Can't get raw-window-handle-06 feature to work.

[maxenko]

My goal is to get raw window handle so i can check if mouse is in the window rectangle using winapi crate using HWND. Maybe I am just confused about the usage (still new to rust and slint).

my Cargo.toml:

[dependencies.slint]
version = "1.6.0"
features = ["default", "raw-window-handle-06"]

my code (relevant):

    let ui = MainWindow::new()?;
    let wh = Window::window_handle(&ui.window());

This compiles, but I am not seeing Result<raw_window_handle_06::WindowHandle<'a>, raw_window_handle_06::HandleError> as described in slint api.rs:

/// This struct represents a persistent handle to a window and implements the
/// [`raw_window_handle_06::HasWindowHandle`] and [`raw_window_handle_06::HasDisplayHandle`]
/// traits for accessing exposing raw window and display handles.
/// Obtain an instance of this by calling [`Window::window_handle()`].
#[cfg(feature = "raw-window-handle-06")]
#[derive(Clone)]
pub struct WindowHandle {
    adapter: alloc::rc::Rc<dyn WindowAdapter>,
}

#[cfg(feature = "raw-window-handle-06")]
impl raw_window_handle_06::HasWindowHandle for WindowHandle {
    fn window_handle<'a>(
        &'a self,
    ) -> Result<raw_window_handle_06::WindowHandle<'a>, raw_window_handle_06::HandleError> {
        self.adapter.window_handle_06()
    }
}

#[cfg(feature = "raw-window-handle-06")]
impl raw_window_handle_06::HasDisplayHandle for WindowHandle {
    fn display_handle<'a>(
        &'a self,
    ) -> Result<raw_window_handle_06::DisplayHandle<'a>, raw_window_handle_06::HandleError> {
        self.adapter.display_handle_06()
    }
}

What I am getting is WindowHandle struct.

How can I get this feature to work and get to raw HWND?

[tronical]

You’re almost there :). let wh = ui.window().window_handle(); gives you the slint::WindowHandle type, which implements the rwh traits. They aren’t implemented on the slint::Window directly because that would be unsafe. The returned WindowHandle type ensures the underlying window stays alive.

[maxenko]

@tronical thank you for the tip, infortunately I am not seeing any special methods, and its still just WindowHandle struct not Result. ie let wh = ui.window().

[tronical]

in order to be able to call raw-window-handle’s window_handle function (https://docs.rs/raw-window-handle/latest/raw_window_handle/trait.HasWindowHandle.html#tymethod.window_handle ) on a slint::WindowHandle, you need to bring the HasWindowHandle trait (https://docs.rs/raw-window-handle/latest/raw_window_handle/trait.HasWindowHandle.html# ) in scope. Add raw-window-handle in version 0.6 to your Cargo.toml and add use raw_window_handle::HasWindowHandle;

[maxenko]

for future readers:

let ui = MainWindow::new()?;
let slint_wh = ui.window().window_handle();
let maybe_raw_window_handle = slint_wh.window_handle(); // Result<WindowHandle, HandleError>
let mut raw_hwnd = NonZeroIsize::new(-1).unwrap();

match maybe_raw_window_handle {
    Ok(win_handle) => {
        match win_handle.as_ref() {
            raw_window_handle::RawWindowHandle::Win32(handle) => {
                raw_hwnd = handle.hwnd;
            },
            _ => {
                // ...
            }
        }
    },
    Err(e) => {
        // ...
    }
}