private void DoAfterListShuffle()
{
if (myPositionManager != null)
{
try
{
if (ListShuffleEnding != null)
{
// Fill in the current positions for each position tracker
// by asking the associated lists where the object is now.
if (myPositionHead != null)
{
NODEPOSITIONTRACKER.UpdateEndPositions(myPositionHead);
}
// Now that all of the PositionTracker structures are up
// to date, notify the listeners to update their selections.
ListShuffleEnding(this, myPositionManager);
}
}
finally
{
NODEPOSITIONTRACKER.DetachAll(ref myPositionHead);
myPositionManager = null;
}
}
}
private void ListShuffleEnding(object sender, PositionManagerEventArgs manager)
{
var lbstate = myShuffleTracker;
myShuffleTracker = null;
if (lbstate != null)
{
var cache = manager.RetrievePositions(this, myMctree != null);
if (cache != null)
{
lbstate.Inner.ApplyPositionTrackerData(cache);
lbstate.Inner.Restore(this);
}
}
}
private void DoBeforeListShuffle()
{
DelayTurnOffRedraw();
// Begin shuffling list by retrieving PositionTracker arrays from
// all of our listeners (if any).
Debug.Assert(myPositionManager == null); // Should be long gone at this point
// Check after as well, Before is useless without an After listener
if (ListShuffleBeginning != null
&& ListShuffleEnding != null)
{
var positionManager = new PositionManagerEventArgs(this);
NODEPOSITIONTRACKER ntHead = null;
NODEPOSITIONTRACKER ntLast = null;
TREENODE tnParent;
int relativeRow;
int relativeColumn;
try
{
ListShuffleBeginning(this, positionManager);
foreach (PositionTracker[] trackerSet in positionManager)
{
var upper = trackerSet.GetUpperBound(0);
for (var i = trackerSet.GetLowerBound(0); i <= upper; ++i)
{
if (TrackPosition(ref trackerSet[i], out tnParent, out relativeRow, out relativeColumn))
{
if (ntHead != null)
{
if (NODEPOSITIONTRACKER.Add(tnParent, trackerSet, i, relativeRow, relativeColumn, ref ntLast))
{
continue;
}
}
else if (NODEPOSITIONTRACKER.Add(tnParent, trackerSet, i, relativeRow, relativeColumn, ref ntHead))
{
ntLast = ntHead;
continue;
}
}
ClearPositionTracker(ref trackerSet[i]);
}
}
}
catch
{
// Errors from the branches are caught during add, so this is a
// failure on our side. Make sure that all position tracking information
// is fully detached from the TREENODE objects before continuing.
if (ntHead != null)
{
NODEPOSITIONTRACKER.DetachAll(ref ntHead);
}
throw;
}
finally
{
// We made it all the way, go ahead and record the results
// with this object. Note that we record our results even if
// the position head is null so that the user gets a ListShuffleEnding
// event if nothing was tracked successfully. This lets the listener
// reduce the set of operations they do during other insert and delete
// notifications while a position manager is active.
myPositionManager = positionManager;
myPositionHead = ntHead;
}
}
}
private void ListShuffleBeginning(object sender, PositionManagerEventArgs manager)
{
myShuffleTracker = new ListBoxStateTrackerClass(this);
var cache = myShuffleTracker.Inner.GetPositionTrackers();
if (cache != null)
{
manager.StorePositions(cache, this, myMctree != null);
}
}