/** resets the workable list, optionally shuffling their order */
private void refreshWorkable(boolean shuffle) {
workable.clear();
for (Exercise e : exercises)
if (e.getDifficulty() == difficulty) workable.add(exercises.indexOf(e));
if (shuffle) Collections.shuffle(workable);
}
/** return percentage of correct marks for given difficulty */
public float getScore(Difficulty difficulty) {
float total = 0;
float completed = 0;
for (Exercise e : exercises)
if (e.getDifficulty() == difficulty) {
total++;
if (e.getMark() == Mark.CORRECT) completed++;
}
return completed / total;
}
/** loop through exercises and remove where the getQuestion() methods match */
public void removeExercise(Exercise exercise) {
for (Exercise e : exercises)
if (exercise.getQuestion().equals(e.getQuestion())) exercises.remove(e);
}