public getJoinedCharacters()

in src/renderer/CharacterJoinerRegistry.ts [34:108]
55 lines of code
10 McCabe index (conditional complexity)

  public getJoinedCharacters(row: number): [number, number][] {
    if (this._characterJoiners.length === 0) {
      return [];
    }

    const line = this._terminal.buffer.lines.get(row);
    if (line.length === 0) {
      return [];
    }

    const ranges: [number, number][] = [];
    const lineStr = this._terminal.buffer.translateBufferLineToString(row, true);

    // Because some cells can be represented by multiple javascript characters,
    // we track the cell and the string indexes separately. This allows us to
    // translate the string ranges we get from the joiners back into cell ranges
    // for use when rendering
    let rangeStartColumn = 0;
    let currentStringIndex = 0;
    let rangeStartStringIndex = 0;
    let rangeAttr = line.get(0)[CHAR_DATA_ATTR_INDEX] >> 9;

    for (let x = 0; x < this._terminal.cols; x++) {
      const charData = line.get(x);
      const chars = charData[CHAR_DATA_CHAR_INDEX];
      const width = charData[CHAR_DATA_WIDTH_INDEX];
      const attr = charData[CHAR_DATA_ATTR_INDEX] >> 9;

      if (width === 0) {
        // If this character is of width 0, skip it.
        continue;
      }

      // End of range
      if (attr !== rangeAttr) {
        // If we ended up with a sequence of more than one character,
        // look for ranges to join.
        if (x - rangeStartColumn > 1) {
          const joinedRanges = this._getJoinedRanges(
            lineStr,
            rangeStartStringIndex,
            currentStringIndex,
            line,
            rangeStartColumn
          );
          for (let i = 0; i < joinedRanges.length; i++) {
            ranges.push(joinedRanges[i]);
          }
        }

        // Reset our markers for a new range.
        rangeStartColumn = x;
        rangeStartStringIndex = currentStringIndex;
        rangeAttr = attr;
      }

      currentStringIndex += chars.length;
    }

    // Process any trailing ranges.
    if (this._terminal.cols - rangeStartColumn > 1) {
      const joinedRanges = this._getJoinedRanges(
        lineStr,
        rangeStartStringIndex,
        currentStringIndex,
        line,
        rangeStartColumn
      );
      for (let i = 0; i < joinedRanges.length; i++) {
        ranges.push(joinedRanges[i]);
      }
    }

    return ranges;
  }