Create timeframe widget in flutter - flutter

Question

I m trying to loop time in minutes and seconds to display them as a list on the widget as shown on the picture below. It might be my math problem that causing this or lack of a better way of achieving this, but I have tried and I m stack.
My problem was on capturing the minutes and seconds, like e.g you have 15minutes.
and you want then to be displayed like this.
[00:00, 00:30, 1:00, 1:30, 2:00, 2:30,3:00, 3:30....15:00],
So the issue is only achieving that.
here the image
void addTime() {
const addSeconds = 1;
setState(() {
int s = 0;
for(int i = 0; i <= Duration(minutes: 15).inMinutes; i++){
timelines.add(buildTime(minute:(i * 60) % 1 * 60.floor(),
sec: i > 0 ? (i * 60).floor() : 0));
}
});
}
So once the app is open then addTime will be called to fill the timelines List[],
Then the timelines will be rendered on the build.
Kindly assist in any way possible for me to get this done.

Answer 1

I manage to solve the problem by looping the seconds inside the minutes loop, here the code.
void addTime() {
setState(() {
for (int i = 0; i <= 15; i++) {
for (int j = 0; j < 60; j++) {
if (j % 30 == 0) {
String minutes = i.toString().padLeft(2, '0');
String seconds = j.toString().padLeft(2, '0');
timelines.add(buildTime(minute: minutes,
sec: seconds));
}
}
}
});
}