LAMW: is it possible to scroll jListView with the scrollbar thumb?
lazarus / 43-Android

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Manlio · 2019-12-24 15:04

I have a jListView control with thousands of items, and it works fine,
but it takes a lot of time to scroll with swiping motions.

A sort of scroll bar appears on the right, but it's very thin, and the
thumb is also very short (because there are many items).

When I try to tap on that tiny scroll bar nothing happens, the list
gets selected instead. I don't know if that is because the scroll bar
thumb is too small of a target for a tap, or because that scroll bar
is not supposed to be used actively and it is only used to show the
current position within the list.

So, does anyone know that?

1. Is it supposed to be possible to scroll long lists with the scroll
bar?

2. If so, how to make the scroll bar thumb bigger, so it can be
actually tapped and dragged?

Thanks!

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lainz · 2019-12-24 15:21

On Android I never used a scrollbar, is just to display where is the
position.

One usually scrolls from the content area.

Maybe you can use filters to reduce the list size?

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Manlio · 2019-12-26 04:49

After further research I found that the XML tag attribute
android:fastScrollEnabled can be used to make scroll bars responsive
to user taps, as for example discussed here:

https://stackoverflow.com/questions/18254370/how-to-add-draggable-
scrollbar-to-scrollview-listview-in-android/18254692

...but the above example is still not enough for me to understand how
to apply it in my own project.

Moreover, in LAMW, the main layout XML file is managed automatically
by the wizard, if I'm not mistaken?

So it would be great if LAMW could implement, for example,
android:fastScrollEnabled="true" and android:fastScrollAlwaysVisible
as two boolean properties of jView and descendants.

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lainz · 2019-12-26 14:37

Notice that ListView is deprecated (at least on Android Studio) and
you should be using RecyclerView instead.

No one is used to scroll with a scrollbar on Android, take that into
consideration, that way is strange.

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Manlio · 2019-12-27 15:25

Quote from: lainz on December 26, 2019, 03:37:15 pmNotice that
ListView is deprecated (at least on Android Studio) and you should be
using RecyclerView instead.

Thanks

Quote from: lainz on December 26, 2019, 03:37:15 pmNo one is used to
scroll with a scrollbar on Android, take that into consideration, that
way is strange.

I understand, and I agree with you for 99.5% of the cases, but there
may be a few cases (e.g. truly huge lists, power user) in which this
feature would be useful. And after all, the
android:fastScrollAlwaysVisible tag is available in the system for
anything scrollable, and therefore, if it's not too much trouble,
perhaps a hook to it could be made in LAMW.

Thanks for the feedback!