Android利用SpannableString实现格式化微博内容

public class WeiboPattern {

 // #话题#
 public static final String REGEX_TOPIC = "#[\\p{Print}\\p{InCJKUnifiedIdeographs}&&[^#]]+#";
 // [表情]
 public static final String REGEX_EMOTION = "\\[(\\S+?)\\]";
 // url
 public static final String REGEX_URL = "http://[a-zA-Z0-9+&@#/%?=~_\\\\-|!:,\\\\.;]*[a-zA-Z0-9+&@#/%=~_|]";
 // @人
 public static final String REGEX_AT = "@[\\w\\p{InCJKUnifiedIdeographs}-]{1,26}";

 
 public static final Pattern PATTERN_TOPIC = Pattern.compile(REGEX_TOPIC);
 public static final Pattern PATTERN_EMOTION = Pattern.compile(REGEX_EMOTION);
 public static final Pattern PATTERN_URL = Pattern.compile(REGEX_URL);
 public static final Pattern PATTERN_AT = Pattern.compile(REGEX_AT);

 public static final String SCHEME_TOPIC = "topic:";
 public static final String SCHEME_URL = "url:";
 public static final String SCHEME_AT = "at:";

}

/**
 * 格式化微博文本
 *
 * @param context 上下文
 * @param source 源文本
 * @param textView 目标 TextView
 * @return SpannableStringBuilder
 */
public static SpannableStringBuilder formatWeiBoContent(Context context, String source, TextView textView) {

 // 获取到 TextView 的文字大小，后面的 ImageSpan 需要用到该值
 int textSize = (int) textView.getTextSize();

 // 若要部分 SpannableString 可点击，需要如下设置
 textView.setMovementMethod(LinkMovementMethod.getInstance());

 // 将要格式化的 String 构建成一个 SpannableStringBuilder
 SpannableStringBuilder value = new SpannableStringBuilder(source);

 // 使用正则匹配话题
 Linkify.addLinks(value, WeiboPattern.PATTERN_TOPIC, WeiboPattern.SCHEME_TOPIC);
 // 使用正则匹配链接
 Linkify.addLinks(value, WeiboPattern.PATTERN_URL, WeiboPattern.SCHEME_URL);
 // 使用正则匹配@用户
 Linkify.addLinks(value, WeiboPattern.PATTERN_AT, WeiboPattern.SCHEME_AT);

 // 自定义的匹配部分的点击效果
 MyClickableSpan clickSpan;

 // 获取上面到所有 addLinks 后的匹配部分(这里一个匹配项被封装成了一个 URLSpan 对象)
 URLSpan[] urlSpans = value.getSpans(0, value.length(), URLSpan.class);

 // 遍历所有的 URLSpan
 for (final URLSpan urlSpan : urlSpans) {
 // 点击匹配部分效果
  clickSpan = new MyClickableSpan() {
   @Override
   public void onClick(View view) {
    ToastUtils.makeShort(urlSpan.getURL());
   }
  };
  // 话题
  if (urlSpan.getURL().startsWith(WeiboPattern.SCHEME_TOPIC)) {
   int start = value.getSpanStart(urlSpan);
   int end = value.getSpanEnd(urlSpan);
   value.removeSpan(urlSpan);
   // 格式化话题部分文本
   value.setSpan(clickSpan, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
  }
  // @用户
  if (urlSpan.getURL().startsWith(WeiboPattern.SCHEME_AT)) {
   int start = value.getSpanStart(urlSpan);
   int end = value.getSpanEnd(urlSpan);
   value.removeSpan(urlSpan);
   // 格式化@用户部分文本
   value.setSpan(clickSpan, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
  }
  // 链接
  if (urlSpan.getURL().startsWith(WeiboPattern.SCHEME_URL)) {
   int start = value.getSpanStart(urlSpan);
   int end = value.getSpanEnd(urlSpan);
   value.removeSpan(urlSpan);
   SpannableStringBuilder urlSpannableString = getUrlTextSpannableString(context, urlSpan.getURL(), textSize);
   value.replace(start, end, urlSpannableString);
   // 格式化链接部分文本
   value.setSpan(clickSpan, start, start + urlSpannableString.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
  }
 }

 // 表情需要单独格式化
 Matcher emotionMatcher = WeiboPattern.PATTERN_EMOTION.matcher(value);
 while (emotionMatcher.find()) {
  String emotion = emotionMatcher.group();
  int start = emotionMatcher.start();
  int end = emotionMatcher.end();
  int resId = EmotionUtils.getImageByName(emotion);
  if (resId != -1) { // 表情匹配
   L.e("find emotion: " + emotion);
   Drawable drawable = context.getResources().getDrawable(resId);
   drawable.setBounds(0, 0, (int) (textSize * 1.3), (int) (textSize * 1.3));
   // 自定义的 VerticalImageSpan ，可解决默认的 ImageSpan 不垂直居中的问题
   VerticalImageSpan imageSpan = new VerticalImageSpan(drawable);
   value.setSpan(imageSpan, start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
  }
 }

 return value;
}

private static SpannableStringBuilder getUrlTextSpannableString(Context context, String source, int size) {
 SpannableStringBuilder builder = new SpannableStringBuilder(source);
 String prefix = " ";
 builder.replace(0, prefix.length(), prefix);
 Drawable drawable = context.getResources().getDrawable(R.drawable.ic_status_link);
 drawable.setBounds(0, 0, size, size);
 builder.setSpan(new VerticalImageSpan(drawable), prefix.length(), source.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
 builder.append(" 网页链接");
 return builder;
}

public class EmotionUtils {

 public static LinkedHashMap<String, Integer> sMap;

 static {
  sMap = new LinkedHashMap<>();
  sMap.put("[doge]", R.drawable.d_doge);
  sMap.put("[污]", R.drawable.d_wu);
 }

 public static int getImageByName(String name) {
  Integer integer = sMap.get(name);
  return integer == null ? -1 : integer;
 }

}

public class MyClickableSpan extends ClickableSpan {

 @Override
 public void onClick(View view) {

 }

 @Override
 public void updateDrawState(TextPaint ds) {
  super.updateDrawState(ds);
  ds.setColor(0xff03A9F4);
  ds.setUnderlineText(false);
 }

}

public class VerticalImageSpan extends ImageSpan {

 public VerticalImageSpan(Drawable drawable) {
  super(drawable);
 }

 /**
  * update the text line height
  */
 @Override
 public int getSize(Paint paint, CharSequence text, int start, int end,
      Paint.FontMetricsInt fontMetricsInt) {
  Drawable drawable = getDrawable();
  Rect rect = drawable.getBounds();
  if (fontMetricsInt != null) {
   Paint.FontMetricsInt fmPaint = paint.getFontMetricsInt();
   int fontHeight = fmPaint.descent - fmPaint.ascent;
   int drHeight = rect.bottom - rect.top;
   int centerY = fmPaint.ascent + fontHeight / 2;

   fontMetricsInt.ascent = centerY - drHeight / 2;
   fontMetricsInt.top = fontMetricsInt.ascent;
   fontMetricsInt.bottom = centerY + drHeight / 2;
   fontMetricsInt.descent = fontMetricsInt.bottom;
  }
  return rect.right;
 }

 /**
  * see detail message in android.text.TextLine
  *
  * @param canvas the canvas, can be null if not rendering
  * @param text the text to be draw
  * @param start the text start position
  * @param end the text end position
  * @param x  the edge of the replacement closest to the leading margin
  * @param top the top of the line
  * @param y  the baseline
  * @param bottom the bottom of the line
  * @param paint the work paint
  */
 @Override
 public void draw(Canvas canvas, CharSequence text, int start, int end,
      float x, int top, int y, int bottom, Paint paint) {

  Drawable drawable = getDrawable();
  canvas.save();
  Paint.FontMetricsInt fmPaint = paint.getFontMetricsInt();
  int fontHeight = fmPaint.descent - fmPaint.ascent;
  int centerY = y + fmPaint.descent - fontHeight / 2;
  int transY = centerY - (drawable.getBounds().bottom - drawable.getBounds().top) / 2;
  canvas.translate(x, transY);
  drawable.draw(canvas);
  canvas.restore();
 }

}

mTextView.setText(formatWeiBoContent(this,mTextView.getText().toString(),mTextView))