public static PlayRange Adjust(this IMediaSource mediaSource, PlayRange playRange)
{
if (!mediaSource.HasNativeDuration())
{
playRange = new PlayRange(playRange.Duration);
}
mediaSource.ValidatePlayRange(playRange);
return(playRange);
}
private static bool IsValidPlayRange(this IMediaSource mediaSource, PlayRange playRange)
{
if (mediaSource.HasNativeDuration())
{
return(mediaSource.GetNativePlayRange().Include(playRange));
}
else
{
return(playRange.StartPosition == TimeSpan.Zero);
}
}
internal PlayRange Adjust(PlayRange range)
{
range = this.MediaSource.Adjust(range);
if (!this.PlayRange.Include(range))
{
throw new ArgumentOutOfRangeException("range",
string.Format("<{0}>无效，有效范围为{1}。", range, this.PlayRange));
}
return(range);
}
internal static PlayRange Adjust(this IPlaySource playSource, PlayRange playRange)
{
var range = playSource.MediaSource.Adjust(playRange);
if (!playSource.PlayRange.Include(range))
{
throw new ArgumentOutOfRangeException("playRange",
string.Format("<{0}>无效，有效范围为{1}。", playRange, playSource.PlayRange));
}
return(range);
}
internal NormalPlaySource(IMediaSource mediaSource, PlayRange range)
{
if (mediaSource == null)
{
throw new ArgumentNullException("mediaSource");
}
range = mediaSource.Adjust(range);
this.MediaSource = mediaSource;
this.PlayRange = range;
}
internal PlaySource Merge(PlaySource nextSource)
{
if (!CanMerge(nextSource))
{
throw new InvalidOperationException();
}
PlayRange range = this.MediaSource.Merge(this.PlayRange, ((PlaySourceSegment)nextSource).PlayRange);
range = this.PlaySource.Adjust(range); // 确保范围不超出this.PlaySource.PlayRange
return(Create(this.PlaySource, range));
}
internal static void Break(this PlaySource playSource, TimeSpan duration, out PlayRange first, out PlayRange second)
{
if (duration <= TimeSpan.Zero)
{
throw new ArgumentOutOfRangeException("duration",
string.Format("<{0}>无效，必须大于TimeSpan.Zero。", duration));
}
if (duration >= playSource.PlayRange.Duration)
{
throw new ArgumentOutOfRangeException("duration",
string.Format("<{0}>无效，必须小于{1}。", duration, playSource.PlayRange.Duration));
}
PlayRange.Break(playSource.PlayRange, duration, out first, out second);
first = playSource.Adjust(first);
second = playSource.Adjust(second);
}
public static PlaySource Create(NormalPlaySource playSource, PlayRange playRange)
{
// Note: 是否在自动垫片上操作？
if (playSource == null)
{
throw new ArgumentNullException("playSource");
}
playRange = playSource.Adjust(playRange);
if (playRange == playSource.PlayRange)
{
return(playSource);
}
return(new PlaySourceSegment(playSource, playRange));
}
private static void ValidatePlayRange(this IMediaSource mediaSource, PlayRange playRange)
{
if (!mediaSource.IsValidPlayRange(playRange))
{
if (mediaSource.HasNativeDuration())
{
throw new ArgumentException(
string.Format("{0}无效，有效范围为：{1}。", playRange, mediaSource.GetNativePlayRange()),
"playRange");
}
else
{
throw new ArgumentException(
string.Format("{0}无效，起始位置必须为TimeSpan.Zero。", playRange),
"playRange");
}
}
}
internal static PlayRange Merge(this IMediaSource mediaSource, PlayRange first, PlayRange second)
{
if (!mediaSource.CanMerge(first, second))
{
throw new InvalidOperationException();
}
first = mediaSource.Adjust(first);
second = mediaSource.Adjust(second);
if (mediaSource.HasNativeDuration())
{
return(PlayRange.Merge(first, second));
}
else
{
return(new PlayRange(first.Duration + second.Duration));
}
}
//public TimeSpan? NativeDuration
//{
// get
// {
// return this.MediaSource.NativeDuration;
// }
//}
public MarkableMediaSource(IMediaSource mediaSource, PlayRange playRange)
{
if (mediaSource == null)
{
throw new ArgumentNullException("mediaSource");
}
var adjustedPlayRange = mediaSource.Adjust(playRange); // 包含对playRange有效性的验证
//MarkableMediaSource markable = mediaSource as MarkableMediaSource;
//if (markable!=null)
//{
// this.MediaSource = markable.MediaSource;
//}
//else
//{
// this.MediaSource = mediaSource;
//}
this.MediaSource = mediaSource;
this.PlayRange = adjustedPlayRange;
}
private PlaySourceSegment(NormalPlaySource playSource, PlayRange playRange)
{
this.PlayRange = playRange;
this.PlaySource = playSource;
}
internal static bool CanMerge(this IMediaSource mediaSource, PlayRange first, PlayRange second)
{
return(mediaSource.HasNativeDuration() ?
PlayRange.IsUnbroken(mediaSource.Adjust(first), mediaSource.Adjust(second)) : true);
}