Android Question Effect CLV

[MarcoRome]

Hi All. It would be nice to insert this effect, that is that when a clv slides, the lower part "turns on" and the upper part "turns off", and vice versa, going down the upper part "turns on" the lower part "turns off". Any idea. ( Already tried with panels 50% of the screen, they do not give the same effect )

Thank you
Have a nice day

 

[LucaMs]

I think that you should hande it in the xCLV event:
CustomListView1_VisibleRangeChanged (FirstIndex As Int, LastIndex As Int)

 

[Erel]

You need to add a semi-transparent panel over each item and make it transparent when the item is in the middle. You should use the ScrollChanged event for this.

 

[Erel]

Better implementation based on incremental changes to the alpha level.

Private Sub CLV1_ScrollChanged (Offset As Int)
    For i = 0 To CLV1.Size - 1
        Dim item As CLVItem = CLV1.GetRawListItem(i)
        Dim a As Float = Max(0, Min(1, 1 - Abs(item.Offset - Offset) / (0.8 * CLV1.AsView.Height)))
        Log(a)
        SetAlpha(item.Panel, a)
    Next
End Sub

SetAlpha: https://www.b4x.com/android/forum/t...iews-alpha-level-transparency.123209/#content

 

[MarcoRome]

View attachment 105895

Better implementation based on incremental changes to the alpha level.

Private Sub CLV1_ScrollChanged (Offset As Int)
    For i = 0 To CLV1.Size - 1
        Dim item As CLVItem = CLV1.GetRawListItem(i)
        Dim a As Float = Max(0, Min(1, 1 - Abs(item.Offset - Offset) / (0.8 * CLV1.AsView.Height)))
        Log(a)
        SetAlpha(item.Panel, a)
    Next
End Sub

SetAlpha: https://www.b4x.com/android/forum/t...iews-alpha-level-transparency.123209/#content

? ?

 

[MarcoRome]

I think that you should hande it in the xCLV event:
CustomListView1_VisibleRangeChanged (FirstIndex As Int, LastIndex As Int)

Thank you anyway Luca.

 

[MarcoRome]

Work, very nice:


Thank you Erel ??

 

[Mahares]

I tested with a PreoptimizedCLV. It works well even in debug mode. I placed the call here:

 CLV1_ScrollChanged(0)  'placed call here
    PCLV.Commit

The only issue is , you cannot use: Sub PCLV_HintRequested (Index As Int) As Object
When you scroll using the hint requested, you get a blank screen, no items display whether in debug or release mode.