TimedDynamicText

TimedDynamicText.java

public class TimedDynamicText extends SpannableStringBuilder {
    private final ArrayDeque<Pair<Integer, CharSequence>> list;
    private Handler handler = new Handler();
    private CharSequence nextText = "";

    public TimedDynamicText(CharSequence initialText, Collection<Pair<Integer, CharSequence>> list) {
        this.list = new ArrayDeque<>(list);
        nextText = initialText;

        next();
    }

    private void next() {
        if (length() == 0) {
            append(nextText);
        } else {
            replace(0, length(), nextText);
        }

        Pair<Integer, CharSequence> item = list.pollFirst();

        if (item != null) {
            nextText = item.second;
            handler.postDelayed(next, item.first);
        } else {
            handler = null;
        }
    }

    private final Runnable next = new Runnable() {
        @Override
        public void run() {TimedDynamicText.this.next();}
    };

    public static class Builder {
        private ArrayList<Pair<Integer, CharSequence>> list = new ArrayList<>();
        private CharSequence initialText;

        public Builder(CharSequence initialText) {
            this.initialText = initialText;
        }

        public Builder addTimedText(int time, CharSequence text) {
            list.add(new Pair<>(time, text));

            return this;
        }

        public TimedDynamicText build() {
            return new TimedDynamicText(initialText, list);
        }
    }
}