/// <summary>
/// Find Stroke from Guid
/// </summary>
/// The original version was much too slow for the archive replay scenario.
/// <param name="scribble"></param>
/// <param name="guid"></param>
/// <param name="stroke"></param>
/// <param name="guidTag"></param>
/// <returns></returns>
private bool FastFindStrokeFromGuid(InkScribble scribble, Guid guid, out Ink.Stroke stroke, Guid guidTag)
{
Ink.Ink ink = scribble.Ink;
if (this.myGuidReverseTable.Contains(guid))
{
if (((ScribbleIntPair)this.myGuidReverseTable[guid]).scribble == scribble)
{
ScribbleIntPair pair = (ScribbleIntPair)this.myGuidReverseTable[guid];
/// The count can be zero right after a clear slide or clear deck operation
/// if count is zero, CreateStrokes will except.
if (pair.scribble.Count == 0)
{
stroke = null;
return(false);
}
Ink.Strokes targetStrokes = null;
try
{
targetStrokes = ink.CreateStrokes(new int[] { pair.id });
}
catch (Exception e)
{ //not clear when this would happen?
stroke = null;
Trace.WriteLine("FastFindStrokeFromGuid: Exception during CreateStrokes: " + e.ToString());
return(false);
}
if (targetStrokes.Count < 1) //not clear when this would happen?
{
stroke = null;
Trace.WriteLine("FastFindStrokeFromGuid: Found target with zero stroke count.");
return(false);
}
// Found it.
stroke = targetStrokes[0];
return(true);
}
else
{ //This happens when we revisit slides we've been on previously
this.myGuidReverseTable.Remove(guid);
stroke = null;
return(false);
}
}
else
{
stroke = null;
return(false);
}
}
private bool FindStrokeFromGuid(InkScribble scribble, Guid guid, out Ink.Stroke stroke, Guid guidTag)
{
Ink.Ink ink = scribble.Ink;
// Check if the guid tables are out of date. This might be indicated by either:
// * The guid is not in the reverse table.
// * The reverse table entry's scribble does not match the given scribble.
// If the tables are out of date, update the entries for this scribble object.
if (!this.myGuidReverseTable.Contains(guid) ||
((ScribbleIntPair)this.myGuidReverseTable[guid]).scribble != scribble)
{
// Ensure that, at the least, the stale entry is removed.
this.myGuidReverseTable.Remove(guid);
// Refresh entries for all strokes in this scribble.
foreach (Ink.Stroke s in ink.Strokes)
{
try
{
if (s.ExtendedProperties.DoesPropertyExist(guidTag))
{
Guid strokeGuid = new Guid((string)s.ExtendedProperties[guidTag].Data);
this.myGuidReverseTable[strokeGuid] = new ScribbleIntPair(scribble, s.Id);
this.myGuidTable[new ScribbleIntPair(scribble, s.Id)] = strokeGuid;
}
}
catch
{
//this try/catch because I once saw an exception thrown here. Not sure if it was a bug
// in the data, the TPC SDK, or in my code.. Anyway it seemed safe to ignore.
}
}
}
// If the guid is still not in the table, it is not found.
if (!this.myGuidReverseTable.Contains(guid))
{
stroke = null;
return(false);
}
// Can we find the specific id sought?
ScribbleIntPair pair = (ScribbleIntPair)this.myGuidReverseTable[guid];
//This try/catch is a hack to deal with multiple-play (archive) scenario.
//I believe the real fix is to catch WMP stop and postion change events and
//to rebuild guid tables and InkScribble appropriately for the new media position.
Ink.Strokes targetStrokes = null;
try
{
targetStrokes = ink.CreateStrokes(new int[] { pair.id });
}
catch
{
stroke = null;
return(false);
}
if (targetStrokes.Count < 1)
{
stroke = null;
return(false);
}
// Found it.
stroke = targetStrokes[0];
return(true);
}
