internal static void StartDrag(object sender, HoldingRoutedEventArgs e, DragDropTrigger trigger, object initializeContext = null)
{
var dragDropElement = sender as IDragDropElement;
if (GetRunningOperation(dragDropElement as DependencyObject) != null)
{
return;
}
var uiSource = sender as UIElement;
var frameworkElementSource = sender as FrameworkElement;
double leftMargin = 0d;
double topMargin = 0d;
if (frameworkElementSource != null)
{
leftMargin = frameworkElementSource.Margin.Left;
topMargin = frameworkElementSource.Margin.Top;
}
if (dragDropElement == null || !dragDropElement.CanStartDrag(trigger, initializeContext))
{
return;
}
var context = dragDropElement.DragStarting(trigger, initializeContext);
var startDragPosition = e.GetPosition(context.DragSurface.RootElement);
var relativeStartDragPosition = e.GetPosition(uiSource);
relativeStartDragPosition = new Point(relativeStartDragPosition.X + leftMargin, relativeStartDragPosition.Y + topMargin);
var dragPositionMode = DragDrop.GetDragPositionMode(uiSource);
AddOperation(new DragDropOperation(context, dragDropElement, dragPositionMode, null, startDragPosition, relativeStartDragPosition));
}
DragStartingContext IDragDropElement.DragStarting(DragDropTrigger trigger, object initializeContext)
{
var dragVisual = this.ParentGrid.DragBehavior.GetReorderVisual(this);
if (dragVisual == null)
{
DataGridFlyoutHeader header = this.CreateHeader();
dragVisual = header;
}
// TODO: Consider exposing this through separate control.
dragVisual.DataContext = this.DataContext;
this.Opacity = 0.0;
var surface = this.OnDragSurfaceRequested();
var payload = new ReorderItemsDragOperation(this);
this.ParentGrid.DragBehavior.OnReorderStarted(this.DataContext as GroupDescriptorBase);
return(new DragStartingContext {
DragVisual = dragVisual, Payload = payload, DragSurface = surface, HitTestStrategy = new ColumnHeaderHittestStrategy(this, surface.RootElement)
});
}
DragStartingContext IDragDropElement.DragStarting(DragDropTrigger trigger, object initializeContext)
{
this.Opacity = 0;
DragStartingContext context = this.CreateDragContext();
this.Owner.DragBehavior.OnDragStarted(this);
this.Owner.CancelEdit();
this.Owner.ContentFlyout.Hide(DataGridFlyoutId.All);
this.IsSelected = false;
return(context);
}
bool IDragDropElement.CanStartDrag(DragDropTrigger trigger, object initializeContext)
{
if (trigger == DragDropTrigger.Hold)
{
return(this.ListView.IsItemReorderEnabled && this.ListView.GroupDescriptors.Count == 0 && !this.IsHandleEnabled);
}
else
{
if (initializeContext == this.reorderHandle && this.reorderHandle != null)
{
return(this.ListView.IsItemReorderEnabled && this.ListView.GroupDescriptors.Count == 0 && this.IsHandleEnabled);
}
return(this.ListView.IsActionOnSwipeEnabled && !(this.ListView.ReorderMode == ListViewReorderMode.Handle && this.ListView.IsItemReorderEnabled == true));
}
}
internal static void StartDrag(object sender, PointerRoutedEventArgs e, DragDropTrigger trigger, object initializeContext = null)
{
var dragDropElement = sender as IDragDropElement;
var uiSource = sender as UIElement;
if (dragDropElement == null)
{
dragDropElement = ElementTreeHelper.FindVisualAncestor <IDragDropElement>(uiSource);
}
if (GetRunningOperation(dragDropElement as DependencyObject) != null)
{
return;
}
UIElement uiDragDropElement = dragDropElement as UIElement;
var frameworkElementSource = dragDropElement as FrameworkElement;
double leftMargin = 0d;
double topMargin = 0d;
if (frameworkElementSource != null)
{
leftMargin = frameworkElementSource.Margin.Left;
topMargin = frameworkElementSource.Margin.Top;
}
if (dragDropElement == null || !dragDropElement.CanStartDrag(trigger, initializeContext))
{
return;
}
var context = dragDropElement.DragStarting(trigger, initializeContext);
if (context == null)
{
return;
}
var startDragPosition = e.GetCurrentPoint(context.DragSurface.RootElement).Position;
var relativeStartDragPosition = e.GetCurrentPoint(uiDragDropElement).Position;
var dragPositionMode = DragDrop.GetDragPositionMode(uiDragDropElement);
AddOperation(new DragDropOperation(context, dragDropElement, dragPositionMode, e.Pointer, startDragPosition, relativeStartDragPosition));
}
bool IDragDropElement.CanStartDrag(DragDropTrigger trigger, object initializeContext)
{
if (trigger == DragDropTrigger.MouseDrag && !this.IsHandleEnabled)
{
return(this.ListView.IsItemReorderEnabled);
}
if (trigger == DragDropTrigger.Hold)
{
return(this.ListView.IsItemReorderEnabled && !this.IsHandleEnabled);
}
else
{
if (this.isHandleEnabled && initializeContext == this.reorderHandle)
{
return(this.ListView.IsItemReorderEnabled && this.IsHandleEnabled);
}
return(this.ListView.IsActionOnSwipeEnabled && !(this.ListView.ReorderMode == ListViewReorderMode.Handle && this.ListView.IsItemReorderEnabled == true));
}
}
bool IDragDropElement.CanStartDrag(DragDropTrigger trigger, object initializeContext)
{
//// TODO: check CanStartReorder parameter
return(this.CanStartDrag(trigger, initializeContext));
}
internal virtual bool CanStartDrag(DragDropTrigger trigger, object initializeContext)
{
return(false);
}
internal void OnItemReorderHandlePressed(RadListViewItem radListViewItem, PointerRoutedEventArgs e, DragDropTrigger trigger, object sender = null)
{
DragDrop.StartDrag(radListViewItem, e, trigger, sender);
}
internal override bool CanStartDrag(DragDropTrigger trigger, object initializeContext)
{
return(this.Owner.Owner.DragBehavior != null && this.Owner.Owner.DragBehavior.CanStartDragInFlyout(this.DataContext as DataGridColumn));
}
DragStartingContext IDragDropElement.DragStarting(DragDropTrigger trigger, object initializeContext)
{
return(null);
}
bool IDragDropElement.CanStartDrag(DragDropTrigger trigger, object initializeContext)
{
return(false);
}
DragStartingContext IDragDropElement.DragStarting(DragDropTrigger trigger, object initializeContext)
{
this.ListView.CleanupSwipedItem();
DragStartingContext context = null;
var dataItem = this.DataContext;
if (dataItem != null)
{
bool isExecuted = false;
DragAction?dragAction = null;
if (trigger == DragDropTrigger.Drag && initializeContext != this.reorderHandle)
{
if (this.ListView.LayoutDefinition is StackLayoutDefinition)
{
if (this.Owner.Orientation == Orientation.Horizontal)
{
if (this.SwipeDirection == ListViewItemSwipeDirection.Forward)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailYForward);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.Backwards)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailYBackwards);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.All)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailY);
}
}
else
{
if (this.SwipeDirection == ListViewItemSwipeDirection.Forward)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailXForward);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.Backwards)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailXBackwards);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.All)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailX);
}
}
isExecuted = this.ListView.commandService.ExecuteCommand(CommandId.ItemDragStarting, new ItemDragStartingContext(dataItem, DragAction.ItemAction, this));
dragAction = DragAction.ItemAction;
this.PrepareDragVisual(dragAction.Value);
}
}
else
{
isExecuted = this.ListView.commandService.ExecuteCommand(CommandId.ItemDragStarting, new ItemDragStartingContext(dataItem, DragAction.Reorder, this));
dragAction = DragAction.Reorder;
this.PrepareDragVisual(dragAction.Value);
}
if (isExecuted && dragAction.HasValue)
{
this.CancelDirectManipulations();
if (dragAction.Value == DragAction.Reorder)
{
context = this.InitializeReorder();
}
else if (dragAction.Value == DragAction.ItemAction)
{
// We might need to cancel manipulations on the dragvisual
//// this.dragVisual.CancelDirectManipulations();
this.UpdateActionContentClipping(0);
context = new DragStartingContext
{
DragSurface = new CanvasDragSurface(this.ListView.childrenPanel, this.ListView.childrenPanel as Canvas, false),
DragVisual = this.dragVisual,
HitTestStrategy = new ListViewItemHittestStrategy(this, this),
Payload = DragAction.ItemAction
};
}
}
}
return(context);
}
internal override bool CanStartDrag(DragDropTrigger trigger, object initializeContext = null)
{
return(this.ParentGrid.DragBehavior != null && this.ParentGrid.DragBehavior.CanStartReorder(this.DataContext as GroupDescriptorBase));
}
bool IDragDropElement.CanStartDrag(DragDropTrigger trigger, object initializeContext)
{
return(this.Owner.DragBehavior != null && this.Owner.DragBehavior.CanStartDrag(this.Column));
}
DragStartingContext IDragDropElement.DragStarting(DragDropTrigger trigger, object initializeContext)
{
throw new NotImplementedException();
}
