有趣的EditView为空时的抖动效果（用户名和密码）--第三方开源--ClearEditText

ClearEditText在github上的链接地址是：https://github.com/zhangphil/ClearEditText

用法十分简单，在布局中使用ClearEditText，在JAVA中setShakeAnimation()即可。

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:background="#95CAE4">

     <com.example.clearedittext.ClearEditText
         android:id="@+id/username"
         android:layout_marginTop="60dp"
         android:layout_width="fill_parent"
         android:background="@drawable/login_edittext_bg"
         android:drawableLeft="@drawable/icon_user"
         android:layout_marginLeft="10dip"
         android:layout_marginRight="10dip"
         android:singleLine="true"
         android:drawableRight="@drawable/delete_selector"
         android:hint="输入用户名"
         android:layout_height="wrap_content" >

     </com.example.clearedittext.ClearEditText>

     <com.example.clearedittext.ClearEditText
         android:id="@+id/password"
         android:layout_marginLeft="10dip"
         android:layout_marginRight="10dip"
         android:layout_marginTop="10dip"
         android:drawableLeft="@drawable/account_icon"
         android:hint="输入密码"
         android:singleLine="true"
         android:password="true"
         android:drawableRight="@drawable/delete_selector"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:layout_below="@id/username"
         android:background="@drawable/login_edittext_bg" >
     </com.example.clearedittext.ClearEditText>

     <Button
         android:id="@+id/login"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:layout_marginLeft="10dip"
         android:layout_marginRight="10dip"
         android:background="@drawable/login_button_bg"
         android:textSize="18sp"
         android:textColor="@android:color/white"
         android:layout_below="@+id/password"
         android:layout_marginTop="25dp"
         android:text="登录" />

 </RelativeLayout>

 package com.example.clearedittext;

 import android.content.Context;
 import android.graphics.drawable.Drawable;
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.View.OnFocusChangeListener;
 import android.view.animation.Animation;
 import android.view.animation.CycleInterpolator;
 import android.view.animation.TranslateAnimation;
 import android.widget.EditText;

 public class ClearEditText extends EditText implements
         OnFocusChangeListener, TextWatcher {
     /**
      * 删除按钮的引用
      */
     private Drawable mClearDrawable;
     /**
      * 控件是否有焦点
      */
     private boolean hasFoucs;

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

     public ClearEditText(Context context, AttributeSet attrs) {
         //这里构造方法也很重要，不加这个很多属性不能再XML里面定义
         this(context, attrs, android.R.attr.editTextStyle);
     } 

     public ClearEditText(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         init();
     }

     private void init() {
         //获取EditText的DrawableRight,假如没有设置我们就使用默认的图片,右边位置图片
         mClearDrawable = getCompoundDrawables()[2];
         if (mClearDrawable == null) {
 //            throw new NullPointerException("You can add drawableRight attribute in XML");
             mClearDrawable = getResources().getDrawable(R.drawable.delete_selector);
         } 

         mClearDrawable.setBounds(0, 0, mClearDrawable.getIntrinsicWidth(), mClearDrawable.getIntrinsicHeight());
         //默认设置隐藏图标
         setClearIconVisible(false);
         //设置焦点改变的监听
         setOnFocusChangeListener(this);
         //设置输入框里面内容发生改变的监听
         addTextChangedListener(this);
     } 

     /**
      * 因为我们不能直接给EditText设置点击事件，所以我们用记住我们按下的位置来模拟点击事件
      * 当我们按下的位置 在  EditText的宽度 - 图标到控件右边的间距 - 图标的宽度  和
      * EditText的宽度 - 图标到控件右边的间距之间我们就算点击了图标，竖直方向就没有考虑
      */
     @Override
     public boolean onTouchEvent(MotionEvent event) {
         if (event.getAction() == MotionEvent.ACTION_UP) {
             if (getCompoundDrawables()[2] != null) {

                 boolean touchable = event.getX() > (getWidth() - getTotalPaddingRight())
                         && (event.getX() < ((getWidth() - getPaddingRight())));

                 if (touchable) {
                     this.setText("");
                 }
             }
         }

         return super.onTouchEvent(event);
     }

     /**
      * 当ClearEditText焦点发生变化的时候，判断里面字符串长度设置清除图标的显示与隐藏
      */
     @Override
     public void onFocusChange(View v, boolean hasFocus) {
         this.hasFoucs = hasFocus;
         if (hasFocus) {
             setClearIconVisible(getText().length() > 0);
         } else {
             setClearIconVisible(false);
         }
     } 

     /**
      * 设置清除图标的显示与隐藏，调用setCompoundDrawables为EditText绘制上去
      * @param visible
      */
     protected void setClearIconVisible(boolean visible) {
         Drawable right = visible ? mClearDrawable : null;
         setCompoundDrawables(getCompoundDrawables()[0],
                 getCompoundDrawables()[1], right, getCompoundDrawables()[3]);
     } 

     /**
      * 当输入框里面内容发生变化的时候回调的方法
      */
     @Override
     public void onTextChanged(CharSequence s, int start, int count,
             int after) {
                 if(hasFoucs){
                     setClearIconVisible(s.length() > 0);
                 }
     } 

     @Override
     public void beforeTextChanged(CharSequence s, int start, int count,
             int after) { 

     } 

     @Override
     public void afterTextChanged(Editable s) { 

     } 

     /**
      * 设置晃动动画
      */
     public void setShakeAnimation(){
         this.setAnimation(shakeAnimation(5));
     }

     /**
      * 晃动动画
      * @param counts 1秒钟晃动多少下
      * @return
      */
     public static Animation shakeAnimation(int counts){
         Animation translateAnimation = new TranslateAnimation(0, 10, 0, 0);
         translateAnimation.setInterpolator(new CycleInterpolator(counts));
         translateAnimation.setDuration(1000);
         return translateAnimation;
     }

 }