public static UIElement GetClosestItemContainerToPosition(ItemsControl itemsControl, Point point, Orientation orientation)
{
Type itemContainerType = ControlMethods.GetItemContainerType(itemsControl);
if (itemContainerType == null)
{
return(null);
}
List <UIElement> containers = new List <UIElement>();
LineGeometry line;
switch (orientation)
{
case Orientation.Horizontal:
line = new LineGeometry(new Point(0d, point.Y), new Point(itemsControl.RenderSize.Width, point.Y));
break;
default:
line = new LineGeometry(new Point(point.X, 0d), new Point(point.X, itemsControl.RenderSize.Height));
break;
}
line.Freeze();
VisualTreeHelper.HitTest(
itemsControl,
null,
testResult =>
{
UIElement itemContainer = testResult.VisualHit.FindVisualTreeAncestor(itemContainerType) as UIElement;
if (itemContainer != null && itemsControl.Equals(ItemsControl.ItemsControlFromItemContainer(itemContainer)))
{
containers.Add(itemContainer);
}
return(HitTestResultBehavior.Continue);
},
new GeometryHitTestParameters(line)
);
switch (containers.Count)
{
case 0:
return(null);
case 1:
return(containers[0]);
}
// Find closest item to the point clicked.
UIElement closest = null;
double closestDistance = double.MaxValue;
foreach (UIElement container in containers)
{
Point transform = container.TransformToAncestor(itemsControl).Transform(default(Point));
double distance = Math.Abs(orientation == Orientation.Horizontal ? point.X - transform.X : point.Y - transform.Y);
if (distance < closestDistance)
{
closest = container;
closestDistance = distance;
}
}
return(closest);
}
public static UIElement GetItemContainer(this ItemsControl itemsControl, UIElement child)
{
Type itemContainerType = ControlMethods.GetItemContainerType(itemsControl);
if (itemContainerType == null)
{
return(null);
}
for (UIElement element = VisualTreeHelper.GetParent(child) as UIElement; element != null && !itemsControl.Equals(element); element = VisualTreeHelper.GetParent(element) as UIElement)
{
if (itemContainerType.IsInstanceOfType(element) && itemsControl.Equals(ItemsControl.ItemsControlFromItemContainer(element)))
{
return(element);
}
}
return(null);
}
private static void TabControl_PreviewMouseMove(object sender, MouseEventArgs e)
{
TabControl tabControl = (TabControl)sender;
Point point = e.GetPosition(tabControl);
if (tabControl.IsMouseCaptured)
{
TabTearOffBehavior.UpdateDragWindowLocation(tabControl);
Window dropWindow = TabTearOffBehavior.GetWindowMouseIsOver(e);
if (dropWindow == null)
{
return;
}
if (!dropWindow.IsActive)
{
dropWindow.Activate();
}
ITabTearOffHandler targetHandler;
TabControl targetTabControl = TabTearOffBehavior.FindTargetTabControl(dropWindow, out targetHandler);
Panel panel = ControlMethods.GetPanel(targetTabControl);
if (TabTearOffBehavior.IsMouseInDropLocation(e, targetTabControl, panel))
{
if (TabTearOffBehavior._adorner == null || !TabTearOffBehavior._adorner.AdornedElement.Equals(targetTabControl))
{
if (TabTearOffBehavior._adorner != null)
{
TabTearOffBehavior._adorner.Detach();
}
TabTearOffBehavior._adorner = new InsertionAdorner(targetTabControl, panel.GetOrientation());
}
TabTearOffBehavior._adorner.UpdateLocation(e);
}
else if (TabTearOffBehavior._adorner != null)
{
TabTearOffBehavior._adorner.Detach();
TabTearOffBehavior._adorner = null;
}
}
else if (TabTearOffBehavior.IsSufficientDragMove(point))
{
Rectangle contentRectangle = TabTearOffBehavior.CreateRectangle((Visual)TabTearOffBehavior.GetContent(tabControl));
Rectangle tabItemRectangle = TabTearOffBehavior.CreateRectangle(TabTearOffBehavior._activeTabItem);
Panel.SetZIndex(tabItemRectangle, 10);
StackPanel stackPanel = new StackPanel
{
Orientation = tabControl.TabStripPlacement == Dock.Right || tabControl.TabStripPlacement == Dock.Left ? Orientation.Horizontal : Orientation.Vertical,
Children =
{
tabItemRectangle
}
};
stackPanel.Children.Insert(tabControl.TabStripPlacement == Dock.Right || tabControl.TabStripPlacement == Dock.Bottom ? 0 : 1, contentRectangle);
TranslateTransform translateTransform = new TranslateTransform();
switch (tabControl.TabStripPlacement)
{
case Dock.Bottom:
translateTransform.Y = -1d;
break;
case Dock.Left:
translateTransform.X = 1d;
break;
case Dock.Right:
translateTransform.X = -1d;
break;
case Dock.Top:
translateTransform.Y = 1d;
break;
}
tabItemRectangle.RenderTransform = translateTransform;
TabTearOffBehavior._dragWindow = new Window
{
Topmost = true,
AllowsTransparency = true,
WindowStyle = WindowStyle.None,
IsHitTestVisible = false,
SizeToContent = SizeToContent.WidthAndHeight,
Background = Brushes.Transparent,
Content = new Border
{
Child = stackPanel,
Opacity = 0.75
}
};
TabTearOffBehavior.UpdateDragWindowLocation(tabControl);
TabTearOffBehavior._dragWindow.Show();
tabControl.MouseLeave -= TabTearOffBehavior.TabControl_MouseLeaveOrLostCapture;
tabControl.CaptureMouse();
e.Handled = true;
}
}
internal static int DetermineInsertionIndex(ItemsControl tabControl, MouseEventArgs mouseEventArgs, Orientation panelOrientation)
{
Point tabControlPosition = mouseEventArgs.GetPosition(tabControl);
UIElement container = tabControl.GetItemContainerAtPosition(tabControlPosition) ?? ControlMethods.GetClosestItemContainerToPosition(tabControl, tabControlPosition, panelOrientation);
if (container == null)
{
return(0);
}
int index = tabControl.ItemContainerGenerator.IndexFromContainer(container);
Point containerPosition = mouseEventArgs.GetPosition(container);
if (panelOrientation == Orientation.Vertical && containerPosition.Y > container.RenderSize.Height / 2d ||
panelOrientation == Orientation.Horizontal && containerPosition.X > container.RenderSize.Width / 2d)
{
index++;
}
return(index);
}
private static void TabControl_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
TabControl sourceTabControl = (TabControl)sender;
sourceTabControl.PreviewMouseLeftButtonUp -= TabTearOffBehavior.TabControl_PreviewMouseLeftButtonUp;
sourceTabControl.PreviewMouseMove -= TabTearOffBehavior.TabControl_PreviewMouseMove;
sourceTabControl.MouseLeave -= TabTearOffBehavior.TabControl_MouseLeaveOrLostCapture;
sourceTabControl.LostMouseCapture -= TabTearOffBehavior.TabControl_MouseLeaveOrLostCapture;
if (sourceTabControl.IsMouseCaptured)
{
TabItem tabItem = TabTearOffBehavior._activeTabItem;
Point dragWindowLocation = new Point
{
X = TabTearOffBehavior._dragWindow.Left,
Y = TabTearOffBehavior._dragWindow.Top
};
sourceTabControl.ReleaseMouseCapture();
if (TabTearOffBehavior._adorner != null)
{
TabTearOffBehavior._adorner.Detach();
TabTearOffBehavior._adorner = null;
}
TabTearOffBehavior._dragWindow.Close();
TabTearOffBehavior._dragWindow = null;
TabTearOffBehavior._activeTabItem = null;
object item = sourceTabControl.ItemContainerGenerator.ItemFromContainer(tabItem);
int sourceIndex = sourceTabControl.ItemContainerGenerator.IndexFromContainer(tabItem);
Window dropWindow = TabTearOffBehavior.GetWindowMouseIsOver(e);
TabControl targetTabControl;
Panel targetPanel;
ITabTearOffHandler targetHandler;
if (dropWindow != null &&
TabTearOffBehavior.IsMouseInDropLocation(e, targetTabControl = TabTearOffBehavior.FindTargetTabControl(dropWindow, out targetHandler), targetPanel = ControlMethods.GetPanel(targetTabControl)))
{
int insertionIndex = TabTearOffBehavior.DetermineInsertionIndex(targetTabControl, e, targetPanel.GetOrientation());
if (!object.ReferenceEquals(sourceTabControl, targetTabControl))
{
if (targetHandler.AllowTargetedDrop(item, sourceTabControl, sourceIndex, targetTabControl, insertionIndex))
{
targetHandler.HandleTargetedDrop(item, sourceTabControl, sourceIndex, targetTabControl, insertionIndex);
}
}
else if (sourceTabControl.Items.Count != 1 &&
insertionIndex != sourceIndex &&
targetHandler.AllowReorder(item, sourceTabControl, sourceIndex, insertionIndex))
{
targetHandler.HandleReorder(item, sourceTabControl, sourceIndex, insertionIndex);
}
}
else
{
ITabTearOffHandler sourceHandler = TabTearOffBehavior.GetHandler(sourceTabControl);
if (sourceHandler.AllowTargetlessDrop(item, sourceTabControl, sourceIndex, dragWindowLocation))
{
sourceHandler.HandleTargetlessDrop(item, sourceTabControl, sourceIndex, dragWindowLocation);
}
}
}
e.Handled = true;
}