/// <summary>
/// Updates the CC Packet State Buffer and Renders it.
/// </summary>
/// <param name="channel">The channel.</param>
/// <param name="clockPosition">The clock position.</param>
public void Render(CaptionsChannel channel, TimeSpan clockPosition)
{
if (Buffer.UpdateState(channel, clockPosition))
{
PaintBuffer();
}
}
/// <summary>
/// Updates the state using the packets that were demuxed into the specified channel.
/// This can be called outside the GUI thread.
/// </summary>
/// <param name="channel">The channel.</param>
/// <param name="clockPosition">The clock position.</param>
/// <returns>A boolean to determine if the display needs repainting.</returns>
public bool UpdateState(CaptionsChannel channel, TimeSpan clockPosition)
{
lock (SyncLock)
{
var needsRepaint = false;
// Reset the buffer state if the channels don't match or if we have a timeout
if (channel != Channel || DateTime.UtcNow.Subtract(LastReceiveTime).TotalSeconds > TimeoutSeconds)
{
Reset();
Channel = channel;
needsRepaint = true;
}
if (channel == CaptionsChannel.CCP)
{
return(needsRepaint);
}
// Dequeue packets for all channels but only process the current channel packets
List <ClosedCaptionPacket> packets = null;
for (var c = 1; c <= 4; c++)
{
var currentChannel = (CaptionsChannel)c;
var dequeuedPackets = DequeuePackets(ChannelPacketBuffer[currentChannel], clockPosition.Ticks);
if (currentChannel == Channel)
{
packets = dequeuedPackets;
}
}
// Check if we have at least 1 dequeued packet
if (packets == null || packets.Count <= 0)
{
return(needsRepaint);
}
// Update the last received time
LastReceiveTime = DateTime.UtcNow;
// Start processing the dequeued packets for the given channel
foreach (var packet in packets)
{
// Skip duplicated control codes
if (CurrentPacket != null && CurrentPacket.IsRepeatedControlCode(packet))
{
CurrentPacket = packet;
continue;
}
// Update the current packet (we need this to detect duplicated control codes)
CurrentPacket = packet;
// Now, go ahead and process the packet updating the state
switch (packet.PacketType)
{
case CaptionsPacketType.Color:
{
if (StateMode == ParserStateMode.Buffered || StateMode == ParserStateMode.Scrolling)
{
if (packet.Color == CaptionsColor.ForegroundBlackUnderline)
{
IsUnderlined = true;
}
if (packet.Color == CaptionsColor.WhiteItalics)
{
IsItalics = true;
}
}
break;
}
case CaptionsPacketType.MidRow:
{
if (StateMode == ParserStateMode.Buffered || StateMode == ParserStateMode.Scrolling)
{
IsItalics = packet.IsItalics;
IsUnderlined = packet.IsUnderlined;
}
break;
}
case CaptionsPacketType.Command:
{
if (ProcessCommandPacket(packet))
{
needsRepaint = true;
}
break;
}
case CaptionsPacketType.Preamble:
{
ProcessPreamblePacket(packet);
break;
}
case CaptionsPacketType.Tabs:
{
if (StateMode == ParserStateMode.Scrolling || StateMode == ParserStateMode.Buffered)
{
CursorColumnIndex += packet.Tabs;
}
break;
}
case CaptionsPacketType.Text:
{
if (ProcessTextPacket(packet))
{
needsRepaint = true;
}
break;
}
case CaptionsPacketType.XdsClass:
{
// Change state back and forth
StateMode = packet.XdsClass == CaptionsXdsClass.EndAll ?
ParserStateMode.None : ParserStateMode.XDS;
break;
}
case CaptionsPacketType.PrivateCharset:
case CaptionsPacketType.Unrecognized:
case CaptionsPacketType.NullPad:
default:
{
break;
}
}
}
return(needsRepaint);
}
}
