B4X Buttons grid example

Sub Class_Globals
    Private Root As B4XView
    Private xui As XUI
#if B4J
    Private Pane1 As Pane
    Private ScrollPane1 As ScrollPane
#End If
#if B4A
    Private Panel1 As Panel
    Private ScrollView1 As ScrollView
#End If
End Sub
Public Sub Initialize
    B4XPages.GetManager.LogEvents = True
End Sub
Private Sub B4XPage_Created (Root1 As B4XView)
    Root = Root1
    Root.LoadLayout("MainPage")
    B4XPages.SetTitle(Me,"Buttons grid")
#if B4J
    set_button_grid(99,50,50,5)
#End If
#if B4A
    Dim scale As Int = GetDeviceLayoutValues.Scale
    Dim tabletsize As Int = GetDeviceLayoutValues.ApproximateScreenSize
    If tabletsize >= 8 Then
        scale = 2
    End If
    set_button_grid(99,50dip*scale,50dip*scale,5dip)
    Panel1.RemoveView
    ScrollView1.Panel.AddView(Panel1,0dip,0dip,ScrollView1.Width,Panel1.Height)
    ScrollView1.Panel.Height = Panel1.Height
#End If
End Sub
Private Sub B4XPage_Resize (Width As Int, Height As Int)
#if B4J
    set_button_grid(99,50,50,5)
    ScrollPane1.InnerNode = Pane1
#End If
End Sub
Private Sub set_button_grid(cnt As Int, width As Int, height As Int, gap As Int)
#if B4J
    Pane1.RemoveAllNodes
#End If
#if B4A
    Panel1.RemoveAllViews
#End If
    Dim rowpos As Int = gap
    Dim colpos As Int = gap
    For i = 0 To cnt
        Dim btn As Button
        btn.Initialize("btn")
        btn.Text = "b" & i
        btn.Tag = btn.Text
#if B4J
        btn.prefWidth = width
        btn.PrefHeight = height
        Pane1.AddNode(btn,colpos,rowpos,width,height)
#End If
#if B4A
        btn.Width = width
        btn.Height = height
        Panel1.AddView(btn,colpos,rowpos,width,height)
#End If
        colpos = colpos + width + gap
        If colpos > (Root.Width - width) Then
            rowpos = rowpos + height + gap
            colpos = gap
        End If
    Next
#if B4J
    Pane1.PrefHeight = rowpos + height + gap
#End If
#if B4A
    Panel1.Height = rowpos + height + gap
#End If
End Sub
Private Sub btn_Click
    Dim btn As Button = Sender
    Log("btn " & btn.Tag & " clicked")
End Sub

#if B4J
        CSSUtils.SetBackgroundImage(btn,File.DirAssets,get_random_background_image)
        btn.prefWidth = width
        btn.PrefHeight = height
        Pane1.AddNode(btn,colpos,rowpos,width,height)
#End If
#if B4A
        btn.SetBackgroundImage(LoadBitmap(File.DirAssets,get_random_background_image))
        btn.Width = width
        btn.Height = height
        Panel1.AddView(btn,colpos,rowpos,width,height)
#End If

Private Sub get_random_background_image As String
    Dim lst As List = Array As String ("add.png","back.png","calendar.png","category.png", _
                        "clear.png","closetab.png","code.png","columns.png","delete.png", _
                        "download.png","")
    Dim num As Int = Rnd(0,10)
    Dim fname As String = lst.Get(num)
    If fname = "" Then fname = lst.Get(0)
    Return fname
End Sub

    For i = 0 To cnt
        ' set grid item to button, label, panel or imageview (uncomment to test)
'        Dim vw As Button = set_button_item(i,Width,Height,gap)
'        Dim vw As Label = set_label_item(i,Width,Height,gap)
        Dim vw As ImageView = set_image_item(i,Width,Height,gap)
#if B4A
'        Dim vw As Panel = set_panel_item(i,Width,Height,gap)
        Panel1.AddView(vw,colpos,rowpos,Width,Height)
#End If
#if B4J
'        Dim vw As Pane = set_panel_item(i,Width,Height,gap)
        Pane1.AddNode(vw,colpos,rowpos,Width,Height)
#End If