Inno Setup Uninstall some components only

Question

I have a common application -like a media player- for each different retail product that is installed in the same folder i.e.

C:\\program files\\myapp

Answer 1

Inno Setup does not support partial uninstallations.

Once the uninstallation completes, your whole application with all installed components (movies) will be deleted.

What you can do is to present a custom form with movies list in the InitializeUninstall. If the user chooses to uninstall only (some) movies, but not whole application (the viewer), you delete the movies with your own code and abort the uninstallation (by returning False from the InitializeUninstall). If the user chooses to uninstall everything, you let the uninstallation complete.

function InitializeUninstall(): Boolean;
var
  Form: TSetupForm;
  OKButton, CancelButton: TNewButton;
  CheckListBox: TNewCheckListBox;
  I, Count, Deleted: Integer;
  FindRec: TFindRec;
  MoviePath: string;
  Movies: TArrayOfString;
begin
  MoviePath := ExpandConstant('{app}\movies\');
  Count := 0;
  if FindFirst(MoviePath + '*', FindRec) then
  begin
    try
      repeat
        if FindRec.Attributes and FILE_ATTRIBUTE_DIRECTORY = 0 then
        begin
          Inc(Count);
          SetArrayLength(Movies, Count);
          Movies[Count - 1] := FindRec.Name;
        end;
      until not FindNext(FindRec);
    finally
      FindClose(FindRec);
    end;
  end;

  if Count = 0 then
  begin
    Log('Found no movies proceeding with a complete uninstallation');
    Result := True;
  end
    else 
  begin
    Log(Format('Found %d movies', [Count]));

    Form := CreateCustomForm();
    try
      Form.ClientWidth := ScaleX(350);
      Form.ClientHeight := ScaleY(250);
      Form.Caption := 'Uninstall';
      Form.Position := poDesktopCenter;

      CheckListBox := TNewCheckListBox.Create(Form);
      CheckListBox.Parent := Form;
      CheckListBox.Left := ScaleX(10);
      CheckListBox.Width := Form.ClientWidth - 2*CheckListBox.Left;
      CheckListBox.Top := ScaleY(10);
      CheckListBox.Height :=
          Form.ClientHeight - ScaleY(23 + 10 + 10 + CheckListBox.Top);

      CheckListBox.AddCheckBox(
        'Uninstall viewer and all movies', '', 0, True, True, True, True, nil);
      for I := 0 to Count - 1 do
      begin
        CheckListBox.AddCheckBox(Movies[I], '', 1, True, True, False, True, nil);
      end;

      OKButton := TNewButton.Create(Form);
      OKButton.Parent := Form;
      OKButton.Width := ScaleX(75);
      OKButton.Height := ScaleY(23);
      OKButton.Left := Form.ClientWidth - ScaleX(75 + 6 + 75 + 10);
      OKButton.Top := Form.ClientHeight - ScaleY(23 + 10);
      OKButton.Caption := 'OK';
      OKButton.ModalResult := mrOk;
      OKButton.Default := True;

      CancelButton := TNewButton.Create(Form);
      CancelButton.Parent := Form;
      CancelButton.Width := OKButton.Width;
      CancelButton.Height := OKButton.Height;
      CancelButton.Left := OKButton.Left + OKButton.Width + ScaleX(6);
      CancelButton.Top := OKButton.Top;
      CancelButton.Caption := 'Cancel';
      CancelButton.ModalResult := mrCancel;
      CancelButton.Cancel := True;

      Form.ActiveControl := CheckListBox;

      if Form.ShowModal() <> mrOk then
      begin
        Log('User cancelled the uninstallation');
        Result := False;
      end
        else
      begin
        if CheckListBox.State[0] = cbChecked then 
        begin
          Log('User selected complete uninstallation');
          Result := True; 
        end
          else
        begin
          for I := 0 to Count - 1 do
          begin
            if CheckListBox.Checked[I + 1] then
            begin
              if DeleteFile(MoviePath + Movies[I]) then
              begin
                Inc(Deleted);
                Log(Format('Deleted movie %s', [Movies[I]]));
              end
                else
              begin
                MsgBox(Format('Error deleting %s', [Movies[I]]), mbError, MB_OK);
              end;
            end;
          end;

          MsgBox(Format('Deleted %d movies', [Deleted]), mbInformation, MB_OK);
          Result := False; 
        end;
      end;
    finally
      Form.Free();
    end;
  end;
end;