internal static CustomPopupPlacement[] PositionPopup(
CustomPlacementMode placement,
Size popupSize,
Size targetSize,
Point offset,
FrameworkElement child = null)
{
Matrix transformToDevice = default;
if (child != null)
{
Helper.TryGetTransformToDevice(child, out transformToDevice);
}
CustomPopupPlacement preferredPlacement = CalculatePopupPlacement(placement, popupSize, targetSize, offset, child, transformToDevice);
CustomPopupPlacement?alternativePlacement = null;
var alternativePlacementMode = GetAlternativePlacementMode(placement);
if (alternativePlacementMode.HasValue)
{
alternativePlacement = CalculatePopupPlacement(alternativePlacementMode.Value, popupSize, targetSize, offset, child, transformToDevice);
}
if (alternativePlacement.HasValue)
{
return(new[] { preferredPlacement, alternativePlacement.Value });
}
else
{
return(new[] { preferredPlacement });
}
}
private static CustomPlacementMode?GetAlternativePlacementMode(CustomPlacementMode placement)
{
switch (placement)
{
case CustomPlacementMode.Top:
return(CustomPlacementMode.Bottom);
case CustomPlacementMode.Bottom:
return(CustomPlacementMode.Top);
case CustomPlacementMode.Left:
return(CustomPlacementMode.Right);
case CustomPlacementMode.Right:
return(CustomPlacementMode.Left);
case CustomPlacementMode.Full:
return(null);
case CustomPlacementMode.TopEdgeAlignedLeft:
return(CustomPlacementMode.BottomEdgeAlignedLeft);
case CustomPlacementMode.TopEdgeAlignedRight:
return(CustomPlacementMode.BottomEdgeAlignedRight);
case CustomPlacementMode.BottomEdgeAlignedLeft:
return(CustomPlacementMode.TopEdgeAlignedLeft);
case CustomPlacementMode.BottomEdgeAlignedRight:
return(CustomPlacementMode.TopEdgeAlignedRight);
case CustomPlacementMode.LeftEdgeAlignedTop:
return(CustomPlacementMode.RightEdgeAlignedTop);
case CustomPlacementMode.LeftEdgeAlignedBottom:
return(CustomPlacementMode.RightEdgeAlignedBottom);
case CustomPlacementMode.RightEdgeAlignedTop:
return(CustomPlacementMode.RightEdgeAlignedTop);
case CustomPlacementMode.RightEdgeAlignedBottom:
return(CustomPlacementMode.LeftEdgeAlignedBottom);
//case CustomPopupPlacementMode.Auto:
default:
return(null);
}
}
private static CustomPopupPlacement CalculatePopupPlacement(
CustomPlacementMode placement,
Size popupSize,
Size targetSize,
Point offset,
FrameworkElement child = null,
Matrix transformToDevice = default)
{
Point point;
PopupPrimaryAxis primaryAxis;
switch (placement)
{
case CustomPlacementMode.Top:
point = new Point((targetSize.Width - popupSize.Width) / 2, -popupSize.Height);
primaryAxis = PopupPrimaryAxis.Horizontal;
break;
case CustomPlacementMode.Bottom:
point = new Point((targetSize.Width - popupSize.Width) / 2, targetSize.Height);
primaryAxis = PopupPrimaryAxis.Horizontal;
break;
case CustomPlacementMode.Left:
point = new Point(-popupSize.Width, (targetSize.Height - popupSize.Height) / 2);
primaryAxis = PopupPrimaryAxis.Vertical;
break;
case CustomPlacementMode.Right:
point = new Point(targetSize.Width, (targetSize.Height - popupSize.Height) / 2);
primaryAxis = PopupPrimaryAxis.Vertical;
break;
case CustomPlacementMode.Full:
point = new Point((targetSize.Width - popupSize.Width) / 2, (targetSize.Height - popupSize.Height) / 2);
primaryAxis = PopupPrimaryAxis.None;
break;
case CustomPlacementMode.TopEdgeAlignedLeft:
point = new Point(0, -popupSize.Height);
primaryAxis = PopupPrimaryAxis.Horizontal;
break;
case CustomPlacementMode.TopEdgeAlignedRight:
point = new Point(targetSize.Width - popupSize.Width, -popupSize.Height);
primaryAxis = PopupPrimaryAxis.Horizontal;
break;
case CustomPlacementMode.BottomEdgeAlignedLeft:
point = new Point(0, targetSize.Height);
primaryAxis = PopupPrimaryAxis.Horizontal;
break;
case CustomPlacementMode.BottomEdgeAlignedRight:
point = new Point(targetSize.Width - popupSize.Width, targetSize.Height);
primaryAxis = PopupPrimaryAxis.Horizontal;
break;
case CustomPlacementMode.LeftEdgeAlignedTop:
point = new Point(-popupSize.Width, 0);
primaryAxis = PopupPrimaryAxis.Vertical;
break;
case CustomPlacementMode.LeftEdgeAlignedBottom:
point = new Point(-popupSize.Width, targetSize.Height - popupSize.Height);
primaryAxis = PopupPrimaryAxis.Vertical;
break;
case CustomPlacementMode.RightEdgeAlignedTop:
point = new Point(targetSize.Width, 0);
primaryAxis = PopupPrimaryAxis.Vertical;
break;
case CustomPlacementMode.RightEdgeAlignedBottom:
point = new Point(targetSize.Width, targetSize.Height - popupSize.Height);
primaryAxis = PopupPrimaryAxis.Vertical;
break;
//case CustomPopupPlacementMode.Auto:
default:
throw new ArgumentOutOfRangeException(nameof(placement));
}
if (child != null)
{
Vector childOffset = VisualTreeHelper.GetOffset(child);
if (transformToDevice != default)
{
childOffset = transformToDevice.Transform(childOffset);
}
point -= childOffset;
}
return(new CustomPopupPlacement(point, primaryAxis));
}
public static void SetPlacement(DependencyObject element, CustomPlacementMode value)
{
element.SetValue(PlacementProperty, value);
}
