https://docs.microsoft.com/en-us/windows/desktop/uxguide/cmd-toolbars
https://docs.microsoft.com/en-us/windows/desktop/controls/cc-faq-iemenubar
https://docs.microsoft.com/en-us/windows/desktop/controls/cc-faq-ietoolbar
https://docs.microsoft.com/en-us/windows/desktop/controls/create-rebar-controls
https://docs.microsoft.com/en-us/windows/desktop/controls/create-toolbars
https://docs.microsoft.com/en-us/windows/desktop/controls/handle-drop-down-buttons
https://docs.microsoft.com/en-us/windows/desktop/controls/tb-buttonstructsize
 https://www.google.com/search?q=winapi+toolbar+dropdown+position&ie=utf-8&oe=utf-8&client=firefox-b-1
https://www.google.com/search?q=winapi+toolbar+dropdown+arrow+position&ie=utf-8&oe=utf-8&client=firefox-b-1