PageController constructor

PageController({int initialPage: 0, bool keepPage: true, double viewportFraction: 1.0 })

Creates a page controller.

The initialPage, keepPage, and viewportFraction arguments must not be null.

Implementation 

PageController({
  this.initialPage = 0,
  this.keepPage = true,
  this.viewportFraction = 1.0,
}) : assert(initialPage != null),
     assert(keepPage != null),
     assert(viewportFraction != null),
     assert(viewportFraction > 0.0);