Disabling smooth scroll in a RichTextBox (RTB)?

[Skram0]

I've search everywhere and tried a bunch of things, but I can't find a way to disable smooth scroll in my rich text box. I'm using the RTB with coloured text, so I can't use the standard TextBox control. Everything's working okay except for the smooth scrolling effect in my RTB.

I've attached some sample code to show you what I mean. Maybe the RTB will scroll normally for you, I don't know. My mouse is set to scroll 3 lines at a time in the control panel, and it works great for the rest of the comp. But in my program if I slam my mouse wheel up/down a bunch of times really fast, I have to wait a few seconds for the window to scroll and catch up.

This smooth scroll crap in the RTB really sucks. Any way to disable it to get normal fast line-scrolling back?

[bushmobile]

what you'll have to do is override the default mouse scroll. So, you subclass the RTB, look for the WM_MOUSEWHEEL messages and send a EM_LINESCROLL message instead.

In module:

Option Explicit

Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
    ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long

Private Declare Function CallWindowProc Lib "user32" 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 Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (dest As _
    Any, source As Any, ByVal bytes As Long)

Private Const GWL_WNDPROC = (-4)
Private Const WM_MOUSEWHEEL = &H20A
Private Const EM_LINESCROLL = &HB6

Private lPrevProc As Long

Public Sub SubClass(ByVal lhWnd As Long)
    lPrevProc = SetWindowLong(lhWnd, GWL_WNDPROC, AddressOf WndProc)
End Sub

Private Function WndProc(ByVal hWnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    Dim intDir As Integer
    
    If Msg = WM_MOUSEWHEEL Then
        CopyMemory intDir, ByVal VarPtr(wParam) + 2, 2
        intDir = -Sgn(intDir) * 3
        WndProc = CallWindowProc(lPrevProc, hWnd, EM_LINESCROLL, 0&, intDir)
    Else
        WndProc = CallWindowProc(lPrevProc, hWnd, Msg, wParam, lParam)
    End If
End Function

Public Sub UnSubClass(ByVal lhWnd As Long)
    SetWindowLong lhWnd, GWL_WNDPROC, lPrevProc
End Sub

[Skram0]

what you'll have to do is override the default mouse scroll. So, you subclass the RTB, look for the WM_MOUSEWHEEL messages and send a EM_LINESCROLL message instead.

Right on.. Thank you very much.. Just the code I was looking for. I thought I was going to be stuck with the slow pixel scrolling. It was even getting slower and slower as more text got added, but this should help greatly.