compoundshape.java

《深入浅出设计模式》的完整源代码

package composite;
import java.util.ArrayList;
public class CompoundShape implements Shape {
  private ArrayList children = new ArrayList ();
  private String name ;
  private Shape parent =null ;
  private int iterationIndex = 0;
  public static class Iterator {
    private CompoundShape rootNode;
    private CompoundShape contextNode;
    boolean hasNextFlag = true;
    boolean isSpecialCase = false;
    public Iterator (CompoundShape t) {
      rootNode = t;
      contextNode = rootNode;
      rootNode.initIteration ();
      hasNextFlag = true;
      int lastIndex = t.children .size ()- 1;
      Object obj = contextNode .children .get (lastIndex );
      if (obj .getClass () == CompoundShape .class ){
        isSpecialCase = true ;
      }
    }
    public boolean hasNext () {
      return hasNextFlag ;
    }
    public PrimitiveShape next () {
      PrimitiveShape s = null ;
      int index = contextNode .iterationIndex ;
      int upperLimit = contextNode .children .size ();
      int i;
      Object obj = null ;
      for (i = index ; i < upperLimit ; ++i){
        obj = contextNode .children .get (i);
        contextNode .iterationIndex = i+1;
        if (obj .getClass () == CompoundShape .class ){
          contextNode = (CompoundShape )obj ;
          s = next ();
          break ;
        }
        else {
          s = (PrimitiveShape )obj ;
          break ;
        }
      }
      if ( isSpecialCase == false && contextNode == rootNode && i == upperLimit -1) {
        hasNextFlag = false ;
      }
      if (i == upperLimit - 1 && obj.getClass () != CompoundShape.class) {
        contextNode = (CompoundShape) contextNode.getParent ();
      }
      if (isSpecialCase == true && contextNode == rootNode &&
          i == upperLimit - 1) {
        hasNextFlag = false;
      }
      return s;
    } // end next()
  } // end class Iterator

  private void initIteration () {
    iterationIndex = 0;
    java.util.Iterator itr = children.iterator ();
    while (itr.hasNext ()) {
      Object obj = (Shape) itr.next ();
      if (this.getClass () == obj.getClass ()) {
        ( (CompoundShape) obj).iterationIndex = 0;
      }
    }
  }

  public CompoundShape () {
    iterationIndex = 0;
  }

  public Shape getParent () {
    return parent;
  }

  public void setParent (Shape s) {
    parent = s;
  }

  public String getName () {
    return name;
  }

  public void setName (String n) {
    name = n;
  }

  public void addShape (Shape shape) {
    children.add (shape);
    shape.setParent (this);
  }

  public void removeShape (Shape shape) {
    children.remove (shape);
  }

  public void printChildren () {
    java.util.Iterator itr = children.iterator ();
    while (itr.hasNext ()) {
      System.out.println ( ( (Shape) itr.next ()).getName ());
    }
  }

  public void draw () {
    java.util.Iterator itr = children.iterator ();
    while (itr.hasNext ()) {
      ( (Shape) itr.next ()).draw ();
    }
  }
}