// Copyright 2015 The Chromium Authors. All rights reserved.// Use of this source code is governed by a BSD-style license that can be// found in the LICENSE file.import'package:flutter/animation.dart';import'package:flutter/painting.dart';/// An interpolation between two fractional offsets.////// This class specializes the interpolation of Tween<FractionalOffset> to be/// appropriate for rectangles.classFractionalOffsetTweenextendsTween<FractionalOffset>{/// Creates a fractional offset tween.////// The [begin] and [end] arguments must not be null.FractionalOffsetTween({FractionalOffsetbegin,FractionalOffsetend}):super(begin:begin,end:end);@overrideFractionalOffsetlerp(doublet)=>FractionalOffset.lerp(begin,end,t);}