TPolygonalNode.md

TPolygonalNode = class(TGraphNode)

This abstract class is the base class of the graph nodes that their shape can be represented by a polygon.

Properties

In addition to the properties of the TGraphNode class, the TPolygonalNode class has the following property:

• public Vertices: TPoints (read-only)
  TPoints = array of TPoint
  Gets the coordinates of the polygon's vertices as an array.

Methods

In addition to the methods of the TGraphNode class, the TPolygonalNode class has the following abstract method:

• procedure DefineVertices(const ARect: TRect; var Points: TPoints); abstract;
  Calculates the coordinates of the polygon's vertices relative to its bounding box.

  Parameter	Description
  ARect	The bounding box of the polygon
  Points	When the procedure returns, this dynamic array contains the coordinates of the polygon's vertices relative to the bounding box

  For example, the TRectangularNode class overrides the DefineVertices method in the following way:

  procedure TRectangularNode.DefineVertices(const ARect: TRect; var Points: TPoints);
  begin
    SetLength(Points, 4);
    Points[0].X := ARect.Left;
    Points[0].Y := ARect.Top;
    Points[1].X := ARect.Right;
    Points[1].Y := ARect.Top;
    Points[2].X := ARect.Right;
    Points[2].Y := ARect.Bottom;
    Points[3].X := ARect.Left;
    Points[3].Y := ARect.Bottom;
  end;