private static void DragSource_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
var elementPosition = e.GetPosition((IInputElement)sender);
if ((sender is TabControl) && !HitTestUtilities.HitTest4Type <TabPanel>(sender, elementPosition))
{
m_DragInfo = null;
m_ClickSupressItem = null;
return;
}
// If we prevented the control's default selection handling in DragSource_PreviewMouseLeftButtonDown
// by setting 'e.Handled = true' and a drag was not initiated, manually set the selection here.
var itemsControl = sender as ItemsControl;
if (itemsControl != null && m_DragInfo != null && m_ClickSupressItem != null && m_ClickSupressItem == m_DragInfo.SourceItem)
{
if ((Keyboard.Modifiers & ModifierKeys.Control) != 0)
{
itemsControl.SetItemSelected(m_DragInfo.SourceItem, false);
}
else if ((Keyboard.Modifiers & ModifierKeys.Shift) == 0)
{
itemsControl.SetSelectedItem(m_DragInfo.SourceItem);
}
}
m_DragInfo = null;
m_ClickSupressItem = null;
}
private static void DoMouseButtonDown(object sender, MouseButtonEventArgs e)
{
m_DragInfo = null;
// Ignore the click if clickCount != 1 or the user has clicked on a scrollbar.
var elementPosition = e.GetPosition((IInputElement)sender);
if (e.ClickCount != 1 ||
(sender as UIElement).IsDragSourceIgnored() ||
(e.Source as UIElement).IsDragSourceIgnored() ||
(e.OriginalSource as UIElement).IsDragSourceIgnored() ||
(sender is TabControl) && !HitTestUtilities.HitTest4Type <TabPanel>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <RangeBase>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <TextBoxBase>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <PasswordBox>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <ComboBox>(sender, elementPosition) ||
HitTestUtilities.HitTest4GridViewColumnHeader(sender, elementPosition) ||
HitTestUtilities.HitTest4DataGridTypes(sender, elementPosition) ||
HitTestUtilities.IsNotPartOfSender(sender, e))
{
return;
}
var dragInfo = new DragInfo(sender, e);
if (dragInfo.VisualSource is ItemsControl control && control.CanSelectMultipleItems())
{
control.Focus();
}
if (dragInfo.VisualSourceItem == null)
{
return;
}
var dragHandler = TryGetDragHandler(dragInfo, sender as UIElement);
if (!dragHandler.CanStartDrag(dragInfo))
{
return;
}
// If the sender is a list box that allows multiple selections, ensure that clicking on an
// already selected item does not change the selection, otherwise dragging multiple items
// is made impossible.
var itemsControl = sender as ItemsControl;
if ((Keyboard.Modifiers & ModifierKeys.Shift) == 0 && (Keyboard.Modifiers & ModifierKeys.Control) == 0 && dragInfo.VisualSourceItem != null && itemsControl != null && itemsControl.CanSelectMultipleItems())
{
var selectedItems = itemsControl.GetSelectedItems().OfType <object>().ToList();
if (selectedItems.Count > 1 && selectedItems.Contains(dragInfo.SourceItem))
{
m_ClickSupressItem = dragInfo.SourceItem;
e.Handled = true;
}
}
m_DragInfo = dragInfo;
}
private static bool IsNonDraggableElement(object sender, Point elementPosition)
{
return(HitTestUtilities.HitTest4Type <RangeBase>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <TextBoxBase>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <PasswordBox>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <ComboBox>(sender, elementPosition) ||
HitTestUtilities.HitTest4GridViewColumnHeader(sender, elementPosition) ||
HitTestUtilities.HitTest4DataGridTypes(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <NoDrag>(sender, elementPosition) ||
HitTestUtilities.HitTest4DataGridTypes(sender, elementPosition));
}
private static void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
// Ignore the click if clickCount != 1 or the user has clicked on a scrollbar.
var elementPosition = e.GetPosition((IInputElement)sender);
if (e.ClickCount != 1 ||
(sender as UIElement).IsDragSourceIgnored() ||
(e.Source as UIElement).IsDragSourceIgnored() ||
(e.OriginalSource as UIElement).IsDragSourceIgnored() ||
HitTestUtilities.HitTest4Type <RangeBase>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <ButtonBase>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <TextBoxBase>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <PasswordBox>(sender, elementPosition) ||
HitTestUtilities.HitTest4Type <ComboBox>(sender, elementPosition) ||
HitTestUtilities.HitTest4GridViewColumnHeader(sender, elementPosition) ||
HitTestUtilities.HitTest4DataGridTypes(sender, elementPosition) ||
HitTestUtilities.IsNotPartOfSender(sender, e))
{
m_DragInfo = null;
return;
}
m_DragInfo = new DragInfo(sender, e);
var dragHandler = TryGetDragHandler(m_DragInfo, sender as UIElement);
if (!dragHandler.CanStartDrag(m_DragInfo))
{
m_DragInfo = null;
return;
}
// If the sender is a list box that allows multiple selections, ensure that clicking on an
// already selected item does not change the selection, otherwise dragging multiple items
// is made impossible.
var itemsControl = sender as ItemsControl;
if (m_DragInfo.VisualSourceItem != null && itemsControl != null && itemsControl.CanSelectMultipleItems())
{
var selectedItems = itemsControl.GetSelectedItems().Cast <object>();
if (selectedItems.Count() > 1 && selectedItems.Contains(m_DragInfo.SourceItem))
{
m_ClickSupressItem = m_DragInfo.SourceItem;
e.Handled = true;
}
}
}
/// <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;
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)
{
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.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: {0}, {1}, {2}, Y={3}", this.InsertPosition, item, this.InsertIndex, currentYPos);
}
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: InsPos={0}, InsIndex={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: {0}, item=NULL, {1}", this.InsertPosition, this.InsertIndex);
}
}
else
{
this.VisualTargetItem = this.VisualTarget;
}
}
/// <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)
{
this.DragInfo = dragInfo;
this.KeyStates = e.KeyStates;
var dataFormat = dragInfo?.DataFormat;
this.Data = dataFormat != null && e.Data.GetDataPresent(dataFormat.Name) ? e.Data.GetData(dataFormat.Name) : e.Data;
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;
}
}
// try find ScrollViewer
if (this.VisualTarget is TabControl)
{
var tabPanel = this.VisualTarget.GetVisualDescendent <TabPanel>();
this.TargetScrollViewer = tabPanel?.GetVisualAncestor <ScrollViewer>();
}
else
{
this.TargetScrollViewer = this.VisualTarget?.GetVisualDescendent <ScrollViewer>();
}
this.TargetScrollingMode = this.VisualTarget != null?DragDrop.GetDropScrollingMode(this.VisualTarget) : ScrollingMode.Both;
// 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 = DropPosition.DirectlyOverElement(this.item, itemsControl);
}
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 = DropPosition.DirectlyOverElement(this.item, itemsControl);
}
}
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.VisualTargetItem = item;
this.TargetItem = itemParent.ItemContainerGenerator.ItemFromContainer(item);
}
var expandedTVItem = tvItem != null && tvItem.HasHeader && tvItem.HasItems && tvItem.IsExpanded;
var itemRenderSize = expandedTVItem ? tvItem.GetHeaderSize() : item.RenderSize;
if (this.VisualTargetOrientation == Orientation.Vertical)
{
var currentYPos = e.GetPosition(item).Y;
var targetHeight = itemRenderSize.Height;
var topGap = targetHeight * 0.25;
var bottomGap = targetHeight * 0.75;
if (currentYPos > targetHeight / 2)
{
if (expandedTVItem && (currentYPos < topGap || currentYPos > bottomGap))
{
this.VisualTargetItem = tvItem.ItemContainerGenerator.ContainerFromIndex(0) as UIElement;
this.TargetItem = this.VisualTargetItem != null?tvItem.ItemContainerGenerator.ItemFromContainer(this.VisualTargetItem) : null;
this.TargetCollection = tvItem.ItemsSource ?? tvItem.Items;
this.InsertIndex = 0;
this.InsertPosition = RelativeInsertPosition.BeforeTargetItem;
}
else
{
this.InsertIndex++;
this.InsertPosition = RelativeInsertPosition.AfterTargetItem;
}
}
else
{
this.InsertPosition = RelativeInsertPosition.BeforeTargetItem;
}
if (currentYPos > topGap && currentYPos < bottomGap)
{
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;
}
}
private static void DropTarget_PreviewDragOver(object sender, DragEventArgs e)
{
var elementPosition = e.GetPosition((IInputElement)sender);
if (HitTestUtilities.HitTest4Type <ScrollBar>(sender, elementPosition) ||
HitTestUtilities.HitTest4GridViewColumnHeader(sender, elementPosition) ||
HitTestUtilities.HitTest4DataGridTypesOnDragOver(sender, elementPosition))
{
e.Effects = DragDropEffects.None;
e.Handled = true;
return;
}
var dropInfo = new DropInfo(sender, e, m_DragInfo);
var dropHandler = TryGetDropHandler(dropInfo, sender as UIElement);
var itemsControl = dropInfo.VisualTarget;
dropHandler.DragOver(dropInfo);
if (DragAdorner == null && m_DragInfo != null)
{
CreateDragAdorner(dropInfo);
}
if (DragAdorner != null)
{
var tempAdornerPos = e.GetPosition(DragAdorner.AdornedElement);
if (tempAdornerPos.X >= 0 && tempAdornerPos.Y >= 0)
{
_adornerPos = tempAdornerPos;
}
// Fixed the flickering adorner - Size changes to zero 'randomly'...?
if (DragAdorner.RenderSize.Width > 0 && DragAdorner.RenderSize.Height > 0)
{
_adornerSize = DragAdorner.RenderSize;
}
if (m_DragInfo != null)
{
// move the adorner
var offsetX = _adornerSize.Width * -GetDragMouseAnchorPoint(m_DragInfo.VisualSource).X;
var offsetY = _adornerSize.Height * -GetDragMouseAnchorPoint(m_DragInfo.VisualSource).Y;
_adornerPos.Offset(offsetX, offsetY);
var maxAdornerPosX = DragAdorner.AdornedElement.RenderSize.Width;
var adornerPosRightX = (_adornerPos.X + _adornerSize.Width);
if (adornerPosRightX > maxAdornerPosX)
{
_adornerPos.Offset(-adornerPosRightX + maxAdornerPosX, 0);
}
if (_adornerPos.Y < 0)
{
_adornerPos.Y = 0;
}
}
DragAdorner.MousePosition = _adornerPos;
DragAdorner.InvalidateVisual();
}
// If the target is an ItemsControl then update the drop target adorner.
if (itemsControl != null)
{
// Display the adorner in the control's ItemsPresenter. If there is no
// ItemsPresenter provided by the style, try getting hold of a
// ScrollContentPresenter and using that.
var adornedElement =
itemsControl is TabControl
? itemsControl.GetVisualDescendent <TabPanel>()
: (itemsControl.GetVisualDescendent <ItemsPresenter>() ?? itemsControl.GetVisualDescendent <ScrollContentPresenter>() as UIElement ?? itemsControl);
if (adornedElement != null)
{
if (dropInfo.DropTargetAdorner == null)
{
DropTargetAdorner = null;
}
else if (!dropInfo.DropTargetAdorner.IsInstanceOfType(DropTargetAdorner))
{
DropTargetAdorner = DropTargetAdorner.Create(dropInfo.DropTargetAdorner, adornedElement);
}
if (DropTargetAdorner != null)
{
DropTargetAdorner.DropInfo = dropInfo;
DropTargetAdorner.InvalidateVisual();
}
}
}
// Set the drag effect adorner if there is one
if (m_DragInfo != null && (EffectAdorner == null || EffectAdorner.Effects != dropInfo.Effects))
{
CreateEffectAdorner(dropInfo);
}
if (EffectAdorner != null)
{
var adornerPos = e.GetPosition(EffectAdorner.AdornedElement);
adornerPos.Offset(20, 20);
EffectAdorner.MousePosition = adornerPos;
EffectAdorner.InvalidateVisual();
}
e.Effects = dropInfo.Effects;
e.Handled = !dropInfo.NotHandled;
if (!dropInfo.IsSameDragDropContextAsSource)
{
e.Effects = DragDropEffects.None;
}
Scroll(dropInfo.VisualTarget, e);
}
private static void DropTargetOnDragOver(object sender, DragEventArgs e, EventType eventType)
{
var elementPosition = e.GetPosition((IInputElement)sender);
var dragInfo = m_DragInfo;
var dropInfo = new DropInfo(sender, e, dragInfo, eventType);
var dropHandler = TryGetDropHandler(dropInfo, sender as UIElement);
var itemsControl = dropInfo.VisualTarget;
dropHandler.DragOver(dropInfo);
if (DragAdorner == null && dragInfo != null)
{
CreateDragAdorner(dropInfo);
}
DragAdorner?.Move(e.GetPosition(DragAdorner.AdornedElement), dragInfo != null ? GetDragMouseAnchorPoint(dragInfo.VisualSource) : default(Point), ref _adornerMousePosition, ref _adornerSize);
Scroll(dropInfo, e);
if (HitTestUtilities.HitTest4Type <ScrollBar>(sender, elementPosition) ||
HitTestUtilities.HitTest4GridViewColumnHeader(sender, elementPosition) ||
HitTestUtilities.HitTest4DataGridTypesOnDragOver(sender, elementPosition))
{
e.Effects = DragDropEffects.None;
e.Handled = true;
return;
}
// If the target is an ItemsControl then update the drop target adorner.
if (itemsControl != null)
{
// Display the adorner in the control's ItemsPresenter. If there is no
// ItemsPresenter provided by the style, try getting hold of a
// ScrollContentPresenter and using that.
UIElement adornedElement = null;
if (itemsControl is TabControl)
{
adornedElement = itemsControl.GetVisualDescendent <TabPanel>();
}
else if (itemsControl is DataGrid || (itemsControl as ListView)?.View is GridView)
{
adornedElement = itemsControl.GetVisualDescendent <ScrollContentPresenter>() as UIElement ?? itemsControl.GetVisualDescendent <ItemsPresenter>() as UIElement ?? itemsControl;
}
else
{
adornedElement = itemsControl.GetVisualDescendent <ItemsPresenter>() as UIElement ?? itemsControl.GetVisualDescendent <ScrollContentPresenter>() as UIElement ?? itemsControl;
}
if (adornedElement != null)
{
if (dropInfo.DropTargetAdorner == null)
{
DropTargetAdorner = null;
}
else if (!dropInfo.DropTargetAdorner.IsInstanceOfType(DropTargetAdorner))
{
DropTargetAdorner = DropTargetAdorner.Create(dropInfo.DropTargetAdorner, adornedElement, dropInfo);
}
var adorner = DropTargetAdorner;
if (adorner != null)
{
var adornerBrush = GetDropTargetAdornerBrush(dropInfo.VisualTarget);
if (adornerBrush != null)
{
adorner.Pen.SetCurrentValue(Pen.BrushProperty, adornerBrush);
}
adorner.DropInfo = dropInfo;
adorner.InvalidateVisual();
}
}
}
// Set the drag effect adorner if there is one
if (dragInfo != null && (EffectAdorner == null || EffectAdorner.Effects != dropInfo.Effects))
{
CreateEffectAdorner(dropInfo);
}
EffectAdorner?.Move(e.GetPosition(EffectAdorner.AdornedElement), default(Point), ref _effectAdornerMousePosition, ref _effectAdornerSize);
e.Effects = dropInfo.Effects;
e.Handled = !dropInfo.NotHandled;
if (!dropInfo.IsSameDragDropContextAsSource)
{
e.Effects = DragDropEffects.None;
}
}
/// <summary>
/// Initializes a new instance of the DropInfo class.
/// </summary>
/// <param name="sender">The sender of the drop event.</param>
/// <param name="e">The drag event arguments.</param>
/// <param name="dragInfo">Information about the drag source, if the drag came from within the framework.</param>
/// <param name="eventType">The type of the underlying event (tunneled or bubbled).</param>
public DropInfo(object sender, DragEventArgs e, /*[CanBeNull]*/ IDragInfo dragInfo, EventType eventType)
{
this.DragInfo = dragInfo;
this.KeyStates = e.KeyStates;
this.EventType = eventType;
var dataFormat = dragInfo?.DataFormat;
this.Data = dataFormat != null && e.Data.GetDataPresent(dataFormat.Name) ? e.Data.GetData(dataFormat.Name) : e.Data;
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;
}
}
// try find ScrollViewer
var dropTargetScrollViewer = DragDrop.GetDropTargetScrollViewer(this.VisualTarget);
if (dropTargetScrollViewer != null)
{
this.TargetScrollViewer = dropTargetScrollViewer;
}
else if (this.VisualTarget is TabControl)
{
var tabPanel = this.VisualTarget.GetVisualDescendent <TabPanel>();
this.TargetScrollViewer = tabPanel?.GetVisualAncestor <ScrollViewer>();
}
else
{
this.TargetScrollViewer = this.VisualTarget?.GetVisualDescendent <ScrollViewer>();
}
this.TargetScrollingMode = this.VisualTarget != null?DragDrop.GetDropScrollingMode(this.VisualTarget) : ScrollingMode.Both;
// 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 itemsControl)
{
//System.Diagnostics.Debug.WriteLine(">>> Name = {0}", itemsControl.Name);
// get item under the mouse
var 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 = this.DropPosition.DirectlyOverElement(item, itemsControl);
}
if (item == null && this.TargetGroup is { IsBottomLevel : true })
private static bool IsDragHandle(object sender, Point elementPosition)
{
return(HitTestUtilities.HitTest4Type <DragHandle>(sender, elementPosition));
}