// Performs custom drop logic for the top ListView.
void dragMgr_ProcessDrop(object sender, ProcessDropEventArgs <Task> e)
{
// This shows how to customize the behavior of a drop.
// Here we perform a swap, instead of just moving the dropped item.
if (!Program.options.interface_databank_swap)
{
MessageBox.Show("*** ERROR: Databank swapping not allowed, since 'OPTION interface databank swap = no'");
return;
}
string text = "";
int higherIdx = Math.Max(e.OldIndex, e.NewIndex);
int lowerIdx = Math.Min(e.OldIndex, e.NewIndex);
Task t_from = list[e.OldIndex];
Task t_to = list[e.NewIndex];
string aliasFromOld = t_from.AliasName;
string aliasToOld = t_to.AliasName;
string s = null;
if (lowerIdx < 0)
{
// The item came from the lower ListView
// so just insert it.
e.ItemsSource.Insert(higherIdx, e.DataItem);
}
else
{
// null values will cause an error when calling Move.
// It looks like a bug in ObservableCollection to me.
if (e.ItemsSource[lowerIdx] == null ||
e.ItemsSource[higherIdx] == null)
{
Program.ShowPeriodInStatusField("");
return;
}
// The item came from the ListView into which
// it was dropped, so swap it with the item
// at the target index.
e.ItemsSource.Move(lowerIdx, higherIdx);
e.ItemsSource.Move(higherIdx - 1, lowerIdx);
Databank lower = Program.databanks.storage[lowerIdx];
Databank higher = Program.databanks.storage[higherIdx];
Program.databanks.storage[lowerIdx] = higher;
Program.databanks.storage[higherIdx] = lower;
//remember that higher is at lowerIdx and vice versa!
if ((lowerIdx == 0 || lowerIdx == 1) && !(G.equal(higher.aliasName, Globals.Work) || G.equal(higher.aliasName, Globals.Ref)))
{
if (!higher.protect)
{
higher.protect = true;
s += "Note that the databank '" + higher.aliasName + "' has been set non-editable. ";
list[lowerIdx].Prot = Globals.protectSymbol;
}
}
//remember that higher is at lowerIdx and vice versa!
if ((higherIdx == 0 || higherIdx == 1) && !(G.equal(lower.aliasName, Globals.Work) || G.equal(lower.aliasName, Globals.Ref)))
{
if (!lower.protect)
{
lower.protect = true;
s += "Note that the databank '" + lower.aliasName + "' has been set non-editable. ";
list[higherIdx].Prot = Globals.protectSymbol;
}
}
int counter = 0;
foreach (var x in e.ItemsSource)
{
counter++;
x.Number = counter.ToString();
if (x.Number == "2")
{
x.LineColor = "Black"; //these numbers are 1-based and are strings!
}
else
{
x.LineColor = "LightGray";
}
}
}
// Set this to 'Move' so that the OnListViewDrop knows to
// remove the item from the other ListView.
e.Effects = DragDropEffects.Move;
//unswap.IsEnabled = Program.AreDatabanksSwapped();
//unswap.IsEnabled = true; //fixme
yellow.Text = "Databanks were swapped. " + s;
Program.ShowPeriodInStatusField("");
}
void listView_Drop(object sender, DragEventArgs e)
{
if (this.ItemUnderDragCursor != null)
{
this.ItemUnderDragCursor = null;
}
e.Effects = DragDropEffects.None;
if (!e.Data.GetDataPresent(typeof(ItemType)))
{
return;
}
// Get the data object which was dropped.
ItemType data = e.Data.GetData(typeof(ItemType)) as ItemType;
if (data == null)
{
return;
}
// Get the ObservableCollection<ItemType> which contains the dropped data object.
ObservableCollection <ItemType> itemsSource = this.listView.ItemsSource as ObservableCollection <ItemType>;
if (itemsSource == null)
{
throw new Exception(
"A ListView managed by ListViewDragManager must have its ItemsSource set to an ObservableCollection<ItemType>.");
}
int oldIndex = itemsSource.IndexOf(data);
int newIndex = this.IndexUnderDragCursor;
if (newIndex < 0)
{
// The drag started somewhere else, and our ListView is empty
// so make the new item the first in the list.
if (itemsSource.Count == 0)
{
newIndex = 0;
}
// The drag started somewhere else, but our ListView has items
// so make the new item the last in the list.
else if (oldIndex < 0)
{
newIndex = itemsSource.Count;
}
// The user is trying to drop an item from our ListView into
// our ListView, but the mouse is not over an item, so don't
// let them drop it.
else
{
return;
}
}
// Dropping an item back onto itself is not considered an actual 'drop'.
if (oldIndex == newIndex)
{
return;
}
if (this.ProcessDrop != null)
{
// Let the client code process the drop.
ProcessDropEventArgs <ItemType> args = new ProcessDropEventArgs <ItemType>(itemsSource, data, oldIndex, newIndex, e.AllowedEffects);
this.ProcessDrop(this, args);
e.Effects = args.Effects;
}
else
{
// Move the dragged data object from it's original index to the
// new index (according to where the mouse cursor is). If it was
// not previously in the ListBox, then insert the item.
if (oldIndex > -1)
{
itemsSource.Move(oldIndex, newIndex);
}
else
{
itemsSource.Insert(newIndex, data);
}
// Set the Effects property so that the call to DoDragDrop will return 'Move'.
e.Effects = DragDropEffects.Move;
}
}
