instead of using its default right mouse menu on the map,
i want to define my own menu ,
how to do it?
thanks for any help.

If you want to extend the current menu with custom actions, you can use MarbleWidget::popupMenu() and MarbleWidgetPopupMenu::addAction(). To disable the menu completely, use MarbleWidget::inputHandler() and MarbleInputHandler::setMouseButtonPopupEnabled(). Showing a custom context menu could be hooked to the rmbRequest(int x, int y) signal of MarbleInputHandler.