Add an example to add a border

examples/add-border.rs

@@ -0,0 +1,33 @@
+extern crate magick_rust;
+use magick_rust::{magick_wand_genesis, CompositeOperator, MagickError, MagickWand, PixelWand};
+use std::fs;
+use std::sync::Once;
+
+// Used to make sure MagickWand is initialized exactly once. Note that we do not
+// bother shutting down, we simply exit when we're done.
+static START: Once = Once::new();
+
+// Read the named file and add a 10 pixel border around the image
+fn add_border(filepath: &str, border_color: &str) -> Result<Vec<u8>, MagickError> {
+    START.call_once(|| {
+        magick_wand_genesis();
+    });
+
+    let wand = MagickWand::new();
+    wand.read_image(filepath)?;
+    
+    let mut border = PixelWand::new();
+    border.set_color(border_color)?;
+
+    wand.border_image(&border, 10, 10, CompositeOperator::Over)?;
+    wand.write_image_blob("jpeg")
+}
+
+fn main() {
+    match add_border("../tests/fixtures/snow-covered-cat.jpg", "red") {
+        Ok(bytes) => {
+            fs::write("border-cat.jpg", bytes).expect("write failed");
+        }
+        Err(err) => println!("error: {}", err),
+    }
+}