From 9089d9fd88833d066f24959fba7d90a5d2d35eb3 Mon Sep 17 00:00:00 2001
From: Alexandre Bury <alexandre.bury@gmail.com>
Date: Wed, 14 Jun 2017 00:43:03 -0700
Subject: [PATCH] Cleaner colors example

---
 examples/colors.rs | 47 ++++++++++++++++++++++++++++++----------------
 src/backend/blt.rs |  2 +-
 2 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/examples/colors.rs b/examples/colors.rs
index 7985421..8b2e834 100644
--- a/examples/colors.rs
+++ b/examples/colors.rs
@@ -1,6 +1,6 @@
 extern crate cursive;
 
-use cursive::Cursive;
+use cursive::{Cursive, Printer};
 use cursive::theme::{ColorStyle, Color};
 use cursive::view::Boxable;
 use cursive::views::Canvas;
@@ -8,23 +8,38 @@ use cursive::views::Canvas;
 fn main() {
     let mut siv = Cursive::new();
 
-    siv.add_layer(Canvas::new(())
-                      .with_draw(|printer, _| for x in 0..20 {
-                                     for y in 0..10 {
-            printer.with_color(ColorStyle::Custom {
-                                   front: Color::Rgb(x * 12,
-                                                     y * 25,
-                                                     (x + 2 * y) * 6),
-                                   back: Color::Rgb(255 - x * 12,
-                                                    255 - y * 25,
-                                                    128 + (40 - x - 2 * y) * 3),
-                               },
-                               |printer| { printer.print((x, y), "+"); });
-        }
-                                 })
-                      .fixed_size((20, 10)));
+    siv.add_layer(Canvas::new(()).with_draw(draw).fixed_size((20, 10)));
 
     siv.add_global_callback('q', |s| s.quit());
 
     siv.run();
 }
+
+fn front_color(x: u8, y: u8, x_max: u8, y_max: u8) -> Color {
+    Color::Rgb(x * (255 / x_max),
+               y * (255 / y_max),
+               (x + 2 * y) * (255 / (x_max + 2 * y_max)))
+}
+
+fn back_color(x: u8, y: u8, x_max: u8, y_max: u8) -> Color {
+
+    Color::Rgb(128 + (2 * y_max + x - 2 * y) * (128 / (x_max + 2 * y_max)),
+               255 - y * (255 / y_max),
+               255 - x * (255 / x_max))
+}
+
+fn draw(p: &Printer, _: &()) {
+    let x_max = p.size.x as u8;
+    let y_max = p.size.y as u8;
+
+    for x in 0..x_max {
+        for y in 0..y_max {
+            let style = ColorStyle::Custom {
+                front: front_color(x, y, x_max, y_max),
+                back: back_color(x, y, x_max, y_max),
+            };
+
+            p.with_color(style, |printer| { printer.print((x, y), "+"); });
+        }
+    }
+}
diff --git a/src/backend/blt.rs b/src/backend/blt.rs
index a097d88..28dd1df 100644
--- a/src/backend/blt.rs
+++ b/src/backend/blt.rs
@@ -241,7 +241,7 @@ fn blt_keycode_to_char(kc: KeyCode, shift: bool) -> char {
         KeyCode::Num9 => '9',
         KeyCode::Num0 => '0',
         _ => {
-            println_stderr!("{:?}", kc);
+            println_stderr!("Found unknown input: {:?}", kc);
             unreachable!()
         }
     }