Android Question why are my animals blank? (BCTextInCLV)

[johnmie]

Wanted to create a very basic tree view menu in B4A, but since I could not find a B4A equivalent for the B4J TreeView and as I already use CLVExpandable and BBlistitem in my app, it seemed logical to use Erel's BCTexInCLV.

#Region Shared Files
#CustomBuildAction: folders ready, %WINDIR%\System32\Robocopy.exe,"..\..\Shared Files" "..\Files"
'Ctrl + click to sync files: ide://run?file=%WINDIR%\System32\Robocopy.exe&args=..\..\Shared+Files&args=..\Files&FilesSync=True
#End Region

'Ctrl + click to export as zip: ide://run?File=%B4X%\Zipper.jar&Args=Project.zip

Sub Class_Globals
    Private Root As B4XView
    Private xui As XUI
    Private CustomListView1 As CustomListView
    Private TextEngine As BCTextEngine
    Private BBListItemIndexInItems As Int = 0
    Private Expandable As CLVExpandable
    Private bc As BitmapCreator
    Private thema(5) As String
    Private SP() As String
    Private CLVpanel As B4XView
End Sub

Public Sub Initialize
'    B4XPages.GetManager.LogEvents = True
End Sub

'This event will be called once, before the page becomes visible.
Private Sub B4XPage_Created (Root1 As B4XView)
    Root = Root1
    If Root.Width = 0 Then
        Wait For B4XPage_Resize (Width As Int, Height As Int)
    End If
    Root.LoadLayout("MainPage")
    CLVpanel.top = 100dip
    CLVpanel.left=40%x
    CLVpanel.width=50%x
    TextEngine.Initialize(Root)
    Expandable.Initialize(CustomListView1)

    thema(0) = "Animals,Antilope,Bear,Dolfin,Elephant,Horse"
    thema(1) = "Boys,Banjamin,Cesar,Napoleon"
    thema(2) = "Cities,Berlin,Chicago,Rome,Zürich"
    thema(3) = "Girls,Jennifer,Sophia,Vanessa"
    thema(4) = "Vehicles,Cars,Steam engines,Tractors,Velos"

    Dim pnl As B4XView = xui.CreatePanel("")
    pnl.SetLayoutAnimated(0, 0, 0, CustomListView1.AsView.Width-100dip, 100dip)
    pnl.LoadLayout("Item")
    For i = 1 To 5
        Dim pnl As B4XView = xui.CreatePanel("")
        pnl.SetLayoutAnimated(0, 0, 0, CustomListView1.AsView.Width-100dip, 100dip)
        pnl.LoadLayout("Item")
        Dim TitlePnl As B4XView = pnl.GetView(0)
        SP = Regex.Split(",",thema(i-1))
        TitlePnl.GetView(0).Text= SP(0) '$"This is item n° ${i}"$
        Dim BB As BBListItem = pnl.GetView(1).GetView(BBListItemIndexInItems).Tag

        BB.TextEngine = TextEngine
        BB.Text = CreateItemText(i)
        Dim ex As ExpandableItemData = Expandable.CreateValue(pnl, "not used")
        ex.CollapsedHeight = 30dip
        ex.ExpandedHeight = Max(ex.CollapsedHeight, BB.mBase.Height + 00dip + TitlePnl.Height)
        Dim arrow As B4XView = pnl.GetView(0).GetView(1)
        If ex.ExpandedHeight > ex.CollapsedHeight Then
            arrow.Visible = True       
        Else
            arrow.Visible = False
        End If
        pnl.SetLayoutAnimated(0, 0, 0, pnl.Width, ex.CollapsedHeight)
        CustomListView1.Add(pnl, ex)
    Next
    CustomListView1_ScrollChanged(0)
End Sub

Private Sub CreateItemText(index As Int) As String
    Dim sb As StringBuilder
    sb.Initialize
'    sb.Append($"[alignment=center][b]Item #${index}[/b][/alignment]"$)
    For j = 1 To SP.Length-1
        sb.Append(CRLF).Append($"[url=${SP(0)}+${SP(j)}]${SP(j)}[/url]"$)
    Next
    Return sb.ToString
End Sub

Private Sub BBListItem1_LinkClicked (URL As String)
    
    Dim bb As BBListItem = Sender
    Dim index As Int = CustomListView1.GetItemFromView(bb.mBase)
    Log("link clicked("&index&"): "&URL)
End Sub


Private Sub CustomListView1_ScrollChanged (Offset As Int)
    For i = 1 To CustomListView1.Size - 1
        Dim pnl As B4XView = CustomListView1.GetPanel(i)
        If pnl.NumberOfViews = 0 Then Return
        Dim BB As BBListItem = pnl.GetView(1).GetView(BBListItemIndexInItems).Tag
        BB.ParentScrolled(Offset, CustomListView1.GetRawListItem(i).Offset, CustomListView1.AsView.Height, pnl.GetView(0).Height)
    Next
End Sub

#if B4i or B4A
Private Sub pnlTitle_Click
#Else If B4J
Private Sub pnlTitle_MouseClicked (EventData As MouseEvent)
#End If
    Dim index As Int = CustomListView1.GetItemFromView(Sender)
    Dim e As ExpandableItemData = Expandable.ToggleItem(index)
    CustomListView1_ScrollChanged(CustomListView1.sv.ScrollViewOffsetY)
End Sub

Sub BBCodeView1_LinkClicked (URL As String)
    Log("link clicked: "&URL)
End Sub

For some reason the first bloc is blanc (see picture), but the text is there since clicking on a line shows the corresponding link. Does anyone know why? Many thanks in advance for your help, john m.

 

[Erel]

Have you seen this: https://www.b4x.com/android/forum/threads/b4x-clvtree-tree-view.132472/#content ?

BBListItem is "lazy drawn". You need to call BB.ParentScrolled to make it draw itself based on the currently visible area.

 

[johnmie]

Thank you very much, Erel, phantastic!
The solution is soooo simple - you just have to ask the right question.
I had been looking high and low for tips on building a B4A tree but I had never noticed the "CLVtree" library item and it did not occur to me to use it as a prompt.

Best, john m.