Android Question Select item in CLV

aeric

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• Jul 18, 2021

• #2

Have you tried ScrollToItem or JumpToItem ?

 

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I

Ilya G.

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• Jul 18, 2021

• #3

aeric said:

Have you tried ScrollToItem or JumpToItem ?

Click to expand...

It place selected item at the left border

 

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aeric

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• Jul 19, 2021

• #4

GanjaKyp said:

It place selected item at the left border

View attachment 116630

Click to expand...

Then you plus or minus 2 index.

 

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I

Ilya G.

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• Jul 19, 2021

• #5

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

 

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William Lancee

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• Jul 19, 2021

• #6

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

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

 

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I

Ilya G.

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• Jul 19, 2021

• #7

Its CLV with 9 panels

 

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William Lancee

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• Jul 19, 2021

• #8

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

Or is it a horizontal CLV?

 

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I

Ilya G.

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• Jul 19, 2021

• #9

Each panel consists of two elements

 

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William Lancee

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• Jul 19, 2021

• #10

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?

 

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I

Ilya G.

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• Jul 19, 2021

• #11

Yes, sorry my english is poor))

 

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William Lancee

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• Jul 19, 2021

• #12

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).

 

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I

Ilya G.

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• Jul 19, 2021

• #13

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

 

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William Lancee

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• Jul 19, 2021

• #14

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

 

Last edited: Jul 19, 2021

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I

Ilya G.

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• Jul 19, 2021

• #15

It doesn't seem to work

B4X:

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

 

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Erel

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• Jul 19, 2021

• #16

1. Remove the call to JumpToItem.
2.

B4X:

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

 

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I

Ilya G.

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• Jul 19, 2021

• #17

B4X:

    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

B4X:

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

and get 225 /150, why is this happening?

 

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Erel

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• Jul 19, 2021

• #18

This is a mistake:

B4X:

DipToCurrent(100dip)

It should be:

B4X:

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

 

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