public void undo() {
if (!mCommandStack.empty()) {
AbstractCommand c = pop();
c.undo();
validateCells();
}
}
public void undoToCheckpoint() {
/*
* I originally planned to just call undo but this way it doesn't need to
* validateCells() until the run is complete
*/
AbstractCommand c;
while (!mCommandStack.empty()) {
c = mCommandStack.pop();
c.undo();
if (mCommandStack.empty() || mCommandStack.peek().isCheckpoint()) {
break;
}
}
validateCells();
}
