protected DesignerThumb CreateThumb(PlacementAlignment alignment, Cursor cursor)
{
DesignerThumb designerThumb = new DesignerThumb { Alignment = alignment, Cursor = cursor, IsPrimarySelection = true};
AdornerPanel.SetPlacement(designerThumb, Place(designerThumb, alignment));
adornerPanel.Children.Add(designerThumb);
DragListener = new DragListener(designerThumb);
DragListener.Started += drag_Started;
DragListener.Changed += drag_Changed;
DragListener.Completed += drag_Completed;
return designerThumb;
}
/// <summary>
/// Places resize thumbs at their respective positions
/// and streches out thumbs which are at the center of outline to extend resizability across the whole outline
/// </summary>
/// <param name="designerThumb"></param>
/// <param name="alignment"></param>
/// <param name="index">if using a polygon or multipoint adorner this is the index of the point in the Points array</param>
/// <returns></returns>
protected PointTrackerPlacementSupport Place(ref DesignerThumb designerThumb, PlacementAlignment alignment, int index = -1)
{
PointTrackerPlacementSupport placement = new PointTrackerPlacementSupport(ExtendedItem.View as Shape, alignment, index);
return placement;
}
/// <summary>
/// Places resize thumbs at their respective positions
/// and streches out thumbs which are at the center of outline to extend resizability across the whole outline
/// </summary>
/// <param name="designerThumb"></param>
/// <param name="alignment"></param>
/// <returns></returns>
private RelativePlacement Place(ref DesignerThumb designerThumb,PlacementAlignment alignment)
{
RelativePlacement placement = new RelativePlacement(alignment.Horizontal,alignment.Vertical);
if (alignment.Horizontal == HorizontalAlignment.Center)
{
placement.WidthRelativeToContentWidth = 1;
placement.HeightOffset = 6;
designerThumb.Opacity = 0;
return placement;
}
if (alignment.Vertical == VerticalAlignment.Center)
{
placement.HeightRelativeToContentHeight = 1;
placement.WidthOffset = 6;
designerThumb.Opacity = 0;
return placement;
}
placement.WidthOffset = 6;
placement.HeightOffset = 6;
return placement;
}
/// <summary>
/// is invoked whenever a line is selected on the canvas, remember that the adorners are created for each line object and never destroyed
/// </summary>
protected override void OnInitialized()
{
base.OnInitialized();
resizeThumbs = new DesignerThumb[]
{
CreateThumb(PlacementAlignment.TopLeft, Cursors.Cross),
CreateThumb(PlacementAlignment.BottomRight, Cursors.Cross)
};
extendedItemArray[0] = this.ExtendedItem;
Invalidate();
this.ExtendedItem.PropertyChanged += OnPropertyChanged;
resizeBehavior = PlacementOperation.GetPlacementBehavior(extendedItemArray);
UpdateAdornerVisibility();
}