InterpolateOnScrollPositionChangeHelper

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public class InterpolateOnScrollPositionChangeHelper

Helper class to handle shape interpolation when shaped views enter or exit the window.

Summary

Public constructors
`InterpolateOnScrollPositionChangeHelper( View shapedView, MaterialShapeDrawable materialShapeDrawable, ScrollView containingScrollView )` Instantiate a scroll position helper.

Public methods
`void`	`setContainingScrollView(ScrollView containingScrollView)` Set the ScrollView which contains the View being interpolated.
`void`	`setMaterialShapeDrawable(MaterialShapeDrawable materialShapeDrawable)` Set the `MaterialShapeDrawable` which will be interpolated.
`void`	`startListeningForScrollChanges(ViewTreeObserver viewTreeObserver)` Start listening for scroll changes and interpolating based on position.
`void`	`stopListeningForScrollChanges(ViewTreeObserver viewTreeObserver)` Stop listening for scroll changes and interpolating based on position.
`void`	`updateInterpolationForScreenPosition()` Updates the `MaterialShapeDrawable`'s interpolation based on the View's position in the containing ScrollView.

Public constructors

InterpolateOnScrollPositionChangeHelper

public InterpolateOnScrollPositionChangeHelper(
    View shapedView,
    MaterialShapeDrawable materialShapeDrawable,
    ScrollView containingScrollView
)

Instantiate a scroll position helper.

Parameters
`View shapedView`	the View whose background is a `MaterialShapeDrawable` and which is scrolled in and out of view.
`MaterialShapeDrawable materialShapeDrawable`	the `MaterialShapeDrawable` which will be interpolated.
`ScrollView containingScrollView`	the ScrollView that contains shapedView.

Public methods

setContainingScrollView

public void setContainingScrollView(ScrollView containingScrollView)

Set the ScrollView which contains the View being interpolated.

Parameters
`ScrollView containingScrollView`

setMaterialShapeDrawable

public void setMaterialShapeDrawable(MaterialShapeDrawable materialShapeDrawable)

Set the MaterialShapeDrawable which will be interpolated.

Parameters
`MaterialShapeDrawable materialShapeDrawable`	the desired drawable.

startListeningForScrollChanges

public void startListeningForScrollChanges(ViewTreeObserver viewTreeObserver)

Start listening for scroll changes and interpolating based on position.

Parameters
`ViewTreeObserver viewTreeObserver`	belonging to the { } being interpolated.

stopListeningForScrollChanges

public void stopListeningForScrollChanges(ViewTreeObserver viewTreeObserver)

Stop listening for scroll changes and interpolating based on position.

Parameters
`ViewTreeObserver viewTreeObserver`	belonging to the { } being interpolated.

updateInterpolationForScreenPosition

public void updateInterpolationForScreenPosition()

Updates the MaterialShapeDrawable's interpolation based on the View's position in the containing ScrollView.