Android Question how to fill area in image

Sub Process_Globals
   Private MainForm As Form
   Private ImageView1 As B4XView
   Private bc As BitmapCreator
   Private xui As XUI
   Private Pane1 As B4XView
End Sub

Sub AppStart (Form1 As Form, Args() As String)
   MainForm = Form1
   MainForm.RootPane.LoadLayout("1") 'Load the layout file.
   MainForm.Show
   Dim bmp As B4XBitmap = xui.LoadBitmapResize(File.DirAssets, "1.png", ImageView1.Width / xui.Scale, ImageView1.Height / xui.Scale, False)
   bc.Initialize(bmp.Width, bmp.Height)
   bc.CopyPixelsFromBitmap(bmp)
   bc.SetBitmapToImageView(bc.Bitmap, ImageView1)
End Sub


Sub Pane1_Touch (Action As Int, X As Float, Y As Float)
   If Action = Pane1.TOUCH_ACTION_UP Then
       FloodFill(x / xui.Scale, y / xui.Scale, Rnd(0xff000000, 0xffffffff))
       bc.SetBitmapToImageView(bc.Bitmap, ImageView1)
   End If
End Sub

Private Sub FloodFill (X As Int, Y As Int, ReplacementColor As Int)
   Dim xx As List
   xx.Initialize
   Dim yy As List
   yy.Initialize
   Dim tpm, rpm As PremultipliedColor
   Dim argb As ARGBColor
   bc.GetPremultipliedColor(X, Y, tpm)
   bc.ARGBToPremultipliedColor(bc.ColorToARGB(ReplacementColor, argb), rpm)
   If ColorsEqual(rpm, tpm) Then Return
   SetAndAddToQueue(X, Y, xx, yy, tpm, rpm)
   Do While xx.Size > 0
       Dim nx As Int = xx.Get(0)
       Dim ny As Int = yy.Get(0)
       xx.RemoveAt(0)
       yy.RemoveAt(0)
       SetAndAddToQueue(nx, ny + 1, xx, yy, tpm, rpm)
       SetAndAddToQueue(nx, ny - 1, xx, yy, tpm, rpm)
       SetAndAddToQueue(nx + 1, ny, xx, yy, tpm, rpm)
       SetAndAddToQueue(nx - 1, ny, xx, yy, tpm, rpm)
   Loop
   
End Sub

Private Sub SetAndAddToQueue (x As Int, y As Int, xx As List, yy As List, tpm As PremultipliedColor, rpm As PremultipliedColor)
   If x < 0 Or x >= bc.mWidth Or y < 0 Or y >= bc.mHeight Then Return
   Dim temp As PremultipliedColor
   If ColorsEqual(bc.GetPremultipliedColor(x, y, temp), tpm) Then
       bc.SetPremultipliedColor(x, y, rpm)
       xx.Add(x)
       yy.Add(y)
   End If
End Sub

Private Sub ColorsEqual(pm1 As PremultipliedColor, pm2 As PremultipliedColor) As Boolean
   Return pm1.r = pm2.r And pm1.g = pm2.g And pm1.b = pm2.b
End Sub

'fills all pixels with the OldColor with the new color
Private Sub FloodFill(x As Int, y As Int, OldColor As Int, NewColor As Int)
    If bc.GetColor(x, y) = OldColor Then
        bc.SetColor(x, y, NewColor)
        If x < bc.Bitmap.Width - 1 Then
            FloodFill(x + 1, y, OldColor, NewColor)           
        End If
        If x > 0 Then
            FloodFill(x - 1, y, OldColor, NewColor)           
        End If
        If y < bmcIcon.Bitmap.Height - 1 Then
            FloodFill(x, y + 1, OldColor, NewColor)           
        End If
        If y > 0 Then
            FloodFill(x, y - 1, OldColor, NewColor)           
        End If
    Else
        Return
    End If
End Sub

Sub ImageView1_MouseClicked (EventData As MouseEvent)
    'Disable the Pane1_Touch event when you are using this event
    FloodFill(EventData.X / xui.Scale, EventData.Y / xui.Scale, Rnd(0xff000000, 0xffffffff))
    bc.SetBitmapToImageView(bc.Bitmap, ImageView1)
End Sub

Dim bmp As B4XBitmap = xui.LoadBitmapResize(File.DirAssets, "11.png", bigImg.Width / xui.Scale, bigImg.Height / xui.Scale, False)