StopLogic

Artifact: androidx.constraintlayout:constraintlayout

Added in 2.2.1

Kotlin |Java

class StopLogic : MotionInterpolator

kotlin.Any
↳	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 functions
`Unit`	`config( currentPos: Float, destination: Float, currentVelocity: Float, maxTime: Float, maxAcceleration: Float, maxVelocity: Float )` Configure the stop logic base on the parameters
`String!`	`debug(desc: String!, time: Float)` Debugging logic to log the state.
`Float`	`getInterpolation(v: Float)` Gets the interpolated given the original interpolation
`Float`	`getVelocity()` Gets the velocity at the last interpolated point
`Float`	`getVelocity(x: Float)` Get the velocity at a point in time
`Boolean`	`isStopped()`
`Unit`	`springConfig( currentPos: Float, destination: Float, currentVelocity: Float, mass: Float, stiffness: Float, damping: Float, stopThreshold: Float, boundaryMode: Int )` This configure the stop logic to be a spring.

Inherited functions

From android.animation.TimeInterpolator

abstract Float

getInterpolation(p: Float)

Public constructors

StopLogic

Added in 2.2.1

StopLogic()

Public functions

config

Added in 2.2.1

fun config(
    currentPos: Float,
    destination: Float,
    currentVelocity: Float,
    maxTime: Float,
    maxAcceleration: Float,
    maxVelocity: Float
): Unit

Configure the stop logic base on the parameters

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

debug

Added in 2.2.1

fun debug(desc: String!, time: Float): String!

Debugging logic to log the state.

Parameters
`desc: String!`	Description to pre append
`time: Float`	Time during animation

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

getInterpolation

Added in 2.2.1

fun getInterpolation(v: Float): Float

Gets the interpolated given the original interpolation

Parameters
`v: Float`

Returns
`Float`

getVelocity

Added in 2.2.1

fun getVelocity(): Float

Gets the velocity at the last interpolated point

Returns
`Float`

getVelocity

Added in 2.2.1

fun getVelocity(x: Float): Float

Get the velocity at a point in time

Parameters
`x: Float`

Returns
`Float`

isStopped

Added in 2.2.1

fun isStopped(): Boolean

springConfig

Added in 2.2.1

fun springConfig(
    currentPos: Float,
    destination: Float,
    currentVelocity: Float,
    mass: Float,
    stiffness: Float,
    damping: Float,
    stopThreshold: Float,
    boundaryMode: Int
): Unit

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