Add key_codes example

Prints the code on key press. Useful tool.

Cargo.toml

@@ -40,3 +40,7 @@ path = "examples/mutation.rs"
 [[example]]
 name = "edit"
 path = "examples/edit.rs"
+
+[[example]]
+name = "key_codes"
+path = "examples/key_codes.rs"

examples/key_codes.rs

@@ -0,0 +1,48 @@
+extern crate cursive;
+
+use cursive::Cursive;
+
+use cursive::view::{View,BoxView};
+use cursive::printer::Printer;
+use cursive::event::EventResult;
+
+fn main() {
+    let mut siv = Cursive::new();
+
+    siv.add_layer(BoxView::new((10,4), KeyCodeView::new(4)));
+
+    siv.run();
+}
+
+struct KeyCodeView {
+    history: Vec<i32>,
+    size: usize,
+}
+
+impl KeyCodeView {
+    fn new(size: usize) -> Self {
+        KeyCodeView {
+            history: Vec::new(),
+            size: size,
+        }
+    }
+}
+
+impl View for KeyCodeView {
+    fn draw(&mut self, printer: &Printer, _: bool) {
+        for (y,n) in self.history.iter().enumerate() {
+            printer.print((0,y), &format!("{}", n));
+        }
+    }
+
+    fn on_key_event(&mut self, ch: i32) -> EventResult {
+        self.history.push(ch);
+
+        while self.history.len() > self.size {
+            self.history.remove(0);
+        }
+
+        EventResult::Consumed(None)
+    }
+}
+