1 files changed, 77 insertions, 15 deletions

diff --git a/src/term.rs b/src/term.rs
index 988786d..daef715 100644
--- a/src/term.rs
+++ b/src/term.rs
@@ -1,6 +1,13 @@
 use libc::{termios, winsize};
 use std::error::Error;
-use std::io::{stdin, stdout, Read, Write};
+use std::io::{stdout, BufRead, Write};
+
+const CTRL_Q: u8 = 17;
+const CTRL_S: u8 = 19;
+const CTRL_Y: u8 = 25;
+const CTRL_Z: u8 = 26;
+const BACKSPACE: u8 = 127;
+const ESC: u8 = 27;
 
 pub fn size() -> Result<winsize, Box<dyn Error>> {
     unsafe {
@@ -41,6 +48,8 @@ fn make_raw() -> termios {
     unsafe {
         let mut attr: termios = std::mem::zeroed();
         libc::cfmakeraw(&mut attr);
+        attr.c_cc[libc::VMIN] = 0; // Return zero bytes on timeout.
+        attr.c_cc[libc::VTIME] = 1; // 100 ms timeout.
         return attr;
     }
 }
@@ -51,7 +60,7 @@ pub struct RawHandle {
 
 impl Drop for RawHandle {
     fn drop(&mut self) {
-        let _ = write!(stdout(), "\x1b[?7h");
+        let _ = write!(stdout(), "\x1b[?7h\x1b[H\x1b[J");
         let _ = stdout().flush();
         let _ = set_attr(&self.old);
     }
@@ -76,19 +85,16 @@ pub enum Key {
     Right,
     Backspace,
     Char(u8),
+    Timeout,
 }
 
-pub fn read_key() -> Result<Key, Box<dyn Error>> {
-    const CTRL_Q: u8 = 17;
-    const CTRL_S: u8 = 19;
-    const CTRL_Y: u8 = 25;
-    const CTRL_Z: u8 = 26;
-    const BACKSPACE: u8 = 127;
-    const ESC: u8 = 27;
-
+pub fn read_key(stdin: &mut dyn BufRead) -> Result<Key, Box<dyn Error>> {
     loop {
         let mut buf = vec![0; 1];
-        stdin().read_exact(&mut buf)?;
+        let n = stdin.read(&mut buf)?;
+        if n == 0 {
+            return Ok(Key::Timeout);
+        }
         if buf[0] == CTRL_Q {
             return Ok(Key::CtrlQ);
         }
@@ -108,13 +114,34 @@ pub fn read_key() -> Result<Key, Box<dyn Error>> {
             return Ok(Key::Char(buf[0]));
         }
         // Try to handle an escape sequence.
-        let mut buf = vec![0; 2];
-        stdin().read_exact(&mut buf)?;
+        let buf = stdin.fill_buf()?;
+        if buf.len() == 0 {
+            // Just an escape. Ignore it I guess.
+            continue;
+        }
         if buf[0] != b'[' {
             // Unknown escape sequence, just read another key.
+            stdin.consume(1);
+            continue;
+        }
+        let mut n = buf.len();
+        for (i, &c) in buf.iter().enumerate() {
+            match c {
+                // Escape sequences usually end with a letter.
+                b'A'..=b'Z' | b'a'..=b'z' => {
+                    n = i + 1;
+                    break;
+                }
+                _ => (),
+            }
+        }
+        let mut escape_sequence = Vec::new();
+        escape_sequence.extend_from_slice(&buf[1..n]);
+        stdin.consume(n);
+        if escape_sequence.len() < 1 {
             continue;
         }
-        match buf[1] {
+        match escape_sequence[0] {
             b'A' => {
                 return Ok(Key::Up);
             }
@@ -128,9 +155,44 @@ pub fn read_key() -> Result<Key, Box<dyn Error>> {
                 return Ok(Key::Left);
             }
             _ => {
-                // Unknown key, just ignore it.
+                // Unknown escape, just skip it.
                 continue;
             }
         }
     }
 }
+
+fn read_status_report(stdin: &mut dyn BufRead) -> Result<(u16, u16), Box<dyn Error>> {
+    let buf = stdin.fill_buf()?;
+    let mut semicolon = buf.len();
+    let mut r = buf.len();
+    for (i, &c) in buf.iter().enumerate() {
+        if c == b';' {
+            semicolon = i;
+        }
+        if c == b'R' {
+            r = i;
+            break;
+        }
+    }
+    if buf.len() < 6 || buf[0] != ESC || buf[1] != b'[' || semicolon + 1 > r || r == buf.len() {
+        return Err(Box::from(format!(
+            "invalid response: {:?}",
+            String::from_utf8_lossy(&buf[0..r])
+        )));
+    }
+    let row_str = std::str::from_utf8(&buf[2..semicolon])?;
+    let col_str = std::str::from_utf8(&buf[semicolon + 1..r])?;
+    let row = row_str.parse::<u16>()?;
+    let col = col_str.parse::<u16>()?;
+    stdin.consume(r + 1);
+    // Yuck... 1 indexing
+    return Ok((row - 1, col - 1));
+}
+
+pub fn cursor_pos(stdin: &mut dyn BufRead) -> Result<(u16, u16), Box<dyn Error>> {
+    write!(stdout(), "\x1b[6n")?;
+    stdout().flush()?;
+    let pos = read_status_report(stdin)?;
+    return Ok(pos);
+}