StopLogic

Artifact: androidx.constraintlayout:constraintlayout

Added in 2.2.0

Kotlin |Java

public class StopLogic extends MotionInterpolator

java.lang.Object
↳	androidx.constraintlayout.motion.widget.MotionInterpolator
	↳	androidx.constraintlayout.motion.utils.StopLogic

This contains the class to provide the logic for an animation to come to a stop. The setup defines a series of velocity gradients that gets to the desired position ending at 0 velocity. The path is computed such that the velocities are continuous

Summary

Public constructors
`StopLogic()`

Public methods
`void`	`config( float currentPos, float destination, float currentVelocity, float maxTime, float maxAcceleration, float maxVelocity )` Configure the stop logic base on the parameters
`String`	`debug(String desc, float time)` Debugging logic to log the state.
`float`	`getInterpolation(float v)` Gets the interpolated given the original interpolation
`float`	`getVelocity()` Gets the velocity at the last interpolated point
`float`	`getVelocity(float x)` Get the velocity at a point in time
`boolean`	`isStopped()`
`void`	`springConfig( float currentPos, float destination, float currentVelocity, float mass, float stiffness, float damping, float stopThreshold, int boundaryMode )` This configure the stop logic to be a spring.

Inherited methods

From android.animation.TimeInterpolator

abstract float

getInterpolation(float p)

Public constructors

StopLogic

Added in 2.2.0

public StopLogic()

Public methods

config

Added in 2.2.0

public void config(
    float currentPos,
    float destination,
    float currentVelocity,
    float maxTime,
    float maxAcceleration,
    float maxVelocity
)

Configure the stop logic base on the parameters

Parameters
`float currentPos`	start position
`float destination`	the ending position
`float currentVelocity`	the starting velocity
`float maxTime`	The maximum time to take
`float maxAcceleration`	the maximum acceleration to use
`float maxVelocity`	the maximum velocity to use

debug

Added in 2.2.0

public String debug(String desc, float time)

Debugging logic to log the state.

Parameters
`String desc`	Description to pre append
`float time`	Time during animation

Returns
`String`	string useful for debugging the state of the StopLogic

getInterpolation

Added in 2.2.0

public float getInterpolation(float v)

Gets the interpolated given the original interpolation

Parameters
`float v`

Returns
`float`

getVelocity

Added in 2.2.0

public float getVelocity()

Gets the velocity at the last interpolated point

Returns
`float`

getVelocity

Added in 2.2.0

public float getVelocity(float x)

Get the velocity at a point in time

Parameters
`float x`

Returns
`float`

isStopped

Added in 2.2.0

public boolean isStopped()

springConfig

Added in 2.2.0

public void springConfig(
    float currentPos,
    float destination,
    float currentVelocity,
    float mass,
    float stiffness,
    float damping,
    float stopThreshold,
    int boundaryMode
)

This configure the stop logic to be a spring. Moving from currentPosition(P0) to destination with an initial velocity of currentVelocity (V0) moving as if it has a mass (m) with spring constant stiffness(k), and friction(c) It moves with the equation acceleration a = (-k.x-c.v)/m. x = current position - destination v is velocity

Parameters
`float currentPos`	The current position
`float destination`	The destination position
`float currentVelocity`	the initial velocity
`float mass`	the mass
`float stiffness`	the stiffness or spring constant (the force by which the spring pulls)
`float damping`	the stiffness or spring constant. (the resistance to the motion)
`float stopThreshold`	(When the max velocity of the movement is below this it stops)
`int boundaryMode`	This controls if it overshoots or bounces when it hits 0 and 1