/// <summary>
/// Handles the MouseLeftButtonDown of the drag source. Starts the dragging operation.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The envet args instance containing event data.</param>
private void DragSource_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
this.dragSource.CaptureMouse();
if (!this.IsDragging)
{
DataTemplate dragTemplate = DragDropManager.GetDragTemplate(this.dragSource);
object dragData = DragDropManager.GetDragData(this.dragSource);
this.DragPopupChild.Children.Clear();
this.IsDragging = true;
DragDropControl dragDropControl = new DragDropControl
{
DragContent = dragData,
DragTemplate = dragTemplate
};
this.DragPopupChild.Children.Add(dragDropControl);
if (!this.DragPopup.IsOpen)
{
this.DragPopupChild.Opacity = 0;
this.DragPopup.IsOpen = true;
}
this.ShowDragDrop(false);
}
}
/// <summary>
/// Toggles the drop allowed value of the current drag drop control.
/// </summary>
/// <param name="dropAllowed">If the drop is allowed or not.</param>
private void ShowDragDrop(bool dropAllowed)
{
if (this.DragPopup != null && this.DragPopupChild != null && this.IsDragging)
{
if (this.DragPopupChild.Children.Count > 0)
{
DragDropControl dragDropControl = this.DragPopupChild.Children[0] as DragDropControl;
if (dragDropControl != null)
{
dragDropControl.DropAllowed = dropAllowed;
}
}
}
}
/// <summary>
/// Check if there are drop zones an specific position.
/// </summary>
/// <param name="e">The mouse event args.</param>
/// <returns>A list of possible drop zones.</returns>
private IList <FrameworkElement> CheckDropZones(MouseEventArgs e)
{
IList <FrameworkElement> dropZonesAtCurrentCord = new List <FrameworkElement>();
if (this.DragPopup != null && this.DragPopupChild != null && this.DragPopupChild.Children.Count > 0)
{
DragDropControl dragDropControl = this.DragPopupChild.Children[0] as DragDropControl;
if (dragDropControl != null)
{
IList <FrameworkElement> invalidDropZones = new List <FrameworkElement>();
foreach (FrameworkElement frameworkElement in DragDropManager.DropZones)
{
IDropInfo dropInfo = DragDropManager.GetDropInfo(frameworkElement);
Type dragSourceType = dragDropControl.DragContent.GetType();
try
{
Point dropPoint = e.GetPosition(frameworkElement);
if ((dropPoint.X >= 0 && dropPoint.X <= frameworkElement.ActualWidth) &&
(dropPoint.Y >= 0 && dropPoint.Y <= frameworkElement.ActualHeight) &&
dropInfo.AllowedDragTypes.Contains(dragSourceType))
{
dropZonesAtCurrentCord.Add(frameworkElement);
}
}
catch (Exception)
{
invalidDropZones.Add(frameworkElement);
}
}
foreach (FrameworkElement element in invalidDropZones)
{
DragDropManager.DropZones.Remove(element);
}
invalidDropZones.Clear();
}
}
return(dropZonesAtCurrentCord);
}
/// <summary>
/// Check if there are drop zones an specific position.
/// </summary>
/// <param name="e">The mouse event args.</param>
/// <returns>A list of possible drop zones.</returns>
private FrameworkElement GetDropZone(MouseEventArgs e)
{
IList <FrameworkElement> dropZonesAtCurrentCord = new List <FrameworkElement>();
if (this.DragPopup != null && this.DragPopupChild != null && this.DragPopupChild.Children.Count > 0)
{
DragDropControl dragDropControl = this.DragPopupChild.Children[0] as DragDropControl;
if (dragDropControl != null)
{
IList <FrameworkElement> invalidDropZones = new List <FrameworkElement>();
foreach (FrameworkElement frameworkElement in DragDropManager.DropZones)
{
IDropInfo dropInfo = DragDropManager.GetDropInfo(frameworkElement);
Type dragSourceType = dragDropControl.DragContent.GetType();
try
{
Point dropPoint = e.GetPosition(frameworkElement);
if (frameworkElement.Visibility == Visibility.Visible &&
frameworkElement.ActualHeight != 0 &&
frameworkElement.ActualWidth != 0 &&
(dropPoint.X >= 0 && dropPoint.X <= frameworkElement.ActualWidth) &&
(dropPoint.Y >= 0 && dropPoint.Y <= frameworkElement.ActualHeight) &&
dropInfo.AllowedDragTypes.Contains(dragSourceType))
{
dropZonesAtCurrentCord.Add(frameworkElement);
}
}
catch (Exception)
{
invalidDropZones.Add(frameworkElement);
}
}
foreach (FrameworkElement element in invalidDropZones)
{
DragDropManager.DropZones.Remove(element);
}
invalidDropZones.Clear();
}
}
int maxIndex = -1;
FrameworkElement topMostDropZone = null;
foreach (FrameworkElement dropZone in dropZonesAtCurrentCord)
{
FloatableWindow parentWindow = dropZone.GetParentControl <FloatableWindow>();
int canvasZIndex = Canvas.GetZIndex(parentWindow);
if (canvasZIndex > maxIndex)
{
maxIndex = canvasZIndex;
topMostDropZone = dropZone;
}
}
return(topMostDropZone);
}
