bool DoSingleDrop(object droppedObject, DragEventArgs args)
{
if (UpdateItem(droppedObject))
{
args.Handled = true;
#pragma warning disable 618
DragDropHelper.SetDragDropCompletedEffects(args, DragDropEffects.Move);
#pragma warning restore 618
if (droppedObject is ModelItem && ((ModelItem)droppedObject).View != null)
{
DragDropHelper.SetDragDropMovedViewElements(args, new WorkflowViewElement[] { ((ModelItem)droppedObject).View as WorkflowViewElement });
}
return(true);
}
return(false);
}
protected override void OnDrop(DragEventArgs e)
{
ModelTreeManager manager = this.Context.Services.GetService <ModelTreeManager>();
// When dragging from toolbox:
// editingScope should not be null
// there should only be one item
// When dragging from canvas:
// editingScope should be null
// Call editingScope.Complete() to commit changes, otherwise the editing scope will be aborted
using (EditingScope editingScope = ModelItemHelper.TryCreateImmediateEditingScope(manager, SR.PropertyChangeEditingScopeDescription))
{
List <object> droppedObjects = this.GetSortedObjectList(e);
#pragma warning disable 618
DragDropHelper.SetDragDropCompletedEffects(e, DragDropEffects.None);
#pragma warning restore 618
if (droppedObjects == null || droppedObjects.Count == 0)
{
return;
}
if (droppedObjects.Count == 1)
{
if (this.DoSingleDrop(droppedObjects[0], e))
{
if (editingScope != null)
{
editingScope.Complete();
}
}
return;
}
else
{
// multi drop
Fx.Assert(editingScope == null, "editingScope should be null for dragging from canvas.");
this.DoAutoWrapDrop(InsertionPosition.None, e, droppedObjects);
}
base.OnDrop(e);
}
}
void OnItemsDropped(DragEventArgs e, int index)
{
ModelItemHelper.TryCreateImmediateEditingScopeAndExecute(this.Items.GetEditingContext(), System.Activities.Presentation.SR.CollectionAddEditingScopeDescription, (es) =>
{
DragDropHelper.SetDragDropCompletedEffects(e, DragDropEffects.None);
List <object> droppedObjects = new List <object>(DragDropHelper.GetDroppedObjects(this, e, Context));
List <WorkflowViewElement> movedViewElements = new List <WorkflowViewElement>();
List <object> externalMoveList = new List <object>();
List <ModelItem> internalMoveList = new List <ModelItem>();
// Step 1: Sort the list
List <object> sortedDroppingList = DragDropHelper.SortSelectedObjects(droppedObjects);
// Step 2: Categorize dropped objects by their source container.
foreach (object droppedObject in sortedDroppingList)
{
ModelItem modelItem = droppedObject as ModelItem;
WorkflowViewElement view = (modelItem == null) ? null : (modelItem.View as WorkflowViewElement);
if (view == null)
{
externalMoveList.Add(droppedObject);
continue;
}
UIElement container = DragDropHelper.GetCompositeView(view);
if (container == this)
{
internalMoveList.Add(modelItem);
continue;
}
movedViewElements.Add(view);
externalMoveList.Add(droppedObject);
}
// Step 3: Internal movement
if (this.ShouldMoveItems(internalMoveList, index))
{
foreach (ModelItem modelItem in internalMoveList)
{
int oldIndex = this.Items.IndexOf(modelItem);
this.Items.Remove(modelItem);
//if element is placed ahead of old location, decrement the index not to include moved object
if (oldIndex < index)
{
this.InsertItem(index - 1, modelItem);
}
else
{
this.InsertItem(index, modelItem);
index++;
}
}
}
// Step 4: External move and drop from toolbox
foreach (object droppedObject in externalMoveList)
{
if (!this.IsDropAllowed(droppedObject))
{
continue;
}
this.InsertItem(index++, droppedObject);
DragDropHelper.SetDragDropCompletedEffects(e, DragDropEffects.Move);
}
DragDropHelper.SetDragDropMovedViewElements(e, movedViewElements);
e.Handled = true;
if (es != null)
{
es.Complete();
}
});
}
bool DoAutoWrapDrop(InsertionPosition insertionPos, DragEventArgs e, IList <object> droppedObjects = null)
{
if (droppedObjects == null)
{
ModelTreeManager manager = this.Context.Services.GetRequiredService <ModelTreeManager>();
EditingScope editingScope = null;
try
{
editingScope = ModelItemHelper.TryCreateImmediateEditingScope(manager, SR.WrapInSequenceDescription);
droppedObjects = this.GetSortedObjectList(e);
if (!this.DoAutoWrapDrop(insertionPos, droppedObjects))
{
return(false);
}
if (editingScope != null)
{
editingScope.Complete();
}
}
finally
{
if (editingScope != null)
{
editingScope.Dispose();
editingScope = null;
}
}
}
else
{
if (!this.DoAutoWrapDrop(insertionPos, droppedObjects))
{
return(false);
}
}
if (!DragDropHelper.IsDraggingFromToolbox(e))
{
List <WorkflowViewElement> movedViewElements = ObjectList2WorkflowViewElementList(droppedObjects);
DragDropHelper.SetDragDropMovedViewElements(e, movedViewElements);
//Backward compatibility for 4.0
if (droppedObjects.Count == 1 && movedViewElements.Count == 1)
{
#pragma warning disable 618
DragDropHelper.SetDragDropCompletedEffects(e, DragDropEffects.Move);
#pragma warning restore 618
}
}
else
{
Fx.Assert(droppedObjects.Count == 1, "Dropping from Toolbox with count != 1");
// Set focus if it is dropping from ToolBox.
// In common drag/drop, the selection setting is done at the end of
// StartDragging().
if (this.Item == null)
{
return(true);
}
Fx.Assert(typeof(Sequence).IsAssignableFrom(this.Item.ItemType),
"Auto Wrap didn't add a sequence. Is Item.Properties[\"Activities\"] still correct?");
foreach (ModelItem item in this.Item.Properties["Activities"].Collection)
{
// Find the ModelItem whose value is an activity from Toolbox.
if (item.GetCurrentValue() == droppedObjects[0])
{
this.Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, (Action)(() =>
{
item.Focus();
}));
break;
}
}
}
return(true);
}