c++winapiwxwidgets

How to work with system menu of a window in wxWidgets?

I have implemented a custom titlebar for my window and I want to display the default system (context) menu when right-clicking on it. My current approach is as follows:

auto sysMenu = ctrl_->MSWGetSystemMenu();
if( sysMenu )
{
  //sysMenu->Bind( wxEVT_MENU, &WxWindow::onSystemMenu, this );
  ctrl_->PopupMenu( sysMenu, pos );
}

system menu

It successfully displays the system menu, but clicking on any item doesn't seem to have any effect. I initially thought it would send a relevant message, such as SC_CLOSE, to the window's message handler, but it's not happening. My second assumption was that I might need to create my own handler and handle the message there. So, I created a handler function named onSystemMenu like below:

void onSystemMenu( wxCommandEvent& e )
{
  int id = e.GetId();

  switch( id )
  {
    case wxID_MAXIMIZE_FRAME: // Maximize the window
      ctrl_->Maximize();
      break;

    case wxID_RESTORE_FRAME: // Restore the window to its previous size and position
      ctrl_->Restore();
      break;

    case wxID_ICONIZE_FRAME: // Minimize the window
      ctrl_->Iconize();
      break;

    case wxID_CLOSE_FRAME: // Close the window
      ctrl_->Close();
      break;

  }
}

However, the received ID is always different from those expected values. For instance, I'm receiving values like -4048, which doesn't correspond to any of the IDs I listed. I still believe there should be a way to achieve this without manually creating a handler. Can someone please provide assistance?

Solution

  • It seems the following code works:

        auto pos = wxGetMousePosition();
    auto hwnd = ctrl_->GetHandle();
    auto menu = GetSystemMenu( hwnd, FALSE );
    if( menu )
    {
      MENUITEMINFO mInfo;
      mInfo.cbSize = sizeof( MENUITEMINFO );
      mInfo.fMask = MIIM_STATE;
      mInfo.fType = 0;

      // update the options
      mInfo.fState = MF_ENABLED;
      SetMenuItemInfo( menu, SC_RESTORE, FALSE, &mInfo );
      SetMenuItemInfo( menu, SC_SIZE, FALSE, &mInfo );
      SetMenuItemInfo( menu, SC_MOVE, FALSE, &mInfo );
      SetMenuItemInfo( menu, SC_MAXIMIZE, FALSE, &mInfo );
      SetMenuItemInfo( menu, SC_MINIMIZE, FALSE, &mInfo );

      mInfo.fState = MF_GRAYED;

      WINDOWPLACEMENT wp;
      GetWindowPlacement( hwnd, &wp );

      switch( wp.showCmd )
      {
        case SW_SHOWMAXIMIZED:
          SetMenuItemInfo( menu, SC_SIZE, FALSE, &mInfo );
          SetMenuItemInfo( menu, SC_MOVE, FALSE, &mInfo );
          SetMenuItemInfo( menu, SC_MAXIMIZE, FALSE, &mInfo );
          SetMenuDefaultItem( menu, SC_CLOSE, FALSE );
          break;
        case SW_SHOWMINIMIZED:
          SetMenuItemInfo( menu, SC_MINIMIZE, FALSE, &mInfo );
          SetMenuDefaultItem( menu, SC_RESTORE, FALSE );
          break;
        case SW_SHOWNORMAL:
          SetMenuItemInfo( menu, SC_RESTORE, FALSE, &mInfo );
          SetMenuDefaultItem( menu, SC_CLOSE, FALSE );
          break;
      }

      auto Selected = TrackPopupMenu(
        menu, TPM_RIGHTBUTTON | TPM_RETURNCMD, pos.x, pos.y, 0, hwnd, NULL );
      if( Selected )
        SendMessage( hwnd, WM_SYSCOMMAND, Selected, 0 );
    }

    Maybe a bug in PopupMenu of wxWidgets?!