public virtual void CompleteDrag(DragVisualContext context, bool dragSuccessful)
{
if (context == null)
{
return;
}
context.ClearDragVisual();
}
public override Windows.Foundation.Rect PositionDragHost(DragVisualContext context, Point dragPoint, Point relativeStartPosition)
{
if (context == null)
{
return(Rect.Empty);
}
Rect position = base.PositionDragHost(context, dragPoint, relativeStartPosition);
Canvas.SetLeft(context.DragVisualHost, position.X);
Canvas.SetTop(context.DragVisualHost, position.Y);
return(position);
}
public override void CompleteDrag(DragVisualContext context, bool dragSuccessful)
{
if (context == null)
{
return;
}
base.CompleteDrag(context, dragSuccessful);
// Check if Adorner is in visual tree (calling this when element is unloaded will throw COM exception).
if (this.adorner.Parent != null)
{
this.adorner.Children.Remove(context.DragVisualHost);
}
}
public DragDropOperation(DragStartingContext startContext, IDragDropElement source, DragPositionMode positionMode, Pointer pointer, Point startClickPosition, Point relativeStartPosition)
{
this.sourceElement = source;
this.dragSurface = startContext.DragSurface;
this.dragContext = new DragContext(startContext.Payload, this);
this.hitTestStrategy = startContext.HitTestStrategy ?? new DragHitTestStrategy(this.dragSurface.RootElement);
this.dragVisualContext = this.dragSurface.CreateDragContext();
this.dragVisualContext.DragStartPosition = new Point(startClickPosition.X - relativeStartPosition.X - startContext.DragVisual.Margin.Left, startClickPosition.Y - relativeStartPosition.Y - startContext.DragVisual.Margin.Top);
this.dragVisualContext.PositionRestriction = positionMode;
this.dragVisualContext.PrepareDragVisual(startContext.DragVisual);
this.startDragPosition = startClickPosition;
this.relativeStartPosition = relativeStartPosition;
this.InitializeVisual();
this.dragVisualContext.DragVisualHost.PointerMoved += this.DragVisualHost_PointerMoved;
this.dragVisualContext.DragVisualHost.PointerReleased += this.DragVisualHost_PointerReleased;
this.dragVisualContext.DragVisualHost.PointerCaptureLost += this.DragVisualHost_PointerCaptureLost;
if (pointer != null && this.dragVisualContext.DragVisualHost.CapturePointer(pointer))
{
this.capturedPointer = pointer;
this.originalFocusedElement = FocusManager.GetFocusedElement() as Control;
if (this.originalFocusedElement != null)
{
this.originalFocusState = this.originalFocusedElement.FocusState;
}
((Control)this.dragVisualContext.DragVisualHost).Focus(FocusState.Programmatic);
}
else if (pointer != null)
{
this.CancelDrag();
}
else
{
this.capturePending = true;
}
this.dragSurface.RootElement.KeyDown += this.RootElement_KeyDown;
}
private static Point GetRestrictedDragPoint(DragVisualContext context, Point dragPoint, Point relativeStartPosition)
{
double x = dragPoint.X - relativeStartPosition.X;
double y = dragPoint.Y - relativeStartPosition.Y;
switch (context.PositionRestriction)
{
case DragPositionMode.RailX:
y = context.DragStartPosition.Y;
break;
case DragPositionMode.RailY:
x = context.DragStartPosition.X;
break;
case DragPositionMode.RailXForward:
y = context.DragStartPosition.Y;
x = Math.Max(0, x);
break;
case DragPositionMode.RailXBackwards:
y = context.DragStartPosition.Y;
x = Math.Min(0, x);
break;
case DragPositionMode.RailYForward:
x = context.DragStartPosition.X;
y = Math.Max(0, y);
break;
case DragPositionMode.RailYBackwards:
x = context.DragStartPosition.X;
y = Math.Min(0, y);
break;
case DragPositionMode.Free:
default:
break;
}
return(new Point(x, y));
}
private static Point GetRestrictedDragPoint(DragVisualContext context, Point dragPoint, Point relativeStartPosition, Thickness maxPositionOffset)
{
double x = RadMath.CoerceValue(dragPoint.X - relativeStartPosition.X, -maxPositionOffset.Right, maxPositionOffset.Left);
double y = RadMath.CoerceValue(dragPoint.Y - relativeStartPosition.Y, -maxPositionOffset.Bottom, maxPositionOffset.Top);
switch (context.PositionRestriction)
{
case DragPositionMode.RailX:
y = context.DragStartPosition.Y;
break;
case DragPositionMode.RailY:
x = context.DragStartPosition.X;
break;
case DragPositionMode.RailXForward:
y = context.DragStartPosition.Y;
x = Math.Max(0, x);
break;
case DragPositionMode.RailXBackwards:
y = context.DragStartPosition.Y;
x = Math.Min(0, x);
break;
case DragPositionMode.RailYForward:
x = context.DragStartPosition.X;
y = Math.Max(0, y);
break;
case DragPositionMode.RailYBackwards:
x = context.DragStartPosition.X;
y = Math.Min(0, y);
break;
case DragPositionMode.Free:
default:
break;
}
return(new Point(x, y));
}
public virtual Rect PositionDragHost(DragVisualContext context, Point dragPoint, Point relativeStartPosition)
{
if (context == null)
{
return(Rect.Empty);
}
Point restrictedPoint = DragSurfaceBase.GetRestrictedDragPoint(context, dragPoint, relativeStartPosition);
if (this.ShouldTruncateToBounds)
{
restrictedPoint = this.TruncateToBounds(context.DragVisualHost, restrictedPoint);
}
var rect = new Rect(restrictedPoint, context.DragVisualHost.RenderSize);
context.DragVisualHost.Arrange(rect);
return(rect);
}
private static Point GetRestrictedDragPoint(DragVisualContext context, Point dragPoint, Point relativeStartPosition)
{
double x = dragPoint.X - relativeStartPosition.X;
double y = dragPoint.Y - relativeStartPosition.Y;
switch (context.PositionRestriction)
{
case DragPositionMode.RailX:
y = context.DragStartPosition.Y;
break;
case DragPositionMode.RailY:
x = context.DragStartPosition.X;
break;
case DragPositionMode.Free:
default:
break;
}
return(new Point(x, y));
}