void listView_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
if (IsMouseOverScrollbar)
{
// 4/13/2007 - Set the flag to false when cursor is over scrollbar.
canInitiateDrag = false;
return;
}
int index = IndexUnderDragCursor;
canInitiateDrag = index > -1;
if (canInitiateDrag)
{
// Remember the location and index of the ListViewItem the user clicked on for later.
ptMouseDown = MouseUtilities.GetMousePosition(listView);
indexToSelect = index;
}
else
{
ptMouseDown = new Point(-10000, -10000);
indexToSelect = -1;
}
}
bool IsMouseOver(Visual target)
{
// We need to use MouseUtilities to figure out the cursor
// coordinates because, during a drag-drop operation, the WPF
// mechanisms for getting the coordinates behave strangely.
Rect bounds = VisualTreeHelper.GetDescendantBounds(target);
Point mousePos = MouseUtilities.GetMousePosition(target);
return(bounds.Contains(mousePos));
}
void UpdateDragAdornerLocation()
{
if (dragAdorner != null)
{
Point ptCursor = MouseUtilities.GetMousePosition(ListView);
double left = ptCursor.X - ptMouseDown.X;
// 4/13/2007 - Made the top offset relative to the item being dragged.
ListViewItem itemBeingDragged = GetListViewItem(indexToSelect);
Point itemLoc = itemBeingDragged.TranslatePoint(new Point(0, 0), ListView);
double top = itemLoc.Y + ptCursor.Y - ptMouseDown.Y;
dragAdorner.SetOffsets(left, top);
}
}
AdornerLayer InitializeAdornerLayer(ListViewItem itemToDrag)
{
// Create a brush which will paint the ListViewItem onto
// a visual in the adorner layer.
VisualBrush brush = new VisualBrush(itemToDrag);
// Create an element which displays the source item while it is dragged.
dragAdorner = new DragAdorner(listView, itemToDrag.RenderSize, brush);
// Set the drag adorner's opacity.
dragAdorner.Opacity = DragAdornerOpacity;
AdornerLayer layer = AdornerLayer.GetAdornerLayer(listView);
layer.Add(dragAdorner);
// Save the location of the cursor when the left mouse button was pressed.
ptMouseDown = MouseUtilities.GetMousePosition(listView);
return(layer);
}
