checkStartRunning method Null safety

  1. @override
void checkStartRunning()
override

Called from startRunningProgram in order to see if it's OK to start running. Throws CalculatorError if not. This is called as part of a solve or integrate operation that is executed in a program. Not called when solve/integrate is entered from the keyboard.

Implementation

@override
void checkStartRunning() {
  ProgramRunner? curr = parent;
  while (curr != null) {
    if (curr is SolveProgramRunner) {
      throw CalculatorError(7);
    }
    curr = curr.parent;
  }
  super.checkStartRunning();
}