package greenfoot.guifx.classes;

import javafx.scene.shape.LineTo;
import javafx.scene.shape.MoveTo;
import javafx.scene.shape.Path;
import threadchecker.OnThread;
import threadchecker.Tag;

import java.util.List;




| I tried many different variants before using this design:
|  - If you have each L piece in the diagram as separate items, it is difficult
|    to get the join to line up
|  - The same applies if you have the triangle as a separate piece
|  - If you use Polyline, it's awkward to draw multiple dangling "side-arms"
|*    as you have to redraw parts of the line.
*  Hence the finished solution: A Path that does all the inheritance arrows for
*  a particular class (down to its subclasses) as a single item, using a mixture
|  of LineTo and MoveTo.
|
@OnThread(Tag.FXPlatform)
public class InheritArrow
extends Path{    
   private final double ARROWHEAD_WIDTH = 10;
   
   private final double ARROWHEAD_HEIGHT = 10;
    
   
   public InheritArrow()
   {
      getStyleClass().add("inherit-arrow");     
      }

   
   


| Set the locations of the subclass arms (the pieces going from the main vertical
| line across to the right to touch the classes).
| @param width The width of each subclass arm from the vertical line
| @param yPositions The Y positions (relative to the top of this inherit arrow) of
|                   the arms to draw.
|
public void setArmLocations(double width, List<Double> yPositions)
   {        
      
      if (yPositions.isEmpty())
       {
         getElements().clear();
           
         return;         
         }
        
       
      
      getElements().setAll(
               
      new MoveTo(ARROWHEAD_WIDTH / 2.0, ARROWHEAD_HEIGHT), 
      new LineTo(0.0, ARROWHEAD_HEIGHT), 
      new LineTo(ARROWHEAD_WIDTH / 2.0, 0.0), 
      new LineTo(ARROWHEAD_WIDTH, ARROWHEAD_HEIGHT), 
      new LineTo(ARROWHEAD_WIDTH / 2.0, ARROWHEAD_HEIGHT) 
      );

       
      double indent = ARROWHEAD_WIDTH / 2.0;
       
      for (Double yPosition : yPositions)
       {            
         
         getElements().addAll(
               
         new LineTo(indent, yPosition),
               
         new LineTo(width, yPosition),
               
         new MoveTo(indent, yPosition)
           
         );         
         }     
      } 
   }