Infinite scrolling in Flutter - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a scroll controller for infinite scrolling.

Flutter

final ScrollController [1] = ScrollController();

Drag options to blanks, or click blank then click option'

AscrollController

BscrollCtrl

Ccontroller

DlistController

Attempts:

3 left

💡 Hint

Common Mistakes

Using vague or unrelated variable names.

Forgetting to declare the ScrollController.

The common and clear name for a scroll controller is 'scrollController'.

2fill in blank

medium

Complete the code to add a listener to the scroll controller.

Flutter

scrollController.[1](() {
  if (scrollController.position.pixels == scrollController.position.maxScrollExtent) {
    // Load more items
  }
});

Drag options to blanks, or click blank then click option'

AonScroll

BaddListener

Clisten

DaddScrollListener

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like 'onScroll' or 'listen'.

Forgetting to add the listener.

In Flutter, 'addListener' is used to listen for scroll events.

3fill in blank

hard

Fix the error in the code to check if the user scrolled to the bottom.

Flutter

if (scrollController.position.[1] == scrollController.position.maxScrollExtent) {
  fetchMoreData();
}

Drag options to blanks, or click blank then click option'

Aposition

Boffset

Cextent

Dpixels

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'offset' or 'position' which are not valid properties here.

Confusing 'extent' with current position.

The 'pixels' property gives the current scroll position in pixels.

4fill in blank

hard

Fill both blanks to create a ListView with infinite scrolling using the scroll controller.

Flutter

ListView.builder(
  controller: [1],
  itemCount: items.length + 1,
  itemBuilder: (context, index) {
    if (index == items.length) {
      return [2];
    }
    return ListTile(title: Text(items[index]));
  },
)

Drag options to blanks, or click blank then click option'

AscrollController

BCircularProgressIndicator()

Cnull

DScrollController()

Attempts:

3 left

💡 Hint

Common Mistakes

Creating a new ScrollController inside the ListView.

Returning null instead of a loading widget.

The ListView uses the existing scrollController and shows a loading spinner at the end.

5fill in blank

hard

Fill all three blanks to dispose the scroll controller properly in a StatefulWidget.

Flutter

@override
void [1]() {
  [2].dispose();
  super.[3]();
}

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Adispose

BscrollController

DinitState

Attempts:

3 left

💡 Hint

Common Mistakes

Calling dispose on the wrong object.

Forgetting to call super.dispose().

The dispose method is overridden to dispose the scrollController and then call super.dispose().