verticalScrollbarVisibility(): number

Gets whether the vertical scrollbar should be visible all the time, or only visible when the content exceeds the size of the viewport.

Returns

number

Set Signature

set verticalScrollbarVisibility(arg: number): void

Sets whether the vertical scrollbar should be visible all the time, or only visible when the content exceeds the size of the viewport.

Parameters
arg

number

Returns

void


viewportEntity

Get Signature

get viewportEntity(): null | Entity

Gets the entity to be used as the masked viewport area, within which the content will scroll.

Returns

null | Entity

Set Signature

set viewportEntity(arg: null | Entity): void

Sets the entity to be used as the masked viewport area, within which the content will scroll. This entity must have an ElementGroup component.

Parameters
arg

null | Entity

Returns

void

Methods

fire()

fire(
   name: string,
   arg1?: any,
   arg2?: any,
   arg3?: any,
   arg4?: any,
   arg5?: any,
   arg6?: any,
   arg7?: any,
   arg8?: any): EventHandler

Fire an event, all additional arguments are passed on to the event listener.

Parameters

name

string

Name of event to fire.

arg1?

any

First argument that is passed to the event handler.

arg2?

any

Second argument that is passed to the event handler.

arg3?

any

Third argument that is passed to the event handler.

arg4?

any

Fourth argument that is passed to the event handler.

arg5?

any

Fifth argument that is passed to the event handler.

arg6?

any

Sixth argument that is passed to the event handler.

arg7?

any

Seventh argument that is passed to the event handler.

arg8?

any

Eighth argument that is passed to the event handler.

Returns

EventHandler

Self for chaining.

Example

obj.fire('test', 'This is the message')

Inherited from

Component.fire

hasEvent()

hasEvent(name: string): boolean

Test if there are any handlers bound to an event name.

Parameters

name

string

The name of the event to test.

Returns

boolean

True if the object has handlers bound to the specified event name.

Example

obj.on('test', () => {}) // bind an event to 'test'
obj.hasEvent('test') // returns true
obj.hasEvent('hello') // returns false

Inherited from

Component.hasEvent

off()

off(
   name?: string,
   callback?: HandleEventCallback,
   scope?: any): EventHandler

Detach an event handler from an event. If callback is not provided then all callbacks are unbound from the event, if scope is not provided then all events with the callback will be unbound.

Parameters

name?

string

Name of the event to unbind.

callback?

HandleEventCallback

Function to be unbound.

scope?

any

Scope that was used as the this when the event is fired.

Returns

EventHandler

Self for chaining.

Example

const handler = () => {}
obj.on('test', handler)

obj.off() // Removes all events
obj.off('test') // Removes all events called 'test'
obj.off('test', handler) // Removes all handler functions, called 'test'
obj.off('test', handler, this) // Removes all handler functions, called 'test' with scope this

Inherited from

Component.off

on()

on(
   name: string,
   callback: HandleEventCallback,
   scope?: any): EventHandle

Attach an event handler to an event.

Parameters

name

string

Name of the event to bind the callback to.

callback

HandleEventCallback

Function that is called when event is fired. Note the callback is limited to 8 arguments.

scope?

any = ...

Object to use as 'this' when the event is fired, defaults to current this.

Returns

EventHandle

Can be used for removing event in the future.

Examples

obj.on('test', (a, b) => {
  console.log(a + b)
})
obj.fire('test', 1, 2) // prints 3 to the console
const evt = obj.on('test', (a, b) => {
  console.log(a + b)
})
// some time later
evt.off()

Inherited from

Component.on

once()

once(
   name: string,
   callback: HandleEventCallback,
   scope?: any): EventHandle

Attach an event handler to an event. This handler will be removed after being fired once.

Parameters

name

string

Name of the event to bind the callback to.

callback

HandleEventCallback

Function that is called when event is fired. Note the callback is limited to 8 arguments.

scope?

any = ...

Object to use as 'this' when the event is fired, defaults to current this.

Returns

EventHandle

  • can be used for removing event in the future.

Example

obj.once('test', (a, b) => {
  console.log(a + b)
})
obj.fire('test', 1, 2) // prints 3 to the console
obj.fire('test', 1, 2) // not going to get handled

Inherited from

Component.once

Events

EVENT_SETSCROLL

static EVENT_SETSCROLL: string = 'set:scroll';

Fired whenever the scroll position changes. The handler is passed a Vec2 containing the horizontal and vertical scroll values in the range 0..1.

Example

entity.scrollview.on('set:scroll', (scroll) => {
  console.log(`Horizontal scroll position: ${'${scroll.x}'}`)
  console.log(`Vertical scroll position: ${'${scroll.y}'}`)
})
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