ScrollZoomHandler

Defined in: src/ui/handler/scroll_zoom.ts:36

The ScrollZoomHandler allows the user to zoom the map by scrolling.

Implements

• Handler

Methods

_shouldBePrevented()

_shouldBePrevented(e: WheelEvent): boolean

Defined in: src/ui/handler/scroll_zoom.ts:160

Determines whether or not the gesture is blocked due to cooperativeGestures.

Parameters

Parameter	Type
e	WheelEvent

Returns

boolean

---

disable()

disable(): void

Defined in: src/ui/handler/scroll_zoom.ts:152

Disables the "scroll to zoom" interaction.

Returns

void

Example

map.scrollZoom.disable();

Implementation of

Handler.disable

---

enable()

enable(options?: boolean | AroundCenterOptions): void

Defined in: src/ui/handler/scroll_zoom.ts:138

Enables the "scroll to zoom" interaction.

Parameters

Parameter	Type	Description
options?	boolean | AroundCenterOptions	Options object.

Returns

void

Example

map.scrollZoom.enable();
map.scrollZoom.enable({ around: 'center' })

Implementation of

Handler.enable

---

isActive()

isActive(): boolean

Defined in: src/ui/handler/scroll_zoom.ts:120

This is used to indicate if the handler is currently active or not. In case a handler is active, it will block other handlers from getting the relevant events. There is an allow list of handlers that can be active at the same time, which is configured when adding a handler.

Returns

boolean

Implementation of

Handler.isActive

---

isEnabled()

isEnabled(): boolean

Defined in: src/ui/handler/scroll_zoom.ts:111

Returns a Boolean indicating whether the "scroll to zoom" interaction is enabled.

Returns

boolean

true if the "scroll to zoom" interaction is enabled.

Implementation of

Handler.isEnabled

---

renderFrame()

renderFrame(): object

Defined in: src/ui/handler/scroll_zoom.ts:269

renderFrame is the only non-dom event. It is called during render frames and can be used to smooth camera changes (see scroll handler).

Returns

object

around

around: Point

needsRenderFrame

needsRenderFrame: boolean = !finished

noInertia

noInertia: boolean = true

originalEvent

originalEvent: any

zoomDelta

zoomDelta: number

Implementation of

Handler.renderFrame

---

reset()

reset(): void

Defined in: src/ui/handler/scroll_zoom.ts:387

reset can be called by the manager at any time and must reset everything to it's original state

Returns

void

Implementation of

Handler.reset

---

setWheelZoomRate()

setWheelZoomRate(wheelZoomRate: number): void

Defined in: src/ui/handler/scroll_zoom.ts:103

Set the zoom rate of a mouse wheel

Parameters

Parameter	Type	Description
wheelZoomRate	number	1/450 The rate used to scale mouse wheel movement to a zoom value.

Returns

void

Example

Slow down zoom of mouse wheel

map.scrollZoom.setWheelZoomRate(1/600);

---

setZoomRate()

setZoomRate(zoomRate: number): void

Defined in: src/ui/handler/scroll_zoom.ts:90

Set the zoom rate of a trackpad

Parameters

Parameter	Type	Description
zoomRate	number	1/100 The rate used to scale trackpad movement to a zoom value.

Returns

void

Example

Speed up trackpad zoom

map.scrollZoom.setZoomRate(1/25);