m: Use the SwResultExt trait in more places

src/error.rs

@@ -1,5 +1,6 @@
 use raw_window_handle::{RawDisplayHandle, RawWindowHandle};
 use std::error::Error;
+use std::fmt;
 use std::num::NonZeroU32;
 use thiserror::Error;
 
@@ -39,16 +40,41 @@ pub enum SoftBufferError {
     PlatformError(Option<String>, Option<Box<dyn Error>>),
 }
 
-#[allow(unused)] // This isn't used on all platforms
-pub(crate) fn unwrap<T, E: std::error::Error + 'static>(
-    res: Result<T, E>,
-    str: &str,
-) -> Result<T, SoftBufferError> {
-    match res {
-        Ok(t) => Ok(t),
-        Err(e) => Err(SoftBufferError::PlatformError(
-            Some(str.into()),
-            Some(Box::new(e)),
-        )),
+/// Convenient wrapper to cast errors into SoftBufferError.
+pub(crate) trait SwResultExt<T> {
+    fn swbuf_err(self, msg: impl Into<String>) -> Result<T, SoftBufferError>;
+}
+
+impl<T, E: std::error::Error + 'static> SwResultExt<T> for Result<T, E> {
+    fn swbuf_err(self, msg: impl Into<String>) -> Result<T, SoftBufferError> {
+        self.map_err(|e| {
+            SoftBufferError::PlatformError(Some(msg.into()), Some(Box::new(LibraryError(e))))
+        })
     }
 }
+
+impl<T> SwResultExt<T> for Option<T> {
+    fn swbuf_err(self, msg: impl Into<String>) -> Result<T, SoftBufferError> {
+        self.ok_or_else(|| SoftBufferError::PlatformError(Some(msg.into()), None))
+    }
+}
+
+/// A wrapper around a library error.
+///
+/// This prevents `x11-dl` and `x11rb` from becoming public dependencies, since users cannot downcast
+/// to this type.
+struct LibraryError<E>(E);
+
+impl<E: fmt::Debug> fmt::Debug for LibraryError<E> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.0, f)
+    }
+}
+
+impl<E: fmt::Display> fmt::Display for LibraryError<E> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&self.0, f)
+    }
+}
+
+impl<E: fmt::Debug + fmt::Display> std::error::Error for LibraryError<E> {}

src/wayland/mod.rs

@@ -1,4 +1,4 @@
-use crate::{error::unwrap, util, SoftBufferError};
+use crate::{error::SwResultExt, util, SoftBufferError};
 use raw_window_handle::{WaylandDisplayHandle, WaylandWindowHandle};
 use std::{
     cell::RefCell,
@@ -29,15 +29,12 @@ impl WaylandDisplayImpl {
         // SAFETY: Ensured by user
         let backend = unsafe { Backend::from_foreign_display(display_handle.display as *mut _) };
         let conn = Connection::from_backend(backend);
-        let (globals, event_queue) = unwrap(
-            registry_queue_init(&conn),
-            "Failed to make round trip to server",
-        )?;
+        let (globals, event_queue) =
+            registry_queue_init(&conn).swbuf_err("Failed to make round trip to server")?;
         let qh = event_queue.handle();
-        let shm: wl_shm::WlShm = unwrap(
-            globals.bind(&qh, 1..=1, ()),
-            "Failed to instantiate Wayland Shm",
-        )?;
+        let shm: wl_shm::WlShm = globals
+            .bind(&qh, 1..=1, ())
+            .swbuf_err("Failed to instantiate Wayland Shm")?;
         Ok(Self {
             conn,
             event_queue: RefCell::new(event_queue),
@@ -60,19 +57,15 @@ impl WaylandImpl {
         display: Rc<WaylandDisplayImpl>,
     ) -> Result<Self, SoftBufferError> {
         // SAFETY: Ensured by user
-        let surface_id = unwrap(
-            unsafe {
-                ObjectId::from_ptr(
-                    wl_surface::WlSurface::interface(),
-                    window_handle.surface as _,
-                )
-            },
-            "Failed to create proxy for surface ID.",
-        )?;
-        let surface = unwrap(
-            wl_surface::WlSurface::from_id(&display.conn, surface_id),
-            "Failed to create proxy for surface ID.",
-        )?;
+        let surface_id = unsafe {
+            ObjectId::from_ptr(
+                wl_surface::WlSurface::interface(),
+                window_handle.surface as _,
+            )
+        }
+        .swbuf_err("Failed to create proxy for surface ID.")?;
+        let surface = wl_surface::WlSurface::from_id(&display.conn, surface_id)
+            .swbuf_err("Failed to create proxy for surface ID.")?;
         Ok(Self {
             display,
             surface,

src/web.rs

@@ -8,6 +8,7 @@ use web_sys::CanvasRenderingContext2d;
 use web_sys::HtmlCanvasElement;
 use web_sys::ImageData;
 
+use crate::error::SwResultExt;
 use crate::SoftBufferError;
 use std::convert::TryInto;
 use std::num::NonZeroU32;
@@ -22,19 +23,9 @@ pub struct WebDisplayImpl {
 impl WebDisplayImpl {
     pub(super) fn new() -> Result<Self, SoftBufferError> {
         let document = web_sys::window()
-            .ok_or_else(|| {
-                SoftBufferError::PlatformError(
-                    Some("`window` is not present in this runtime".into()),
-                    None,
-                )
-            })?
+            .swbuf_err("`window` is not present in this runtime")?
             .document()
-            .ok_or_else(|| {
-                SoftBufferError::PlatformError(
-                    Some("`document` is not present in this runtime".into()),
-                    None,
-                )
-            })?;
+            .swbuf_err("`document` is not present in this runtime")?;
 
         Ok(Self { document })
     }
@@ -61,31 +52,19 @@ impl WebImpl {
             .query_selector(&format!("canvas[data-raw-handle=\"{}\"]", handle.id))
             // `querySelector` only throws an error if the selector is invalid.
             .unwrap()
-            .ok_or_else(|| {
-                SoftBufferError::PlatformError(
-                    Some("No canvas found with the given id".into()),
-                    None,
-                )
-            })?
+            .swbuf_err("No canvas found with the given id")?
             // We already made sure this was a canvas in `querySelector`.
             .unchecked_into();
 
         let ctx = canvas
-        .get_context("2d")
-        .map_err(|_| {
-            SoftBufferError::PlatformError(
-                Some("Canvas already controlled using `OffscreenCanvas`".into()),
-                None,
-            )
-        })?
-        .ok_or_else(|| {
-            SoftBufferError::PlatformError(
-                Some("A canvas context other than `CanvasRenderingContext2d` was already created".into()),
-                None,
-            )
-        })?
-        .dyn_into()
-        .expect("`getContext(\"2d\") didn't return a `CanvasRenderingContext2d`");
+            .get_context("2d")
+            .ok()
+            .swbuf_err("Canvas already controlled using `OffscreenCanvas`")?
+            .swbuf_err(
+                "A canvas context other than `CanvasRenderingContext2d` was already created",
+            )?
+            .dyn_into()
+            .expect("`getContext(\"2d\") didn't return a `CanvasRenderingContext2d`");
 
         Ok(Self {
             canvas,

src/x11.rs

@@ -5,6 +5,7 @@
 
 #![allow(clippy::uninlined_format_args)]
 
+use crate::error::SwResultExt;
 use crate::{util, SoftBufferError};
 use nix::libc::{shmat, shmctl, shmdt, shmget, IPC_PRIVATE, IPC_RMID};
 use raw_window_handle::{XcbDisplayHandle, XcbWindowHandle, XlibDisplayHandle, XlibWindowHandle};
@@ -650,19 +651,6 @@ impl From<io::Error> for PushBufferError {
     }
 }
 
-/// Convenient wrapper to cast errors into SoftBufferError.
-trait SwResultExt<T, E> {
-    fn swbuf_err(self, msg: impl Into<String>) -> Result<T, SoftBufferError>;
-}
-
-impl<T, E: std::error::Error + 'static> SwResultExt<T, E> for Result<T, E> {
-    fn swbuf_err(self, msg: impl Into<String>) -> Result<T, SoftBufferError> {
-        self.map_err(|e| {
-            SoftBufferError::PlatformError(Some(msg.into()), Some(Box::new(LibraryError(e))))
-        })
-    }
-}
-
 /// Convenient wrapper to cast errors into PushBufferError.
 trait PushResultExt<T, E> {
     fn push_err(self) -> Result<T, PushBufferError>;
@@ -674,26 +662,6 @@ impl<T, E: Into<PushBufferError>> PushResultExt<T, E> for Result<T, E> {
     }
 }
 
-/// A wrapper around a library error.
-///
-/// This prevents `x11-dl` and `x11rb` from becoming public dependencies, since users cannot downcast
-/// to this type.
-struct LibraryError<E>(E);
-
-impl<E: fmt::Debug> fmt::Debug for LibraryError<E> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Debug::fmt(&self.0, f)
-    }
-}
-
-impl<E: fmt::Display> fmt::Display for LibraryError<E> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt::Display::fmt(&self.0, f)
-    }
-}
-
-impl<E: fmt::Debug + fmt::Display> std::error::Error for LibraryError<E> {}
-
 /// Get the length that a slice needs to be to hold a buffer of the given dimensions.
 #[inline(always)]
 fn total_len(width: u16, height: u16) -> usize {