drop font_size, just add window_size() -> WindowSize

examples/is_tty.rs

@@ -1,6 +1,6 @@
 use crossterm::{
     execute,
-    terminal::{font_size, size, SetSize},
+    terminal::{size, window_size, SetSize},
     tty::IsTty,
 };
 use std::io::{stdin, stdout};
@@ -10,7 +10,7 @@ pub fn main() {
     execute!(stdout(), SetSize(10, 10)).unwrap();
     println!("resized: {:?}", size().unwrap());
 
-    println!("font_size: {:?}", font_size().unwrap());
+    println!("pixel size: {:?}", window_size().unwrap());
 
     if stdin().is_tty() {
         println!("Is TTY");

src/terminal.rs

@@ -137,9 +137,20 @@ pub fn size() -> io::Result<(u16, u16)> {
     sys::size()
 }
 
-/// Returns the terminal font size in pixels.
-pub fn font_size() -> io::Result<(u16, u16)> {
-    sys::font_size()
+#[derive(Debug)]
+pub struct WindowSize {
+    pub rows: u16,
+    pub columns: u16,
+    pub width: u16,
+    pub height: u16,
+}
+
+/// Returns the terminal size `[WindowSize]`.
+///
+/// The width and height in pixels may not be reliably implemented and default to 0, as
+/// https://man7.org/linux/man-pages/man4/tty_ioctl.4.html documents them as "unused".
+pub fn window_size() -> io::Result<WindowSize> {
+    sys::window_size()
 }
 
 /// Disables line wrapping.

src/terminal/sys.rs

@@ -5,7 +5,7 @@
 pub use self::unix::supports_keyboard_enhancement;
 #[cfg(unix)]
 pub(crate) use self::unix::{
-    disable_raw_mode, enable_raw_mode, font_size, is_raw_mode_enabled, size,
+    disable_raw_mode, enable_raw_mode, window_size, is_raw_mode_enabled, size,
 };
 #[cfg(windows)]
 #[cfg(feature = "events")]

src/terminal/sys/unix.rs

@@ -1,6 +1,9 @@
 //! UNIX related logic for terminal manipulation.
 
-use crate::terminal::sys::file_descriptor::{tty_fd, FileDesc};
+use crate::terminal::{
+    sys::file_descriptor::{tty_fd, FileDesc},
+    WindowSize,
+};
 use libc::{
     cfmakeraw, ioctl, tcgetattr, tcsetattr, termios as Termios, winsize, STDOUT_FILENO, TCSANOW,
     TIOCGWINSZ,
@@ -20,36 +23,19 @@ pub(crate) fn is_raw_mode_enabled() -> bool {
     TERMINAL_MODE_PRIOR_RAW_MODE.lock().is_some()
 }
 
-#[allow(clippy::useless_conversion)]
-pub(crate) fn size() -> io::Result<(u16, u16)> {
-    // http://rosettacode.org/wiki/Terminal_control/Dimensions#Library:_BSD_libc
-    let mut size = winsize {
-        ws_row: 0,
-        ws_col: 0,
-        ws_xpixel: 0,
-        ws_ypixel: 0,
-    };
-
-    let file = File::open("/dev/tty").map(|file| (FileDesc::new(file.into_raw_fd(), true)));
-    let fd = if let Ok(file) = &file {
-        file.raw_fd()
-    } else {
-        // Fallback to libc::STDOUT_FILENO if /dev/tty is missing
-        STDOUT_FILENO
-    };
-
-    if wrap_with_result(unsafe { ioctl(fd, TIOCGWINSZ.into(), &mut size) }).is_ok()
-        && size.ws_col != 0
-        && size.ws_row != 0
-    {
-        return Ok((size.ws_col, size.ws_row));
+impl From<winsize> for WindowSize {
+    fn from(size: winsize) -> WindowSize {
+        WindowSize {
+            columns: size.ws_col,
+            rows: size.ws_row,
+            width: size.ws_xpixel,
+            height: size.ws_ypixel,
+        }
     }
-
-    tput_size().ok_or_else(|| std::io::Error::last_os_error().into())
 }
 
 #[allow(clippy::useless_conversion)]
-pub(crate) fn font_size() -> io::Result<(u16, u16)> {
+pub(crate) fn window_size() -> io::Result<WindowSize> {
     // http://rosettacode.org/wiki/Terminal_control/Dimensions#Library:_BSD_libc
     let mut size = winsize {
         ws_row: 0,
@@ -67,12 +53,21 @@ pub(crate) fn font_size() -> io::Result<(u16, u16)> {
     };
 
     if wrap_with_result(unsafe { ioctl(fd, TIOCGWINSZ.into(), &mut size) }).is_ok() {
-        return Ok((size.ws_xpixel / size.ws_col, size.ws_ypixel / size.ws_row));
+        return Ok(size.into());
     }
 
     Err(std::io::Error::last_os_error().into())
 }
 
+#[allow(clippy::useless_conversion)]
+pub(crate) fn size() -> io::Result<(u16, u16)> {
+    if let Ok(window_size) = window_size() {
+        return Ok((window_size.columns, window_size.rows));
+    }
+
+    tput_size().ok_or_else(|| std::io::Error::last_os_error().into())
+}
+
 pub(crate) fn enable_raw_mode() -> io::Result<()> {
     let mut original_mode = TERMINAL_MODE_PRIOR_RAW_MODE.lock();
 

src/terminal/sys/windows.rs

@@ -58,9 +58,16 @@ pub(crate) fn size() -> io::Result<(u16, u16)> {
     ))
 }
 
-pub(crate) fn font_size() -> io::Result<(u16, u16)> {
-    let size = ScreenBuffer::current()?.font_info()?.size();
-    Ok((size.width as u16, size.height as u16))
+pub(crate) fn window_size() -> io::Result<WindowSize> {
+    let (columns, rows) = size()?;
+    let font_size = ScreenBuffer::current()?.font_info()?.size();
+    Ok(WindowSize {
+        columns,
+        rows,
+        // `(columns,rows)` start at index 1.
+        width: (columns - 1) * font_size.0,
+        height: (rows - 1) * font_size.1,
+    })
 }
 
 /// Queries the terminal's support for progressive keyboard enhancement.