generateObjectTree function

String generateObjectTree([ int objectNum = 1 ])

Returns a string containing a pretty-print visual tree of game objects. This function crawls the tree structure until all objects have been found although there is the possibility that some orphaned objects may not be found if they are above the highest "found" object number and are not referenced as a sibling/child/parent of any other object.

This function requires that a story file is alread loaded into the Z machine and will throw an exception if no file is loaded.

Provide an optional objectNum to begin the tree construction at a known point. Override the default value at your own risk, as the function does not check if the provided objectNum is valid.

Implementation

String generateObjectTree([int objectNum = 1]) {
  if (!Z.isLoaded){
    throw "Z-machine must be loaded with a story file before calling this function (use Z.load(storybytes)).";
  }

  if (objectNum < 1){
    throw "objectNum argument must be greater than 0.  Found: $objectNum.";
  }

  _resetObjectState();
  _updateObjectState(objectNum);

  final sb = StringBuffer();

  //first find root parent, which we assume is 0...
  final rootObject = GameObject(objectNum);

  void doTree(GameObject currentObject) {
    while (currentObject.parent != 0) {
      currentObject = GameObject(currentObject.parent);
    }

    sb.writeln(
        "${currentObject.shortName}(${currentObject.id}) child: ${currentObject.child}, sib: ${currentObject.sibling}");

    if (currentObject.child != 0) {
      _updateObjectState(currentObject.child);
      sb.write(_writeChildren(currentObject.child, 3));
    }

    if (currentObject.sibling != 0) {
      _updateObjectState(currentObject.sibling);
      sb.write(_writeChildren(currentObject.sibling, 0));
    }
  }

  doTree(rootObject);

  while (_highestObject > _objects.length) {
    final nextObjectId = _getNextAvailableObject();
    if (nextObjectId < 1) break;
    _updateObjectState(nextObjectId);
    final next = GameObject(nextObjectId);
    doTree(next);
  }

  sb.writeln("");
  sb.writeln("Total Objects Found: ${_objects.length}");
  sb.writeln(
      "Highest Object: ${GameObject(_highestObject).shortName}($_highestObject)");
  return sb.toString();
}