新浪微博客户端(47)-在TextView中插入表情

// 发送点击广播(和android类似,区别在于android的广播是只要有上下文对象context,就可以发送)
    // iOS中的通知发送和接收都是通过NSNotificationCenter完成
    NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
    userInfo[DJEmotionDidSelctedEmotionKey] = btn.emotion;
    
    [[NSNotificationCenter defaultCenter] postNotificationName:DJEmotionDidSelectedNotification object:nil userInfo:userInfo];

- (void)registerNotificationReceiver {

    
    // 注册监听表情按钮点击通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onReceiveEmotionBtnClick:) name:DJEmotionDidSelectedNotification object:nil];
    
    
}


/** 接收到表情按钮点击通知 */
- (void)onReceiveEmotionBtnClick:(NSNotification *)notification {

    NSDictionary *intent =  notification.userInfo;
    DJEmotion *emotion = intent[DJEmotionDidSelctedEmotionKey];
    [self.textView insertEmotion:emotion];
    
}

- (void)insertEmotion:(DJEmotion *)emotion {


    // 插入表情
    if (emotion.code) { // Emoji表情
        [self insertText:[NSString emojiWithStringCode:emotion.code]];
    } else if (emotion.png) { // 表情图片
        NSString *emotionName = emotion.png;
        NSString *imagePath;
        if ([emotionName hasPrefix:@"d_"] || [emotionName hasPrefix:@"f_"] ||
            [emotionName hasPrefix:@"h_"] || [emotionName hasPrefix:@"l_"] || [emotionName hasPrefix:@"o_"] || [emotionName hasPrefix:@"w_"]) {
            imagePath = [NSString stringWithFormat:@"EmotionIcons/default/%@",emotion.png]; // 默认表情路径
        } else if ([emotionName hasPrefix:@"lxh_"]) {
            imagePath = [NSString stringWithFormat:@"EmotionIcons/lxh/%@",emotion.png]; // 浪小花表情路径
        }
        
        // 以textView的原本内容为基础构造一个attrStr
        NSMutableAttributedString *attrStr = [[NSMutableAttributedString alloc] initWithAttributedString:self.attributedText];
        
        // 构造表情附件
        NSTextAttachment *attachment = [[NSTextAttachment alloc] init];
        attachment.image = [UIImage imageNamed:imagePath];
        CGFloat attachmentWH = self.font.lineHeight;
        attachment.bounds = CGRectMake(0, -4, attachmentWH, attachmentWH);
        
        // 连接表情图片
        NSAttributedString *attachStr = [NSAttributedString attributedStringWithAttachment:attachment];
        
        // 将附件文本插入到光标所在的位置
        NSUInteger cursorLocation = self.selectedRange.location;
        [attrStr insertAttributedString:attachStr atIndex:cursorLocation];
        
        // 设置当前attrStr的字体,因为attrStr的字体无法通过textview.font属性来设置
        [attrStr addAttribute:NSFontAttributeName value:self.font range:NSMakeRange(0, attrStr.length)];
        
        // 更新当前textView内容
        self.attributedText = attrStr;
        
        // 修正当前光标位置(将光标移动到插入表情末尾,默认光标会跳转到所有文本最后)
        self.selectedRange = NSMakeRange(cursorLocation + 1, 0);
        
    }
    

}