[Discussions] How to define cacheExtent to jump correct position?

[thaidmfinnick]

Content

Hi again,
I use flutter_scrollview_observer for rendering list messages, and my case is after I jump to specific message, I want to back to latest message, but when I use jumpTo(index: 0), it's wrong in some cases.

Now, I set cache extent is very large: 9999999999. But if I don't set cache extent, the jumping is not correct anymore.
I have followed wiki, but not clear about reasonable value you mention.

My snippet code below:

// load API when scroll to latest message
MessageChannelController.getMessageChannelUp(token, widget.selectedChannelId, selectedWorkspaceId, isNotifyListeners: true, limit: 30).then((v) {
   // when loaded
    final obItem = observerController.observeItem(index: 0);
    print('0: ${obItem?.scrollOffset} --- ${obItem?.displayPercentage}');
    observerController.jumpTo(index: 0);
    print(observerController.controller?.offset);
});

[LinXunFeng]

Can you provide a demo that reproduces the problem?

It is recommended to use the following code to back to latest message, so that there is no need to go through redundant calculations inside scrollview_observer.

flutter_scrollview_observer/example/lib/features/scene/chat_demo/page/chat_page.dart

Lines 229 to 233 in ef7dfc5

	scrollController.animateTo(
	0,
	duration: const Duration(milliseconds: 300),
	curve: Curves.easeInOut,
	);

[thaidmfinnick]

Sorry for my late response. Using animate to works as expected. Thank you!