diff --git a/src/console.rs b/src/console.rs index f85928e..afefa15 100644 --- a/src/console.rs +++ b/src/console.rs @@ -1,13 +1,21 @@ use std::io; use std::mem; +use winapi::shared::minwindef::WORD; use winapi::um::consoleapi::{GetConsoleMode, SetConsoleMode}; use winapi::um::wincon::{ - GetConsoleScreenBufferInfo, SetConsoleTextAttribute, - CONSOLE_SCREEN_BUFFER_INFO, + self, GetConsoleScreenBufferInfo, SetConsoleTextAttribute, + CONSOLE_SCREEN_BUFFER_INFO, FOREGROUND_BLUE as FG_BLUE, + FOREGROUND_GREEN as FG_GREEN, FOREGROUND_INTENSITY as FG_INTENSITY, + FOREGROUND_RED as FG_RED, }; -use crate::AsHandleRef; +use crate::{AsHandleRef, HandleRef}; + +const FG_CYAN: WORD = FG_BLUE | FG_GREEN; +const FG_MAGENTA: WORD = FG_BLUE | FG_RED; +const FG_YELLOW: WORD = FG_GREEN | FG_RED; +const FG_WHITE: WORD = FG_BLUE | FG_GREEN | FG_RED; /// Query the given handle for information about the console's screen buffer. /// @@ -119,3 +127,251 @@ impl ScreenBufferInfo { (self.0.dwMaximumWindowSize.X, self.0.dwMaximumWindowSize.Y) } } + +/// A Windows console. +/// +/// This represents a very limited set of functionality available to a Windows +/// console. In particular, it can only change text attributes such as color +/// and intensity. This may grow over time. If you need more routines, please +/// file an issue and/or PR. +/// +/// There is no way to "write" to this console. Simply write to +/// stdout or stderr instead, while interleaving instructions to the console +/// to change text attributes. +/// +/// A common pitfall when using a console is to forget to flush writes to +/// stdout before setting new text attributes. +/// +/// # Example +/// ```no_run +/// # #[cfg(windows)] +/// # { +/// use winapi_util::console::{Console, Color, Intense}; +/// +/// let mut con = Console::stdout().unwrap(); +/// con.fg(Intense::Yes, Color::Cyan).unwrap(); +/// println!("This text will be intense cyan."); +/// con.reset().unwrap(); +/// println!("This text will be normal."); +/// # } +/// ``` +#[derive(Debug)] +pub struct Console { + kind: HandleKind, + start_attr: TextAttributes, + cur_attr: TextAttributes, +} + +#[derive(Clone, Copy, Debug)] +enum HandleKind { + Stdout, + Stderr, +} + +impl HandleKind { + fn handle(&self) -> HandleRef { + match *self { + HandleKind::Stdout => HandleRef::stdout(), + HandleKind::Stderr => HandleRef::stderr(), + } + } +} + +impl Console { + /// Get a console for a standard I/O stream. + fn create_for_stream(kind: HandleKind) -> io::Result { + let h = kind.handle(); + let info = screen_buffer_info(&h)?; + let attr = TextAttributes::from_word(info.attributes()); + Ok(Console { kind: kind, start_attr: attr, cur_attr: attr }) + } + + /// Create a new Console to stdout. + /// + /// If there was a problem creating the console, then an error is returned. + pub fn stdout() -> io::Result { + Self::create_for_stream(HandleKind::Stdout) + } + + /// Create a new Console to stderr. + /// + /// If there was a problem creating the console, then an error is returned. + pub fn stderr() -> io::Result { + Self::create_for_stream(HandleKind::Stderr) + } + + /// Applies the current text attributes. + fn set(&mut self) -> io::Result<()> { + set_text_attributes(self.kind.handle(), self.cur_attr.to_word()) + } + + /// Apply the given intensity and color attributes to the console + /// foreground. + /// + /// If there was a problem setting attributes on the console, then an error + /// is returned. + pub fn fg(&mut self, intense: Intense, color: Color) -> io::Result<()> { + self.cur_attr.fg_color = color; + self.cur_attr.fg_intense = intense; + self.set() + } + + /// Apply the given intensity and color attributes to the console + /// background. + /// + /// If there was a problem setting attributes on the console, then an error + /// is returned. + pub fn bg(&mut self, intense: Intense, color: Color) -> io::Result<()> { + self.cur_attr.bg_color = color; + self.cur_attr.bg_intense = intense; + self.set() + } + + /// Reset the console text attributes to their original settings. + /// + /// The original settings correspond to the text attributes on the console + /// when this `Console` value was created. + /// + /// If there was a problem setting attributes on the console, then an error + /// is returned. + pub fn reset(&mut self) -> io::Result<()> { + self.cur_attr = self.start_attr; + self.set() + } + + /// Toggle virtual terminal processing. + /// + /// This method attempts to toggle virtual terminal processing for this + /// console. If there was a problem toggling it, then an error returned. + /// On success, the caller may assume that toggling it was successful. + /// + /// When virtual terminal processing is enabled, characters emitted to the + /// console are parsed for VT100 and similar control character sequences + /// that control color and other similar operations. + pub fn set_virtual_terminal_processing( + &mut self, + yes: bool, + ) -> io::Result<()> { + let vt = wincon::ENABLE_VIRTUAL_TERMINAL_PROCESSING; + + let handle = self.kind.handle(); + let old_mode = mode(&handle)?; + let new_mode = if yes { old_mode | vt } else { old_mode & !vt }; + if old_mode == new_mode { + return Ok(()); + } + set_mode(&handle, new_mode) + } +} + +/// A representation of text attributes for the Windows console. +#[derive(Copy, Clone, Debug, Eq, PartialEq)] +struct TextAttributes { + fg_color: Color, + fg_intense: Intense, + bg_color: Color, + bg_intense: Intense, +} + +impl TextAttributes { + fn to_word(&self) -> WORD { + let mut w = 0; + w |= self.fg_color.to_fg(); + w |= self.fg_intense.to_fg(); + w |= self.bg_color.to_bg(); + w |= self.bg_intense.to_bg(); + w + } + + fn from_word(word: WORD) -> TextAttributes { + TextAttributes { + fg_color: Color::from_fg(word), + fg_intense: Intense::from_fg(word), + bg_color: Color::from_bg(word), + bg_intense: Intense::from_bg(word), + } + } +} + +/// Whether to use intense colors or not. +#[allow(missing_docs)] +#[derive(Clone, Copy, Debug, Eq, PartialEq)] +pub enum Intense { + Yes, + No, +} + +impl Intense { + fn to_bg(&self) -> WORD { + self.to_fg() << 4 + } + + fn from_bg(word: WORD) -> Intense { + Intense::from_fg(word >> 4) + } + + fn to_fg(&self) -> WORD { + match *self { + Intense::No => 0, + Intense::Yes => FG_INTENSITY, + } + } + + fn from_fg(word: WORD) -> Intense { + if word & FG_INTENSITY > 0 { + Intense::Yes + } else { + Intense::No + } + } +} + +/// The set of available colors for use with a Windows console. +#[allow(missing_docs)] +#[derive(Clone, Copy, Debug, Eq, PartialEq)] +pub enum Color { + Black, + Blue, + Green, + Red, + Cyan, + Magenta, + Yellow, + White, +} + +impl Color { + fn to_bg(&self) -> WORD { + self.to_fg() << 4 + } + + fn from_bg(word: WORD) -> Color { + Color::from_fg(word >> 4) + } + + fn to_fg(&self) -> WORD { + match *self { + Color::Black => 0, + Color::Blue => FG_BLUE, + Color::Green => FG_GREEN, + Color::Red => FG_RED, + Color::Cyan => FG_CYAN, + Color::Magenta => FG_MAGENTA, + Color::Yellow => FG_YELLOW, + Color::White => FG_WHITE, + } + } + + fn from_fg(word: WORD) -> Color { + match word & 0b111 { + FG_BLUE => Color::Blue, + FG_GREEN => Color::Green, + FG_RED => Color::Red, + FG_CYAN => Color::Cyan, + FG_MAGENTA => Color::Magenta, + FG_YELLOW => Color::Yellow, + FG_WHITE => Color::White, + _ => Color::Black, + } + } +}