private IDisposable BindFromSource <TModel>(TModel model, Expression <Func <TModel, SelectionData> > propertyExpr, Func <IDisposable> startTransaction)
{
return(model.WhenAnyValue(propertyExpr)
.Buffer(2, 1)
.Where(b => b.Count == 2)
.Select(b =>
{
var previous = b[0].ObjectIds.ToList();
var current = b[1].ObjectIds.ToList();
var sections = Diff.CalculateSections(previous, current);
var alignedElements = Diff
.AlignElements(previous, current, sections,
new BasicInsertDeleteDiffElementAligner <SelectionData.ObjectId>())
.ToList();
var oldObjectIds = alignedElements
.Where(e => e.Operation == DiffOperation.Delete || e.Operation == DiffOperation.Replace)
.Select(e => e.ElementFromCollection1.Value);
var newObjectIds = alignedElements
.Where(e => e.Operation == DiffOperation.Insert || e.Operation == DiffOperation.Replace)
.Select(e => e.ElementFromCollection2.Value);
return new { oldSelectionData = b[0], oldObjectIds, newSelectionData = b[1], newObjectIds };
})
.Subscribe(o =>
{
using (startTransaction())
{
ModelDoc.ClearSelection(o.oldSelectionData.WithObjectIds(o.oldObjectIds));
ModelDoc.AddSelection(o.newSelectionData.WithObjectIds(o.newObjectIds));
}
}));
}