EditText 表情符号过滤

import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
import android.widget.Toast;

import com.taihe.mplus.util.L;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
* @outher 孙磊磊
* create at 2016/2/23 17:38
* description 表情过滤
*/
public class ValidCharacterListener implements TextWatcher {
TextWatcher mListener;
EditText editText;
//匹配非表情符号的正则表达式
//    private final String reg="^[0-9A-Za-z\u4e00-\u9fa50~·！@#￥%……&*（）“”‘’：；《》？，。、<>?/.,';\":\\|~`!@#$%^&*()+-=_]*$";
private final String reg = "^[\u4e00-\u9fa5\u0020-\u007E\uFE30-\uFFA0。、……“”‘’《》——￥~]*$";
private Pattern pattern = Pattern.compile(reg);
//输入表情前的光标位置
private int cursorPos;
//输入表情前EditText中的文本
private String tmp;
//是否重置了EditText的内容
private boolean resetText;

@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
if (mListener != null)
mListener.beforeTextChanged(s, start, count, after);
if (!resetText) {
cursorPos = editText.getSelectionEnd();
tmp = s.toString();//这里用s.toString()而不直接用s是因为如果用s，那么，tmp和s在内存中指向的是同一个地址，s改变了，tmp也就改变了，那么表情过滤就失败了
}
}

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (mListener != null)
mListener.onTextChanged(s, start, before, count);
if(count>=0)
if (!resetText) {
//                CharSequence input = s.subSequence(cursorPos, cursorPos + count);
//正则匹配是否是表情符号
Matcher matcher = pattern.matcher(s.toString());
if (!matcher.matches()) {
resetText = true;
//是表情符号就将文本还原为输入表情符号之前的内容
editText.setText(tmp);
editText.setSelection(cursorPos);
editText.invalidate();

}
} else {
resetText = false;
}
}

@Override
public void afterTextChanged(Editable s) {
if (mListener != null) mListener.afterTextChanged(s);
}

public ValidCharacterListener setEditText(EditText editText) {
this.editText = editText;
editText.addTextChangedListener(this);
tmp = editText.getText().toString();
return  this;
}

public ValidCharacterListener addListener(TextWatcher listener) {
this.mListener = listener;
return this;
}
}