PinchGesture
NOTE This gesture is supported since API version 7. Updates will be marked with a superscript to indicate their earliest API version.
Required Permissions
None
APIs
PinchGesture(options?: { fingers?: number, distance?: number })
- Parameters
| Name | Type | Mandatory | Default Value | Description |
|---|---|---|---|---|
| fingers | number | No | 2 | Minimum number of fingers to trigger a pinch. The value ranges from 2 to 5. |
| distance | number | No | 3.0 | Minimum recognition distance, in vp. |
Events
| Name | Description |
|---|---|
| onActionStart((event?: GestureEvent) => void) | Callback invoked when a pinch gesture is recognized. |
| onActionUpdate((event?: GestureEvent) => void) | Callback invoked during the movement of a pinch gesture. |
| onActionEnd((event?: GestureEvent) => void) | Callback invoked when the finger used for a pinch gesture is lift. |
| onActionCancel(event: () => void) | Callback invoked when a tap cancellation event is received after a pinch gesture is recognized. |
- GestureEvent attributes related to the pinch gesture
| Name | Type | Description |
|---|---|---|
| scale | number | Scale ratio. This attribute is used for the pinch gesture. |
| pinchCenterX | number | X-coordinate of the center of the pinch gesture, in px. |
| pinchCenterY | number | Y-coordinate of the center of the pinch gesture, in px. |
Example
@Entry
@Component
struct PinchGestureExample {
@State scale: number = 1
build() {
Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.SpaceBetween }) {
Text('PinchGesture scale:' + this.scale)
}
.height(100).width(200).padding(20).border({ width: 1 }).margin(80)
.scale({ x: this.scale, y: this.scale, z: this.scale })
.gesture(
PinchGesture()
.onActionStart((event: GestureEvent) => {
console.info('Pinch start')
})
.onActionUpdate((event: GestureEvent) => {
this.scale = event.scale
})
.onActionEnd(() => {
console.info('Pinch end')
})
)
}
}
