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1# Single Gesture
2
3
4## TapGesture
5
6
7```ts
8TapGesture(value?:{count?:number; fingers?:number})
9```
10
11
12Triggers a tap gesture with one or more taps. This API has two optional parameters:
13
14
15- **count**: number of consecutive taps required for gesture recognition. The default value is 1. A value less than 1 evaluates to the default value **1**. If multi-tap is configured, the timeout interval between a lift and the next tap is 300 ms.
16
17- **fingers**: number of fingers required for gesture recognition. The value ranges from 1 to 10. The default value is **1**. If the number of fingers used for the tap is less than the specified one within 300 ms after the first finger is tapped, the gesture fails to be recognized. Gesture recognition also fails if the number of fingers used for the tap exceeds the value of **fingers**.
18    The following example binds a double-tap gesture (a tap gesture whose **count** value is **2**) to the **\<Text>** component:
19
20  ```ts
21  // xxx.ets
22  @Entry
23  @Component
24  struct Index {
25    @State value: string = "";
26
27    build() {
28      Column() {
29        Text('Click twice').fontSize(28)
30          .gesture(
31            // Bind a tap gesture whose count value is 2.
32            TapGesture({ count: 2 })
33              .onAction((event: GestureEvent) => {
34                this.value = JSON.stringify(event.fingerList[0]);
35              }))
36        Text(this.value)
37      }
38      .height(200)
39      .width(250)
40      .padding(20)
41      .border({ width: 3 })
42      .margin(30)
43    }
44  }
45  ```
46
47  ![tap](figures/tap.gif)
48
49
50## LongPressGesture
51
52
53```ts
54LongPressGesture(value?:{fingers?:number; repeat?:boolean; duration?:number})
55```
56
57
58Triggers a long press gesture, which requires one or more fingers with a minimum 500 ms hold-down time. This API has three optional parameters:
59
60
61- **fingers**: minimum number of fingers required for gesture recognition. The value ranges from 1 to 10. The default value is **1**.
62
63- **repeat**: whether to continuously trigger the event callback. The default value is **false**.
64
65- **duration**: minimum hold-down time, in ms. The default value is **500**.
66
67
68The following exemplifies how to bind a long press gesture that can be repeatedly triggered to the **\<Text>** component:
69
70
71
72```ts
73// xxx.ets
74@Entry
75@Component
76struct Index {
77  @State count: number = 0;
78
79  build() {
80    Column() {
81      Text('LongPress OnAction:' + this.count).fontSize(28)
82        .gesture(
83          // Bind the long press gesture that can be triggered repeatedly.
84          LongPressGesture({ repeat: true })
85            .onAction((event: GestureEvent) => {
86              if (event.repeat) {
87                this.count++;
88              }
89            })
90            .onActionEnd(() => {
91              this.count = 0;
92            })
93        )
94    }
95    .height(200)
96    .width(250)
97    .padding(20)
98    .border({ width: 3 })
99    .margin(30)
100  }
101}
102```
103
104
105![longPress](figures/longPress.gif)
106
107
108## PanGesture
109
110
111```ts
112PanGestureOptions(value?:{ fingers?:number; direction?:PanDirection; distance?:number})
113```
114
115
116Triggers a pan gesture, which requires the minimum movement distance (5 vp by default) of a finger on the screen. This API has three optional parameters:
117
118
119- **fingers**: minimum number of fingers required for gesture recognition. The value ranges from 1 to 10. The default value is **1**.
120
121- **direction**: pan direction. The enumerated value supports the AND (&amp;) and OR (\|) operations. The default value is **Pandirection.All.**
122
123- **distance**: minimum pan distance required for gesture recognition, in vp. The default value is **5**.
124
125
126The following exemplifies how to bind a pan gesture to the **\<Text>** component. You can pan a component by modifying the layout and position information of the component in the **PanGesture** callback.
127
128
129
130```ts
131// xxx.ets
132@Entry
133@Component
134struct Index {
135  @State offsetX: number = 0;
136  @State offsetY: number = 0;
137  @State positionX: number = 0;
138  @State positionY: number = 0;
139
140  build() {
141    Column() {
142      Text('PanGesture Offset:\nX: ' + this.offsetX + '\n' + 'Y: ' + this.offsetY)
143        .fontSize(28)
144        .height(200)
145        .width(300)
146        .padding(20)
147        .border({ width: 3 })
148          // Bind the layout and position information to the component.
149        .translate({ x: this.offsetX, y: this.offsetY, z: 0 })
150        .gesture(
151          // Bind the pan gesture to the component.
152          PanGesture()
153            .onActionStart((event: GestureEvent) => {
154              console.info('Pan start');
155            })
156              // When the drag gesture is triggered, modify the layout and position information of the component based on the callback.
157            .onActionUpdate((event: GestureEvent) => {
158              this.offsetX = this.positionX + event.offsetX;
159              this.offsetY = this.positionY + event.offsetY;
160            })
161            .onActionEnd(() => {
162              this.positionX = this.offsetX;
163              this.positionY = this.offsetY;
164            })
165        )
166    }
167    .height(200)
168    .width(250)
169  }
170}
171```
172
173
174![pan](figures/pan.gif)
175
176
177>**NOTE**
178>
179>Most slidable components, such as **\<List>**, **\<Grid>**, **\<Scroll>**, and **\<Tab>**, slide through the pan gesture. Therefore, binding the [pan gesture](#pangesture) or [swipe gesture](#swipegesture) to child components will cause gesture competition.
180>
181>When a child component is bound to the pan gesture, sliding in the child component area triggers only the pan gesture of the child component. If the parent component needs to respond, you need to modify the gesture binding method or transfer messages from the child component to the parent component, or modify the **PanGesture** parameter distance of the parent and child components to make the panning more sensitive. When a child component is bound to the swipe gesture, you need to modify the parameters of **PanGesture** and **SwipeGesture** to achieve the required effect because the triggering conditions of **PanGesture** and **SwipeGesture** are different.
182
183
184## PinchGesture
185
186
187```ts
188PinchGesture(value?:{fingers?:number; distance?:number})
189```
190
191
192The pinch gesture is used to trigger a pinch gesture event. A minimum quantity of fingers that trigger the pinch gesture is two fingers, a maximum quantity of fingers that trigger the pinch gesture is five fingers, a minimum recognition distance is 3vp, and there are two optional parameters:
193
194
195- fingers: specifies the minimum number of fingers required to trigger a pinch gesture. This parameter is optional. The minimum value is 2 and the maximum value is 5. The default value is 2.
196
197- distance: specifies the minimum distance for triggering the pinch gesture. This parameter is optional. The unit is vp. The default value is 3.
198
199
200For example, to bind a three-finger pinch gesture to the Column component, you can obtain the zoom ratio from the function callback of the pinch gesture to zoom out or zoom in the component.
201
202
203
204```ts
205// xxx.ets
206@Entry
207@Component
208struct Index {
209  @State scaleValue: number = 1;
210  @State pinchValue: number = 1;
211  @State pinchX: number = 0;
212  @State pinchY: number = 0;
213
214  build() {
215    Column() {
216      Column() {
217        Text('PinchGesture scale:\n' + this.scaleValue)
218        Text('PinchGesture center:\n(' + this.pinchX + ',' + this.pinchY + ')')
219      }
220      .height(200)
221      .width(300)
222      .border({ width: 3 })
223      .margin({ top: 100 })
224      // Bind the zoom ratio to the component. You can change the zoom ratio to zoom out or zoom in the component.
225      .scale({ x: this.scaleValue, y: this.scaleValue, z: 1 })
226      .gesture(
227        // Bind the pinch gesture triggered by three fingers to the widget.
228        PinchGesture({ fingers: 3 })
229          .onActionStart((event: GestureEvent) => {
230            console.info('Pinch start');
231          })
232            // When the pinch gesture is triggered, the callback function can be used to obtain the zoom ratio to change the zoom ratio of the component.
233          .onActionUpdate((event: GestureEvent) => {
234            this.scaleValue = this.pinchValue * event.scale;
235            this.pinchX = event.pinchCenterX;
236            this.pinchY = event.pinchCenterY;
237          })
238          .onActionEnd(() => {
239            this.pinchValue = this.scaleValue;
240            console.info('Pinch end');
241          })
242      )
243    }
244  }
245}
246```
247
248
249![pinch](figures/pinch.png)
250
251
252## RotationGesture
253
254
255```ts
256RotationGesture(value?:{fingers?:number; angle?:number})
257```
258
259
260The rotation gesture is used to trigger a rotation gesture event. A minimum quantity of fingers that trigger the rotation gesture is two fingers, a maximum quantity of fingers that trigger the rotation gesture is five fingers, a minimum change degree is one degree, and there are two optional parameters:
261
262
263- **fingers**: minimum number of fingers required to trigger a rotation gesture. This parameter is optional. The minimum value is 2 and the maximum value is 5. The default value is 2.
264
265- **angle**: minimum change degree for triggering the rotation gesture. This parameter is optional. The unit is deg. The default value is 1.
266
267
268For example, a rotation gesture is bound to a **\<Text>** component to implement rotation of the component. A rotation angle may be obtained from a callback function of the rotation gesture, so as to implement rotation of the component:
269
270
271
272```ts
273// xxx.ets
274@Entry
275@Component
276struct Index {
277  @State angle: number = 0;
278  @State rotateValue: number = 0;
279
280  build() {
281    Column() {
282      Text('RotationGesture angle:' + this.angle).fontSize(28)
283        // Bind the rotation layout to the component. You can change the rotation angle to rotate the component.
284        .rotate({ angle: this.angle })
285        .gesture(
286          RotationGesture()
287            .onActionStart((event: GestureEvent) => {
288              console.info('RotationGesture is onActionStart');
289            })
290              // When the rotation gesture takes effect, the rotation angle is obtained by using the callback function of the rotation gesture, so as to modify the rotation angle of the component.
291            .onActionUpdate((event: GestureEvent) => {
292              this.angle = this.rotateValue + event.angle;
293              console.info('RotationGesture is onActionEnd');
294            })
295              // Angle of the fixed component at the end of the rotation when the rotation ends and the handle is raised
296            .onActionEnd(() => {
297              this.rotateValue = this.angle;
298              console.info('RotationGesture is onActionEnd');
299            })
300            .onActionCancel(() => {
301              console.info('RotationGesture is onActionCancel');
302            })
303        )
304    }
305    .height(200)
306    .width(250)
307  }
308}
309```
310
311
312![rotation](figures/rotation.png)
313
314
315## SwipeGesture
316
317
318```ts
319SwipeGesture(value?:{fingers?:number; direction?:SwipeDirection; speed?:number})
320```
321
322
323Swipe gestures are used to trigger swipe events. A swipe gesture is recognized when the swipe speed is 100 vp/s or higher. There are three optional parameters:
324
325
326- **fingers**: minimum number of fingers required to trigger a swipe gesture. TThe minimum value is 1 and the maximum value is 10. The default value is 1.
327
328- **direction**: swipe direction. The enumerated values support the AND and OR operations. The default value is **SwipeDirection.All**.
329
330- **speed**: minimum speed of the swipe gesture, in vp/s. The default value is **100**.
331
332
333The following describes how to bind a sliding gesture to the Column component to rotate the component:
334
335
336
337```ts
338// xxx.ets
339@Entry
340@Component
341struct Index {
342  @State rotateAngle: number = 0;
343  @State speed: number = 1;
344
345  build() {
346    Column() {
347      Column() {
348        Text("SwipeGesture speed\n" + this.speed)
349        Text("SwipeGesture angle\n" + this.rotateAngle)
350      }
351      .border({ width: 3 })
352      .width(300)
353      .height(200)
354      .margin(100)
355      // Bind rotation to the Column component and change the rotation angle based on the sliding speed and angle of the sliding gesture.
356      .rotate({ angle: this.rotateAngle })
357      .gesture(
358        // Bind the sliding gesture and restrict it to be triggered only when the user slides in the vertical direction.
359        SwipeGesture({ direction: SwipeDirection.Vertical })
360          // When the swipe gesture is triggered, the swipe speed and angle are obtained, which can be used to modify the layout parameters.
361          .onAction((event: GestureEvent) => {
362            this.speed = event.speed;
363            this.rotateAngle = event.angle;
364          })
365      )
366    }
367  }
368}
369```
370
371
372![swipe](figures/swipe.gif)
373
374
375>**NOTE**
376>
377>When SwipeGesture and PanGesture are bound at the same time, competition occurs if they are bound in default mode or mutually exclusive mode. The trigger condition of SwipeGesture is that the sliding speed reaches 100 vp/s. The trigger condition of PanGesture is that the sliding distance reaches 5 vp and the trigger condition is met first. You can modify the parameters of SwipeGesture and PanGesture to achieve different effects.
378