How to use

insert

method

in

android.text.SpannableStringBuilder

private FixingResult addSpacesAroundSpansUntilFixed(SpannableStringBuilder builder,
                          int widthMeasureSpec, int heightMeasureSpec) {
  Object[] spans = builder.getSpans(0, builder.length(), Object.class);
  List<Object> spansWithSpacesBefore = new ArrayList<>(spans.length);
  List<Object> spansWithSpacesAfter = new ArrayList<>(spans.length);
  for (Object span : spans) {
    int spanStart = builder.getSpanStart(span);
    if (isNotSpace(builder, spanStart - 1)) {
      builder.insert(spanStart, " ");
      spansWithSpacesBefore.add(span);
    }
    int spanEnd = builder.getSpanEnd(span);
    if (isNotSpace(builder, spanEnd)) {
      builder.insert(spanEnd, " ");
      spansWithSpacesAfter.add(span);
    }
    try {
      setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec);
      return FixingResult.fixed(spansWithSpacesBefore, spansWithSpacesAfter);
    } catch (IndexOutOfBoundsException ignored) {
    }
  }
  if (HtmlTextView.DEBUG) {
    Log.d(HtmlTextView.TAG, "Could not fix the Spanned by adding spaces around spans");
  }
  return FixingResult.notFixed();
}

@SuppressLint("WrongCall")
private void removeUnneededSpaces(int widthMeasureSpec, int heightMeasureSpec,
                 SpannableStringBuilder builder, FixingResult result) {
  for (Object span : result.spansWithSpacesAfter) {
    int spanEnd = builder.getSpanEnd(span);
    builder.delete(spanEnd, spanEnd + 1);
    try {
      setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec);
    } catch (IndexOutOfBoundsException ignored) {
      builder.insert(spanEnd, " ");
    }
  }
  boolean needReset = true;
  for (Object span : result.spansWithSpacesBefore) {
    int spanStart = builder.getSpanStart(span);
    builder.delete(spanStart - 1, spanStart);
    try {
      setTextAndMeasure(builder, widthMeasureSpec, heightMeasureSpec);
      needReset = false;
    } catch (IndexOutOfBoundsException ignored) {
      needReset = true;
      int newSpanStart = spanStart - 1;
      builder.insert(newSpanStart, " ");
    }
  }
  if (needReset) {
    setText(builder);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  }
}

 public static Spannable applyKerning(CharSequence src, float kerning)
{
  if (src == null) return null;
  final int srcLength = src.length();
  if (srcLength < 2) return src instanceof Spannable
               ? (Spannable)src
               : new SpannableString(src);

  final String nonBreakingSpace = "\u00A0";
  final SpannableStringBuilder builder = src instanceof SpannableStringBuilder
                      ? (SpannableStringBuilder)src
                      : new SpannableStringBuilder(src);
  for (int i = src.length() - 1; i >= 1; i--)
  {
    builder.insert(i, nonBreakingSpace);
    builder.setSpan(new ScaleXSpan(kerning), i, i + 1,
            Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
  }

  return builder;
}

@Override
public SpannableStringBuilder insert(int where, CharSequence tb) {
 super.insert(where, tb);
 return this;
}

@Override
public SpannableStringBuilder insert(int where, CharSequence tb, int start, int end) {
 super.insert(where, tb, start, end);
 return this;
}

 CharSequence firstPart = "First Part";
CharSequence thirdPart = "Third Part";
SpannableStringBuilder middlePart = new SpannableStringBuilder("Middle Part");

int spacing = 2;
final String nonBreakingSpace = "\u00A0";


for (int i = middlePart.length() - 1; i >= 1; i--){
  middlePart.insert(i, nonBreakingSpace);
  middlePart.setSpan(new ScaleXSpan(spacing), i, i + 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}

((TextView) rootView.findViewById(R.id.text_view)).setText(TextUtils.concat(firstPart, " ", middlePart, " ", thirdPart));

private void formatLinks(SpannableStringBuilder titleSpan) {
  Matcher matcher = urlPattern.matcher(titleSpan);
  while(matcher.find()) {
    titleSpan.delete(matcher.start(), matcher.end());
    titleSpan.insert(matcher.start(), matcher.group(1));
    titleSpan.setSpan(new ForegroundColorSpan(Style.blue),
        matcher.start(), matcher.start() + matcher.group(1).length(), 0);
    matcher = urlPattern.matcher(titleSpan);
  }
}

private static MDBaseListSpan setOrderSpan(int nested, int start, @NonNull String line, @NonNull SpannableStringBuilder ssb, int number, int originalNumber) {
  ssb.delete(start, start + nested * SyntaxKey.KEY_LIST_HEADER.length() + String.valueOf(originalNumber).length());
  ssb.insert(start, String.valueOf(number));
  MDOrderListSpan mdOrderListSpan = new MDOrderListSpan(10, nested, number);
  ssb.setSpan(mdOrderListSpan,
      start, start + line.length() - (nested * SyntaxKey.KEY_LIST_HEADER.length() + String.valueOf(originalNumber).length()),
      Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
  return mdOrderListSpan;
}

/**
 * set key number
 *
 * @param nested         the nested number
 * @param start          start position
 * @param line           the content
 * @param ssb            the content
 * @param number         the key number
 * @param originalNumber the original number
 */
private void setSSB(int nested, int start, @NonNull String line, @NonNull SpannableStringBuilder ssb, int number, int originalNumber) {
  ssb.delete(start, start + nested * SyntaxKey.KEY_LIST_HEADER.length() + String.valueOf(originalNumber).length());
  ssb.insert(start, String.valueOf(number));
  ssb.setSpan(new MDOrderListSpan(10, nested, number),
      start, start + line.length() - (nested * SyntaxKey.KEY_LIST_HEADER.length() + String.valueOf(originalNumber).length()),
      Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}

private void handleBlockquote(int start) {
  spannedBuilder.insert(start, "“ ");
  spannedBuilder.append("”");
  position += 3;
  setSpan(start, new Quote());
}

public void insertIcon(String name) {
  String curString = getText().toString();
  if ((curString.length() + name.length()) > maxLength) {
    return;
  }
  Drawable drawable = ContextCompat.getDrawable(mContext, ParseIconResId(name));
  if (drawable == null)
    return;
  drawable.setBounds(0, 0, size, size);//这里设置图片的大小
  ImageSpan imageSpan = new ImageSpan(drawable);
  SpannableString spannableString = new SpannableString(name);
  spannableString.setSpan(imageSpan, 0, spannableString.length(), SpannableString.SPAN_EXCLUSIVE_EXCLUSIVE);
  int index = Math.max(getSelectionStart(), 0);
  SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder(getText());
  spannableStringBuilder.insert(index, spannableString);
  setText(spannableStringBuilder);
  setSelection(index + spannableString.length());
}

spannableStringBuilder.insert(index, htmlText);
spannableStringBuilder.insert(index + htmlText.length(), "\b");
setText(spannableStringBuilder);
setSelection(index + htmlText.length() + 1);

public CharSequence getHeading(Printrequest printRequest) {
   String name = printRequest.sentbyname;
   String permission;
   if (printRequest.mediaobject.permission != null && !printRequest.mediaobject.permission.equalsIgnoreCase("public")) {
     permission =  printRequest.mediaobject.permission;
   } else {
     permission = "";
   }
   String photoHeading = mContext.getString(R.string.photo_heading);
   SpannableStringBuilder builder = new SpannableStringBuilder(photoHeading);
   int pos = builder.toString().indexOf("%s");
   builder.replace(pos, pos+2, getStyledName(name));
   pos = builder.toString().indexOf("%s");
   builder.replace(pos, pos+2, getStyledItalic(permission));
   pos = builder.toString().indexOf("%s");
   if (printRequest.mediaobject.hyperphoto != null) {
     builder.replace(pos, pos+2, getStyledItalic(mContext.getString(R.string.hyperphoto)));
     builder.insert(pos, " ");
   } else {
     builder.replace(pos, pos+2, mContext.getString(R.string.photo));
     builder.insert(pos, " ");
   }
   return builder;
 }

ssBuilder.removeSpan(span);
if (span.getStyle() == Typeface.BOLD) {
  ssBuilder.insert(start, "<b>");
  ssBuilder.insert(end + 3, "</b>");
} else if (span.getStyle() == Typeface.ITALIC) {
  ssBuilder.insert(start, "<i>");
  ssBuilder.insert(end + 3, "</i>");
end = ssBuilder.getSpanEnd(span);
ssBuilder.removeSpan(span);
ssBuilder.insert(start, "<u>");
ssBuilder.insert(end + 3, "</u>");

int lineHeight = mLayout.getLineBottom(line) - mLayout.getLineTop(line);
mText.insert(offsetStart, " ");

  index--;
spannableStringBuilder.insert(index, spannableString);
GifTextUtil.setTextWithReuseDrawable(this, spannableStringBuilder, true);
setSelection(index + spannableString.length());