B4J Question [SOLVED] how can i drag with mouse borderless window ?

private Sub mainpane_MouseDragged (EventData As MouseEvent)
    frm.WindowLeft = EventData.X
    frm.WindowTop = EventData.Y
End Sub

Sub Class_Globals
    Private Root As B4XView
    Private xui As XUI
    Private Pane1 As Pane
    Private Pane2 As Pane
    
    Private pointInPanelX As Float
    Private pointInPanelY As Float
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
    Root.LoadLayout("MainPage")
End Sub

Private Sub Pane1_MouseDragged (EventData As MouseEvent)
    Pane1.Left = Pane1.Left + (EventData.X - pointInPanelX)
    Pane1.Top = Pane1.Top  + (EventData.Y - pointInPanelY)
    Pane2.Left = Pane1.Left
    Pane2.Top = Pane1.Top + Pane1.height
End Sub

Private Sub Pane1_MousePressed (EventData As MouseEvent)
    pointInPanelX = EventData.X
    pointInPanelY = EventData.Y
End Sub

Sub Class_Globals
    Private Root As B4XView 'ignore
    Private xui As XUI 'ignore
  
    Private Button1 As Button

    Private SystemMenu As Pane
    
    Private pointInPanelX As Float
    Private pointInPanelY As Float
    Dim GameForm As Form
End Sub

'You can add more parameters here.
Public Sub Initialize As Object
    Return Me
End Sub

'This event will be called once, before the page becomes visible.
Private Sub B4XPage_Created (Root1 As B4XView)
    Root = Root1
    'load the layout to Root
    Root.LoadLayout("game")
    GameForm = B4XPages.GetNativeParent(Me)
    GameForm.SetFormStyle("UNDECORATED")
End Sub

'You can see the list of page related events in the B4XPagesManager object. The event name is B4XPage.

Sub Button1_Click
    B4XPages.ShowPageAndRemovePreviousPages("mainpage")
    
End Sub

Private Sub B4XPage_CloseRequest As ResumableSub

    Log("Game CloseRequest")
  
    ExitApplication
    Return True
  
End Sub

Private Sub SystemMenu_MouseDragged (EventData As MouseEvent)
    
    
    GameForm.WindowLeft = GameForm.WindowLeft + (EventData.X - pointInPanelX)
    GameForm.WindowTop = GameForm.WindowTop  + (EventData.Y - pointInPanelY)
    
    Log(GameForm.WindowLeft)
    Log(GameForm.WindowTop)
    
End Sub

Private Sub SystemMenu_MousePressed (EventData As MouseEvent)
    pointInPanelX = EventData.X
    pointInPanelY = EventData.Y
End Sub

Private Sub SystemMenu_MouseDragged (EventData As MouseEvent)
   
   
    SystemMenu.WindowLeft = SystemMenu.WindowLeft + (EventData.X - pointInPanelX)
    SystemMenu.WindowTop = SystemMenu.WindowTop  + (EventData.Y - pointInPanelY)
   
    Log(SystemMenu.WindowLeft)
    Log(SystemMenu.WindowTop)
   
End Sub

Sub SystemMenu_MousePressed (EventData As MouseEvent)
    downX = EventData.X
    downY = EventData.Y
End Sub

Sub SystemMenu_MouseDragged (EventData As MouseEvent)
    Dim jo As JavaObject = EventData
    B4XPages.GetNativeParent(Me).WindowLeft = jo.RunMethod("getScreenX", Null) - downX
    B4XPages.GetNativeParent(Me).WindowTop  = jo.RunMethod("getScreenY", Null) - downY
End Sub