设计模式-创建型-构建者模式

基本概念：

1. 构建者模式的定义
   将构建的过程和表示过程进行分离
   构建的过程：隐藏
   表示过程 ： 开放

2. 构建者模式的场景
   创建一个复杂的对象，同时改复杂对象有很多默认值（初始化）的时候，可以使用构建者模式。（典型：给对象设置可选参数）

3. 构建者模式案例
   AlretDialog

4. 构建者模式-UML类图结构
   4.1 分析角色划分
   角色一：产品
   角色二：抽象构建者
   角色三：具体构建者
   角色四：组装

   public class ComListDialog extends Dialog {

   public static Context mContext;
   
   private TextView btnCancel;
   
   private LinearLayout lyContents;
   
   private static List<CommonListMenuItem> btnMenu;
   
   public ComListDialog(@NonNull Context context) {
       super(context, R.style.common_dialog);
   }
   
   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       Window win = getWindow();
       win.getDecorView().setPadding(0, 0, 0, 0);
       WindowManager.LayoutParams lp = win.getAttributes();
       lp.width = WindowManager.LayoutParams.MATCH_PARENT;
       lp.height = WindowManager.LayoutParams.MATCH_PARENT;
       win.setWindowAnimations(R.style.listDialogWindowAnim);
       win.setAttributes(lp);
       setContentView(R.layout.common_list_dialog);
       setCanceledOnTouchOutside(true);
       setCancelable(true);
       findViewById(R.id.menu_base_content).setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               dismiss();
           }
       });
       btnCancel = (TextView) findViewById(R.id.menu_cancel);
       btnCancel.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
               dismiss();
           }
       });
       lyContents = (LinearLayout) findViewById(R.id.menu_content);
       if (btnMenu != null && btnMenu.size() > 0) {
           for (int i = 0; i < btnMenu.size(); i++) {
               View v = View.inflate(mContext, R.layout.common_list_dialog_item, null);
               if (i == 0) {
                   v.findViewById(R.id.menu_line).setVisibility(View.GONE);
               }
               TextView tv = (TextView) v.findViewById(R.id.menu_button);
               tv.setText(btnMenu.get(i).getName());
               tv.setTextColor(btnMenu.get(i).color);
               tv.setPadding(20, 0, 20, 0);
               tv.setGravity(Gravity.CENTER);
               if (btnMenu.get(i).textsize != 0) {
                   tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, btnMenu.get(i).textsize);
               }
               tv.setOnClickListener(btnMenu.get(i).getClickListener());
               lyContents.addView(v);
           }
       }
   }
   //  类似于Javabean
   public static class CommonListMenuItem {
       private String name;
       private View.OnClickListener clickListener;
       private int color = Color.parseColor("#209E89");
       private int textsize = 0;
       public CommonListMenuItem(String name, View.OnClickListener clickListener, int color) {
           this.name = name;
           this.clickListener = clickListener;
           this.color = color;
       }
       public CommonListMenuItem(String name, View.OnClickListener clickListener, int color, int textsize) {
           this.name = name;
           this.clickListener = clickListener;
           this.color = color;
           this.textsize = textsize;
       }
       public CommonListMenuItem(String name, int color, int textsize) {
           this.name = name;
           this.color = color;
           this.textsize = textsize;
       }
       public CommonListMenuItem(String name, View.OnClickListener clickListener) {
           this.name = name;
           this.clickListener = clickListener;
       }
       public String getName() {
           return name;
       }
       public void setName(String name) {
           this.name = name;
       }
       public View.OnClickListener getClickListener() {
           return clickListener;
       }
       public void setClickListener(View.OnClickListener clickListener) {
           this.clickListener = clickListener;
       }
   }
   //构建
   public static class Builder {
       public Builder(Context context) {
           mContext = context;
           btnMenu = new ArrayList<CommonListMenuItem>();
       }
       public Builder addMenuItem(CommonListMenuItem item) {
           btnMenu.add(item);
           return this;
       }
       public ComListDialog show() {
           if (null != mContext && (!(mContext instanceof Activity) || !((Activity) mContext).isFinishing())) {
               ComListDialog dialog = new ComListDialog(mContext);
               dialog.show();
               return dialog;
           }
           return null;
       }
   }
   @Override
   public void dismiss() {
       super.dismiss();
       btnMenu = null;
       mContext = null;
   }}