monitorModule.bas

Attribute VB_Name = "Module2"
    ' 23/01/2021 .01 monitorModule.bas DAEB added if then else if you can't get device context

Option Explicit

'Constants for the return value when finding a monitor
Public Enum dwFlags
    MONITOR_DEFAULTTONULL = &H0       'If the monitor is not found, return 0
    MONITOR_DEFAULTTOPRIMARY& = &H1   'If the monitor is not found, return the primary monitor
    MONITOR_DEFAULTTONEAREST = &H2    'If the monitor is not found, return the nearest monitor
End Enum

'Public Const MONITORINFOF_PRIMARY As Integer = 1

Private Type UDTMonitor
    handle As Long
    Left As Long
    Right As Long
    Top As Long
    Bottom As Long
    
    WorkLeft As Long
    WorkRight As Long
    WorkTop As Long
    Workbottom As Long
    
    Height As Long
    Width As Long
    
    WorkHeight As Long
    WorkWidth As Long
    
    IsPrimary As Boolean
End Type

Private Type RECT
  Left As Long
  Top As Long
  Right As Long ' This is +1 (right - left = width)
  Bottom As Long ' This is +1 (bottom - top = height)
End Type

'Structure for the position of a monitor
Private Type tagMONITORINFO
    cbSize      As Long 'Size of structure
    rcMonitor   As RECT 'Monitor rect
    rcWork      As RECT 'Working area rect
    dwFlags     As Long 'Flags
End Type

Private Declare Function EnumDisplayMonitors Lib "user32" (ByVal hdc As Long, lprcClip As Any, ByVal lpfnEnum As Long, dwData As Long) As Long
Private Declare Function GetSystemMetrics Lib "user32" (ByVal nIndex As Long) As Long
Public Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Public Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Public Declare Function GetDeviceCaps Lib "gdi32" (ByVal hdc As Long, ByVal nIndex As Long) As Long
Private Declare Function CreateDC Lib "gdi32" Alias "CreateDCA" (ByVal lpDriverName As String, ByVal lpDeviceName As String, ByVal lpOutput As String, ByVal lpInitData As Long) As Long
Private Declare Function UnionRect Lib "user32" (lprcDst As RECT, lprcSrc1 As RECT, lprcSrc2 As RECT) As Long
Private Declare Function OffsetRect Lib "user32" (lpRect As RECT, ByVal X As Long, ByVal Y As Long) As Long
Private Declare Function MoveWindow Lib "user32" (ByVal hwnd As Long, ByVal X As Long, ByVal Y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal bRepaint As Long) As Long
Private Declare Function GetWindowRect Lib "user32.dll" (ByVal hwnd As Long, lpRect As RECT) As Long
Private Declare Function MonitorFromRect Lib "user32" (rc As RECT, ByVal dwFlags As dwFlags) As Long
Private Declare Function GetMonitorInfo Lib "user32" Alias "GetMonitorInfoA" (ByVal hMonitor As Long, MonInfo As tagMONITORINFO) As Long

Private rcMonitors() As RECT 'coordinate array for all monitors
Private rcVS         As RECT 'coordinates for Virtual Screen

' vars to obtain correct screen width (to correct VB6 bug) STARTS
Public Const HORZRES As Integer = 8
Public Const VERTRES As Integer = 10

Public screenTwipsPerPixelX As Long ' .07 DAEB 26/04/2021 common.bas changed to use pixels alone, removed all unnecessary twip conversion
Public screenTwipsPerPixelY As Long ' .07 DAEB 26/04/2021 common.bas changed to use pixels alone, removed all unnecessary twip conversion
'Public screenWidthTwips As Long
'Public screenHeightTwips As Long

'Function EnumMonitors(F As Form) As Long
'    Dim N As Long
'    EnumDisplayMonitors 0, ByVal 0&, AddressOf MonitorEnumProc, N
'    With F
'        .Move .Left, .Top, (rcVS.Right - rcVS.Left) * 2 + .Width - .ScaleWidth, (rcVS.Bottom - rcVS.Top) * 2 + .Height - .ScaleHeight
'    End With
'    F.Scale (rcVS.Left, rcVS.Top)-(rcVS.Right, rcVS.Bottom)
'    F.Caption = N & " Monitor" & IIf(N > 1, "s", vbNullString)
'    F.lblMonitors(0).Appearance = 0 'Flat
'    F.lblMonitors(0).BorderStyle = 1 'FixedSingle
'    For N = 0 To N - 1
'        If N Then
'            Load F.lblMonitors(N)
'            F.lblMonitors(N).Visible = True
'        End If
'        With rcMonitors(N)
'            F.lblMonitors(N).Move .Left, .Top, .Right - .Left, .Bottom - .Top
'            F.lblMonitors(N).Caption = "Monitor " & N + 1 & vbLf & _
'                .Right - .Left & " x " & .Bottom - .Top & vbLf & _
'                "(" & .Left & ", " & .Top & ")-(" & .Right & ", " & .Bottom & ")"
'        End With
'    Next
'End Function


'Public Function fVirtualScreenWidth()
'    ' This works even on Tablet PC.  The problem is: when the tablet screen is rotated, the "Screen" object of VB doesn't pick it up.
'    Dim Pixels As Long: Pixels = 0
'    Const SM_CXVIRTUALSCREEN = 78
'    '
'    Pixels = GetSystemMetrics(SM_CXVIRTUALSCREEN)
'    fVirtualScreenWidth = Pixels * fTwipsPerPixelX
'End Function

'Public Function fVirtualScreenHeight(Optional bSubtractTaskbar As Boolean = False)
'    ' This works even on Tablet PC.  The problem is: when the tablet screen is rotated, the "Screen" object of VB doesn't pick it up.
'    Dim Pixels As Long: Pixels = 0
'    Const CYVIRTUALSCREEN = 79
'    '
'    Pixels = GetSystemMetrics(CYVIRTUALSCREEN)
'    If bSubtractTaskbar Then
'        ' The taskbar is typically 30 pixels or 450 twips, or, at least, this is the assumption made here.
'        ' It can actually be multiples of this, or possibly moved to the side or top.
'        ' This procedure does not account for these possibilities.
'        fVirtualScreenHeight = (Pixels - 30) * fTwipsPerPixelY
'    Else
'        fVirtualScreenHeight = Pixels * fTwipsPerPixelY
'    End If
'End Function

' Author    : Elroy from Vbforums
'Public Function fCurrentScreenWidth()
'    ' This works even on Tablet PC.  The problem is: when the tablet screen is rotated, the "Screen" object of VB doesn't pick it up.
'    Dim Pixels As Long: Pixels = 0
'    Const SM_CXSCREEN = 0
'    '
'    Pixels = GetSystemMetrics(SM_CXSCREEN)
'    fCurrentScreenWidth = Pixels * fTwipsPerPixelX
'End Function

' Author    : Elroy from Vbforums
'Public Function fCurrentScreenHeight(Optional bSubtractTaskbar As Boolean = False)
'    ' This works even on Tablet PC.  The problem is: when the tablet screen is rotated, the "Screen" object of VB doesn't pick it up.
'    Dim Pixels As Long: Pixels = 0
'    Const SM_CYSCREEN = 1
'    '
'    Pixels = GetSystemMetrics(SM_CYSCREEN)
'    If bSubtractTaskbar Then
'        ' The taskbar is typically 30 pixels or 450 twips, or, at least, this is the assumption made here.
'        ' It can actually be multiples of this, or possibly moved to the side or top.
'        ' This procedure does not account for these possibilities.
'        fCurrentScreenHeight = (Pixels - 30) * fTwipsPerPixelY
'    Else
'        fCurrentScreenHeight = Pixels * fTwipsPerPixelY
'    End If
'End Function



'---------------------------------------------------------------------------------------
' Procedure : fTwipsPerPixelX
' Author    : Elroy from Vbforums
' Date      : 23/01/2021
' Purpose   : This works even on Tablet PC.  The problem is: when the tablet screen is rotated, the "Screen" object of VB doesn't pick it up.
'---------------------------------------------------------------------------------------
'
Public Function fTwipsPerPixelX() As Single
    Dim hdc As Long: hdc = 0
    Dim lPixelsPerInch As Long: lPixelsPerInch = 0
    
    Const LOGPIXELSX As Integer = 88       '  Logical pixels/inch in X
    Const POINTS_PER_INCH As Long = 72 ' A point is defined as 1/72 inches.
    Const TWIPS_PER_POINT As Long = 20 ' Also, by definition.
    '
    On Error GoTo fTwipsPerPixelX_Error
    
    ' 23/01/2021 .01 monitorModule.bas DAEB added if then else if you can't get device context
    hdc = GetDC(0)
    If hdc <> 0 Then
        lPixelsPerInch = GetDeviceCaps(hdc, LOGPIXELSX)
        ReleaseDC 0, hdc
        fTwipsPerPixelX = TWIPS_PER_POINT * (POINTS_PER_INCH / lPixelsPerInch) ' Cancel units to see it.
    Else
        fTwipsPerPixelX = Screen.TwipsPerPixelX
    End If

   On Error GoTo 0
   Exit Function

fTwipsPerPixelX_Error:

    MsgBox "Error " & Err.Number & " (" & Err.Description & ") in procedure fTwipsPerPixelX of Module Module1"
End Function

'---------------------------------------------------------------------------------------
' Procedure : fTwipsPerPixelY
' Author    : Elroy from Vbforums
' Date      : 23/01/2021
' Purpose   : This works even on Tablet PC.  The problem is: when the tablet screen is rotated, the "Screen" object of VB doesn't pick it up.
'---------------------------------------------------------------------------------------
'
Public Function fTwipsPerPixelY() As Single
    Dim hdc As Long: hdc = 0
    Dim lPixelsPerInch As Long: lPixelsPerInch = 0
    
    Const LOGPIXELSY As Integer = 90        '  Logical pixels/inch in Y
    Const POINTS_PER_INCH As Long = 72 ' A point is defined as 1/72 inches.
    Const TWIPS_PER_POINT As Long = 20 ' Also, by definition.
    
   On Error GoTo fTwipsPerPixelY_Error
   
    ' 23/01/2021 .01 monitorModule.bas DAEB added if then else if you can't get device context
    hdc = GetDC(0)
    If hdc <> 0 Then
        lPixelsPerInch = GetDeviceCaps(hdc, LOGPIXELSY)
        ReleaseDC 0, hdc
        fTwipsPerPixelY = TWIPS_PER_POINT * (POINTS_PER_INCH / lPixelsPerInch) ' Cancel units to see it.
    Else
        fTwipsPerPixelY = Screen.TwipsPerPixelY
    End If

   On Error GoTo 0
   Exit Function

fTwipsPerPixelY_Error:

    MsgBox "Error " & Err.Number & " (" & Err.Description & ") in procedure fTwipsPerPixelY of Module Module1"

End Function

Public Function fGetMonitorCount() As Long
    EnumDisplayMonitors 0, ByVal 0&, AddressOf MonitorEnumProc, fGetMonitorCount
End Function

Private Function MonitorEnumProc(ByVal hMonitor As Long, ByVal hdcMonitor As Long, ByRef lprcMonitor As RECT, ByRef dwData As Long) As Long
    ReDim Preserve rcMonitors(dwData)
    rcMonitors(dwData) = lprcMonitor
    UnionRect rcVS, rcVS, lprcMonitor 'merge all monitors together to get the virtual screen coordinates
    dwData = dwData + 1 'increase monitor count
    MonitorEnumProc = 1 'continue
End Function

'---------------------------------------------------------------------------------------
' Procedure : adjustFormPositionToCorrectMonitor
' Author    : Hypetia from TekTips https://www.tek-tips.com/userinfo.cfm?member=Hypetia
' Date      : 01/03/2023
' Purpose   : Called on startup - restores the form's saved position and puts it on screen
'             if the form finds itself offscreen due to monitor position/resolution changes.
'---------------------------------------------------------------------------------------
'
Public Sub adjustFormPositionToCorrectMonitor(ByRef hwnd As Long, ByVal Left As Long, ByVal Top As Long)

    Dim rc As RECT
'    Dim Left As Long: Left = 0
'    Dim Top As Long: Top = 0
    Dim hMonitor As Long: hMonitor = 0
    Dim mi As tagMONITORINFO
    
    On Error GoTo adjustFormPositionToCorrectMonitor_Error

    GetWindowRect hwnd, rc 'obtain the current form's window rectangle co-ords and assign it a handle
        
    'move the window rectangle to position saved previously
    OffsetRect rc, Left - rc.Left, Top - rc.Top
    
    'find the monitor closest to window rectangle
    hMonitor = MonitorFromRect(rc, MONITOR_DEFAULTTONEAREST)
    
    'get info about monitor coordinates and working area
    mi.cbSize = Len(mi)
    GetMonitorInfo hMonitor, mi
    
    'adjust the window rectangle so it fits inside the work area of the monitor
    If rc.Left < mi.rcWork.Left Then OffsetRect rc, mi.rcWork.Left - rc.Left, 0
    If rc.Right > mi.rcWork.Right Then OffsetRect rc, mi.rcWork.Right - rc.Right, 0
    If rc.Top < mi.rcWork.Top Then OffsetRect rc, 0, mi.rcWork.Top - rc.Top
    If rc.Bottom > mi.rcWork.Bottom Then OffsetRect rc, 0, mi.rcWork.Bottom - rc.Bottom
    
    'move the window to new calculated position
    MoveWindow hwnd, rc.Left, rc.Top, rc.Right - rc.Left, rc.Bottom - rc.Top, 0

    On Error GoTo 0
    Exit Sub

adjustFormPositionToCorrectMonitor_Error:

    With Err
         If .Number <> 0 Then
            MsgBox "Error " & Err.Number & " (" & Err.Description & ") in procedure adjustFormPositionToCorrectMonitor of Module Module1"
            Resume Next
          End If
    End With
End Sub

'---------------------------------------------------------------------------------------
' Procedure : monitorProperties
' Author    :
' Date      : 23/01/2021
' Purpose   : All this subroutne does at the moment is to set the screenTwipsPerPixel,
'             all the other stuff is currently commented out. Might need it later.
'---------------------------------------------------------------------------------------
'
Public Function monitorProperties(ByVal frm As Form) As UDTMonitor
    
    'Return the properties (in Twips) of the monitor on which most of Frm is mapped
    
'    Dim hMonitor As Long: hMonitor = 0
'    Dim MONITORINFO As tagMONITORINFO
'    Dim Frect As RECT
'    Dim ad As Double: ad = 0
    
    ' reads the size and position of the window
    On Error GoTo monitorProperties_Error
   
    If debugflg = 1 Then MsgBox "%" & " func monitorProperties"

'    GetWindowRect frm.hwnd, Frect
'    hMonitor = MonitorFromRect(Frect, MONITOR_DEFAULTTOPRIMARY) ' get handle for monitor containing most of Frm
                                                                ' if disconnected return handle (and properties) for primary monitor
    ' STARTS 23/01/2021 .01 common.bas DAEB calls twipsperpixelsX/Y function when determining the twips for high DPI screens

    ' only calling TwipsPerPixelX/Y once on startup
    screenTwipsPerPixelX = fTwipsPerPixelX
    screenTwipsPerPixelY = fTwipsPerPixelY
    
    'MsgBox "Harry - send me this please screenTwipsPerPixelX - " & screenTwipsPerPixelX
    
    ' ENDS 23/01/2021 .01 common.bas DAEB calls twipsperpixelsX/Y function when determining the twips for high DPI screens
    
    On Error GoTo GetMonitorInformation_Err
'    MONITORINFO.cbSize = Len(MONITORINFO)
'    GetMonitorInfo hMonitor, MONITORINFO
'    With monitorProperties
'        .handle = hMonitor
'        'convert all dimensions from pixels to twips
'        .Left = MONITORINFO.rcMonitor.Left * screenTwipsPerPixelX
'        .Right = MONITORINFO.rcMonitor.Right * screenTwipsPerPixelX
'        .Top = MONITORINFO.rcMonitor.Top * screenTwipsPerPixelY
'        .Bottom = MONITORINFO.rcMonitor.Bottom * screenTwipsPerPixelY
'
'        .WorkLeft = MONITORINFO.rcWork.Left * screenTwipsPerPixelX
'        .WorkRight = MONITORINFO.rcWork.Right * screenTwipsPerPixelX
'        .WorkTop = MONITORINFO.rcWork.Top * screenTwipsPerPixelY
'        .Workbottom = MONITORINFO.rcWork.Bottom * screenTwipsPerPixelY
'
'        .Height = (MONITORINFO.rcMonitor.Bottom - MONITORINFO.rcMonitor.Top) * screenTwipsPerPixelY
'        .Width = (MONITORINFO.rcMonitor.Right - MONITORINFO.rcMonitor.Left) * screenTwipsPerPixelX
'
'        .WorkHeight = (MONITORINFO.rcWork.Bottom - MONITORINFO.rcWork.Top) * screenTwipsPerPixelY
'        .WorkWidth = (MONITORINFO.rcWork.Right - MONITORINFO.rcWork.Left) * screenTwipsPerPixelX
'
'        .IsPrimary = MONITORINFO.dwFlags And MONITORINFOF_PRIMARY
'    End With
'
    Exit Function
GetMonitorInformation_Err:
    'Beep
'    If Err.Number = 453 Then
'        'should be handled if pre win2k compatibility is required
'        'Non-Multimonitor OS, return -1
'        'GetMonitorInformation = -1
'        'etc
'    End If

   On Error GoTo 0
   Exit Function

monitorProperties_Error:

    MsgBox "Error " & Err.Number & " (" & Err.Description & ") in procedure monitorProperties of Module common"
End Function