src/libterm/win.rs

   1 // Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Windows console handling
  12
  13 // FIXME (#13400): this is only a tiny fraction of the Windows console api
  14
  15 extern crate libc;
  16
  17 use std::io;
  18 use std::io::prelude::*;
  19
  20 use Attr;
  21 use color;
  22 use Terminal;
  23
  24 /// A Terminal implementation which uses the Win32 Console API.
  25 pub struct WinConsole<T> {
  26     buf: T,
  27     def_foreground: color::Color,
  28     def_background: color::Color,
  29     foreground: color::Color,
  30     background: color::Color,
  31 }
  32
  33 type WORD = u16;
  34 type DWORD = u32;
  35 type BOOL = i32;
  36 type HANDLE = *mut u8;
  37
  38 #[allow(non_snake_case)]
  39 #[repr(C)]
  40 struct CONSOLE_SCREEN_BUFFER_INFO {
  41     dwSize: [libc::c_short; 2],
  42     dwCursorPosition: [libc::c_short; 2],
  43     wAttributes: WORD,
  44     srWindow: [libc::c_short; 4],
  45     dwMaximumWindowSize: [libc::c_short; 2],
  46 }
  47
  48 #[allow(non_snake_case)]
  49 #[link(name = "kernel32")]
  50 extern "system" {
  51     fn SetConsoleTextAttribute(handle: HANDLE, attr: WORD) -> BOOL;
  52     fn GetStdHandle(which: DWORD) -> HANDLE;
  53     fn GetConsoleScreenBufferInfo(handle: HANDLE, info: *mut CONSOLE_SCREEN_BUFFER_INFO) -> BOOL;
  54 }
  55
  56 fn color_to_bits(color: color::Color) -> u16 {
  57     // magic numbers from mingw-w64's wincon.h
  58
  59     let bits = match color % 8 {
  60         color::BLACK => 0,
  61         color::BLUE => 0x1,
  62         color::GREEN => 0x2,
  63         color::RED => 0x4,
  64         color::YELLOW => 0x2 | 0x4,
  65         color::MAGENTA => 0x1 | 0x4,
  66         color::CYAN => 0x1 | 0x2,
  67         color::WHITE => 0x1 | 0x2 | 0x4,
  68         _ => unreachable!(),
  69     };
  70
  71     if color >= 8 {
  72         bits | 0x8
  73     } else {
  74         bits
  75     }
  76 }
  77
  78 fn bits_to_color(bits: u16) -> color::Color {
  79     let color = match bits & 0x7 {
  80         0 => color::BLACK,
  81         0x1 => color::BLUE,
  82         0x2 => color::GREEN,
  83         0x4 => color::RED,
  84         0x6 => color::YELLOW,
  85         0x5 => color::MAGENTA,
  86         0x3 => color::CYAN,
  87         0x7 => color::WHITE,
  88         _ => unreachable!(),
  89     };
  90
  91     color | (bits & 0x8) // copy the hi-intensity bit
  92 }
  93
  94 impl<T: Write+Send+'static> WinConsole<T> {
  95     fn apply(&mut self) {
  96         let _unused = self.buf.flush();
  97         let mut accum: WORD = 0;
  98         accum |= color_to_bits(self.foreground);
  99         accum |= color_to_bits(self.background) << 4;
 100
 101         unsafe {
 102             // Magic -11 means stdout, from
 103             // http://msdn.microsoft.com/en-us/library/windows/desktop/ms683231%28v=vs.85%29.aspx
 104             //
 105             // You may be wondering, "but what about stderr?", and the answer
 106             // to that is that setting terminal attributes on the stdout
 107             // handle also sets them for stderr, since they go to the same
 108             // terminal! Admittedly, this is fragile, since stderr could be
 109             // redirected to a different console. This is good enough for
 110             // rustc though. See #13400.
 111             let out = GetStdHandle(-11i32 as DWORD);
 112             SetConsoleTextAttribute(out, accum);
 113         }
 114     }
 115
 116     /// Returns `None` whenever the terminal cannot be created for some
 117     /// reason.
 118     pub fn new(out: T) -> io::Result<WinConsole<T>> {
 119         let fg;
 120         let bg;
 121         unsafe {
 122             let mut buffer_info = ::std::mem::uninitialized();
 123             if GetConsoleScreenBufferInfo(GetStdHandle(-11i32 as DWORD), &mut buffer_info) != 0 {
 124                 fg = bits_to_color(buffer_info.wAttributes);
 125                 bg = bits_to_color(buffer_info.wAttributes >> 4);
 126             } else {
 127                 fg = color::WHITE;
 128                 bg = color::BLACK;
 129             }
 130         }
 131         Ok(WinConsole {
 132             buf: out,
 133             def_foreground: fg,
 134             def_background: bg,
 135             foreground: fg,
 136             background: bg,
 137         })
 138     }
 139 }
 140
 141 impl<T: Write> Write for WinConsole<T> {
 142     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
 143         self.buf.write(buf)
 144     }
 145
 146     fn flush(&mut self) -> io::Result<()> {
 147         self.buf.flush()
 148     }
 149 }
 150
 151 impl<T: Write+Send+'static> Terminal for WinConsole<T> {
 152     type Output = T;
 153
 154     fn fg(&mut self, color: color::Color) -> io::Result<bool> {
 155         self.foreground = color;
 156         self.apply();
 157
 158         Ok(true)
 159     }
 160
 161     fn bg(&mut self, color: color::Color) -> io::Result<bool> {
 162         self.background = color;
 163         self.apply();
 164
 165         Ok(true)
 166     }
 167
 168     fn attr(&mut self, attr: Attr) -> io::Result<bool> {
 169         match attr {
 170             Attr::ForegroundColor(f) => {
 171                 self.foreground = f;
 172                 self.apply();
 173                 Ok(true)
 174             }
 175             Attr::BackgroundColor(b) => {
 176                 self.background = b;
 177                 self.apply();
 178                 Ok(true)
 179             }
 180             _ => Ok(false),
 181         }
 182     }
 183
 184     fn supports_attr(&self, attr: Attr) -> bool {
 185         // it claims support for underscore and reverse video, but I can't get
 186         // it to do anything -cmr
 187         match attr {
 188             Attr::ForegroundColor(_) | Attr::BackgroundColor(_) => true,
 189             _ => false,
 190         }
 191     }
 192
 193     fn reset(&mut self) -> io::Result<bool> {
 194         self.foreground = self.def_foreground;
 195         self.background = self.def_background;
 196         self.apply();
 197
 198         Ok(true)
 199     }
 200
 201     fn get_ref<'a>(&'a self) -> &'a T {
 202         &self.buf
 203     }
 204
 205     fn get_mut<'a>(&'a mut self) -> &'a mut T {
 206         &mut self.buf
 207     }
 208
 209     fn into_inner(self) -> T
 210         where Self: Sized
 211     {
 212         self.buf
 213     }
 214 }