How to detect if a widget reaches the bottom of the screen in flutter?

Question

My widget renders a list of photos and installs a ScrollController to detect when the user scrolls to the bottom so new photos can be loaded. On some devices however the initial loaded photos don't cover the whole screen. In this case I want to load more photos until the whole screen is covered. How can I achieve that?

scrollController.addListener(() async {
  final pos = scrollController.position;
  final triggerFetchMoreSize = 0.9 * pos.maxScrollExtent;
  if (pos.pixels > triggerFetchMoreSize) {
       // scrolling to bottom detected
  }
}



SingleChildScrollView(controller: scrollController,
          physics: const AlwaysScrollableScrollPhysics(),
          child: PhotoList());

do you have all of those photos in a listview..?

srikanth7785
– srikanth7785

2020-05-14 15:09:01 +00:00
Commented May 14, 2020 at 15:09 — srikanth7785
– srikanth7785, Commented May 14, 2020 at 15:09
all photos are in a gridview

MarcS82
– MarcS82

2020-05-14 15:17:26 +00:00
Commented May 14, 2020 at 15:17 — MarcS82
– MarcS82, Commented May 14, 2020 at 15:17

srikanth7785 · Accepted Answer · 2020-05-15 03:43:28Z

2

You can use the extentAfter property to know how much more space is left till the end..

I guess this is something you are trying to do..

https://stackoverflow.com/a/49509349/13460232

answered May 15, 2020 at 3:43

srikanth7785

1,5421 gold badge9 silver badges22 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Humble · Accepted Answer · 2020-05-14 15:05:49Z

-1

You could use MediaQuery to do it. You could find the height of the device by using MediaQuery.of<context>.size.height or width of the Device Screen using MediaQuery.of<context>.size.width

Reference: https://api.flutter.dev/flutter/widgets/MediaQuery-class.html

answered May 14, 2020 at 15:05

Humble

412 silver badges8 bronze badges

1 Comment

MarcS82 Over a year ago

Ok but how can find out if my list of photos is larger as MediaQuery.of<context>.size.height? And where can I do the comparation makeing sure that my photolist is already drawn?

Collectives™ on Stack Overflow

How to detect if a widget reaches the bottom of the screen in flutter?

2 Answers 2

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related