[message-list] implement a scrollTo(item) or similar

[manolo]

Describe your motivation

When using message list in a AI like chat, it should happen that each time we write new tokens to the message item, we could do something like messageList.scrollTo(item, bottom) so as we can read new text without having to manually scroll.

Describe the solution you'd like

.

Describe alternatives you've considered

No response

Additional context

No response

[jouni]

There’s already a feature that keeps the list scrolled to the bottom if the user hasn't scrolled too far from it (50 px threshold):

web-components/packages/message-list/src/vaadin-message-list-mixin.js

Lines 98 to 108 in 0f061c1

	const closeToBottom = this.scrollHeight < this.clientHeight + this.scrollTop + 50;
	this._renderMessages(items);
	this._setTabIndexesByIndex(focusedIndex);
	requestAnimationFrame(() => {
	if (items.length > oldItems.length && closeToBottom) {
	this._scrollToLastMessage();
	}
	});
	}

[jouni]

Perhaps that doesn't work when tokens are appended to the last message?

[tomivirkki]

Related feature request to scroller: #10257

[manolo]

There’s already a feature that keeps the list scrolled

Is there any java api for that?

[manolo]

feature request to scroller

It means that messageList needs to be encapsulated in a scroller in flow?

[jouni]

Is there any java api for that?

Should happen automatically/by default whenever new messages are added to the list.