void host_MouseDown(object sender, MouseButtonEventArgs e)
{
// Perform a hist test.
HitTest hitTest = new HitTest();
hitTest.DoHitTest(host, e.GetPosition(host));
// Go through the hits, looking for a draggable object.
foreach (var hit in hitTest.Hits)
{
// Is this a draggable object?
FrameworkElement foundDragElement, foundDragSource;
if (hit is FrameworkElement &&
IsInDraggableElement((FrameworkElement)hit, out foundDragElement, out foundDragSource))
{
// We've found an object to drag - store its data.
dragElement = foundDragElement;
dragData = dragElement.DataContext;
dragSource = foundDragSource;
initialMousePosition = e.GetPosition(host);
initialElementOffset = e.GetPosition(dragElement);
break;
}
}
}
void host_MouseMove(object sender, MouseEventArgs e)
{
// We only care about mouse moves if we have a drag element.
if (dragElement == null)
{
return;
}
// Update the current mouse position.
currentMousePosition = e.GetPosition(host);
// We have a drag element - are we dragging?
if (dragging == false)
{
// We're not - have we moved enough to start a drag?
// Apex.Consistency.SystemParamters returns drag distances
// as SystemParameters doesn't have it in silverlight.
if (
(Math.Abs(initialMousePosition.X - currentMousePosition.X) >=
MinimumHorizontalDragDistance) &&
(Math.Abs(initialMousePosition.Y - currentMousePosition.Y) >=
MinimumHorizontalDragDistance))
{
// We'll try starting a drag and drop.
DoDragAndDropStart(dragSource, dragElement, dragData);
if (dragging)
{
host.CaptureMouse();
}
}
}
// If we're still not dragging, we're done.
if (dragging == false)
{
return;
}
// If we have an adorner, move it.
if (dragAdorner != null)
{
dragAdorner.Translation.X = currentMousePosition.X - initialElementOffset.X;
dragAdorner.Translation.Y = currentMousePosition.Y - initialElementOffset.Y;
}
// Are we over a drop target?
FrameworkElement dropTargetOver = null;
// Perform a hist test.
HitTest hitTest = new HitTest();
hitTest.DoHitTest(host, e.GetPosition(host));
foreach (var dt in hitTest.Hits)
{
FrameworkElement foundDropTarget;
if (dt is FrameworkElement &&
IsInDropTarget((FrameworkElement)dt, out foundDropTarget))
{
dropTargetOver = foundDropTarget;
break;
}
}
// If we are not over a drop target, clear the drop over.
if (dropTargetOver == null)
{
dropTarget = null;
return;
}
// If we are over a drop target and it's a new one, check
// for continuing.
if (dropTargetOver != dropTarget)
{
DoContinueDragAndDrop(dropTargetOver);
}
}
