protected override bool CanStart(object context)
{
RadItem draggedItem = context as RadItem;
if (draggedItem == null)
{
return(false);
}
if (!this.beginPoint.HasValue)
{
this.beginPoint = Control.MousePosition;
}
Point mouseDownStartPostion = draggedItem.ElementTree.Control.PointToClient(this.beginPoint.Value);
bool canStartDrag = (draggedItem as ISupportDrag).CanDrag(mouseDownStartPostion);
PreviewDragStartEventArgs args = new PreviewDragStartEventArgs(draggedItem);
args.CanStart = canStartDrag;
this.OnPreviewDragStart(args);
if (!args.CanStart)
{
this.beginPoint = null;
}
return(args.CanStart);
}
protected virtual void OnPreviewDragStart(PreviewDragStartEventArgs e)
{
EventHandler <PreviewDragStartEventArgs> eh = this.Events[PreviewDragStartEventKey] as EventHandler <PreviewDragStartEventArgs>;
if (eh != null)
{
eh(this, e);
}
}
protected virtual void OnPreviewDragStart(PreviewDragStartEventArgs e)
{
EventHandler <PreviewDragStartEventArgs> eventHandler = this.Events[RadDragDropService.PreviewDragStartEventKey] as EventHandler <PreviewDragStartEventArgs>;
if (eventHandler == null)
{
return;
}
eventHandler((object)this, e);
}
protected override bool CanStart(object context)
{
RadItem radItem = context as RadItem;
if (radItem == null)
{
return(false);
}
if (!this.beginPoint.HasValue)
{
this.beginPoint = new Point?(Control.MousePosition);
}
Point client = radItem.ElementTree.Control.PointToClient(this.beginPoint.Value);
bool flag = ((ISupportDrag)radItem).CanDrag(client);
PreviewDragStartEventArgs e = new PreviewDragStartEventArgs((ISupportDrag)radItem);
e.CanStart = flag;
this.OnPreviewDragStart(e);
if (!e.CanStart)
{
this.beginPoint = new Point?();
}
return(e.CanStart);
}
