private static void _distinct_internal <T>(this IOperationController controller, object key,
Func <T, T, IOperation> generateMergedOperation)
where T : class, IMergeableOperation
{
var operations = controller.Operations.ToList();
var mergeable = operations
.OfType <T>()
.Where(x => x.MergeJudge.GetMergeKey() == key)
.ToArray();
var first = mergeable.FirstOrDefault();
var last = mergeable.LastOrDefault();
if (first is null || last is null)
{
return;
}
var lastIndex = 0;
foreach (var operation in mergeable)
{
lastIndex = operations.IndexOf(operation);
operations.RemoveAt(lastIndex);
}
var newOperation = generateMergedOperation(first, last);
operations.Insert(lastIndex, newOperation);
controller.Flush();
operations.ForEach(x => controller.Push(x));
}
public static IOperation PushTo(this IOperation _this, IOperationController controller)
{
if (_this is IMergeableOperation mergeableOperation)
{
_this = mergeableOperation.Merge(controller);
}
return(controller.Push(_this));
}
public static IOperation ExecuteAndCombineTop(this IOperation _this, IOperationController controller)
{
if (controller.Operations.Any())
{
var prev = controller.Pop();
_this.RollForward();
var newOperation = prev.CombineOperations(_this).ToCompositeOperation();
newOperation.Messaage = _this.Messaage;
return(controller.Push(newOperation));
}
return(controller.Execute(_this));
}
public static IDisposable BindPropertyChanged <T>(this IOperationController controller, INotifyPropertyChanged owner, string propertyName, bool autoMerge = true)
{
var prevValue = FastReflection.GetProperty <T>(owner, propertyName);
var callFromOperation = false;
owner.PropertyChanged += PropertyChanged;
return(new Disposer(() => owner.PropertyChanged -= PropertyChanged));
// local function
void PropertyChanged(object sender, PropertyChangedEventArgs args)
{
if (callFromOperation)
{
return;
}
if (args.PropertyName == propertyName)
{
callFromOperation = true;
T newValue = FastReflection.GetProperty <T>(owner, propertyName);
var operation = owner
.GenerateAutoMergeOperation(propertyName, newValue, prevValue, $"{sender.GetHashCode()}.{propertyName}", Operation.DefaultMergeSpan);
if (autoMerge)
{
operation = operation.Merge(controller);
}
operation
.AddPreEvent(() => callFromOperation = true)
.AddPostEvent(() => callFromOperation = false);
prevValue = newValue;
controller.Push(operation);
callFromOperation = false;
}
}
}