Inno Setup disable component selection when a specific component is selected

Question

I would like to be able to disable the selection of a component based on a specific component being selected. I cannot do this through nesting of components, as the componen

Answer 1

You had TLama's solution which was probably better than the following, but still this code is also a way to achieve the goal (though you will need innocallback.dll):

[Setup]
AppName=My Program
AppVersion=1.5
DefaultDirName={pf}\My Program

[Files]
Source: ".\InnoCallback.dll"; DestDir: "{tmp}"; Flags: dontcopy nocompression

[Components]
Name: "Client"; Description: "Client"; Types: custom
Name: "Sync"; Description: "Sync"; Types: custom

[Code]
var
TimerID: Integer;

type
TTimerProc = procedure(Wnd: HWND; Msg: UINT; TimerID: UINT_PTR; 
SysTime: DWORD);
function WrapTimerProc(Callback: TTimerProc; ParamCount: Integer): LongWord;
external 'wrapcallback@files:InnoCallback.dll stdcall';    
function SetTimer(hWnd: HWND; nIDEvent, uElapse: UINT;
lpTimerFunc: UINT): UINT; external 'SetTimer@user32.dll stdcall';

function KillTimer(hWnd: HWND; uIDEvent: UINT): BOOL; 
external 'KillTimer@user32.dll stdcall'; 

procedure KillComponentsTimer;
begin
  if TimerID <> 0 then 
    begin
      if KillTimer(0, TimerID) then
        TimerID := 1;
    end;
end;

procedure OnComponentsCheck(Wnd: HWND; Msg: UINT; TimerID: UINT_PTR; 
SysTime: DWORD);
begin
    if IsComponentSelected('Client') then begin
        WizardForm.ComponentsList.Checked[1] := False;
        WizardForm.ComponentsList.ItemEnabled[1] := False;
    end
    else begin
        WizardForm.ComponentsList.ItemEnabled[1] := True;
    end;    
    if IsComponentSelected('Sync') then begin
        WizardForm.ComponentsList.Checked[0] := False;
        WizardForm.ComponentsList.ItemEnabled[0] := False;
    end
    else begin 
        WizardForm.ComponentsList.ItemEnabled[0] := True;
    end;
end;

procedure ComponentsCheck();
var
  TimerCallback: LongWord;
begin
  TimerCallback := WrapTimerProc(@OnComponentsCheck, 4);
  TimerID := SetTimer(0, 0, 100, TimerCallback);
end;

procedure CurPageChanged(CurPageID: Integer);
begin
if CurPageID = wpSelectComponents then
  begin
    ComponentsCheck;
  end;
if CurPageID = not wpSelectComponents then 
  begin
   KillComponentsTimer;
  end;
end;