/// <summary>
/// Checks for markers whose position has been reached or left.
/// </summary>
public void CheckMarkerPositions(TimeSpan mediaPosition, MediaMarkerCollection <TMediaMarker> markers, bool seeking = false, bool ignoreSearchWindow = false)
{
lock (_syncObject)
{
// clean up any previously active markers that are no longer in the markers list
PreviouslyActiveMarkers.ToList()
.Where(i => !markers.Contains(i))
.ForEach(OnMarkerLeft)
.ForEach(i => PreviouslyActiveMarkers.Remove(i));
//Safeguard against large unusual position changes
if (!seeking && PreviousPosition.HasValue)
{
var rangeStart = PreviousPosition.Value < mediaPosition ? PreviousPosition.Value : mediaPosition;
var rangeEnd = PreviousPosition.Value > mediaPosition ? PreviousPosition.Value : mediaPosition;
seeking = rangeEnd.Subtract(rangeStart) > LargestNormalStepSize;
}
IList <TMediaMarker> activeMarkers;
var searchAfter = SeekingSearchWindow.HasValue && !ignoreSearchWindow
? mediaPosition.Subtract(SeekingSearchWindow.Value)
: (TimeSpan?)null;
if (!seeking && PreviousPosition.HasValue)
{
var rangeStart = PreviousPosition.Value < mediaPosition ? PreviousPosition.Value : mediaPosition;
var rangeEnd = PreviousPosition.Value > mediaPosition ? PreviousPosition.Value : mediaPosition;
activeMarkers = markers.WhereActiveInRange(rangeStart, rangeEnd, searchAfter).ToList();
}
else
{
activeMarkers = markers.WhereActiveAtPosition(mediaPosition, searchAfter).ToList();
}
PreviouslyActiveMarkers.Where(i => !i.IsActiveAtPosition(mediaPosition))
.ForEach(OnMarkerLeft)
.ForEach(i => activeMarkers.Remove(i));
activeMarkers.Where(i => !PreviousPosition.HasValue || !PreviouslyActiveMarkers.Contains(i))
.ForEach(i => OnMarkerReached(i, seeking));
PreviouslyActiveMarkers = PreviouslyActiveMarkers.Where(i => i.IsActiveAtPosition(mediaPosition) && !activeMarkers.Contains(i))
.Concat(activeMarkers)
.ToList();
PreviousPosition = mediaPosition;
}
}
public void CheckMarkerPosition(TimeSpan mediaPosition, TMediaMarker marker, bool seeking = false)
{
lock (_syncObject)
{
bool isActive = false;
if (!seeking && PreviousPosition.HasValue)
{
var rangeStart = PreviousPosition.Value < mediaPosition ? PreviousPosition.Value : mediaPosition;
var rangeEnd = PreviousPosition.Value > mediaPosition ? PreviousPosition.Value : mediaPosition;
isActive = marker.IsActiveInRange(rangeStart, rangeEnd);
}
else
{
isActive = marker.IsActiveAtPosition(mediaPosition);
}
if (isActive && (!PreviousPosition.HasValue || !PreviouslyActiveMarkers.Contains(marker)))
{
OnMarkerReached(marker, seeking);
PreviouslyActiveMarkers.Add(marker);
}
}
}