protected virtual void OnDropped(OlvDropEventArgs args)
{
if (this.Dropped != null)
{
this.Dropped(this, args);
}
}
protected virtual void OnCanDrop(OlvDropEventArgs args)
{
if (this.CanDrop != null)
{
this.CanDrop(this, args);
}
}
/// <summary>
/// Update the state of our sink to reflect the information that
/// may have been written into the drop event args.
/// </summary>
/// <param name="args"></param>
protected virtual void UpdateAfterCanDropEvent(OlvDropEventArgs args)
{
this.DropTargetIndex = args.DropTargetIndex;
this.DropTargetLocation = args.DropTargetLocation;
this.DropTargetSubItemIndex = args.DropTargetSubItemIndex;
if (this.Billboard != null)
{
Point pt = args.MouseLocation;
pt.Offset(5, 5);
if (this.Billboard.Text != this.dropEventArgs.InfoMessage || this.Billboard.Location != pt)
{
this.Billboard.Text = this.dropEventArgs.InfoMessage;
this.Billboard.Location = pt;
this.ListView.Invalidate();
}
}
}
/// <summary>
/// When the mouse is at the given point, what should the target of the drop be?
/// </summary>
/// <remarks>This method should update the DropTarget* members of the given arg block</remarks>
/// <param name="pt">The mouse point, in client co-ordinates</param>
protected virtual void CalculateDropTarget(OlvDropEventArgs args, Point pt)
{
const int SMALL_VALUE = 3;
DropTargetLocation location = DropTargetLocation.None;
int targetIndex = -1;
int targetSubIndex = 0;
if (this.CanDropOnBackground)
{
location = DropTargetLocation.Background;
}
// Which item is the mouse over?
// If it is not over any item, it's over the background.
//ListViewHitTestInfo info = this.ListView.HitTest(pt.X, pt.Y);
OlvListViewHitTestInfo info = this.ListView.OlvHitTest(pt.X, pt.Y);
if (info.Item != null && this.CanDropOnItem)
{
location = DropTargetLocation.Item;
targetIndex = info.Item.Index;
if (info.SubItem != null && this.CanDropOnSubItem)
{
targetSubIndex = info.Item.SubItems.IndexOf(info.SubItem);
}
}
// Check to see if the mouse is "between" rows.
// ("between" is somewhat loosely defined)
if (this.CanDropBetween && this.ListView.GetItemCount() > 0)
{
// If the mouse is over an item, check to see if it is near the top or bottom
if (location == DropTargetLocation.Item)
{
if (pt.Y - SMALL_VALUE <= info.Item.Bounds.Top)
{
location = DropTargetLocation.AboveItem;
}
if (pt.Y + SMALL_VALUE >= info.Item.Bounds.Bottom)
{
location = DropTargetLocation.BelowItem;
}
}
else
{
// Is there an item a little below the mouse?
// If so, we say the drop point is above that row
info = this.ListView.OlvHitTest(pt.X, pt.Y + SMALL_VALUE);
if (info.Item != null)
{
targetIndex = info.Item.Index;
location = DropTargetLocation.AboveItem;
}
else
{
// Is there an item a little above the mouse?
info = this.ListView.OlvHitTest(pt.X, pt.Y - SMALL_VALUE);
if (info.Item != null)
{
targetIndex = info.Item.Index;
location = DropTargetLocation.BelowItem;
}
}
}
}
args.DropTargetLocation = location;
args.DropTargetIndex = targetIndex;
args.DropTargetSubItemIndex = targetSubIndex;
}
