Trait AppLike

pub trait AppLike<Helper>
where
    Self: Sized,
{
    // Required methods
    fn new() -> Result<(Helper, Rc<ReentrantRefCell<Option<Self>>>)>;
    fn startup_wnd_proc(
        hwnd: HWND,
        msg_id: u32,
        wparam: WPARAM,
        lparam: LPARAM,
    ) -> (Option<Self>, Option<LRESULT>);
    fn wnd_proc(
        &mut self,
        hwnd: HWND,
        msg_id: u32,
        wparam: WPARAM,
        lparam: LPARAM,
    ) -> Option<LRESULT>;

    // Provided method
    fn reenter_wnd_proc<F, T>(&mut self, f: F) -> T
       where F: FnOnce(&mut Self) -> T { ... }
}

Required Methods

fn new() -> Result<(Helper, Rc<ReentrantRefCell<Option<Self>>>)>

Where you let the helper make your app.

fn startup_wnd_proc( hwnd: HWND, msg_id: u32, wparam: WPARAM, lparam: LPARAM, ) -> (Option<Self>, Option<LRESULT>)

The window procedure called initially, until you provide an instance through the first return value. The second return value is as in Self::wnd_proc(). You can, e.g., create the instance on WM_CREATE.

fn wnd_proc( &mut self, hwnd: HWND, msg_id: u32, wparam: WPARAM, lparam: LPARAM, ) -> Option<LRESULT>

The regular window procedure called when Self::startup_wnd_proc() isn’t called anymore.

See also [window::WindowClass].

Safety

You must use Self::reenter_wnd_proc() when appropriate.

Provided Methods

fn reenter_wnd_proc<F, T>(&mut self, f: F) -> T

where F: FnOnce(&mut Self) -> T,

A helper function that simply takes the same self parameter as Self::wnd_proc() to cause compiler errors, if necessary, when functions are called that synchronously call the window procedure and thus borrow &mut self again (via ReentrantRefCell). Anything other than simple reborrowing is against the rules. This prevents multiple simultaneous borrows.

The function can be viewed as adding a self parameter to Windows API functions, as if they would belong to the type.

See ReentrantRefCell::borrow_mut_reentrant() for more information.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors