effectsBuilder property

EffectsBuilder effectsBuilder
final

This method is responsible for animating the children based on the current scroll position.

It is called once per visible child each time the scroll updates, and is passed the following arguments:

  • index: the index of the child in the children list
  • scrollRatio: the child's scroll position relative to the "center" of the scroll. This is a range between -1 and 1, where:
    • -1 indicates the furthest extent in the "before" direction
    • 0 indicates the center; the neutral resting point for the selected item
    • +1 indicates the furthest extent in the "after" direction
  • child: the child widget

The method should return a widget that wraps the child, and applies the desired effects based on scrollRatio.

Note that scrollRatio may exceed -1 to 1, if the user overscrolls.

See the "Cover Slider" and "Circular Menu" demos in /example/lib/views/ for examples.

Implementation

final EffectsBuilder effectsBuilder;