/* ____________________________________________________________________
* Drag Source events
* ____________________________________________________________________
*/
static void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
// Make this the new drag source
_currentSourceAdvisor = GetDragSourceAdvisor(sender as DependencyObject);
if (_currentSourceAdvisor.IsDraggable(e.Source as UIElement) == false) return;
_draggedElt = e.Source as UIElement;
_startPoint = e.GetPosition(GetTopContainer());
_isMouseDown = true;
}
public DragInfo(IDragSourceAdvisor adv)
{
if (adv == null)
throw new ArgumentNullException();
SourceAdvisor = adv;
}
public DragInfo(IDragSourceAdvisor adv)
{
if (adv == null)
{
throw new ArgumentNullException();
}
SourceAdvisor = adv;
}
static void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
IDragSourceAdvisor adv = GetDragSourceAdvisor(sender as UIElement);
if (!adv.IsDraggable(e.Source as UIElement))
{
return;
}
DragSource = new DragInfo(adv);
DragSource.DraggedElement = e.Source as UIElement;
DragSource.StartPoint = e.GetPosition(DragSource.DraggedElement);
DragSource.IsMouseDown = true;
}
private static void DragSourcePreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
// Make this the new drag source
IDragSourceAdvisor advisor = GetDragSourceAdvisor(sender as DependencyObject);
if (advisor.CanBeDragged(e.Source as UIElement) == false)
{
return;
}
s_DraggedElement = e.Source as UIElement;
s_DragStartPoint = e.GetPosition(GetTopContainer());
s_OffsetPoint = e.GetPosition(s_DraggedElement);
s_IsMouseDown = true;
}
private static void DragStarted(UIElement uiElement)
{
s_IsMouseDown = false;
Mouse.Capture(uiElement);
IDragSourceAdvisor advisor = GetDragSourceAdvisor(uiElement);
DataObject data = advisor.GetDataObject(s_DraggedElement, s_OffsetPoint);
DragDropEffects supportedEffects = advisor.SupportedEffects;
// Perform DragDrop
DragDropEffects effects = DragDrop.DoDragDrop(s_DraggedElement, data, supportedEffects);
advisor.FinishDrag(s_DraggedElement, effects);
// Clean up
RemovePreviewAdorner();
Mouse.Capture(null);
s_DraggedElement = null;
}
private static void OnDragSourceAdvisorChanged(DependencyObject depObj, DependencyPropertyChangedEventArgs args)
{
UIElement sourceElt = depObj as UIElement;
if (args.NewValue != null && args.OldValue == null)
{
sourceElt.PreviewMouseLeftButtonDown += DragSource_PreviewMouseLeftButtonDown;
sourceElt.PreviewMouseMove += DragSource_PreviewMouseMove;
sourceElt.PreviewMouseUp += DragSource_PreviewMouseUp;
// Set the Drag source UI
IDragSourceAdvisor advisor = args.NewValue as IDragSourceAdvisor;
advisor.SourceUI = sourceElt;
}
else if (args.NewValue == null && args.OldValue != null)
{
sourceElt.PreviewMouseLeftButtonDown -= DragSource_PreviewMouseLeftButtonDown;
sourceElt.PreviewMouseMove -= DragSource_PreviewMouseMove;
sourceElt.PreviewMouseUp -= DragSource_PreviewMouseUp;
}
}
/// <summary>
/// Called when the left mouse button is pressed while the mouse pointer is over drag source element.
/// </summary>
/// <param name="sender">Drag source element.</param>
/// <param name="e">Provides data for mouse button.</param>
private static void DragSourcePreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
// Make this the new drag source
currentSourceAdvisor = GetDragSourceAdvisor(sender as DependencyObject);
// Todo: consider to pass FrameworkElement.DataContext directly instead if UIElement
if (currentSourceAdvisor.IsDraggable(e.Source as UIElement) == false)
{
return;
}
dragElement = e.Source as UIElement;
// Important: for global (i.e. "window root grid") adorner layer use local (to element) mouse position as start point.
startPoint = e.GetPosition((UIElement)e.Source);
// For local (to element) adorner layer use global mouse position as start point instead.
//startPoint = e.GetPosition(GetTopContainer());
isMouseDown = true;
}
static void DragStarted(object uiObject)
{
// prepare
DragSource.IsMouseDown = false;
Mouse.Capture(DragSource.DraggedElement);
// gather data
IDragSourceAdvisor adv = GetDragSourceAdvisor(uiObject as UIElement);
DataObject data = DragSource.SourceAdvisor.GetDataObject(DragSource.DraggedElement, DragSource.StartPoint);
DragDropEffects supportedEffects = adv.SupportedEffects;
adv.SourceUI = uiObject as UIElement;
// Perform DragDrop
DragDropEffects effects = System.Windows.DragDrop.DoDragDrop(DragSource.DraggedElement, data, supportedEffects);
adv.FinishDrag(DragSource.DraggedElement, effects);
// Clean up
Mouse.Capture(null);
DragSource = null;
adv.SourceUI = null;
}
//private static WeakReference _CurrentDropTargetAdvisor = new WeakReference(null);
//private static IDropTargetAdvisor CurrentDropTargetAdvisor
//{
// get { return _CurrentDropTargetAdvisor.Target as IDropTargetAdvisor; }
// set { _CurrentDropTargetAdvisor.Target = value; }
//}
#region Dependency Properties Getter/Setters
public static void SetDragSourceAdvisor(DependencyObject depObj, IDragSourceAdvisor advisor)
{
depObj.SetValue(DragSourceAdvisorProperty, advisor);
}
private static void DragStarted(UIElement uiElt)
{
_isMouseDown = false;
Mouse.Capture(uiElt);
DataObject data = CurrentDragSourceAdvisor.GetDataObject(_draggedElt);
data.SetData(DragOffsetFormat, _offsetPoint);
DragDropEffects supportedEffects = CurrentDragSourceAdvisor.SupportedEffects;
// Perform DragDrop
DragDropEffects effects = System.Windows.DragDrop.DoDragDrop(_draggedElt, data, supportedEffects);
CurrentDragSourceAdvisor.FinishDrag(data, effects, _IsDropCompletedOK);
// Clean up
RemovePreviewAdorner();
Mouse.Capture(null);
_draggedElt = null;
CurrentDragSourceAdvisor = null;
_IsDropCompletedOK = false;
}
/* ____________________________________________________________________
* Drag Source events
* ____________________________________________________________________
*/
private static void DragSource_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
// Make this the new drag source
CurrentDragSourceAdvisor = GetDragSourceAdvisor(sender as DependencyObject);
//UIElement candidat = e.Source as UIElement;
//if (CurrentDragSourceAdvisor.IsDraggable(candidat) == false)
//{
// candidat = e.OriginalSource as UIElement;
// if (CurrentDragSourceAdvisor.IsDraggable(candidat) == false)
// return;
//}
UIElement candidat = e.OriginalSource as UIElement;
if (CurrentDragSourceAdvisor.IsDraggable(candidat) == false)
{
candidat = e.Source as UIElement;
if (CurrentDragSourceAdvisor.IsDraggable(candidat) == false)
return;
}
_draggedElt = candidat;
_dragStartPoint = e.GetPosition(null);
_offsetPoint = e.GetPosition(_draggedElt);
_isMouseDown = true;
}
public static void SetDragSourceAdvisor(DependencyObject depObj,
IDragSourceAdvisor advisor)
{
depObj.SetValue(DragSourceAdvisorProperty, advisor);
}
public static void SetDragSourceAdvisor(UIElement depo, IDragSourceAdvisor advisor)
{
depo.SetValue(DragSourceAdvisorProperty, advisor);
}
public static void SetDragSourceAdvisor(UIElement depo, IDragSourceAdvisor advisor)
{
depo.SetValue(DragSourceAdvisorProperty, advisor);
}
