From d8e3c7d8e934c6841585d6dd30237bac5a473451 Mon Sep 17 00:00:00 2001
From: Yash Karandikar <nerdstep710@gmail.com>
Date: Thu, 16 Sep 2021 18:08:58 -0500
Subject: [PATCH] Move cursor with arrow keys

---
 src/interrupts.rs | 32 ++++++++++++++++++++++++++++++--
 src/vga_buffer.rs |  6 ++----
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/src/interrupts.rs b/src/interrupts.rs
index f41f014..2df9c36 100644
--- a/src/interrupts.rs
+++ b/src/interrupts.rs
@@ -44,7 +44,7 @@ extern "x86-interrupt" fn timer_interrupt_handler(_stack_frame: InterruptStackFr
 
 extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: InterruptStackFrame) {
     use x86_64::instructions::port::Port;
-    use pc_keyboard::{layouts, DecodedKey, HandleControl, Keyboard, ScancodeSet1};
+    use pc_keyboard::{layouts, DecodedKey, KeyCode, HandleControl, Keyboard, ScancodeSet1};
 
     lazy_static! {
         static ref KEYBOARD: Mutex<Keyboard<layouts::Us104Key, ScancodeSet1>> = {
@@ -65,8 +65,36 @@ extern "x86-interrupt" fn keyboard_interrupt_handler(_stack_frame: InterruptStac
                     } else {
                         print!("{}", character)
                     }
+
+                    let writer = crate::vga_buffer::WRITER.lock();
+                    let col = writer.column_position;
+                    let row = crate::vga_buffer::BUFFER_HEIGHT - 1;
+
+                    crate::vga_buffer::move_cursor(col as u16, row as u16);
                 },
-                DecodedKey::RawKey(key) => print!("{:#?}", key), }
+                DecodedKey::RawKey(key) => {
+                    match key {
+                        // TODO
+                        KeyCode::ArrowLeft => {
+                            let mut writer = crate::vga_buffer::WRITER.lock();
+                            let col = writer.column_position;
+                            let row = crate::vga_buffer::BUFFER_HEIGHT - 1;
+
+                            crate::vga_buffer::move_cursor((col as u16) - 1, row as u16);
+                            writer.column_position -= 1;
+                        },
+                        KeyCode::ArrowRight => {
+                            let mut writer = crate::vga_buffer::WRITER.lock();
+                            let col = writer.column_position;
+                            let row = crate::vga_buffer::BUFFER_HEIGHT - 1;
+
+                            crate::vga_buffer::move_cursor((col as u16) + 1, row as u16);
+                            writer.column_position += 1;
+                        },
+                        _ => {}                        
+                    }
+                }, 
+            }
         }
     }
 
diff --git a/src/vga_buffer.rs b/src/vga_buffer.rs
index e1e920c..68d4092 100644
--- a/src/vga_buffer.rs
+++ b/src/vga_buffer.rs
@@ -43,7 +43,7 @@ struct ScreenChar {
     color_code: ColorCode
 }
 
-const BUFFER_HEIGHT: usize = 25;
+pub(crate) const BUFFER_HEIGHT: usize = 25;
 const BUFFER_WIDTH: usize = 80;
 
 #[repr(transparent)]
@@ -52,7 +52,7 @@ struct Buffer {
 }
 
 pub struct Writer {
-    column_position: usize,
+    pub column_position: usize,
     color_code: ColorCode,
     buffer: &'static mut Buffer
 }
@@ -168,7 +168,6 @@ pub fn backspace() {
 pub struct Cursor {
     port_low: Port<u8>,
     port_high: Port<u8>,
-    cursor_pos: u16
 }
 
 impl Cursor {
@@ -176,7 +175,6 @@ impl Cursor {
         Cursor {
             port_low: Port::new(0x3D4),
             port_high: Port::new(0x3D5),
-            cursor_pos: 0
         }
     }