checkStartRunning method Null safety
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 IntegrateProgramRunner) {
throw CalculatorError(7);
}
curr = curr.parent;
}
super.checkStartRunning();
}