buildPptx function

Uint8List buildPptx(List<String> slides, { Map<String, List<int>> media = const {}, Map<int, String> slideRels = const {}, (int, int)? slideSize, })

Builds a minimal .pptx for tests: just the parts PptxParser reads - presentation.xml + its rels, the slides + their rels, and media. slides are slide-tree bodies (p:spTree children), in presentation order; they're stored in reverse file-name order so a test can tell p:sldIdLst order from file order. slideSize (EMUs) writes a p:sldSz.

Implementation

Uint8List buildPptx(
  List<String> slides, {
  Map<String, List<int>> media = const {},
  Map<int, String> slideRels = const {},
  (int, int)? slideSize,
}) {
  const ns =
      'xmlns:p="http://schemas.openxmlformats.org/presentationml/2006/main" '
      'xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" '
      'xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships"';
  final archive = Archive();
  void add(String name, List<int> bytes) => archive.addFile(ArchiveFile.bytes(name, bytes));
  void addText(String name, String text) => add(name, utf8.encode(text));

  String fileFor(int index) => 'slide${slides.length - index}.xml';

  addText(
    'ppt/presentation.xml',
    '<?xml version="1.0" encoding="UTF-8"?><p:presentation $ns><p:sldIdLst>'
        '${[for (var i = 0; i < slides.length; i++) '<p:sldId id="${256 + i}" r:id="rId${i + 1}"/>'].join()}'
        '</p:sldIdLst>${slideSize == null ? '' : '<p:sldSz cx="${slideSize.$1}" cy="${slideSize.$2}"/>'}</p:presentation>',
  );
  addText(
    'ppt/_rels/presentation.xml.rels',
    '<?xml version="1.0" encoding="UTF-8"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">'
        '${[for (var i = 0; i < slides.length; i++) '<Relationship Id="rId${i + 1}" Type="slide" Target="slides/${fileFor(i)}"/>'].join()}'
        '</Relationships>',
  );
  for (var i = 0; i < slides.length; i++) {
    addText(
      'ppt/slides/${fileFor(i)}',
      '<?xml version="1.0" encoding="UTF-8"?><p:sld $ns><p:cSld><p:spTree>${slides[i]}</p:spTree></p:cSld></p:sld>',
    );
    if (slideRels[i] case final rels?) {
      addText(
        'ppt/slides/_rels/${fileFor(i)}.rels',
        '<?xml version="1.0" encoding="UTF-8"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">$rels</Relationships>',
      );
    }
  }
  media.forEach((name, bytes) => add('ppt/media/$name', bytes));
  return Uint8List.fromList(ZipEncoder().encodeBytes(archive));
}