程序包 ohos.agp.components

类 VelocityDetector

java.lang.Object

ohos.agp.components.VelocityDetector

public final class VelocityDetector
extends Object

Helper for detecting the velocity of touch events, for implementing flinging and other similar gestures.

从以下版本开始:

3

嵌套类概要

嵌套类

限定符和类型	类	说明
protected static class	VelocityDetector.VelocityDetectorCleaner	The callback for releasing native Style object.

方法概要

限定符和类型	方法	说明
void	addEvent(TouchEvent event)	Adds a user's movement to the Detector.
void	calculateCurrentVelocity(int units)	Calculates the current velocity based on points that have been collected.
void	calculateCurrentVelocity(int units, float maxVxVelocity, float maxVyVelocity)	Calculates the current velocity based on points that have been collected and specifies upper limits for calculated X and Y velocities.
void	clear()	Resets a VelocityDetector instance to the initial state.
float	getHorizontalVelocity()	Obtains the X velocity calculated most recently.
float[]	getVelocity()	Obtains the velocity calculated most recently.
float	getVerticalVelocity()	Obtains the Y velocity calculated most recently.
static VelocityDetector	obtainInstance()	Obtains a new VelocityDetector instance to detect the velocity of a motion.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

方法详细资料

obtainInstance

public static VelocityDetector obtainInstance()

Obtains a new VelocityDetector instance to detect the velocity of a motion.

返回:

Returns the VelocityDetector instance.

从以下版本开始:

4

clear

public void clear()

Resets a VelocityDetector instance to the initial state.

addEvent

public void addEvent(TouchEvent event)

Adds a user's movement to the Detector.

You can call this method to detect any movement.

参数:

event - Indicates the event that you want to detect, which is a TouchEvent instance.

从以下版本开始:

4

calculateCurrentVelocity

public void calculateCurrentVelocity(int units)

Calculates the current velocity based on points that have been collected.

After the calculation is completed, you can use getHorizontalVelocity() and getVerticalVelocity() to retrieve the velocity result.

参数:

units - Indicates the unit for the velocity result. The value 1 indicates pixels per millisecond, 1000 indicates pixels per second, and so on.

calculateCurrentVelocity

public void calculateCurrentVelocity(int units,
                                     float maxVxVelocity,
                                     float maxVyVelocity)

Calculates the current velocity based on points that have been collected and specifies upper limits for calculated X and Y velocities.

After the calculation is completed, you can use getHorizontalVelocity() and getVerticalVelocity() to retrieve the velocity result.

参数:

units - Indicates the for the velocity result. The value 1 indicates pixels per millisecond, 1000 indicates pixels per second, and so on.

maxVxVelocity - Indicates the maximum X velocity.

maxVyVelocity - Indicates the maximum Y velocity.

getHorizontalVelocity

public float getHorizontalVelocity()

Obtains the X velocity calculated most recently.

You must first call calculateCurrentVelocity(int) before calling this function.

返回:

Returns the most recently calculated X velocity.

从以下版本开始:

4

getVerticalVelocity

public float getVerticalVelocity()

Obtains the Y velocity calculated most recently.

You must call calculateCurrentVelocity(int) before calling this function.

返回:

Returns the most recently calculated Y velocity.

从以下版本开始:

4

getVelocity

public float[] getVelocity()

Obtains the velocity calculated most recently.

Before calling this method, you must call calculateCurrentVelocity(int).

返回:

Returns the most recently calculated velocity.

从以下版本开始:

4