Fully implement dimensions functions on Windows

Author: camerondm9

src/platform/windows.rs

@@ -4,7 +4,64 @@ use winapi::um::winbase::{STD_ERROR_HANDLE, STD_INPUT_HANDLE, STD_OUTPUT_HANDLE}
 use winapi::um::wincon::GetConsoleScreenBufferInfo;
 use winapi::um::wincon::{CONSOLE_SCREEN_BUFFER_INFO, COORD, SMALL_RECT};
 
-/// Query the current processes's output, returning its width and height as a
+/// Calls GetConsoleScreenBufferInfo. Returns None if all of the streams are
+/// not to a terminal, or there is an error.
+fn get_dimensions_any() -> Option<(usize, usize)> {
+    let null_coord = COORD { X: 0, Y: 0 };
+    let null_smallrect = SMALL_RECT {
+        Left: 0,
+        Top: 0,
+        Right: 0,
+        Bottom: 0,
+    };
+
+    let mut console_data = CONSOLE_SCREEN_BUFFER_INFO {
+        dwSize: null_coord,
+        dwCursorPosition: null_coord,
+        wAttributes: 0,
+        srWindow: null_smallrect,
+        dwMaximumWindowSize: null_coord,
+    };
+
+    if unsafe { GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &mut console_data) } != 0 ||
+        unsafe { GetConsoleScreenBufferInfo(GetStdHandle(STD_INPUT_HANDLE), &mut console_data) } != 0 ||
+        unsafe { GetConsoleScreenBufferInfo(GetStdHandle(STD_ERROR_HANDLE), &mut console_data) } != 0 {
+        Some(((console_data.srWindow.Right - console_data.srWindow.Left + 1) as usize,
+                (console_data.srWindow.Bottom - console_data.srWindow.Top + 1) as usize))
+    } else {
+        None
+    }
+}
+
+/// Calls GetConsoleScreenBufferInfo. Returns None if the stream is not to a
+/// terminal, or there is an error.
+fn get_dimensions(hdl: DWORD) -> Option<(usize, usize)> {
+    let null_coord = COORD { X: 0, Y: 0 };
+    let null_smallrect = SMALL_RECT {
+        Left: 0,
+        Top: 0,
+        Right: 0,
+        Bottom: 0,
+    };
+
+    let mut console_data = CONSOLE_SCREEN_BUFFER_INFO {
+        dwSize: null_coord,
+        dwCursorPosition: null_coord,
+        wAttributes: 0,
+        srWindow: null_smallrect,
+        dwMaximumWindowSize: null_coord,
+    };
+
+    if unsafe { GetConsoleScreenBufferInfo(GetStdHandle(hdl), &mut console_data) } != 0 {
+        Some(((console_data.srWindow.Right - console_data.srWindow.Left + 1) as usize,
+                (console_data.srWindow.Bottom - console_data.srWindow.Top + 1) as usize))
+    } else {
+        None
+    }
+}
+
+/// Query the current processes's output (`stdout`), input (`stdin`), and
+/// error (`stderr`) in that order, returning its width and height as a
 /// number of characters.
 ///
 /// # Errors
@@ -24,11 +81,12 @@ use winapi::um::wincon::{CONSOLE_SCREEN_BUFFER_INFO, COORD, SMALL_RECT};
 /// }
 /// ```
 pub fn dimensions() -> Option<(usize, usize)> {
-    query(STD_INPUT_HANDLE)
+    get_dimensions_any()
 }
 
-/// Query the current processes's output, returning its width and height as a
-/// number of characters. Returns `None` if the output isn't to a terminal.
+/// Query the current processes's output (`stdout`) *only*, returning its
+/// width and height as a number of characters. Returns `None` if the output
+/// isn't to a terminal.
 ///
 /// # Errors
 ///
@@ -47,51 +105,53 @@ pub fn dimensions() -> Option<(usize, usize)> {
 /// }
 /// ```
 pub fn dimensions_stdout() -> Option<(usize, usize)> {
-    query(STD_OUTPUT_HANDLE)
+    get_dimensions(STD_OUTPUT_HANDLE)
 }
 
-/// This isn't implemented for Windows
+/// Query the current processes's input (`stdin`) *only*, returning its width
+/// and height as a number of characters. Returns `None` if the output isn't
+/// to a terminal.
+///
+/// # Errors
 ///
-/// # Panics
+/// Returns `None` if the output isn't to a terminal.
 ///
-/// This function `panic!`s unconditionally with the `unimplemented!`
-/// macro
+/// # Example
+///
+/// To get the dimensions of your terminal window, simply use the following:
+///
+/// ```no_run
+/// # use term_size;
+/// if let Some((w, h)) = term_size::dimensions() {
+///     println!("Width: {}\nHeight: {}", w, h);
+/// } else {
+///     println!("Unable to get term size :(")
+/// }
+/// ```
 pub fn dimensions_stdin() -> Option<(usize, usize)> {
-    query(STD_INPUT_HANDLE)
+    get_dimensions(STD_INPUT_HANDLE)
 }
 
-/// This isn't implemented for Windows
+/// Query the current processes's error output (`stderr`) *only*, returning
+/// its width and height as a number of characters. Returns `None` if the
+/// output isn't to a terminal.
 ///
-/// # Panics
+/// # Errors
 ///
-/// This function `panic!`s unconditionally with the `unimplemented!`
-/// macro
+/// Returns `None` if the output isn't to a terminal.
+///
+/// # Example
+///
+/// To get the dimensions of your terminal window, simply use the following:
+///
+/// ```no_run
+/// # use term_size;
+/// if let Some((w, h)) = term_size::dimensions() {
+///     println!("Width: {}\nHeight: {}", w, h);
+/// } else {
+///     println!("Unable to get term size :(")
+/// }
+/// ```
 pub fn dimensions_stderr() -> Option<(usize, usize)> {
-    query(STD_ERROR_HANDLE)
-}
-
-fn query(hdl: DWORD) -> Option<(usize, usize)> {
-    let null_coord = COORD { X: 0, Y: 0 };
-    let null_smallrect = SMALL_RECT {
-        Left: 0,
-        Top: 0,
-        Right: 0,
-        Bottom: 0,
-    };
-
-    let hdl = unsafe { GetStdHandle(hdl) };
-    let mut console_data = CONSOLE_SCREEN_BUFFER_INFO {
-        dwSize: null_coord,
-        dwCursorPosition: null_coord,
-        wAttributes: 0,
-        srWindow: null_smallrect,
-        dwMaximumWindowSize: null_coord,
-    };
-
-    if unsafe { GetConsoleScreenBufferInfo(hdl, &mut console_data) } != 0 {
-        Some(((console_data.srWindow.Right - console_data.srWindow.Left + 1) as usize,
-                (console_data.srWindow.Bottom - console_data.srWindow.Top + 1) as usize))
-    } else {
-        None
-    }
+    get_dimensions(STD_ERROR_HANDLE)
 }