##RichEditor 类似新浪微博EditText,可@某人,#插入话题,表情。

###实现思路

1. 在光标处插入特殊字符

    //将特殊字符插入到EditText 中显示
    int index = getSelectionStart();//光标位置
    Editable editable = getText();//原先内容
    SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder(editable);
    Spanned htmlText = Html.fromHtml(String.format(String.format("<font color='%s'>" + insertContent + "</font>", insertColor)));
    spannableStringBuilder.insert(index, htmlText);
    spannableStringBuilder.insert(index + htmlText.length(), "\b");
    setText(spannableStringBuilder);
    setSelection(index + htmlText.length() + 1);
   

2. 实现特殊字符选中删除效果

    /**
    * 监听删除键 <br/>
    * 1.光标在话题后面,将整个话题内容删除 <br/>
    * 2.光标在普通文字后面,删除一个字符
    *
    */
    this.setOnKeyListener(new View.OnKeyListener() {
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_DEL && event.getAction() == KeyEvent.ACTION_DOWN) {
    int selectionStart = getSelectionStart();
    int selectionEnd = getSelectionEnd();
    /**
    * 如果光标起始和结束不在同一位置,删除文本
    */
    if (selectionStart != selectionEnd) {
    // 查询文本是否属于目标对象,若是移除列表数据
    String tagetText = getText().toString().substring(
    selectionStart, selectionEnd);
    for (int i = 0; i < insertModelList.size(); i++) {
    InsertModel object = insertModelList.get(i);
    if (tagetText.equals(object.getInsertContent())) {
    insertModelList.remove(object);
    }
    }
    return false;
    }
    int lastPos = 0;
    Editable editable = getText();
    // 遍历判断光标的位置
    for (int i = 0; i < insertModelList.size(); i++) {
    String objectText = insertModelList.get(i).getInsertContent();
    lastPos = getText().toString().indexOf(objectText, lastPos);
    if (lastPos != -1) {
    if (selectionStart != 0 && selectionStart >= lastPos && selectionStart <= (lastPos + objectText.length())) {
    // 选中话题
    setSelection(lastPos, lastPos + objectText.length());
    // 设置背景色
    editable.setSpan(new BackgroundColorSpan(BACKGROUND_COLOR), lastPos, lastPos + objectText.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    return true;
    }
    }
    lastPos += objectText.length();
    }
    }
    return false;
    }
    });
   

3. 设置点击特殊字符光标自动移动到特殊字符之后

    /**
    * 监听光标的位置,若光标处于话题内容中间则移动光标到话题结束位置
    *
    */
    @Override
    protected void onSelectionChanged(int selStart, int selEnd) {
    super.onSelectionChanged(selStart, selEnd);
    if (insertModelList == null || insertModelList.size() == 0)
    return;
    int startPostion = 0;
    int endPostion = 0;
    String insertContent = "";
    for (int i = 0; i < insertModelList.size(); i++) {
    insertContent = insertModelList.get(i).getInsertContent();
    startPostion = getText().toString().indexOf(insertContent);
    endPostion = startPostion + insertContent.length();
    if (startPostion != -1 && selStart > startPostion
    && selStart <= endPostion) {// 若光标处于话题内容中间则移动光标到话题结束位置
    setSelection(endPostion);
    }
    }}