Android Question Select item in CLV

[Ilya G.]

Please tell me how to place selected item in the middle of screen? I already broke my brain

 

[aeric]

Have you tried ScrollToItem or JumpToItem ?

 

[Ilya G.]

Have you tried ScrollToItem or JumpToItem ?

It place selected item at the left border

 

[aeric]

It place selected item at the left border

View attachment 116630

Then you plus or minus 2 index.

 

[Ilya G.]

But if the screen is narrow and only 4 elements are visible, how to show the selected one exactly in the center?

 

[William Lancee]

Are all five circular elements in one panel? In a list of panels?

If so it is more complicated but doable, let us know.

 

[Ilya G.]

Its CLV with 9 panels

 

[William Lancee]

What I mean is are there five parts to each panel? How do define them?

Or is it a horizontal CLV?

 

[Ilya G.]

Each panel consists of two elements

 

[William Lancee]

So it is a horizontal CLV. Now what is your question? How to scroll to the selected item and then make sure it is in the center of the screen?

 

[Ilya G.]

Yes, sorry my english is poor))

 

[William Lancee]

That is ok.
As @aeric pointed out you can simply scroll to the selected item with an adjustment based on screen size.

In other words, in CustomListView1_ItemClick, CustomListView1.JumpToItem (index + adjustmentForScreenwidth).

 

[Ilya G.]

I understand that, but how to place it exactly in the middle?

 

[William Lancee]

In B4Xpages center of screen is Root.width / 2
In standard android apps it is Activity.Width / 2
leftMarginTarget = the center of screen minus the panel width / 2

The underlying scrollView is found in CustomlistView1.sv

CustomListView1.JumpToItem (index)
CustomListView1.sv.ScrollViewOffsetX = CustomListView1.sv.ScrollViewOffsetX - leftMarginTarget

Let me know if this works.

Edit. If you looked at this a few minutes ago, I changed the + sign to a - sign

 

[Ilya G.]

It doesn't seem to work

clv.JumpToItem(index)
clv.sv.ScrollViewOffsetX = clv.sv.ScrollViewOffsetX + ((clv.AsView.Width / 2)  - (clv.GetPanel(index).Width / 2))

 

[Erel]

1. Remove the call to JumpToItem.
2.

Dim item As CLVItem = clv.GetRawListItem(index)
clv.sv.ScrollViewOffsetX = item.Offset + clv.AsView.Width / 2 - item.Size

 

[Ilya G.]

    Dim x As XUI, p As B4XView = x.CreatePanel("")
    p.Width = 100dip
    p.Height = 100dip
    p.LoadLayout("category_2")
    clv.Add(p, 0)

then check

    Dim item As CLVItem = clv.GetRawListItem(index)
    Log(DipToCurrent(100dip) & " / " & item.Size)

and get 225 /150, why is this happening?

 

[Erel]

This is a mistake:

DipToCurrent(100dip)

It should be:

Log(100dip & " / " & item.Size)
'or
Log(DipToCurrent(100) & " / " & item.Size)