Helper method for updating constraints on a ConstraintLayout with Transitions.

UpdateConstraints.kt

import androidx.constraintlayout.widget.ConstraintLayout
import androidx.constraintlayout.widget.ConstraintSet
import androidx.transition.Transition
import androidx.transition.TransitionManager

/**
 * Runs the given `updateBlock` on the current `ConstraintSet` and applies them back to the
 * [ConstraintLayout].
 *
 * @param animated Whether or not to run [TransitionManager.beginDelayedTransition] on the next
 *                 frame.
 * @param transition The transition to use if `animated` is `true`. Falls back to
 *                   [TransitionManager]'s default [Transition] if null.
 * @param updateBlock The block used to updated the [ConstraintLayout]'s current [ConstraintSet].
 * @return The updated [ConstraintSet]
 */
fun ConstraintLayout.updateConstraints(
    animated: Boolean = true,
    transition: Transition? = null,
    updateBlock: ConstraintSet.() -> Unit
): ConstraintSet {
    // Queue up a transition on the next frame if an animation is requested.
    if (animated) {
        // TransitionManager will fallback to the default Transition if the given one is null
        TransitionManager.beginDelayedTransition(this, transition)
    }

    // Copy the current constraints
    val constraintSet = ConstraintSet().apply { clone(this@updateConstraints) }

    // Execute the update block
    updateBlock(constraintSet)

    // Apply the updated constraints
    constraintSet.applyTo(this)

    return constraintSet
}