android随机生成圆形云标签效果

package com.dyl.cloudtags; 
 
import java.util.ArrayList; 
import java.util.Arrays; 
import java.util.Random; 
 
import android.app.Activity; 
import android.content.SharedPreferences; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.EditText; 
import android.widget.ImageView; 
import android.widget.TextView; 
import android.widget.Toast; 
 
public class MainActivity extends Activity { 
 
 private KeywordsFlow keywordsFlow; 
 private String[] keywords; 
 public static final String SEARCH_HISTORY = "search_history"; 
 private ArrayList<SearchDataPojo> searchItem; 
 private String longhistory; 
 private SharedPreferences sp; 
 private ArrayList<String> history; 
 private EditText world_shopping_search_input; 
 private TextView world_city_refresh, clear_history; 
 private ImageView toSearch; 
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
  initView(); 
  initSearchHistory(); 
  refreshTags(); 
 } 
 
 private void initView() { 
  world_shopping_search_input = (EditText) findViewById(R.id.world_shopping_search_input); 
  keywordsFlow = (KeywordsFlow) findViewById(R.id.keywordsflow); 
 
  world_city_refresh = (TextView) findViewById(R.id.world_city_refresh); 
  world_city_refresh.setOnClickListener(new OnClickListener() { 
 
   @Override 
   public void onClick(View arg0) { 
    refreshTags(); 
   } 
  }); 
 
  clear_history = (TextView) findViewById(R.id.clear_history); 
  clear_history.setOnClickListener(new OnClickListener() { 
 
   @Override 
   public void onClick(View arg0) { 
    clearSearchHistory(); 
   } 
  }); 
 
  toSearch = (ImageView) findViewById(R.id.toSearch); 
  toSearch.setOnClickListener(new OnClickListener() { 
 
   @Override 
   public void onClick(View arg0) { 
    saveSearchHistory(); 
    refreshTags(); 
   } 
  }); 
 } 
 
 private void refreshTags() { 
  initSearchHistory(); 
  keywordsFlow.setDuration(800l); 
  keywordsFlow.setOnItemClickListener(new OnClickListener() { 
 
   @Override 
   public void onClick(View v) { 
    String keyword = ((TextView) v).getText().toString();// 获得点击的标签 
    world_shopping_search_input.setText(keyword); 
   } 
  }); 
  // 添加 
  feedKeywordsFlow(keywordsFlow, keywords); 
  keywordsFlow.go2Show(KeywordsFlow.ANIMATION_IN); 
 } 
 
 private static void feedKeywordsFlow(KeywordsFlow keywordsFlow, String[] arr) { 
  Random random = new Random(); 
  for (int i = 0; i < KeywordsFlow.MAX; i++) { 
   int ran = random.nextInt(arr.length); 
   String tmp = arr[ran]; 
   keywordsFlow.feedKeyword(tmp); 
  } 
 } 
 
 /** 
  * 读取历史搜索记录 
  */ 
 private void initSearchHistory() { 
  sp = getSharedPreferences(MainActivity.SEARCH_HISTORY, 0); 
  longhistory = sp.getString(MainActivity.SEARCH_HISTORY, ""); 
  if (!longhistory.equals("")) { 
   keywords = longhistory.split(","); 
   searchItem = new ArrayList<SearchDataPojo>(); 
   for (int i = 0; i < keywords.length; i++) { 
    searchItem.add(new SearchDataPojo().setContent(keywords[i])); 
   } 
  } else {// 如果SharedPreferences没有值得话，就显示默认的数据 
   keywords = new String[] { "口味虾", "牛蛙", "火锅", "真功夫", "料理", 
     "密室逃", "天成房", "波比艾" }; 
  } 
 } 
 
 /* 
  * 保存搜索记录 
  */ 
 private void saveSearchHistory() { 
  String text = world_shopping_search_input.getText().toString().trim(); 
  Toast.makeText(this, text, Toast.LENGTH_LONG).show(); 
  if (!text.equals("") && text != null) { 
   if (text.length() < 1) { 
    return; 
   } 
   sp = getSharedPreferences(SEARCH_HISTORY, 0); 
   String longhistory = sp.getString(SEARCH_HISTORY, ""); 
   String[] tmpHistory = longhistory.split(","); 
   history = new ArrayList<String>(Arrays.asList(tmpHistory)); 
   if (history.size() > 0) { 
    int i; 
    for (i = 0; i < history.size(); i++) { 
     if (text.equals(history.get(i))) { 
      history.remove(i); 
      break; 
     } 
    } 
    history.add(0, text); 
   } 
   if (history.size() > 0) { 
    StringBuilder sb = new StringBuilder(); 
    for (int i = 0; i < history.size(); i++) { 
     sb.append(history.get(i) + ","); 
    } 
    sp.edit().putString(SEARCH_HISTORY, sb.toString()).commit(); 
   } else { 
    sp.edit().putString(SEARCH_HISTORY, text + ",").commit(); 
   } 
   clear_history.setVisibility(View.VISIBLE); 
  } 
 } 
 
 // 清除历史数据 
 private void clearSearchHistory() { 
  searchItem.removeAll(searchItem); 
  sp.edit().clear().commit(); 
  Toast.makeText(this, "清除历史记录", Toast.LENGTH_LONG).show(); 
 } 
} 

package com.dyl.cloudtags; 
 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.PaintFlagsDrawFilter; 
import android.util.AttributeSet; 
import android.widget.TextView; 
 
public class CircleView extends TextView { 
 
 private Paint mBgPaint = new Paint(); 
 
 PaintFlagsDrawFilter pfd = new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG|Paint.FILTER_BITMAP_FLAG); 
 
 public CircleView(Context context, AttributeSet attrs, int defStyle) { 
  super(context, attrs, defStyle); 
  // TODO Auto-generated constructor stub 
 } 
 
 public CircleView(Context context, AttributeSet attrs) { 
  super(context, attrs); 
  // TODO Auto-generated constructor stub 
  mBgPaint.setColor(Color.WHITE); 
  mBgPaint.setAntiAlias(true); 
 } 
 
 public CircleView(Context context) { 
  super(context); 
  // TODO Auto-generated constructor stub 
  mBgPaint.setColor(Color.WHITE); 
  mBgPaint.setAntiAlias(true); 
 } 
 
 @Override 
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
  // TODO Auto-generated method stub 
  super.onMeasure(widthMeasureSpec, heightMeasureSpec); 
  int measuredWidth = getMeasuredWidth(); 
  int measuredHeight = getMeasuredHeight(); 
  int max = Math.max(measuredWidth, measuredHeight); 
  setMeasuredDimension(max, max); 
 } 
 
 @Override 
 public void setBackgroundColor(int color) { 
  // TODO Auto-generated method stub 
  mBgPaint.setColor(color); 
 } 
 
 /** 
  * 设置通知个数显示 
  * @param text 
  */ 
 public void setNotifiText(int text){ 
  //  if(text>99){ 
  //   String string = 99+"+"; 
  //   setText(string); 
  //   return; 
  //  } 
  setText(text+""); 
 } 
 
 @Override 
 public void draw(Canvas canvas) { 
  // TODO Auto-generated method stub 
  canvas.setDrawFilter(pfd); 
  canvas.drawCircle(getWidth()/2, getHeight()/2, Math.max(getWidth(), getHeight())/2, mBgPaint); 
  super.draw(canvas); 
 } 
} 

package com.dyl.cloudtags; 
 
import java.util.LinkedList; 
import java.util.Random; 
import java.util.Vector; 
import android.content.Context; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.drawable.GradientDrawable; 
import android.util.AttributeSet; 
import android.view.Gravity; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewTreeObserver.OnGlobalLayoutListener; 
import android.view.animation.AlphaAnimation; 
import android.view.animation.Animation; 
import android.view.animation.Animation.AnimationListener; 
import android.view.animation.AnimationSet; 
import android.view.animation.AnimationUtils; 
import android.view.animation.Interpolator; 
import android.view.animation.ScaleAnimation; 
import android.view.animation.TranslateAnimation; 
import android.widget.FrameLayout; 
 
public class KeywordsFlow extends FrameLayout implements OnGlobalLayoutListener { 
 
 public static final int IDX_X = 0; 
 public static final int IDX_Y = 1; 
 public static final int IDX_TXT_LENGTH = 2; 
 public static final int IDX_DIS_Y = 3; 
 /** 由外至内的动画。 */ 
 public static final int ANIMATION_IN = 1; 
 /** 由内至外的动画。 */ 
 public static final int ANIMATION_OUT = 2; 
 /** 位移动画类型：从外围移动到坐标点。 */ 
 public static final int OUTSIDE_TO_LOCATION = 1; 
 /** 位移动画类型：从坐标点移动到外围。 */ 
 public static final int LOCATION_TO_OUTSIDE = 2; 
 /** 位移动画类型：从中心点移动到坐标点。 */ 
 public static final int CENTER_TO_LOCATION = 3; 
 /** 位移动画类型：从坐标点移动到中心点。 */ 
 public static final int LOCATION_TO_CENTER = 4; 
 public static final long ANIM_DURATION = 800l; 
 public static final int MAX = 12; 
 public static final int TEXT_SIZE_MAX = 20; 
 public static final int TEXT_SIZE_MIN = 10; 
 private OnClickListener itemClickListener; 
 private static Interpolator interpolator; 
 private static AlphaAnimation animAlpha2Opaque; 
 private static AlphaAnimation animAlpha2Transparent; 
 private static ScaleAnimation animScaleLarge2Normal, animScaleNormal2Large, 
   animScaleZero2Normal, animScaleNormal2Zero; 
 /** 存储显示的关键字。 */ 
 private Vector<String> vecKeywords; 
 private int width, height; 
 /** 
  * go2Show()中被赋值为true，标识开发人员触发其开始动画显示。<br/> 
  * 本标识的作用是防止在填充keywrods未完成的过程中获取到width和height后提前启动动画。<br/> 
  * 在show()方法中其被赋值为false。<br/> 
  * 真正能够动画显示的另一必要条件：width 和 height不为0。<br/> 
  */ 
 private boolean enableShow; 
 private Random random; 
 
 private int txtAnimInType, txtAnimOutType; 
 /** 最近一次启动动画显示的时间。 */ 
 private long lastStartAnimationTime; 
 /** 动画运行时间。 */ 
 private long animDuration; 
 private Context context; 
 public KeywordsFlow(Context context) { 
  super(context); 
  init(); 
 } 
 
 public KeywordsFlow(Context context, AttributeSet attrs) { 
  super(context, attrs); 
  init(); 
 } 
 
 public KeywordsFlow(Context context, AttributeSet attrs, int defStyle) { 
  super(context, attrs, defStyle); 
  init(); 
 } 
 
 private void init() { 
  lastStartAnimationTime = 0l; 
  animDuration = ANIM_DURATION; 
  random = new Random(); 
  vecKeywords = new Vector<String>(MAX); 
  getViewTreeObserver().addOnGlobalLayoutListener(this); 
  interpolator = AnimationUtils.loadInterpolator(getContext(), 
    android.R.anim.decelerate_interpolator); 
  animAlpha2Opaque = new AlphaAnimation(0.0f, 1.0f); 
  animAlpha2Transparent = new AlphaAnimation(1.0f, 0.0f); 
  animScaleLarge2Normal = new ScaleAnimation(2, 1, 2, 1); 
  animScaleNormal2Large = new ScaleAnimation(1, 2, 1, 2); 
  animScaleZero2Normal = new ScaleAnimation(0, 1, 0, 1); 
  animScaleNormal2Zero = new ScaleAnimation(1, 0, 1, 0); 
 } 
 
 public long getDuration() { 
  return animDuration; 
 } 
 
 public void setDuration(long duration) { 
  animDuration = duration; 
 } 
 
 public boolean feedKeyword(String keyword) { 
  boolean result = false; 
  if (vecKeywords.size() < MAX) { 
   result = vecKeywords.add(keyword); 
  } 
  return result; 
 } 
 
 /** 
  * 开始动画显示。<br/> 
  * 之前已经存在的TextView将会显示退出动画。<br/> 
  * 
  * @return 正常显示动画返回true；反之为false。返回false原因如下：<br/> 
  *   1.时间上不允许，受lastStartAnimationTime的制约；<br/> 
  *   2.未获取到width和height的值。<br/> 
  */ 
 public boolean go2Show(int animType) { 
  if (System.currentTimeMillis() - lastStartAnimationTime > animDuration) { 
   enableShow = true; 
   if (animType == ANIMATION_IN) { 
    txtAnimInType = OUTSIDE_TO_LOCATION; 
    txtAnimOutType = LOCATION_TO_CENTER; 
   } else if (animType == ANIMATION_OUT) { 
    txtAnimInType = CENTER_TO_LOCATION; 
    txtAnimOutType = LOCATION_TO_OUTSIDE; 
   } 
   disapper(); 
   boolean result = show(); 
   return result; 
  } 
  return false; 
 } 
 
 private void disapper() { 
  int size = getChildCount(); 
  for (int i = size - 1; i >= 0; i--) { 
   final CircleView txv = (CircleView) getChildAt(i); 
   if (txv.getVisibility() == View.GONE) { 
    removeView(txv); 
    continue; 
   } 
   FrameLayout.LayoutParams layParams = (LayoutParams) txv 
     .getLayoutParams(); 
   int[] xy = new int[] { layParams.leftMargin, layParams.topMargin, 
     txv.getWidth() }; 
   AnimationSet animSet = getAnimationSet(xy, (width >> 1), 
     (height >> 1), txtAnimOutType); 
   txv.startAnimation(animSet); 
   animSet.setAnimationListener(new AnimationListener() { 
    public void onAnimationStart(Animation animation) { 
    } 
 
    public void onAnimationRepeat(Animation animation) { 
    } 
 
    public void onAnimationEnd(Animation animation) { 
     txv.setOnClickListener(null); 
     txv.setClickable(false); 
     txv.setVisibility(View.GONE); 
    } 
   }); 
  } 
 } 
 
 private boolean show() { 
  if (width > 0 && height > 0 && vecKeywords != null 
    && vecKeywords.size() > 0 && enableShow) { 
   enableShow = false; 
   lastStartAnimationTime = System.currentTimeMillis(); 
   int xCenter = width >> 1, yCenter = height >> 1; 
   int size = vecKeywords.size(); 
   int xItem = width / size, yItem = height / size; 
   LinkedList<Integer> listX = new LinkedList<Integer>(), listY = new LinkedList<Integer>(); 
   for (int i = 0; i < size; i++) { 
    // 准备随机候选数，分别对应x/y轴位置 
    listX.add(i * xItem); 
    listY.add(i * yItem + (yItem >> 2)); 
   } 
   LinkedList<CircleView> listTxtTop = new LinkedList<CircleView>(); 
   LinkedList<CircleView> listTxtBottom = new LinkedList<CircleView>(); 
   for (int i = 0; i < size; i++) { 
    String keyword = vecKeywords.get(i); 
    // 随机位置，糙值 
    int xy[] = randomXY(random, listX, listY, xItem); 
    // 实例化TextView 
    final CircleView txv = new CircleView(getContext()); 
    txv.setBackgroundResource(R.drawable.text_view_border); 
    txv.setGravity(Gravity.CENTER); 
    txv.setOnClickListener(itemClickListener); 
    txv.setText(keyword); 
    txv.setTextColor(Color.WHITE); 
    txv.setPadding(8, 6, 8, 6); 
    txv.setSingleLine(true); 
    int r = random.nextInt(256); 
    int g= random.nextInt(256); 
    int b = random.nextInt(256); 
    int mColor = Color.rgb(r, g, b); 
    GradientDrawable myGrad = (GradientDrawable)txv.getBackground(); 
    myGrad.setColor(mColor); 
//    txv.setBackgroundColor(mColor); 
    // 获取文本长度 
    Paint paint = txv.getPaint(); 
    int strWidth = (int) Math.ceil(paint.measureText(keyword)); 
    xy[IDX_TXT_LENGTH] = strWidth; 
    // 第一次修正:修正x坐标 
    if (xy[IDX_X] + strWidth > width - (xItem >> 1)) { 
     int baseX = width - strWidth; 
     // 减少文本右边缘一样的概率 
     xy[IDX_X] = baseX - xItem + random.nextInt(xItem >> 1); 
    } else if (xy[IDX_X] == 0) { 
     // 减少文本左边缘一样的概率 
     xy[IDX_X] = Math.max(random.nextInt(xItem), xItem / 3); 
    } 
    xy[IDX_DIS_Y] = Math.abs(xy[IDX_Y] - yCenter); 
    txv.setTag(xy); 
    if (xy[IDX_Y] > yCenter) { 
     listTxtBottom.add(txv); 
    } else { 
     listTxtTop.add(txv); 
    } 
   } 
   attach2Screen(listTxtTop, xCenter, yCenter, yItem); 
   attach2Screen(listTxtBottom, xCenter, yCenter, yItem); 
   return true; 
  } 
  return false; 
 } 
 
 /** 修正TextView的Y坐标将将其添加到容器上。 */ 
 private void attach2Screen(LinkedList<CircleView> listTxt, int xCenter, 
   int yCenter, int yItem) { 
  int size = listTxt.size(); 
  sortXYList(listTxt, size); 
  for (int i = 0; i < size; i++) { 
   CircleView txv = listTxt.get(i); 
   int[] iXY = (int[]) txv.getTag(); 
   // 第二次修正:修正y坐标 
   int yDistance = iXY[IDX_Y] - yCenter; 
   // 对于最靠近中心点的，其值不会大于yItem<br/> 
   // 对于可以一路下降到中心点的，则该值也是其应调整的大小<br/> 
   int yMove = Math.abs(yDistance); 
   inner: for (int k = i - 1; k >= 0; k--) { 
    int[] kXY = (int[]) listTxt.get(k).getTag(); 
    int startX = kXY[IDX_X]; 
    int endX = startX + kXY[IDX_TXT_LENGTH]; 
    // y轴以中心点为分隔线，在同一侧 
    if (yDistance * (kXY[IDX_Y] - yCenter) > 0) { 
     if (isXMixed(startX, endX, iXY[IDX_X], iXY[IDX_X] 
       + iXY[IDX_TXT_LENGTH])) { 
      int tmpMove = Math.abs(iXY[IDX_Y] - kXY[IDX_Y]); 
      if (tmpMove > yItem) { 
       yMove = tmpMove; 
      } else if (yMove > 0) { 
       // 取消默认值。 
       yMove = 0; 
      } 
      break inner; 
     } 
    } 
   } 
   if (yMove > yItem) { 
    int maxMove = yMove - yItem; 
    int randomMove = random.nextInt(maxMove); 
    int realMove = Math.max(randomMove, maxMove >> 1) * yDistance 
      / Math.abs(yDistance); 
    iXY[IDX_Y] = iXY[IDX_Y] - realMove; 
    iXY[IDX_DIS_Y] = Math.abs(iXY[IDX_Y] - yCenter); 
    // 已经调整过前i个需要再次排序 
    sortXYList(listTxt, i + 1); 
   } 
   FrameLayout.LayoutParams layParams = new FrameLayout.LayoutParams( 
     FrameLayout.LayoutParams.WRAP_CONTENT, 
     FrameLayout.LayoutParams.WRAP_CONTENT); 
   layParams.gravity = Gravity.LEFT | Gravity.TOP; 
   layParams.leftMargin = iXY[IDX_X]; 
   layParams.topMargin = iXY[IDX_Y]; 
   addView(txv, layParams); 
   // 动画 
   AnimationSet animSet = getAnimationSet(iXY, xCenter, yCenter, 
     txtAnimInType); 
   txv.startAnimation(animSet); 
  } 
 } 
 
 public AnimationSet getAnimationSet(int[] xy, int xCenter, int yCenter, 
   int type) { 
  AnimationSet animSet = new AnimationSet(true); 
  animSet.setInterpolator(interpolator); 
  if (type == OUTSIDE_TO_LOCATION) { 
   animSet.addAnimation(animAlpha2Opaque); 
   animSet.addAnimation(animScaleLarge2Normal); 
   TranslateAnimation translate = new TranslateAnimation((xy[IDX_X] 
     + (xy[IDX_TXT_LENGTH] >> 1) - xCenter) << 1, 0, 
     (xy[IDX_Y] - yCenter) << 1, 0); 
   animSet.addAnimation(translate); 
  } else if (type == LOCATION_TO_OUTSIDE) { 
   animSet.addAnimation(animAlpha2Transparent); 
   animSet.addAnimation(animScaleNormal2Large); 
   TranslateAnimation translate = new TranslateAnimation(0, (xy[IDX_X] 
     + (xy[IDX_TXT_LENGTH] >> 1) - xCenter) << 1, 0, 
     (xy[IDX_Y] - yCenter) << 1); 
   animSet.addAnimation(translate); 
  } else if (type == LOCATION_TO_CENTER) { 
   animSet.addAnimation(animAlpha2Transparent); 
   animSet.addAnimation(animScaleNormal2Zero); 
   TranslateAnimation translate = new TranslateAnimation(0, 
     (-xy[IDX_X] + xCenter), 0, (-xy[IDX_Y] + yCenter)); 
   animSet.addAnimation(translate); 
  } else if (type == CENTER_TO_LOCATION) { 
   animSet.addAnimation(animAlpha2Opaque); 
   animSet.addAnimation(animScaleZero2Normal); 
   TranslateAnimation translate = new TranslateAnimation( 
     (-xy[IDX_X] + xCenter), 0, (-xy[IDX_Y] + yCenter), 0); 
   animSet.addAnimation(translate); 
  } 
  animSet.setDuration(animDuration); 
  return animSet; 
 } 
 
 /** 
  * 根据与中心点的距离由近到远进行冒泡排序。 
  * 
  * @param endIdx 
  *   起始位置。 
  * @param txtArr 
  *   待排序的数组。 
  * 
  */ 
 private void sortXYList(LinkedList<CircleView> listTxt, int endIdx) { 
  for (int i = 0; i < endIdx; i++) { 
   for (int k = i + 1; k < endIdx; k++) { 
    if (((int[]) listTxt.get(k).getTag())[IDX_DIS_Y] < ((int[]) listTxt 
      .get(i).getTag())[IDX_DIS_Y]) { 
     CircleView iTmp = listTxt.get(i); 
     CircleView kTmp = listTxt.get(k); 
     listTxt.set(i, kTmp); 
     listTxt.set(k, iTmp); 
    } 
   } 
  } 
 } 
 
 /** A线段与B线段所代表的直线在X轴映射上是否有交集。 */ 
 private boolean isXMixed(int startA, int endA, int startB, int endB) { 
  boolean result = false; 
  if (startB >= startA && startB <= endA) { 
   result = true; 
  } else if (endB >= startA && endB <= endA) { 
   result = true; 
  } else if (startA >= startB && startA <= endB) { 
   result = true; 
  } else if (endA >= startB && endA <= endB) { 
   result = true; 
  } 
  return result; 
 } 
 
 //得到随机坐标 
 private int[] randomXY(Random ran, LinkedList<Integer> listX, 
   LinkedList<Integer> listY, int xItem) { 
  int[] arr = new int[4]; 
  arr[IDX_X] = listX.remove(ran.nextInt(listX.size())); 
  arr[IDX_Y] = listY.remove(ran.nextInt(listY.size())); 
  return arr; 
 } 
 
 public void onGlobalLayout() { 
  int tmpW = getWidth(); 
  int tmpH = getHeight(); 
  if (width != tmpW || height != tmpH) { 
   width = tmpW; 
   height = tmpH; 
   show(); 
  } 
 } 
 
 public Vector<String> getKeywords() { 
  return vecKeywords; 
 } 
 
 public void rubKeywords() { 
  vecKeywords.clear(); 
 } 
 
 /** 直接清除所有的TextView。在清除之前不会显示动画。 */ 
 public void rubAllViews() { 
  removeAllViews(); 
 } 
 
 public void setOnItemClickListener(OnClickListener listener) { 
  itemClickListener = listener; 
 } 
} 

package com.dyl.cloudtags; 
 
 
/** 
 * 搜索记录 
 * @author dengyalan 
 * 
 */ 
public class SearchDataPojo { 
 
 private String content = ""; 
 
 public String getContent() { 
  return content; 
 } 
 
 public SearchDataPojo setContent(String content) { 
  this.content = content; 
  return this; 
 } 
}