public override void OnDragOver(DragEventArgs e)
{
base.OnDragOver(e);
try
{
e.Effects = DragDropEffects.None;
StructureViewDragDropHandler.HittestResult hittestResult = this.Hittest(e.GetPosition((IInputElement)this.StructureView));
ModifierKeys modifiers = Keyboard.Modifiers;
if (this.lastModifierKeys != modifiers || this.lastAllowedEffects != e.AllowedEffects || !object.Equals((object)this.hittestResult, (object)hittestResult))
{
this.lastModifierKeys = modifiers;
this.lastAllowedEffects = e.AllowedEffects;
this.hittestResult = hittestResult;
e.Effects = this.ComputeDropEffects(e);
}
else
{
if (this.DragDropContext == null)
{
return;
}
e.Effects = this.DragDropContext.Descriptor.ResultEffects;
}
}
finally
{
this.UpdateFeedback(true, e);
e.Handled = true;
}
}
private StructureViewDragDropHandler.HittestResult Hittest(Point position)
{
StructureViewDragDropHandler.HittestResult hittestResult = new StructureViewDragDropHandler.HittestResult();
if (this.StructureView.TimelineItemManager != null)
{
double indentMultiplier = this.StructureView.IndentMultiplier;
int num = (int)Math.Floor((position.X - indentMultiplier) / this.StructureView.IndentMultiplier);
IList <TimelineItem> list = (IList <TimelineItem>) this.StructureView.TimelineItemManager.ItemList;
if (list != null)
{
for (int index = list.Count - 1; index >= 0; --index)
{
TimelineItem timelineItem = list[index];
if (timelineItem != null && timelineItem.Depth <= num)
{
ElementTimelineItem elementTimelineItem = timelineItem as ElementTimelineItem;
bool flag = elementTimelineItem != null && elementTimelineItem.Element.IsContainer;
hittestResult.allowDropInside = flag || timelineItem.Depth <= num - 1;
hittestResult.candidateItem = timelineItem;
break;
}
}
}
}
return(hittestResult);
}
public override void OnDrop(DragEventArgs e)
{
try
{
e.Effects = DragDropEffects.None;
this.UpdateFeedback(false, (DragEventArgs)null);
if (this.TargetItem != null)
{
if (this.DragDropContext != null)
{
IDropAction instance = DropActionFactory.CreateInstance(this.DragDropContext);
if (instance != null)
{
e.Effects = instance.HandleDrop(this.DragDropContext.Descriptor.ResultEffects);
}
}
}
}
finally
{
this.hittestResult = (StructureViewDragDropHandler.HittestResult)null;
e.Handled = true;
}
base.OnDrop(e);
}
public override void OnDragLeave(DragEventArgs e)
{
this.hittestResult = (StructureViewDragDropHandler.HittestResult)null;
this.UpdateFeedback(false, (DragEventArgs)null);
e.Handled = true;
base.OnDragLeave(e);
}
public override bool Equals(object obj)
{
StructureViewDragDropHandler.HittestResult hittestResult = obj as StructureViewDragDropHandler.HittestResult;
if (hittestResult != null && hittestResult.candidateItem == this.candidateItem)
{
return(hittestResult.allowDropInside == this.allowDropInside);
}
return(false);
}
public override void OnDragEnter(DragEventArgs e)
{
base.OnDragEnter(e);
try
{
e.Effects = DragDropEffects.None;
this.lastModifierKeys = Keyboard.Modifiers;
this.lastAllowedEffects = e.AllowedEffects;
this.hittestResult = this.Hittest(e.GetPosition((IInputElement)this.StructureView));
e.Effects = this.ComputeDropEffects(e);
}
finally
{
this.UpdateFeedback(true, e);
e.Handled = true;
}
}