private void MoveSoundClassUp()
{
int index = _soundClasses.IndexOf(_selectedSoundClass);
IsChanged = true;
_soundClasses.Move(index, index - 1);
}
private void updateArrangement()
{
var localPos = ListContainer.ToLocalSpace(screenSpaceDragPosition);
int srcIndex = Items.IndexOf(currentlyDraggedItem.Model);
// Find the last item with position < mouse position. Note we can't directly use
// the item positions as they are being transformed
float heightAccumulator = 0;
int dstIndex = 0;
for (; dstIndex < Items.Count; dstIndex++)
{
var drawable = itemMap[Items[dstIndex]];
if (!drawable.IsLoaded)
{
continue;
}
// Using BoundingBox here takes care of scale, paddings, etc...
float height = drawable.BoundingBox.Height;
// Rearrangement should occur only after the mid-point of items is crossed
heightAccumulator += height / 2;
// Check if the midpoint has been crossed (i.e. cursor is located above the midpoint)
if (heightAccumulator > localPos.Y)
{
if (dstIndex > srcIndex)
{
// Suppose an item is dragged just slightly below its own midpoint. The rearrangement condition (accumulator > pos) will be satisfied for the next immediate item
// but not the currently-dragged item, which will invoke a rearrangement. This is an off-by-one condition.
// Rearrangement should not occur until the midpoint of the next item is crossed, and so to fix this the next item's index is discarded.
dstIndex--;
}
break;
}
// Add the remainder of the height of the current item
heightAccumulator += height / 2 + ListContainer.Spacing.Y;
}
dstIndex = Math.Clamp(dstIndex, 0, Items.Count - 1);
if (srcIndex == dstIndex)
{
return;
}
Items.Move(srcIndex, dstIndex);
// Todo: this could be optimised, but it's a very simple iteration over all the items
reSort();
}