add composite pattern example

Author: QianMo

Assets/Structural Patterns/Composite Pattern/Exmaple1.meta

@@ -0,0 +1,128 @@
+//-------------------------------------------------------------------------------------
+//	CompositePatternExample1.cs
+//-------------------------------------------------------------------------------------
+
+using System;
+using UnityEngine;
+using System.Collections;
+using System.Collections.Generic;
+
+
+//This real-world code demonstrates the Composite pattern used in building a graphical tree structure made up of primitive nodes(lines, circles, etc) and composite 
+// nodes(groups of drawing elements that make up more complex elements).
+
+namespace CompositePatternExample1
+{
+ public class CompositePatternExample1 : MonoBehaviour
+ {
+ void Start()
+ {
+ // Create a tree structure 
+ CompositeElement root =
+ new CompositeElement("Picture");
+ root.Add(new PrimitiveElement("Red Line"));
+ root.Add(new PrimitiveElement("Blue Circle"));
+ root.Add(new PrimitiveElement("Green Box"));
+
+ // Create a branch
+ CompositeElement comp =
+ new CompositeElement("Two Circles");
+ comp.Add(new PrimitiveElement("Black Circle"));
+ comp.Add(new PrimitiveElement("White Circle"));
+ root.Add(comp);
+
+ // Add and remove a PrimitiveElement
+ PrimitiveElement pe =
+ new PrimitiveElement("Yellow Line");
+ root.Add(pe);
+ root.Remove(pe);
+
+ // Recursively display nodes
+ root.Display(1);
+
+ }
+ }
+
+
+ /// <summary>
+ /// The 'Component' Treenode
+ /// </summary>
+ abstract class DrawingElement
+ {
+ protected string _name;
+
+ // Constructor
+ public DrawingElement(string name)
+ {
+ this._name = name;
+ }
+
+ public abstract void Add(DrawingElement d);
+ public abstract void Remove(DrawingElement d);
+ public abstract void Display(int indent);
+ }
+
+ /// <summary>
+ /// The 'Leaf' class
+ /// </summary>
+ class PrimitiveElement : DrawingElement
+ {
+ // Constructor
+ public PrimitiveElement(string name)
+ : base(name)
+ {
+ }
+
+ public override void Add(DrawingElement c)
+ {
+ Debug.Log("Cannot add to a PrimitiveElement");
+ }
+
+ public override void Remove(DrawingElement c)
+ {
+ Debug.Log("Cannot remove from a PrimitiveElement");
+ }
+
+ public override void Display(int indent)
+ {
+ Debug.Log(new String('-', indent) + " " + _name);
+ }
+ }
+
+ /// <summary>
+ /// The 'Composite' class
+ /// </summary>
+ class CompositeElement : DrawingElement
+ {
+ private List<DrawingElement> elements =
+ new List<DrawingElement>();
+
+ // Constructor
+ public CompositeElement(string name)
+ : base(name)
+ {
+ }
+
+ public override void Add(DrawingElement d)
+ {
+ elements.Add(d);
+ }
+
+ public override void Remove(DrawingElement d)
+ {
+ elements.Remove(d);
+ }
+
+ public override void Display(int indent)
+ {
+ Debug.Log(new String('-', indent) +
+ "+ " + _name);
+
+ // Display each child element on this node
+ foreach (DrawingElement d in elements)
+ {
+ d.Display(indent + 2);
+ }
+ }
+ }
+}

Assets/Structural Patterns/Composite Pattern/Exmaple1/CompositePatternExample1.cs

@@ -134,6 +134,7 @@
  <Compile Include="Assets\Structural Patterns\Adapter Pattern\Structure\AdapterStructure.cs" />
  <Compile Include="Assets\Structural Patterns\Bridge Pattern\Exmaple1\BridgePatternExample1.cs" />
  <Compile Include="Assets\Structural Patterns\Bridge Pattern\Structure\BridgeStructure.cs" />
+ <Compile Include="Assets\Structural Patterns\Composite Pattern\Exmaple1\CompositePatternExample1.cs" />
  <Compile Include="Assets\Structural Patterns\Composite Pattern\Structure\CompositeStructure.cs" />
  <Compile Include="Assets\Structural Patterns\Decorator Pattern\Structure\DecoratorStructure.cs" />
  <Compile Include="Assets\Structural Patterns\Facade Pattern\Structure\FacadeStructure.cs" />