/// <summary>
/// Initializes a new instance of the DropInfo class.
/// </summary>
///
/// <param name="sender">
/// The sender of the drag event.
/// </param>
///
/// <param name="e">
/// The drag event.
/// </param>
///
/// <param name="dragInfo">
/// Information about the source of the drag, if the drag came from within the framework.
/// </param>
public DropInfo(object sender, DragEventArgs e, DragInfo dragInfo)
{
var dataFormat = DragDrop.DataFormat.Name;
this.Data = (e.Data.GetDataPresent(dataFormat)) ? e.Data.GetData(dataFormat) : e.Data;
this.DragInfo = dragInfo;
this.KeyStates = e.KeyStates;
this.VisualTarget = sender as UIElement;
// if there is no drop target, find another
if (!this.VisualTarget.IsDropTarget())
{
// try to find next element
var element = this.VisualTarget.TryGetNextAncestorDropTargetElement();
if (element != null)
{
this.VisualTarget = element;
}
}
// visual target can be null, so give us a point...
this.DropPosition = this.VisualTarget != null ? e.GetPosition(this.VisualTarget) : new Point();
if (this.VisualTarget is TabControl) {
if (!HitTestUtilities.HitTest4Type<TabPanel>(this.VisualTarget, this.DropPosition)) {
return;
}
}
if (this.VisualTarget is ItemsControl) {
var itemsControl = (ItemsControl)this.VisualTarget;
//System.Diagnostics.Debug.WriteLine(">>> Name = {0}", itemsControl.Name);
// get item under the mouse
item = itemsControl.GetItemContainerAt(this.DropPosition);
var directlyOverItem = item != null;
this.TargetGroup = itemsControl.FindGroup(this.DropPosition);
this.VisualTargetOrientation = itemsControl.GetItemsPanelOrientation();
this.VisualTargetFlowDirection = itemsControl.GetItemsPanelFlowDirection();
if (item == null) {
// ok, no item found, so maybe we can found an item at top, left, right or bottom
item = itemsControl.GetItemContainerAt(this.DropPosition, this.VisualTargetOrientation);
directlyOverItem = false;
}
if (item == null && this.TargetGroup != null && this.TargetGroup.IsBottomLevel)
{
var itemData = this.TargetGroup.Items.FirstOrDefault();
if (itemData != null)
{
item = itemsControl.ItemContainerGenerator.ContainerFromItem(itemData) as UIElement;
directlyOverItem = false;
}
}
if (item != null)
{
itemParent = ItemsControl.ItemsControlFromItemContainer(item);
this.VisualTargetOrientation = itemParent.GetItemsPanelOrientation();
this.VisualTargetFlowDirection = itemParent.GetItemsPanelFlowDirection();
this.InsertIndex = itemParent.ItemContainerGenerator.IndexFromContainer(item);
this.TargetCollection = itemParent.ItemsSource ?? itemParent.Items;
var tvItem = item as TreeViewItem;
if (directlyOverItem || tvItem != null)
{
this.TargetItem = itemParent.ItemContainerGenerator.ItemFromContainer(item);
this.VisualTargetItem = item;
}
var itemRenderSize = item.RenderSize;
if (this.VisualTargetOrientation == Orientation.Vertical) {
var currentYPos = e.GetPosition(item).Y;
var targetHeight = itemRenderSize.Height;
if (currentYPos > targetHeight / 2) {
this.InsertIndex++;
this.InsertPosition = RelativeInsertPosition.AfterTargetItem;
} else {
this.InsertPosition = RelativeInsertPosition.BeforeTargetItem;
}
if (currentYPos > targetHeight * 0.25 && currentYPos < targetHeight * 0.75) {
if (tvItem != null)
{
this.TargetCollection = tvItem.ItemsSource ?? tvItem.Items;
this.InsertIndex = this.TargetCollection != null ? this.TargetCollection.OfType<object>().Count() : 0;
}
this.InsertPosition |= RelativeInsertPosition.TargetItemCenter;
}
//System.Diagnostics.Debug.WriteLine("==> DropInfo: pos={0}, idx={1}, Y={2}, Item={3}", this.InsertPosition, this.InsertIndex, currentYPos, item);
}
else {
var currentXPos = e.GetPosition(item).X;
var targetWidth = itemRenderSize.Width;
if (this.VisualTargetFlowDirection == FlowDirection.RightToLeft) {
if (currentXPos > targetWidth / 2) {
this.InsertPosition = RelativeInsertPosition.BeforeTargetItem;
} else {
this.InsertIndex++;
this.InsertPosition = RelativeInsertPosition.AfterTargetItem;
}
} else if (this.VisualTargetFlowDirection == FlowDirection.LeftToRight) {
if (currentXPos > targetWidth / 2) {
this.InsertIndex++;
this.InsertPosition = RelativeInsertPosition.AfterTargetItem;
} else {
this.InsertPosition = RelativeInsertPosition.BeforeTargetItem;
}
}
if (currentXPos > targetWidth * 0.25 && currentXPos < targetWidth * 0.75) {
if (tvItem != null)
{
this.TargetCollection = tvItem.ItemsSource ?? tvItem.Items;
this.InsertIndex = this.TargetCollection != null ? this.TargetCollection.OfType<object>().Count() : 0;
}
this.InsertPosition |= RelativeInsertPosition.TargetItemCenter;
}
//System.Diagnostics.Debug.WriteLine("==> DropInfo: pos={0}, idx={1}, X={2}, Item={3}", this.InsertPosition, this.InsertIndex, currentXPos, item);
}
}
else
{
this.TargetCollection = itemsControl.ItemsSource ?? itemsControl.Items;
this.InsertIndex = itemsControl.Items.Count;
//System.Diagnostics.Debug.WriteLine("==> DropInfo: pos={0}, item=NULL, idx={1}", this.InsertPosition, this.InsertIndex);
}
} else {
this.VisualTargetItem = this.VisualTarget;
}
}