wpLicese Page check if ScrollBars position is max

Question

Is it possible to check the position of ScrollBar in wpLicense Page in Inno Setup without having to write custom memo page?

e.g.

procedure CurPageChanged(CurPageID: Integer);
 begin

     if CurPageID = wpLicense then
        WizardForm.LicenseAcceptedRadio.Enabled := False;
        WizardForm.LicenseNotAcceptedRadio.Enabled := False;

     if ScrollBar.Position := ScrollBar.Max then
        WizardForm.LicenseAcceptedRadio.Enabled := True;
        WizardForm.LicenseNotAcceptedRadio.Enabled := True;
  end;

Answer 1

There is no direct access to those scroll bars, however you can use the GetScrollInfo function this way:

[code]
const
  SB_VERT = 1;
  SIF_RANGE = 1;
  SIF_POS = 4;
  SIF_PAGE = 2;

type
  TScrollInfo = record
    cbSize: UINT;
    fMask: UINT;
    nMin: Integer;
    nMax: Integer;
    nPage: UINT;
    nPos: Integer;
    nTrackPos: Integer;
  end;

function GetScrollInfo(hWnd: HWND; BarFlag: Integer; 
  var ScrollInfo: TScrollInfo): BOOL;
  external '[e-mail] stdcall';

procedure CurPageChanged(CurPageID: Integer);
var
  ScrollInfo: TScrollInfo;
begin
  if CurPageID = wpLicense then
  begin
    ScrollInfo.cbSize := SizeOf(ScrollInfo);
    ScrollInfo.fMask := SIF_RANGE or SIF_POS or SIF_PAGE;
    if GetScrollInfo(WizardForm.LicenseMemo.Handle, SB_VERT, ScrollInfo) then
      if ScrollInfo.nPos = ScrollInfo.nMax - ScrollInfo.nPage then
        MsgBox('You are at the end of the license!', mbInformation, MB_OK);
  end;
end;

Answer 2

That is what I have now. It works, however if you find any issues, just say as I like comments.

procedure OnScrollPosition(Wnd: HWND; Msg: UINT; TimerID: UINT_PTR; 
  SysTime: DWORD);
  var
    ScrollInfo: TScrollInfo;
begin
  ScrollInfo.cbSize := SizeOf(ScrollInfo);
  ScrollInfo.fMask := SIF_RANGE or SIF_POS or SIF_PAGE;
    if GetScrollInfo(WizardForm.LicenseMemo.Handle, SB_VERT, ScrollInfo) then
       if ScrollInfo.nPos = ScrollInfo.nMax - ScrollInfo.nPage then
          begin
            WizardForm.LicenseAcceptedRadio.Enabled := True;
            WizardForm.LicenseNotAcceptedRadio.Enabled := True;
          end;
end;

procedure ScrollPosition();
var
  TimerCallback: LongWord;
begin
  TimerCallback := WrapTimerProc(@OnScrollPosition, 4);
  TimerID := SetTimer(0, 0, 500, TimerCallback);
end;

procedure CurPageChanged(CurPageID: Integer);
var
  ScrollInfo: TScrollInfo;
begin
   if CurPageID = wpInstalling then
     StartSlideTimer
   else
     KillSlideTimer;
if CurPageID = wpLicense then
  WizardForm.LicenseAcceptedRadio.Enabled := False;
  WizardForm.LicenseNotAcceptedRadio.Enabled := False;
  ScrollPosition
end;