Native Windows GUI: Raw handles

Native windows controls handle are public and always accessible using the field handle.

For example, here's the definition of ControlHandle and the Window control:

#[derive(Default)]
pub struct Window {
    pub handle: ControlHandle
}

pub enum ControlHandle {
    NoHandle,
    Hwnd(HWND),

    /// (Parent menu / Menu). 
    /// Parent menu must be there as WINAPI does not have any function to fetch the parent
    Menu(HMENU, HMENU),

    /// (Parent window / Menu). 
    PopMenu(HWND, HMENU),

    /// (Parent menu / Unique ID). 
    MenuItem(HMENU, u32),

    /// Notice control
    Notice(HWND, u32),

    /// Timer control
    Timer(HWND, u32),

    /// System tray control
    SystemTray(HWND)
}

Unwrapping window handles

Assuming you know the handle on the control and want to directly access it's content, the ControlHandle object has those methods:

pub fn hwnd(&self) -> Option<HWND>
pub fn hmenu(&self) -> Option<(HMENU, HMENU)>
pub fn pop_hmenu(&self) -> Option<(HWND, HMENU)>
pub fn hmenu_item(&self) -> Option<(HMENU, u32)>
pub fn timer(&self) -> Option<(HWND, u32)>
pub fn notice(&self) -> Option<(HWND, u32)>
pub fn tray(&self) -> Option<HWND>

Wrapping external handles

Wrapping external handles should only be done on a Window as it only control that doesn't expose window class specific functions. Wrapping external handles should be considered unsafe.

pub fn wrap_extern_window(hwnd: HWND) -> nwg::Window {
    nwg::Window {
        handle: nwg::ControlHandle::Hwnd(hwnd)
    }
}