1 abstract class Component {
 2     protected String name;
 3
 4     public Component(String name) {
 5         this.name = name;
 6     }
 7
 8     public abstract void Add(Component c);
 9     public abstract void Remove(Component c);
10     public abstract void Display(int depth);
11 }

 1 class Leaf extends Component {
 2
 3     public Leaf(String name) {
 4         super(name);
 5     }
 6
 7     @Override
 8     public void Add(Component c) {
 9         System.out.println("Can not add to a leaf");
10     }
11
12     @Override
13     public void Remove(Component c) {
14         System.out.println("Can not remove from a leaf");
15     }
16
17     @Override
18     public void Display(int depth) {
19         String temp = "";
20         for (int i = 0; i < depth; i++)
21             temp += '-';
22         System.out.println(temp + name);
23     }
24
25 }

 1 class Composite extends Component {
 2
 3     private List<Component> children = new ArrayList<Component>();
 4
 5     public Composite(String name) {
 6         super(name);
 7     }
 8
 9     @Override
10     public void Add(Component c) {
11         children.add(c);
12     }
13
14     @Override
15     public void Remove(Component c) {
16         children.remove(c);
17     }
18
19     @Override
20     public void Display(int depth) {
21         String temp = "";
22         for (int i = 0; i < depth; i++)
23             temp += '-';
24         System.out.println(temp + name);
25
26         for (Component c : children) {
27             c.Display(depth + 2);
28         }
29     }
30
31 }

 1 public class CompositePattern {
 2
 3 public static void main(String[] args) {
 4     Composite root = new Composite("root");
 5     root.Add(new Leaf("Leaf A"));
 6     root.Add(new Leaf("Leaf B"));
 7
 8     Composite compX = new Composite("Composite X");
 9     compX.Add(new Leaf("Leaf XA"));
10     compX.Add(new Leaf("Leaf XB"));
11     root.Add(compX);
12
13     Composite compXY = new Composite("Composite XY");
14     compXY.Add(new Leaf("Leaf XYA"));
15     compXY.Add(new Leaf("Leaf XYB"));
16     compX.Add(compXY);
17
18     root.Display(1);
19 }
20
21 }

/** @attr ref android.R.styleable#ViewGroup_clipChildren * @attr ref android.R.styleable#ViewGroup_clipToPadding * @attr ref android.R.styleable#ViewGroup_layoutAnimation * @attr ref android.R.styleable#ViewGroup_animationCache * @attr ref android.R.styleable#ViewGroup_persistentDrawingCache * @attr ref android.R.styleable#ViewGroup_alwaysDrawnWithCache * @attr ref android.R.styleable#ViewGroup_addStatesFromChildren * @attr ref android.R.styleable#ViewGroup_descendantFocusability * @attr ref android.R.styleable#ViewGroup_animateLayoutChanges */ public abstract class ViewGroup extends View implements ViewParent, ViewManager {

  /*** Adds a child view. If no layout parameters are already set on the child, the* default parameters for this ViewGroup are set on the child.** @param child the child view to add** @see #generateDefaultLayoutParams()*/public void addView(View child) { addView(child, -1); } /** * Adds a child view. If no layout parameters are already set on the child, the * default parameters for this ViewGroup are set on the child. * * @param child the child view to add * @param index the position at which to add the child * * @see #generateDefaultLayoutParams() */ public void addView(View child, int index) { LayoutParams params = child.getLayoutParams(); if (params == null) { params = generateDefaultLayoutParams(); if (params == null) { throw new IllegalArgumentException("generateDefaultLayoutParams() cannot return null"); } } addView(child, index, params); } /** * Adds a child view with this ViewGroup's default layout parameters and the * specified width and height. * * @param child the child view to add */ public void addView(View child, int width, int height) { final LayoutParams params = generateDefaultLayoutParams(); params.width = width; params.height = height; addView(child, -1, params); } /** * Adds a child view with the specified layout parameters. * * @param child the child view to add * @param params the layout parameters to set on the child */ public void addView(View child, LayoutParams params) { addView(child, -1, params); } /** * Adds a child view with the specified layout parameters. * * @param child the child view to add * @param index the position at which to add the child * @param params the layout parameters to set on the child */ public void addView(View child, int index, LayoutParams params) { if (DBG) { System.out.println(this