toMultiLine static method

String toMultiLine(ExtractSettings settings, String prefix, String value)

Converts single line value into prefixed multi line PO string.

For example, this call:

_toMultiLine("msgid", "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.");

returns following:

msgid ""
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod "
"tempor incididunt ut labore et dolore magna aliqua."

Implementation

static String toMultiLine(
    ExtractSettings settings, String prefix, String value) {
  // We create multi lines just for strings that doesn't contain `\n` or are
  // longer than the set text width including the length of the prefix.
  if (!value.contains("\\n") &&
      '$prefix "$value"'.length <= settings.textWidth) {
    return '$prefix "$value"'; // Counting the quotes and the space as well.
  }

  // The ideal would be to split the text along `\n` and it would fit into
  // the text width. Let's give it a try.
  // Also, we need to put that `\n` back.
  final lines = value.split("\\n");
  for (int i = 0; i < lines.length - 1; i++) {
    lines.insert(i, "${lines.removeAt(i)}\\n");
  }

  // Let's check how it went. We will go through each line and correct those
  // that are longer than the set text width.
  for (int i = 0; i < lines.length; i++) {
    var line = lines[i];

    // It worked? Then skip this line.
    if (line.length + 2 <= settings.textWidth) {
      continue;
    }

    // Remove the line from the list, we'll add two new ones back later.
    lines.removeAt(i);

    final words = line.split(" "); // List of words in the line.
    var part = ""; // The first part of the line that fits in the set width.

    // Gradually add words until they fit into the set text width.
    // + 3 = quotes + space
    while (part.length + words[0].length + 3 <= settings.textWidth) {
      part += "${words.removeAt(0)} "; // Add the space back as well.
    }

    // Insert both parts of the line in the original place.
    lines.insertAll(i, [part, line.replaceFirst(part, "")]);
  }

  return [
    '$prefix ""',
    // Filter out blank lines and enclose them in quotes.
    ...lines.where((line) => line.isNotEmpty).map((line) => '"$line"')
  ].join("\n"); // Concatenate the rows back into a single string.
}