// // Tweener.cs // // Author: // Jason Smith // // Copyright (c) 2012 Xamarin Inc. // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. using System; using System.Collections; using System.Collections.Generic; namespace Xamarin.Forms { public class Animation : IEnumerable { readonly List _children; readonly Easing _easing; readonly Action _finished; readonly Action _step; double _beginAt; double _finishAt; bool _finishedTriggered; public Animation() { _children = new List(); _easing = Easing.Linear; _step = f => { }; } public Animation(Action callback, double start = 0.0f, double end = 1.0f, Easing easing = null, Action finished = null) { _children = new List(); _easing = easing ?? Easing.Linear; _finished = finished; Func transform = AnimationExtensions.Interpolate(start, end); _step = f => callback(transform(f)); } public IEnumerator GetEnumerator() { return _children.GetEnumerator(); } public void Add(double beginAt, double finishAt, Animation animation) { if (beginAt < 0 || beginAt > 1) throw new ArgumentOutOfRangeException("beginAt"); if (finishAt < 0 || finishAt > 1) throw new ArgumentOutOfRangeException("finishAt"); if (finishAt <= beginAt) throw new ArgumentException("finishAt must be greater than beginAt"); animation._beginAt = beginAt; animation._finishAt = finishAt; _children.Add(animation); } public void Commit(IAnimatable owner, string name, uint rate = 16, uint length = 250, Easing easing = null, Action finished = null, Func repeat = null) { owner.Animate(name, this, rate, length, easing, finished, repeat); } public Action GetCallback() { Action result = f => { _step(_easing.Ease(f)); foreach (Animation animation in _children) { if (animation._finishedTriggered) continue; double val = Math.Max(0.0f, Math.Min(1.0f, (f - animation._beginAt) / (animation._finishAt - animation._beginAt))); if (val <= 0.0f) // not ready to process yet continue; Action callback = animation.GetCallback(); callback(val); if (val >= 1.0f) { animation._finishedTriggered = true; if (animation._finished != null) animation._finished(); } } }; return result; } internal void ResetChildren() { foreach (var anim in _children) anim._finishedTriggered = false; } public Animation Insert(double beginAt, double finishAt, Animation animation) { Add(beginAt, finishAt, animation); return this; } public Animation WithConcurrent(Animation animation, double beginAt = 0.0f, double finishAt = 1.0f) { animation._beginAt = beginAt; animation._finishAt = finishAt; _children.Add(animation); return this; } public Animation WithConcurrent(Action callback, double start = 0.0f, double end = 1.0f, Easing easing = null, double beginAt = 0.0f, double finishAt = 1.0f) { var child = new Animation(callback, start, end, easing); child._beginAt = beginAt; child._finishAt = finishAt; _children.Add(child); return this; } } }