android仿微信联系人索引列表功能

public class SlideBar extends Button{ 

 public interface OnTouchAssortListener{ 
 public void onTouchAssortListener(String s); 
 } 

 // 分类 
 private static final String[] ASSORT_TEXT = {"A", "B", "C", "D", "E", "F", "G", 
  "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", 
  "U", "V", "W", "X", "Y", "Z" ,"#"};

 private Paint mPaint = new Paint(); 
 private int mSelectIndex = -1; 
 private OnTouchAssortListener mListener = null;
 private Activity mAttachActivity;
 PopupWindow mPopupWindow = null;
 View layoutView;
 TextView text;

 public SlideBar(Context context){ 
 this(context,null); 
 } 

 public SlideBar(Context context, AttributeSet attrs) { 
 this(context, attrs,0); 
 } 

 public SlideBar(Context context, AttributeSet attrs, int defStyle){ 
 super(context, attrs, defStyle);
 mAttachActivity = (Activity)context;
 init(context);
 } 
 private void init(Context context) {
 layoutView = LayoutInflater.from(context).inflate(R.layout.alert_dialog_menu_layout, null);
 text = (TextView) layoutView.findViewById(R.id.content);
 }

 public void setOnTouchAssortListener(OnTouchAssortListener listener) {
 this.mListener = listener;
 }

 @Override 
 protected void onDraw(Canvas canvas){ 
 super.onDraw(canvas);
 int nHeight = getHeight(); 
 int hWidth = getWidth(); 
 int nAssortCount = ASSORT_TEXT.length;
 int nInterval = nHeight / nAssortCount;

 for (int i = 0; i < nAssortCount; i++){ 
  mPaint.setAntiAlias(true); // 抗锯齿 
  mPaint.setTypeface(Typeface.DEFAULT_BOLD); // 默认粗体 
  mPaint.setColor(Color.parseColor("#5f5f5f")); // 白色 
  if (i == mSelectIndex){ 
  // 被选择的字母改变颜色和粗体 
  mPaint.setColor(Color.parseColor("#3399ff")); 
  mPaint.setFakeBoldText(true); 
  mPaint.setTextSize(30); 
  } 
  float xPos = hWidth / 2 - mPaint.measureText(ASSORT_TEXT[i]) / 2; // 计算字母的X坐标 
  float yPos = nInterval * i + nInterval; // 计算字母的Y坐标 
  canvas.drawText(ASSORT_TEXT[i], xPos, yPos, mPaint); 
  mPaint.reset(); 
 } 
 } 

 @Override
 public boolean dispatchTouchEvent(MotionEvent event) {
 //判断是哪一个字母被点击了
 int nIndex = (int) (event.getY() / getHeight() * ASSORT_TEXT.length);
 if (nIndex >= 0 && nIndex < ASSORT_TEXT.length){
  switch (event.getAction()){ 
  case MotionEvent.ACTION_MOVE: 
  // 如果滑动改变 
  if (mSelectIndex != nIndex){ 
   mSelectIndex = nIndex;
   showCharacter(ASSORT_TEXT[mSelectIndex]);
   if (mListener != null){
   mListener.onTouchAssortListener(ASSORT_TEXT[mSelectIndex]);
   }
  } 
  break; 
  case MotionEvent.ACTION_DOWN: 
  mSelectIndex = nIndex; 
  showCharacter(ASSORT_TEXT[mSelectIndex]);
  if (mListener != null){ 
   mListener.onTouchAssortListener(ASSORT_TEXT[mSelectIndex]); 
  } 

  break; 
  case MotionEvent.ACTION_UP: 
  disShowCharacter();
  mSelectIndex = -1; 
  break; 
  } 
 } else { 
  mSelectIndex = -1; 
  disShowCharacter();
 } 
 invalidate();
 return true;
 }

 private void disShowCharacter() {
 if (mPopupWindow != null) {
  mPopupWindow.dismiss();
  mPopupWindow=null;
 }
 }

 /**
 * 显示弹出的字符
 * @param string
 */
 private void showCharacter(String string){

 if (mPopupWindow != null){
  text.setText(string);
 } else{ 
  mPopupWindow = new PopupWindow(layoutView, 100, 100, false);
  mPopupWindow.showAtLocation(mAttachActivity.getWindow().getDecorView(), Gravity.CENTER, 0, 0);
 }
 text.setText(string);
 }
} 

public class DataBean {

 public static final int TYPE_CHARACTER = 0;
 public static final int TYPE_DATA = 1;
 private int item_type;
 private String item_en;
 private String name;
 private String phone;
 /*其他成员*/

 public DataBean(String name,String phone,int type){
 CharacterParser parser = CharacterParser.getInstance();
 this.name = name;
 this.phone = phone;
 this.item_type = type;
 this.item_en = parser.getSelling(name).toUpperCase().trim();
 if(!item_en.matches("[A-Z]+")){
  item_en = "#"+item_en;
 }
 }

 /*
 *省略geter和seter方法 
 */
}

public class PinyinComparator implements Comparator{
 public int compare(DataBean o1, DataBean o2){
 if (o1.getItem_en().equals("@")
  || o2.getItem_en().equals("#")){
  return -1;
 } else if (o1.getItem_en().equals("#")
  || o2.getItem_en().equals("@")) {
  return 1;
 } else {
  return o1.getItem_en().compareTo(o2.getItem_en());
 }
 }
}

public class ListUtil {
 public static void sortList(List list){
 List _List = new ArrayList();
 Collections.sort(list, new PinyinComparator());
 DataBean dataBean = new DataBean(getFirstCharacter(list.get(0).getItem_en()), "",DataBean.TYPE_CHARACTER);
 String currentCharacter = getFirstCharacter(list.get(0).getItem_en());
 _List.add(dataBean);
 _List.add(list.get(0));
 for(int i=1;i