internal void HandleItemManipulation(TimeLineItemControl ctrl, TimeLineItemChangedEventArgs e)
{
Boolean doStretch = false;
TimeSpan deltaT = e.DeltaTime;
TimeSpan zeroT = new TimeSpan();
int direction = deltaT.CompareTo(zeroT);
if (direction == 0)
return;//shouldn't happen
TimeLineItemControl previous = null;
TimeLineItemControl after = null;
int afterIndex = -1;
int previousIndex = -1;
after = GetTimeLineItemControlStartingAfter(ctrl.StartTime, ref afterIndex);
previous = GetTimeLineItemControlStartingBefore(ctrl.StartTime, ref previousIndex);
if (after != null)
after.ReadyToDraw = false;
if (ctrl != null)
ctrl.ReadyToDraw = false;
Double useDeltaX = e.DeltaX;
Double cLeft = 0;
Double cWidth = 0;
Double cEnd = 0;
ctrl.GetPlacementInfo(ref cLeft, ref cWidth, ref cEnd);
switch (e.Action)
{
case TimeLineAction.Move:
#region move
Double chainGap = Double.MaxValue;
if (direction > 0)
{
//find chain connecteds that are after this one
//delta each one in that chain that we are pushing
List<TimeLineItemControl> afterChain = GetTimeLineForwardChain(ctrl, afterIndex, ref chainGap);
if (chainGap < useDeltaX)
useDeltaX = chainGap;
foreach (var ti in afterChain)
{
ti.MoveMe(useDeltaX);
}
//find the size of our chain so we bring it into view
var first = afterChain[0];
var last = afterChain[afterChain.Count - 1];
BringChainIntoView(first, last, direction);
}
if (direction < 0)
{
Boolean previousBackToStart = false;
List<TimeLineItemControl> previousChain = GetTimeLineBackwardsChain(ctrl, previousIndex, ref previousBackToStart, ref chainGap);
if (-chainGap > useDeltaX)
{
useDeltaX = chainGap;
}
if (!previousBackToStart)
{
foreach (var ti in previousChain)
{
ti.MoveMe(useDeltaX);
}
}
var first = previousChain[0];//previousChain[previousChain.Count - 1];
var last = previousChain[previousChain.Count - 1];
BringChainIntoView(last, first, direction);
}
#endregion
break;
case TimeLineAction.StretchStart:
switch (e.Mode)
{
#region stretchstart
case TimeLineManipulationMode.Linked:
#region linked
Double gap = Double.MaxValue;
if (previous != null)
{
Double pLeft = 0;
Double pWidth = 0;
Double pEnd = 0;
previous.GetPlacementInfo(ref pLeft, ref pWidth, ref pEnd);
gap = cLeft - pEnd;
}
if (direction < 0 && Math.Abs(gap) < Math.Abs(useDeltaX) && Math.Abs(gap) > _bumpThreshold)//if we are negative and not linked, but about to bump
useDeltaX = -gap;
if (Math.Abs(gap) < _bumpThreshold)
{//we are linked
if (ctrl.CanDelta(0, useDeltaX) && previous.CanDelta(1, useDeltaX))
{
ctrl.MoveStartTime(useDeltaX);
previous.MoveEndTime(useDeltaX);
}
}
else if (ctrl.CanDelta(0, useDeltaX))
{
ctrl.MoveStartTime(useDeltaX);
}
break;
#endregion
case TimeLineManipulationMode.Free:
#region free
gap = Double.MaxValue;
doStretch = direction > 0;
if (direction < 0)
{
//disallow us from free stretching into another item
if (previous != null)
{
Double pLeft = 0;
Double pWidth = 0;
Double pEnd = 0;
previous.GetPlacementInfo(ref pLeft, ref pWidth, ref pEnd);
gap = cLeft - pEnd;
}
else
{
//don't allow us to stretch further than the gap between current and start time
DateTime s = (DateTime)GetValue(StartDateProperty);
gap = cLeft;
}
doStretch = gap > _bumpThreshold;
if (gap < useDeltaX)
{
useDeltaX = gap;
}
}
doStretch &= ctrl.CanDelta(0, useDeltaX);
if (doStretch)
{
ctrl.MoveStartTime(useDeltaX);
}
#endregion
break;
default:
break;
#endregion
}
break;
case TimeLineAction.StretchEnd:
switch (e.Mode)
{
#region stretchend
case TimeLineManipulationMode.Linked:
#region linked
Double gap = Double.MaxValue;
if (after != null)
{
Double aLeft = 0;
Double aWidth = 0;
Double aEnd = 0;
after.GetPlacementInfo(ref aLeft, ref aWidth, ref aEnd);
gap = aLeft - cEnd;
}
if (direction > 0 && gap > _bumpThreshold && gap < useDeltaX)//if we are positive, not linked but about to bump
useDeltaX = -gap;
if (gap < _bumpThreshold)
{//we are linked
if (ctrl.CanDelta(1, useDeltaX) && after.CanDelta(0, useDeltaX))
{
ctrl.MoveEndTime(useDeltaX);
after.MoveStartTime(useDeltaX);
}
}
else if (ctrl.CanDelta(0, useDeltaX))
{
ctrl.MoveEndTime(useDeltaX);
}
break;
#endregion
case TimeLineManipulationMode.Free:
#region free
Double nextGap = Double.MaxValue;
doStretch = true;
if (direction > 0 && after != null)
{
//disallow us from free stretching into another item
Double nLeft = 0;
Double nWidth = 0;
Double nEnd = 0;
after.GetPlacementInfo(ref nLeft, ref nWidth, ref nEnd);
nextGap = nLeft - cEnd;
doStretch = nextGap > _bumpThreshold;
if (nextGap < useDeltaX)
useDeltaX = nextGap;
}
doStretch &= ctrl.CanDelta(1, useDeltaX);
if (doStretch)
{
ctrl.MoveEndTime(useDeltaX);
}
break;
#endregion
default:
break;
#endregion
}
break;
default:
break;
}
}
