Alex,
Here's a cut at it using Windows call backs which is MUCH more complex than
the Mabry ocx, but if they want to be difficult... I've updated my site to
say that Mabry have discontinued the control as well. Thanks for the heads
up on that.
Anyway, it's fairly simple (NOT).
There's an open invitation to anyone who wants to try and improve on this! I
certainly haven't perfected it yet.
PLEASE save your work and any data first before trying this. It is not fully
tested and if the callback routine is left outstanding due to abnormal
termination Excel can hang or weird things might happen. Debugging is also a
touch difficult, since Windows wants to react to events but they are being
trapped by the call back. I have only tried this in Excel XP and Win XP at
present.
And, this will only work in versions of Excel that can handle the AddressOf
function. I can't remember when it was introduced offhand.
HTH,
Robin Hammond
www.enhanceddatasystems.com
'CODE
'Create a userform, add 3 listboxes and a commandbutton. Name them to work
with the code below. In your form code:
Option Explicit
Private Sub cmdOK_Click()
Unload Me
End Sub
Private Sub UserForm_Initialize()
Dim lCounter As Long
For lCounter = 1 To 1000
lst1.AddItem lCounter
lst2.AddItem lCounter
lst3.AddItem lCounter
Next lCounter
HookWheel Me, Me.Width, Me.Height, 3
End Sub
Private Sub UserForm_Terminate()
'THIS MUST BE CALLED OR WE HAVE A PROBLEM WITH THE CALLBACK
UnHookWheel
End Sub
'Create a Module mWheelHandler as follows:
Option Explicit
Option Private Module
'************************************************************
'APIs
'************************************************************
Private Declare Function CallWindowProc Lib "user32.dll" Alias _
"CallWindowProcA" ( _
ByVal lpPrevWndFunc As Long, _
ByVal hWnd As Long, _
ByVal Msg As Long, _
ByVal wParam As Long, _
ByVal lParam As Long) As Long
Private Declare Function SetWindowLong Lib "user32.dll" Alias _
"SetWindowLongA" ( _
ByVal hWnd As Long, _
ByVal nIndex As Long, _
ByVal dwNewLong As Long) As Long
Private Declare Function FindWindowA Lib "user32" ( _
ByVal lpClassName As String, _
ByVal lpWindowName As String) As Long
Private Declare Function GetSystemMetrics Lib "user32" _
(ByVal nIndex As Long) As Long
Private Declare Function GetWindowRect Lib "user32" ( _
ByVal hWnd As Long, lpRect As typeRect) As Long
'used to store screen position for GetWindowRect call
Private Type typeRect
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
'screen factor constants
Private dXFactor As Double 'hold screen Conversion coordinates
Private dYFactor As Double
Private lCaptionHeight As Long
'************************************************************
'Constants
'************************************************************
Private Const GWL_WNDPROC = -4
Private Const WM_MOUSEWHEEL = &H20A
Private Const SM_MOUSEWHEELPRESENT = 75
Private lLines As Long
'************************************************************
'Variables
'************************************************************
Private hForm As Long
Public lPrevWndProc As Long
Private lX As Long
Private lY As Long
Private bUp As Boolean
Private frmContainer As msForms.UserForm
'*************************************************************
'WindowProc
'*************************************************************
Private Function WindowProc( _
ByVal lWnd As Long, _
ByVal lMsg As Long, _
ByVal wParam As Long, _
ByVal lParam As Long) As Long
'converted from code by Kevin Wilson on thevbzone
'Test if the message is WM_MOUSEWHEEL
If lMsg = WM_MOUSEWHEEL Then
lX = lParam And 65535
lY = lParam \ 65535
bUp = (wParam > 0)
WheelHandler bUp
End If
'Sends message to previous procedure if not MOUSEWHEEL
'This is VERY IMPORTANT!!!
If lMsg <> WM_MOUSEWHEEL Then
WindowProc = CallWindowProc(lPrevWndProc, lWnd, lMsg, wParam,
lParam)
End If
End Function
Public Sub HookWheel(ByVal frmName As msForms.UserForm, dWidth As Double, _
dHeight As Double, ByVal lLinesToScroll As Long)
If WheelPresent Then
Set frmContainer = frmName
hForm = GetFormHandle(frmName)
GetScreenFactors hForm, dWidth, dHeight
lLines = lLinesToScroll
'create the call back procedure
'addressof doesn't work in earlier versions but not sure which ones
lPrevWndProc = SetWindowLong(hForm, GWL_WNDPROC, AddressOf WindowProc)
End If
End Sub
Public Sub UnHookWheel()
'very important that this is called when the form is unloaded to remove the
call back
Call SetWindowLong(hForm, GWL_WNDPROC, lPrevWndProc)
End Sub
Private Function GetFormHandle(ByVal frmName As msForms.UserForm, _
Optional bByClass As Boolean = True) As Long
'returns a handle to the userform
Dim strClassName As String
Dim strCaption As String
strClassName = IIf(Val(Application.Version) > 8, "ThunderDFrame", _
"ThunderXFrame") & vbNullChar
strCaption = vbNullString
GetFormHandle = FindWindowA(strClassName, strCaption)
End Function
Public Sub GetScreenFactors(lHwnd As Long, _
dWidth As Double, _
dHeight As Double)
'returns screen factors for conversion to Excel units rather than win coords
Dim uRect As typeRect
GetWindowRect lHwnd, uRect
dXFactor = dWidth / (uRect.Right - uRect.Left)
dYFactor = dHeight / (uRect.Bottom - uRect.Top)
lCaptionHeight = dHeight - frmContainer.InsideHeight
End Sub
Private Function WheelPresent() As Boolean
'function by Kevin Wilson from
www.thevbzone.com
' Check for wheel mouse on Win98, WinNT 4.0, & Win2000
If GetSystemMetrics(SM_MOUSEWHEELPRESENT) Then
WheelPresent = True
' Check for wheel mouse on Win32's, Win95, & WinNT 3.5x
ElseIf FindWindowA("MouseZ", "Magellan MSWHEEL") <> 0 Then
WheelPresent = True
End If
End Function
Sub WheelHandler(bUp As Boolean)
Dim ctlFocus As msForms.Control
Dim ctlName As msForms.Control
Dim lTopIndex As Long
Dim bMultiPage As Boolean
Dim lPage As Long
Dim lMove As Long
If Not IsOverForm Then Exit Sub
Set ctlFocus = frmContainer.ActiveControl
'if we are in a multipage then need to set the control
'to whatever the subcontrol is on the active page
If TypeOf ctlFocus Is msForms.MultiPage Then
'set the multipage flag
bMultiPage = True
'store the page number for the MP
lPage = ctlFocus.Value
'set the focus control to the control on the current page
Set ctlFocus = ctlFocus.SelectedItem.ActiveControl
End If
'convert screen coords
lX = lX * dXFactor
lY = lY * dYFactor
lY = lY - lCaptionHeight
'for anything but a commandbutton and textbox lx is relative to the left
'and top of the control, so adjust
If Not (TypeOf ctlFocus Is msForms.CommandButton Or _
TypeOf ctlFocus Is msForms.TextBox) Then
'lX = lX + ctlFocus.Left
'lY = lY + ctlFocus.Top
End If
'loop controls, looking for list boxes
For Each ctlName In frmContainer.Controls
With ctlName
If TypeOf ctlName Is msForms.ListBox Then
'if we are in a multipage
If bMultiPage = True Then
'if we are not on the correct page then skip this control
If lPage <> .Parent.Index Then GoTo SkipControl
End If
'check right of left bound
If lX > .Left Then
'check within width
If lX < .Left + .Width Then
'check below top bound
If lY > .Top Then
'check within height
If lY < .Top + .Height Then
'WE FOUND THE RIGHT CONTROL SO HANDLE THE SCROLL
'if the list is empty there is nothing to scroll
If .ListCount = 0 Then Exit Sub
'check scroll direction
lMove = IIf(bUp, -lLines, lLines)
'get the new top index
lTopIndex = .TopIndex + lMove
'check it is within valid limits
If lTopIndex < 0 Then
lTopIndex = 0
ElseIf lTopIndex > .ListCount - (.Height / 10) +
2 Then
lTopIndex = .TopIndex
End If
'set the new top index
.TopIndex = lTopIndex
'scroll has been handled so stop looping
Exit Sub
End If
End If
End If
End If
End If
End With
SkipControl:
Next ctlName
End Sub
Public Function IsOverForm() As Boolean
'we can't get the form's coordinates directly when referenced as a form
'rather than ME within the form's code
'so call GetWindowRect again in case the form has been moved
Dim uRect As typeRect
GetWindowRect hForm, uRect
With uRect
If lX >= .Left Then
If lX <= .Right Then
If lY >= .Top Then
If lY <= .Bottom Then
IsOverForm = True
lX = lX - .Left
lY = lY - .Top
End If
End If
End If
End If
End With
End Function
That's almost certainly the longest post I've ever made to this group. Any
improvements suggested?
Robin Hammond
www.enhanceddatasystems.com