带清空按钮的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) {
        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,假如没有设置使用默认的图片
        mClearDrawable = getCompoundDrawables()[2];
        if (mClearDrawable == null) {
            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);
    }
    @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
     */
    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) {
    }
}