Firefox does not retain browser's scroll position when switching tab in TabSheet

[mikke-alekstra]

Hello!

There seems to be a problem with Firefox retaining browser's scroll position when switching tab in TabSheet component.

Vaadin Framework version 8.16.1 (the problem was originally found with 8.14.3) Debian 10 (buster) Linux: latest versions of Firefox (and Chromium) Windows 10: latest versions of Firefox (and Chrome)

In my test I had a VerticalLayout where I first had 25 filler (Label) rows to get a vertical scroll bar to appear in browser and then a TabSheet containing two tabs with 10 tab (Label) rows in each of them.

Test steps:

1. Scroll to bottom of page to see the TabSheet
2. Click tab 2 to switch tab

Expected behavior (Chrome and Chromium): scroll position is retained, full tab 2 content is visible Actual behavior (Firefox): scroll position is not retained. Scroll bar jumps upwards and only first line of tab 2 content is seen.

Please see below the simple test code the case can be re-produced with.

    @Override
    protected void init(VaadinRequest vaadinRequest) {

        VerticalLayout layout = new VerticalLayout();

        for (int i = 1; i <= 25; i ++) {
            layout.addComponent(new Label("filler row " + i));
        }

        TabSheet tabSheet = new TabSheet();

        for (int i = 1; i <= 2; i ++) {

            VerticalLayout tabLayout = new VerticalLayout();

            for (int j = 1; j <= 10; j ++) {
                tabLayout.addComponent(new Label("tab row " + j));
            }

            tabSheet.addTab(tabLayout, "tab " + i);

        }

        layout.addComponent(tabSheet);

        setContent(layout);

    }

[Ansku]

This is a timing issue, and unfortunately all the solutions I've tried have either made the problem worse (anything that relies on measuring things) or broken something else on the side in a way that is more disruptive than this issue (anything that relies on adding delays). Currently I'm out of ideas, but I'll get back to this if I think of something else to try.