public async Task NotifyStateChanged(ListUpdateEventArgs e = null)
{
var overrideDebug = false;
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine("Notifying state has changed");
}
if (DnDState.BaseContainer != null)
{
DnDState.BaseContainer.StateHasChanged();
if (DnDState.BaseContainer.OnStatusUpdated.HasDelegate && e != null)
{
await DnDState.BaseContainer.OnStatusUpdated.InvokeAsync(e);
}
}
else
{
StateHasChanged();
if (OnStatusUpdated.HasDelegate && e != null)
{
await OnStatusUpdated.InvokeAsync(e);
}
}
}
protected async Task HandleMove(DragEventArgs e, int index, bool isDropOnExisting = false, bool dropIntoFirst = false)
{
var overrideDebug = false;
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine($"Handling Move (Drop)");
}
DnDState.ShowDropAtEnd = false;
if (DnDState.BaseContainer is null)
{
Console.Error.WriteLine("Could not retrieve the Base Container information."); return;
}
index = Math.Max(0, Math.Min(index, List.Count()));
var pl = DnDState.Payload;
if (string.IsNullOrWhiteSpace(pl.Address))
{
// Drop not allowed when there is no payload (the address is empty)
Console.Error.WriteLine("Could not retrieve the payload information.");
return;
}
else if (Address.StartsWith(pl.Address) && pl.IsContainer)
{
// when the payload is a DnDContainer and it is being dropped as a descendant of itself
Console.WriteLine("A container cannot be dropped as a child of itself.");
return;
}
if (pl.FromContainer is null || pl.FromIndex < 0)
{
Console.Error.WriteLine("No item to drop"); return;
}
if (pl.FromIndex >= pl.FromContainer.List.Count())
{
Console.Error.WriteLine("Index of the item being dragged was out of range"); return;
}
var itemToMove = pl.FromContainer.List[pl.FromIndex];
// If dropping on empty, index out of range possibly
var myItemAtIndex = List.Count() > 0 && index < List.Count() ? List[index] : default(TListItem);
var childProp = string.IsNullOrWhiteSpace(DnDState.ChildrenPropertyName) ? null : myItemAtIndex?.GetType().GetProperty(DnDState.ChildrenPropertyName);
if (pl.FromContainer == this && pl.FromIndex == index)
{
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine("The item was dropped onto itself.");
}
return;
}
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine($"itemToMove's address: {pl.Address}");
Console.WriteLine($"itemToMove's container's address: {pl.FromContainer.Address}");
Console.WriteLine($"myItemAtIndex's address: {Address}.{index}");
Console.WriteLine($"this's address: {Address}");
}
bool makeNewGroup = // The parameter to allow grouping when dropping on existing items is set to True AND
AllowDropToGroup &&
// The picked up item is being dropped on an existing item AND
isDropOnExisting &&
(
// The item being dropped is a container and the item at the drop target index is not an ancestor of the item being dropped OR
(pl.IsContainer && !pl.FromContainer.Address.StartsWith($"{Address}.{index}")) ||
// The item being dropped is not a container and the item at the drop target index is not a container either
(!pl.IsContainer && childProp is null)
);
var updateEventArgs = new ListUpdateEventArgs();
// TODO: Fill in the appropriate fields for the updateEventArgs
if (makeNewGroup)
{
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine($"Making a new group");
}
// TODO: Add an argument to determine if this is a drop before/after
var newGroup = Activator.CreateInstance <TGroup>();
var children = new List <TListItem>();
children.Add(dropIntoFirst ? itemToMove : myItemAtIndex);
children.Add(dropIntoFirst ? myItemAtIndex : itemToMove);
childProp = typeof(TGroup).GetProperty(DnDState.ChildrenPropertyName);
childProp.SetValue(newGroup, children);
List.RemoveAt(index);
List.Insert(index, (TListItem)(object)newGroup);
}
else
{
List.Insert(index, itemToMove);
}
var removeIndex = pl.FromContainer == this && !makeNewGroup ? pl.FromIndex + (pl.FromIndex > index && !makeNewGroup ? 1 : 0) : pl.FromIndex;
pl.FromContainer.List.RemoveAt(removeIndex);
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine("Removing drop css styles");
}
DnDState.DropCssStylesDict.Clear();
DnDState.ShowGroupWithDict.Clear();
// ================> Test for ungroup <================
var containerToCheck = pl.FromContainer;
// Test the fromContainer to see if there is <= 1 element and is not the DnDState.BaseContainer and has a Parent container
if (containerToCheck.List.Count() <= 1 && containerToCheck != DnDState.BaseContainer && containerToCheck.Parent != null)
{
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine($"There {(containerToCheck.List.Count() == 0 ? "are 0 items" : "is 1 item")} in the container, so it should be ungrouped.");
}
// Determine the index within the parent container's list using the provided container's Address
if (!int.TryParse(containerToCheck.Address.Split('.').Last(), out int indexInParentContainer))
{
Console.Error.WriteLine("Could not determine the container's index in the parent container.");
}
else
{
var parent = containerToCheck.Parent;
// Add 1 to the index if the item being moved is being dropped into its previous parent's parent at an index before or equal to its previous parent's index
if (this == containerToCheck.Parent && index <= indexInParentContainer)
{
indexInParentContainer += 1;
}
CheckForUngroup(containerToCheck, indexInParentContainer);
}
}
await SetPayload(null, -1);
await DnDState.BaseContainer.OnStatusUpdated.InvokeAsync(updateEventArgs);
if (DnDState.ShowDebugInfo || overrideDebug)
{
Console.WriteLine($"Drop method complete");
}
}
