maui-linux/Xamarin.Forms.Core/Tweener.cs

125 строки
2.6 KiB
C#

//
// Tweener.cs
//
// Author:
// Jason Smith <jason.smith@xamarin.com>
//
// 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 Xamarin.Forms.Internals;
namespace Xamarin.Forms
{
internal class Tweener
{
long _lastMilliseconds;
int _timer;
public Tweener(uint length)
{
Value = 0.0f;
Length = length;
Loop = false;
}
public AnimatableKey Handle { get; set; }
public uint Length { get; }
public bool Loop { get; set; }
public double Value { get; private set; }
public event EventHandler Finished;
public void Pause()
{
if (_timer != 0)
{
Ticker.Default.Remove(_timer);
_timer = 0;
}
}
public void Start()
{
Pause();
_lastMilliseconds = 0;
_timer = Ticker.Default.Insert(step =>
{
long ms = step + _lastMilliseconds;
Value = Math.Min(1.0f, ms / (double)Length);
_lastMilliseconds = ms;
if (ValueUpdated != null)
ValueUpdated(this, EventArgs.Empty);
if (Value >= 1.0f)
{
if (Loop)
{
_lastMilliseconds = 0;
Value = 0.0f;
return true;
}
if (Finished != null)
Finished(this, EventArgs.Empty);
Value = 0.0f;
_timer = 0;
return false;
}
return true;
});
}
public void Stop()
{
Pause();
Value = 1.0f;
if (Finished != null)
Finished(this, EventArgs.Empty);
Value = 0.0f;
}
public event EventHandler ValueUpdated;
~Tweener()
{
if (_timer != 0)
{
try
{
Ticker.Default.Remove(_timer);
}
catch (InvalidOperationException)
{
}
}
_timer = 0;
}
}
}