Introduce first-class `image` module in `iced_native`

1 files changed, 122 insertions, 0 deletions

diff --git a/native/src/image.rs b/native/src/image.rs
new file mode 100644
index 00000000..05e086de
--- /dev/null
+++ b/native/src/image.rs
@@ -0,0 +1,122 @@
+use crate::{Hasher, Rectangle};
+
+use std::hash::{Hash, Hasher as _};
+use std::path::PathBuf;
+use std::sync::Arc;
+
+/// An [`Image`] handle.
+#[derive(Debug, Clone)]
+pub struct Handle {
+    id: u64,
+    data: Arc<Data>,
+}
+
+impl Handle {
+    /// Creates an image [`Handle`] pointing to the image of the given path.
+    ///
+    /// Makes an educated guess about the image format by examining the data in the file.
+    pub fn from_path<T: Into<PathBuf>>(path: T) -> Handle {
+        Self::from_data(Data::Path(path.into()))
+    }
+
+    /// Creates an image [`Handle`] containing the image pixels directly. This
+    /// function expects the input data to be provided as a `Vec<u8>` of BGRA
+    /// pixels.
+    ///
+    /// This is useful if you have already decoded your image.
+    pub fn from_pixels(width: u32, height: u32, pixels: Vec<u8>) -> Handle {
+        Self::from_data(Data::Pixels {
+            width,
+            height,
+            pixels,
+        })
+    }
+
+    /// Creates an image [`Handle`] containing the image data directly.
+    ///
+    /// Makes an educated guess about the image format by examining the given data.
+    ///
+    /// This is useful if you already have your image loaded in-memory, maybe
+    /// because you downloaded or generated it procedurally.
+    pub fn from_memory(bytes: Vec<u8>) -> Handle {
+        Self::from_data(Data::Bytes(bytes))
+    }
+
+    fn from_data(data: Data) -> Handle {
+        let mut hasher = Hasher::default();
+        data.hash(&mut hasher);
+
+        Handle {
+            id: hasher.finish(),
+            data: Arc::new(data),
+        }
+    }
+
+    /// Returns the unique identifier of the [`Handle`].
+    pub fn id(&self) -> u64 {
+        self.id
+    }
+
+    /// Returns a reference to the image [`Data`].
+    pub fn data(&self) -> &Data {
+        &self.data
+    }
+}
+
+impl<T> From<T> for Handle
+where
+    T: Into<PathBuf>,
+{
+    fn from(path: T) -> Handle {
+        Handle::from_path(path.into())
+    }
+}
+
+impl Hash for Handle {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.id.hash(state);
+    }
+}
+
+/// The data of an [`Image`].
+#[derive(Clone, Hash)]
+pub enum Data {
+    /// File data
+    Path(PathBuf),
+
+    /// In-memory data
+    Bytes(Vec<u8>),
+
+    /// Decoded image pixels in BGRA format.
+    Pixels {
+        /// The width of the image.
+        width: u32,
+        /// The height of the image.
+        height: u32,
+        /// The pixels.
+        pixels: Vec<u8>,
+    },
+}
+
+impl std::fmt::Debug for Data {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Data::Path(path) => write!(f, "Path({:?})", path),
+            Data::Bytes(_) => write!(f, "Bytes(...)"),
+            Data::Pixels { width, height, .. } => {
+                write!(f, "Pixels({} * {})", width, height)
+            }
+        }
+    }
+}
+
+/// A [`Renderer`] that can render images.
+///
+/// [renderer]: crate::renderer
+pub trait Renderer: crate::Renderer {
+    /// Returns the dimensions of an [`Image`] located on the given path.
+    fn dimensions(&self, handle: &Handle) -> (u32, u32);
+
+    // Draws an [`Image`].
+    fn draw(&mut self, handle: Handle, bounds: Rectangle);
+}