Android 解析聊天表情的笔记

    应用需要用到聊天功能，考虑到开始需求不大，暂时先用第三方的。

    一研究发现界面风格有点不符合整体的风格，加上需要一些自己的特定的需求和界面显示，于是就决定调用第三方数据接口，界面自己写。功能只需要文字，表情和语音就ok，我选择先做表情的。

    表情一般都是用 [] 或者类似这种 "/:^_^", "/:^$^", "/:Q" 方式表示，我们用到的就是后者。解析消息类似于：  /:^_^你好，abc。

    基本思路就是：找到每个/:开头的，然后截取后面的N位，放到表情数组去匹配，然后继续下一个，直到末尾。接着统计了表情数组，记录了总共有哪些长度的表情字符，还按统计的数目对长度排了个序，出现次数多的长度排在前面。

public CharSequence initMessageRecord(String content){
        SpannableStringBuilder ssb = new SpannableStringBuilder(content);
        int[] smileLen = IMSmilyCache.getLenIndex();
        int contentLen = content.length();
        int index = 0;
        String tempContent = content;
        while (index < contentLen) {
            content = tempContent.substring(index);
            int nextIndex = content.indexOf("/:", 1);

            String tmpStr;
            if (nextIndex >= 0) {
                tmpStr = content.substring(0, nextIndex);
            } else {
                tmpStr = content;
            }
            int resId = IMSmilyCache.getInstance().getSimpleShortCutDrawable(tmpStr);
            if (resId != -1) {
                initFace(ssb, resId, index,index + tmpStr.length());
            } else {
                //截取的字符串没直接匹配到表情
                String tmpTarget;
                for (int tmpLen : smileLen) {
                    if (tmpStr.length() < tmpLen)
                        continue;
                    tmpTarget = tmpStr.substring(0, tmpLen);
                    resId = IMSmilyCache.getInstance().getSimpleShortCutDrawable(tmpTarget);
                    if (resId != -1) {
                        initFace(ssb, resId, index, index + tmpTarget.length());

                        tmpStr = tmpTarget;
                        break;
                    }
                }
            }
            index += tmpStr.length();
        }
        return ssb;
    }

    private void initFace(SpannableStringBuilder ssb, int resId, int start, int end) {
        Drawable d = activity.getResources().getDrawable(resId);
        d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());
        ImageSpan span = new ImageSpan(d, ImageSpan.ALIGN_BASELINE);
        ssb.setSpan(span, start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    }

public class IMSmilyCache {
    private static String[] meanings = {"微笑", "害羞", "吐舌头", "偷笑", "爱幕", "大笑", "跳舞", "飞吻", "安慰", "抱抱", "加油", "胜利", "强", "亲亲", "花痴", "露齿笑", "查找", "呼叫", "算账", "财迷", "好主意", "鬼脸", "天使", "再见", "流口水", "享受", "色情狂", "呆若木鸡", "思考", "迷惑", "疑问", "没钱了", "无聊", "怀疑", "嘘", "小样", "摇头", "感冒", "尴尬", "傻笑", "不会吧", "无奈", "流汗", "凄凉", "困了", "晕", "忧伤", "委屈", "悲泣", "大哭", "痛哭", "I服了U", "对不起", "再见", "皱眉", "好累", "生病", "吐", "背", "惊讶", "惊愕", "闭嘴", "欠扁", "鄙视你", "大怒", "生气", "财神", "学习雷锋", "恭喜发财", "小二", "老大", "邪恶", "单挑", "CS", "隐形人", "炸弹", "惊声尖叫", "漂亮MM", "帅哥", "招财猫", "成交", "鼓掌", "握手", "红唇", "玫瑰", "残花", "爱心", "心碎", "钱", "财物", "礼物", "收邮件", "电话", "举杯庆祝", "时钟", "等待", "很晚了", "飞机", "支付宝"};
    private static IMSmilyCache mSmilyCache = new IMSmilyCache();
    private static int[] lenIndex;

    /**
     * 此处优化表情查找速度，按出现次数的概率从大到小排序
     */
    static {
        HashMap<Integer, Integer> map = new HashMap<>();
        int[] len = new int[20];
        for (int i = 0; i < shortCuts.length; i++) {
            int cutsLen = shortCuts[i].length();
            len[cutsLen]++;
        }

        for (int i = 0; i < len.length; i++) {
            if (len[i] != 0) {
                map.put(len[i], i);
            }
        }

        SortUtil sortUtil = new SortUtil();
        sortUtil.sort(len);

        int size = 0;
        for (int i = 0; i < len.length; i++) {
            if (len[i] == 0) {
                size = i;
                break;
            }
        }
        lenIndex = new int[size];
        for (int i = 0; i < size; i++) {
            lenIndex[i] = map.get(len[i]);
        }

        LogUtils.fff(""+ Arrays.toString(lenIndex));
    }

    public static void main(String[] args) {
        System.out.println(shortCuts.length);
        System.out.println(meanings.length);
    }

    public static IMSmilyCache getInstance() {
        return mSmilyCache;
    }

    public String[] getShortCuts() {
        return shortCuts;
    }

    public int getSimpleShortCutDrawable(String context){
        for (int i = 0; i < shortCuts.length; i++) {
            if (context.equals(shortCuts[i])) {
                return smileResArray[i];
            }
        }
        if (context.equals("shanchu")) {
            return R.drawable.aliwx_shanchu_dw;
        }
        return -1;
    }

    public static int[] getLenIndex() {
        return lenIndex;
    }
}

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关于删除表情的操作，在使用过程用发现，使用系统自带的键盘能够正确的删除整个表情，于是删除按钮事件就只有两行代码

KeyEvent keyEventDown = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DEL);
editText.onKeyDown(KeyEvent.KEYCODE_DEL, keyEventDown);