1 files changed, 103 insertions, 0 deletions
diff --git a/src/library/insert.rs b/src/library/insert.rs
new file mode 100644
index 00000000..db1e9e17
--- /dev/null
+++ b/src/library/insert.rs
@@ -0,0 +1,103 @@
+use std::fmt::{self, Debug, Formatter};
+use std::fs::File;
+use std::io::BufReader;
+
+use image::io::Reader;
+use image::RgbaImage;
+
+use crate::layout::*;
+use crate::prelude::*;
+
+/// `image`: Insert an image.
+///
+/// # Positional arguments
+/// - The path to the image (string)
+pub fn image(mut args: Args, ctx: &mut EvalContext) -> Value {
+    let path = args.need::<_, Spanned<String>>(ctx, 0, "path");
+    let width = args.get::<_, Linear>(ctx, "width");
+    let height = args.get::<_, Linear>(ctx, "height");
+
+    if let Some(path) = path {
+        if let Ok(file) = File::open(path.v) {
+            match Reader::new(BufReader::new(file))
+                .with_guessed_format()
+                .map_err(|err| err.into())
+                .and_then(|reader| reader.decode())
+                .map(|img| img.into_rgba8())
+            {
+                Ok(buf) => {
+                    ctx.push(Image {
+                        buf,
+                        width,
+                        height,
+                        align: ctx.state.align,
+                    });
+                }
+                Err(err) => ctx.diag(error!(path.span, "invalid image: {}", err)),
+            }
+        } else {
+            ctx.diag(error!(path.span, "failed to open image file"));
+        }
+    }
+
+    Value::None
+}
+
+/// An image node.
+#[derive(Clone, PartialEq)]
+struct Image {
+    /// The image.
+    buf: RgbaImage,
+    /// The fixed width, if any.
+    width: Option<Linear>,
+    /// The fixed height, if any.
+    height: Option<Linear>,
+    /// How to align this image node in its parent.
+    align: BoxAlign,
+}
+
+impl Layout for Image {
+    fn layout(&self, _: &mut LayoutContext, areas: &Areas) -> Layouted {
+        let Area { rem, full } = areas.current;
+        let (pixel_width, pixel_height) = self.buf.dimensions();
+        let pixel_ratio = (pixel_width as f64) / (pixel_height as f64);
+
+        let width = self.width.map(|w| w.resolve(full.width));
+        let height = self.height.map(|w| w.resolve(full.height));
+
+        let size = match (width, height) {
+            (Some(width), Some(height)) => Size::new(width, height),
+            (Some(width), None) => Size::new(width, width / pixel_ratio),
+            (None, Some(height)) => Size::new(height * pixel_ratio, height),
+            (None, None) => {
+                let ratio = rem.width / rem.height;
+                if ratio < pixel_ratio {
+                    Size::new(rem.width, rem.width / pixel_ratio)
+                } else {
+                    // TODO: Fix issue with line spacing.
+                    Size::new(rem.height * pixel_ratio, rem.height)
+                }
+            }
+        };
+
+        let mut boxed = BoxLayout::new(size);
+        boxed.push(
+            Point::ZERO,
+            LayoutElement::Image(ImageElement { buf: self.buf.clone(), size }),
+        );
+
+        Layouted::Layout(boxed, self.align)
+    }
+}
+
+impl Debug for Image {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.pad("Image")
+    }
+}
+
+impl From<Image> for LayoutNode {
+    fn from(image: Image) -> Self {
+        Self::dynamic(image)
+    }
+}