private void DoDragAndDropEnd(FrameworkElement dropTarget)
{
// Get the event handler.
DragAndDropDelegate dragAndDropEnd = DragAndDropEnd;
// If we have the event handler, fire it.
if (dragAndDropEnd != null)
{
DragAndDropEventArgs args = new DragAndDropEventArgs()
{
Allow = true,
DragSource = dragSource,
DragElement = dragElement,
DragData = dragData,
DropTarget = dropTarget
};
dragAndDropEnd(this, args);
}
// We're done.
dragging = false;
dragData = null;
dragElement = null;
dragSource = null;
dropTarget = null;
dragAdorner = null;
}
/// <summary>
/// Continues drag and drop, calling the appropriate event if it is registered.
/// </summary>
/// <param name="potentialDropTarget">The potential drop target.</param>
private void DoContinueDragAndDrop(FrameworkElement potentialDropTarget)
{
// If we have a start handler, call it.
DragAndDropDelegate dragAndDropContinue = DragAndDropContinue;
if (dragAndDropContinue != null)
{
// Create the drag and drop event args.
DragAndDropEventArgs args = new DragAndDropEventArgs()
{
DragSource = dragSource,
DragElement = dragElement,
DragData = dragData,
DropTarget = potentialDropTarget,
Allow = true
};
// Call the event.
dragAndDropContinue(this, args);
// If the operation has been disallowed, return.
if (args.Allow == false)
{
return;
}
}
// Store the potential drop target.
dropTarget = potentialDropTarget;
}
/// <summary>
/// Starts drag and drop, calling the appropriate event if it is registered.
/// </summary>
/// <param name="dragSource">The drag source.</param>
/// <param name="dragElement">The drag element.</param>
/// <param name="dragData">The drag data.</param>
private void DoDragAndDropStart(FrameworkElement dragSource, FrameworkElement dragElement,
object dragData)
{
// If we have a start handler, call it.
DragAndDropDelegate dragAndDropStart = DragAndDropStart;
if (dragAndDropStart != null)
{
// Create the drag args.
DragAndDropEventArgs args = new DragAndDropEventArgs()
{
DragSource = dragSource,
DragElement = dragElement,
DragData = dragData,
Allow = true
};
// Call the event handler.
dragAndDropStart(this, args);
// Has the operation been disallowed?
if (args.Allow == false)
{
// todo extrapolate to function
dragging = false;
dragData = null;
dragElement = null;
dragSource = null;
dropTarget = null;
dragAdorner = null;
return;
}
// Do we have an adorner?
if (args.DragAdorner != null)
{
// Add the adorner.
dragAdorner = args.DragAdorner;
adornerLayer.AddAdorner(dragAdorner);
}
}
// Allow the drag.
dragging = true;
}
private void DoContinueDragAndDrop(FrameworkElement potentialDropTarget)
{
// If we have a start handler, call it.
DragAndDropDelegate dragAndDropContinue = DragAndDropContinue;
if (dragAndDropContinue != null)
{
DragAndDropEventArgs args = new DragAndDropEventArgs()
{
DragSource = dragSource,
DragElement = dragElement,
DragData = dragData,
DropTarget = potentialDropTarget,
Allow = true
};
dragAndDropContinue(this, args);
if (args.Allow == false)
{
return;
}
}
dropTarget = potentialDropTarget;
}
