Move Icon to iced crate and introduce Error

src/window/icon.rs

@@ -0,0 +1,132 @@
+//! Attach an icon to the window of your application.
+use std::fmt;
+use std::io;
+
+/// The icon of a window.
+#[cfg(not(target_arch = "wasm32"))]
+#[derive(Debug, Clone)]
+pub struct Icon(iced_winit::winit::window::Icon);
+
+/// The icon of a window.
+#[cfg(target_arch = "wasm32")]
+#[derive(Debug, Clone)]
+pub struct Icon;
+
+impl Icon {
+    /// Creates an icon from 32bpp RGBA data.
+    #[cfg(not(target_arch = "wasm32"))]
+    pub fn from_rgba(
+        rgba: Vec<u8>,
+        width: u32,
+        height: u32,
+    ) -> Result<Self, Error> {
+        let raw =
+            iced_winit::winit::window::Icon::from_rgba(rgba, width, height)?;
+
+        Ok(Icon(raw))
+    }
+
+    /// Creates an icon from 32bpp RGBA data.
+    #[cfg(target_arch = "wasm32")]
+    pub fn from_rgba(
+        _rgba: Vec<u8>,
+        _width: u32,
+        _height: u32,
+    ) -> Result<Self, Error> {
+        Ok(Icon)
+    }
+}
+
+/// An error produced when using `Icon::from_rgba` with invalid arguments.
+#[derive(Debug)]
+pub enum Error {
+    /// The provided RGBA data isn't divisble by 4.
+    ///
+    /// Therefore, it cannot be safely interpreted as 32bpp RGBA pixels.
+    InvalidData {
+        /// The length of the provided RGBA data.
+        byte_count: usize,
+    },
+
+    /// The number of RGBA pixels does not match the provided dimensions.
+    DimensionsMismatch {
+        /// The provided width.
+        width: u32,
+        /// The provided height.
+        height: u32,
+        /// The amount of pixels of the provided RGBA data.
+        pixel_count: usize,
+    },
+
+    /// The underlying OS failed to create the icon.
+    OsError(io::Error),
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+impl From<iced_winit::winit::window::BadIcon> for Error {
+    fn from(error: iced_winit::winit::window::BadIcon) -> Self {
+        use iced_winit::winit::window::BadIcon;
+
+        match error {
+            BadIcon::ByteCountNotDivisibleBy4 { byte_count } => {
+                Error::InvalidData { byte_count }
+            }
+            BadIcon::DimensionsVsPixelCount {
+                width,
+                height,
+                pixel_count,
+                ..
+            } => Error::DimensionsMismatch {
+                width,
+                height,
+                pixel_count,
+            },
+            BadIcon::OsError(os_error) => Error::OsError(os_error),
+        }
+    }
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+impl From<Icon> for iced_winit::winit::window::Icon {
+    fn from(icon: Icon) -> Self {
+        icon.0
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Error::InvalidData { byte_count } => {
+                write!(f,
+                "The provided RGBA data (with length {:?}) isn't divisble by \
+                4. Therefore, it cannot be safely interpreted as 32bpp RGBA \
+                pixels.",
+                byte_count,
+            )
+            }
+            Error::DimensionsMismatch {
+                width,
+                height,
+                pixel_count,
+            } => {
+                write!(f,
+                "The number of RGBA pixels ({:?}) does not match the provided \
+                dimensions ({:?}x{:?}).",
+                width, height, pixel_count,
+            )
+            }
+            Error::OsError(e) => write!(
+                f,
+                "The underlying OS failed to create the window \
+                icon: {:?}",
+                e
+            ),
+        }
+    }
+}
+
+impl std::error::Error for Error {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        Some(self)
+    }
+}