Changed vec of Attributes to bitfield (#380)

examples/interactive-demo/src/test/attribute.rs

@@ -5,7 +5,7 @@ use crossterm::{cursor, queue, style};
 use std::io::Write;
 
 const ATTRIBUTES: [(style::Attribute, style::Attribute); 6] = [
-    (style::Attribute::Bold, style::Attribute::NoBold),
+    (style::Attribute::Bold, style::Attribute::NormalIntensity),
     (style::Attribute::Italic, style::Attribute::NoItalic),
     (style::Attribute::Underlined, style::Attribute::NoUnderline),
     (style::Attribute::Reverse, style::Attribute::NoReverse),

src/style.rs

@@ -118,6 +118,7 @@ use crate::{impl_display, Command};
 
 pub(crate) use self::enums::Colored;
 pub use self::{
+    attributes::Attributes,
     content_style::ContentStyle,
     enums::{Attribute, Color},
     styled_content::StyledContent,
@@ -127,6 +128,7 @@ pub use self::{
 #[macro_use]
 mod macros;
 mod ansi;
+mod attributes;
 mod content_style;
 mod enums;
 mod styled_content;
@@ -290,6 +292,30 @@ impl Command for SetAttribute {
     }
 }
 
+/// A command that sets several attributes.
+///
+/// See [`Attributes`](struct.Attributes.html) for more info.
+///
+/// # Notes
+///
+/// Commands must be executed/queued for execution otherwise they do nothing.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct SetAttributes(pub Attributes);
+
+impl Command for SetAttributes {
+    type AnsiType = String;
+
+    fn ansi_code(&self) -> Self::AnsiType {
+        ansi::set_attrs_csi_sequence(self.0)
+    }
+
+    #[cfg(windows)]
+    fn execute_winapi(&self) -> Result<()> {
+        // attributes are not supported by WinAPI.
+        Ok(())
+    }
+}
+
 /// A command that prints styled content.
 ///
 /// See [`StyledContent`](struct.StyledContent.html) for more info.

src/style/ansi.rs

@@ -3,7 +3,7 @@
 
 use crate::{
     csi,
-    style::{Attribute, Color, Colored},
+    style::{Attribute, Attributes, Color, Colored},
 };
 
 pub(crate) fn set_fg_csi_sequence(fg_color: Color) -> String {
@@ -21,7 +21,17 @@ pub(crate) fn set_bg_csi_sequence(bg_color: Color) -> String {
 }
 
 pub(crate) fn set_attr_csi_sequence(attribute: Attribute) -> String {
-    format!(csi!("{}m"), attribute as i16)
+    format!(csi!("{}m"), attribute.sgr())
+}
+
+pub(crate) fn set_attrs_csi_sequence(attributes: Attributes) -> String {
+    let mut ansi = String::new();
+    for attr in Attribute::iterator() {
+        if attributes.has(attr) {
+            ansi.push_str(&format!(csi!("{}m"), attr.sgr()));
+        }
+    }
+    ansi
 }
 
 pub(crate) const RESET_CSI_SEQUENCE: &str = csi!("0m");

src/style/attributes.rs

@@ -0,0 +1,119 @@
+use crate::style::Attribute;
+use std::ops::{BitAnd, BitOr, BitXor};
+
+/// a bitset for all possible attributes
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+pub struct Attributes(u32);
+
+impl From<Attribute> for Attributes {
+    fn from(attribute: Attribute) -> Self {
+        Self(attribute.bytes())
+    }
+}
+
+impl From<&[Attribute]> for Attributes {
+    fn from(arr: &[Attribute]) -> Self {
+        let mut attributes = Attributes::default();
+        for &attr in arr {
+            attributes.set(attr);
+        }
+        attributes
+    }
+}
+
+impl BitAnd<Attribute> for Attributes {
+    type Output = Self;
+    fn bitand(self, rhs: Attribute) -> Self {
+        Self(self.0 & rhs.bytes())
+    }
+}
+impl BitAnd for Attributes {
+    type Output = Self;
+    fn bitand(self, rhs: Self) -> Self {
+        Self(self.0 & rhs.0)
+    }
+}
+
+impl BitOr<Attribute> for Attributes {
+    type Output = Self;
+    fn bitor(self, rhs: Attribute) -> Self {
+        Self(self.0 | rhs.bytes())
+    }
+}
+impl BitOr for Attributes {
+    type Output = Self;
+    fn bitor(self, rhs: Self) -> Self {
+        Self(self.0 | rhs.0)
+    }
+}
+
+impl BitXor<Attribute> for Attributes {
+    type Output = Self;
+    fn bitxor(self, rhs: Attribute) -> Self {
+        Self(self.0 ^ rhs.bytes())
+    }
+}
+impl BitXor for Attributes {
+    type Output = Self;
+    fn bitxor(self, rhs: Self) -> Self {
+        Self(self.0 ^ rhs.0)
+    }
+}
+
+impl Attributes {
+    /// Sets the attribute.
+    /// If it's already set, this does nothing.
+    #[inline(always)]
+    pub fn set(&mut self, attribute: Attribute) {
+        self.0 |= attribute.bytes();
+    }
+
+    /// Unsets the attribute.
+    /// If it's not set, this changes nothing.
+    #[inline(always)]
+    pub fn unset(&mut self, attribute: Attribute) {
+        self.0 &= !attribute.bytes();
+    }
+
+    /// Sets the attribute if it's unset, unset it
+    /// if it is set.
+    #[inline(always)]
+    pub fn toggle(&mut self, attribute: Attribute) {
+        self.0 ^= attribute.bytes();
+    }
+
+    /// Returns whether the attribute is set.
+    #[inline(always)]
+    pub fn has(self, attribute: Attribute) -> bool {
+        self.0 & attribute.bytes() != 0
+    }
+
+    /// Sets all the passed attributes. Removes none.
+    #[inline(always)]
+    pub fn extend(&mut self, attributes: Attributes) {
+        self.0 |= attributes.0;
+    }
+
+    /// Returns whether there is no attribute set.
+    #[inline(always)]
+    pub fn is_empty(self) -> bool {
+        self.0 == 0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{Attribute, Attributes};
+
+    #[test]
+    fn test_attributes() {
+        let mut attributes: Attributes = Attribute::Bold.into();
+        assert!(attributes.has(Attribute::Bold));
+        attributes.set(Attribute::Italic);
+        assert!(attributes.has(Attribute::Italic));
+        attributes.unset(Attribute::Italic);
+        assert!(!attributes.has(Attribute::Italic));
+        attributes.toggle(Attribute::Bold);
+        assert!(attributes.is_empty());
+    }
+}

src/style/content_style.rs

@@ -2,7 +2,7 @@
 
 use std::fmt::Display;
 
-use crate::style::{Attribute, Color, StyledContent};
+use crate::style::{Attribute, Attributes, Color, StyledContent};
 
 /// The style that can be put on content.
 #[derive(Debug, Clone, Default)]
@@ -12,7 +12,7 @@ pub struct ContentStyle {
     /// The background color.
     pub background_color: Option<Color>,
     /// List of attributes.
-    pub attributes: Vec<Attribute>,
+    pub attributes: Attributes,
 }
 
 impl ContentStyle {
@@ -51,7 +51,7 @@ impl ContentStyle {
     /// You can add more attributes by calling this method multiple times.
     #[inline]
     pub fn attribute(mut self, attr: Attribute) -> ContentStyle {
-        self.attributes.push(attr);
+        self.attributes.set(attr);
         self
     }
 }
@@ -65,11 +65,11 @@ mod tests {
         let content_style = ContentStyle::new()
             .foreground(Color::Blue)
             .background(Color::Red)
-            .attribute(Attribute::Reset);
+            .attribute(Attribute::Bold);
 
         assert_eq!(content_style.foreground_color, Some(Color::Blue));
         assert_eq!(content_style.background_color, Some(Color::Red));
-        assert_eq!(content_style.attributes[0], Attribute::Reset);
+        assert!(content_style.attributes.has(Attribute::Bold));
     }
 
     #[test]
@@ -83,6 +83,6 @@ mod tests {
 
         assert_eq!(styled_content.style().foreground_color, Some(Color::Blue));
         assert_eq!(styled_content.style().background_color, Some(Color::Red));
-        assert_eq!(styled_content.style().attributes[0], Attribute::Reset);
+        assert!(styled_content.style().attributes.has(Attribute::Reset));
     }
 }

src/style/enums/attribute.rs

@@ -5,59 +5,89 @@ use serde::{Deserialize, Serialize};
 
 use super::super::SetAttribute;
 
-/// Represents an attribute.
-///
-/// # Platform-specific Notes
-///
-/// * Only UNIX and Windows 10 terminals do support text attributes.
-/// * Keep in mind that not all terminals support all attributes.
-/// * Crossterm implements almost all attributes listed in the
-///   [SGR parameters](https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters).
-///
-/// | Attribute | Windows | UNIX | Notes |
-/// | :-- | :--: | :--: | :-- |
-/// | `Reset` | ✓ | ✓ | |
-/// | `Bold` | ✓ | ✓ | |
-/// | `Dim` | ✓ | ✓ | |
-/// | `Italic` | ? | ? | Not widely supported, sometimes treated as inverse. |
-/// | `Underlined` | ✓ | ✓ | |
-/// | `SlowBlink` | ? | ? | Not widely supported, sometimes treated as inverse. |
-/// | `RapidBlink` | ? | ? | Not widely supported. MS-DOS ANSI.SYS; 150+ per minute. |
-/// | `Reverse` | ✓ | ✓ | |
-/// | `Hidden` | ✓ | ✓ | Also known as Conceal. |
-/// | `Fraktur` | ✗ | ✓ | Legible characters, but marked for deletion. |
-/// | `DefaultForegroundColor` | ? | ? | Implementation specific (according to standard). |
-/// | `DefaultBackgroundColor` | ? | ? | Implementation specific (according to standard). |
-/// | `Framed` | ? | ? | Not widely supported. |
-/// | `Encircled` | ? | ? | This should turn on the encircled attribute. |
-/// | `OverLined` | ? | ? | This should draw a line at the top of the text. |
-///
-/// # Examples
-///
-/// Basic usage:
-///
-/// ```no_run
-/// use crossterm::style::Attribute;
-///
-/// println!(
-///     "{} Underlined {} No Underline",
-///     Attribute::Underlined,
-///     Attribute::NoUnderline
-/// );
-/// ```
-///
-/// Style existing text:
-///
-/// ```no_run
-/// use crossterm::style::Styler;
-///
-/// println!("{}", "Bold text".bold());
-/// println!("{}", "Underlined text".underlined());
-/// println!("{}", "Negative text".negative());
-/// ```
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Ord, PartialOrd, Hash)]
-pub enum Attribute {
+// This macro generates the Attribute enum, its iterator
+// function, and the static array containing the sgr code
+// of each attribute
+macro_rules! Attribute {
+    (
+        $(
+            $(#[$inner:ident $($args:tt)*])*
+            $name:ident = $sgr:expr,
+        )*
+    ) => {
+        /// Represents an attribute.
+        ///
+        /// # Platform-specific Notes
+        ///
+        /// * Only UNIX and Windows 10 terminals do support text attributes.
+        /// * Keep in mind that not all terminals support all attributes.
+        /// * Crossterm implements almost all attributes listed in the
+        ///   [SGR parameters](https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters).
+        ///
+        /// | Attribute | Windows | UNIX | Notes |
+        /// | :-- | :--: | :--: | :-- |
+        /// | `Reset` | ✓ | ✓ | |
+        /// | `Bold` | ✓ | ✓ | |
+        /// | `Dim` | ✓ | ✓ | |
+        /// | `Italic` | ? | ? | Not widely supported, sometimes treated as inverse. |
+        /// | `Underlined` | ✓ | ✓ | |
+        /// | `SlowBlink` | ? | ? | Not widely supported, sometimes treated as inverse. |
+        /// | `RapidBlink` | ? | ? | Not widely supported. MS-DOS ANSI.SYS; 150+ per minute. |
+        /// | `Reverse` | ✓ | ✓ | |
+        /// | `Hidden` | ✓ | ✓ | Also known as Conceal. |
+        /// | `Fraktur` | ✗ | ✓ | Legible characters, but marked for deletion. |
+        /// | `DefaultForegroundColor` | ? | ? | Implementation specific (according to standard). |
+        /// | `DefaultBackgroundColor` | ? | ? | Implementation specific (according to standard). |
+        /// | `Framed` | ? | ? | Not widely supported. |
+        /// | `Encircled` | ? | ? | This should turn on the encircled attribute. |
+        /// | `OverLined` | ? | ? | This should draw a line at the top of the text. |
+        ///
+        /// # Examples
+        ///
+        /// Basic usage:
+        ///
+        /// ```no_run
+        /// use crossterm::style::Attribute;
+        ///
+        /// println!(
+        ///     "{} Underlined {} No Underline",
+        ///     Attribute::Underlined,
+        ///     Attribute::NoUnderline
+        /// );
+        /// ```
+        ///
+        /// Style existing text:
+        ///
+        /// ```no_run
+        /// use crossterm::style::Styler;
+        ///
+        /// println!("{}", "Bold text".bold());
+        /// println!("{}", "Underlined text".underlined());
+        /// println!("{}", "Negative text".negative());
+        /// ```
+        #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+        #[non_exhaustive]
+        #[derive(Copy, Clone, Debug, PartialEq, Eq, Ord, PartialOrd, Hash)]
+        pub enum Attribute {
+            $(
+                $(#[$inner $($args)*])*
+                $name,
+            )*
+        }
+        pub static SGR: &'static[i16] = &[
+            $($sgr,)*
+        ];
+        impl Attribute {
+            /// Iterates over all the variants of the Attribute enum.
+            pub fn iterator() -> impl Iterator<Item = Attribute> {
+                use self::Attribute::*;
+                [ $($name,)* ].iter().copied()
+            }
+        }
+    }
+}
+
+Attribute! {
     /// Resets all the attributes.
     Reset = 0,
     /// Increases the text intensity.
@@ -82,7 +112,7 @@ pub enum Attribute {
     ///
     /// Mostly used for [mathematical alphanumeric symbols](https://en.wikipedia.org/wiki/Mathematical_Alphanumeric_Symbols).
     Fraktur = 20,
-    /// Turns off the `Bold` attribute.
+    /// Turns off the `Bold` attribute. - Inconsistent - Prefer to use NormalIntensity
     NoBold = 21,
     /// Switches the text back to normal intensity (no bold, italic).
     NormalIntensity = 22,
@@ -108,8 +138,6 @@ pub enum Attribute {
     NotFramedOrEncircled = 54,
     /// Turns off the `OverLined` attribute.
     NotOverLined = 55,
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 impl Display for Attribute {
@@ -118,3 +146,22 @@ impl Display for Attribute {
         Ok(())
     }
 }
+
+impl Attribute {
+    /// Returns a u32 with one bit set, which is the
+    /// signature of this attribute in the Attributes
+    /// bitset.
+    ///
+    /// The +1 enables storing Reset (whose index is 0)
+    ///  in the bitset Attributes.
+    #[inline(always)]
+    pub const fn bytes(self) -> u32 {
+        1 << ((self as u32) + 1)
+    }
+    /// Returns the SGR attribute value.
+    ///
+    /// See https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters
+    pub fn sgr(self) -> i16 {
+        SGR[self as usize]
+    }
+}

src/style/macros.rs

@@ -39,7 +39,7 @@ macro_rules! def_str_attr {
         fn $name(self) -> StyledContent<&'static str> {
             StyledContent::new(
                 ContentStyle {
-                    attributes: vec![ $attr ],
+                    attributes: $attr.into(),
                     ..Default::default()
                 },
                 self

src/style/styled_content.rs

@@ -8,7 +8,7 @@ use std::{
 use crate::{
     queue,
     style::{
-        Attribute, Color, Colorize, ContentStyle, ResetColor, SetAttribute, SetBackgroundColor,
+        Attribute, Color, Colorize, ContentStyle, ResetColor, SetAttributes, SetBackgroundColor,
         SetForegroundColor, Styler,
     },
 };
@@ -104,8 +104,8 @@ impl<D: Display> Display for StyledContent<D> {
             reset = true;
         }
 
-        for attr in &self.style.attributes {
-            queue!(f, SetAttribute(*attr)).map_err(|_| fmt::Error)?;
+        if !self.style.attributes.is_empty() {
+            queue!(f, SetAttributes(self.style.attributes)).map_err(|_| fmt::Error)?;
             reset = true;
         }
 
@@ -183,7 +183,7 @@ mod tests {
         let style = ContentStyle::new()
             .foreground(Color::Blue)
             .background(Color::Red)
-            .attribute(Attribute::Reset);
+            .attribute(Attribute::Bold);
 
         let mut styled_content = style.apply("test");
 
@@ -194,8 +194,7 @@ mod tests {
 
         assert_eq!(styled_content.style.foreground_color, Some(Color::Green));
         assert_eq!(styled_content.style.background_color, Some(Color::Magenta));
-        assert_eq!(styled_content.style.attributes.len(), 2);
-        assert_eq!(styled_content.style.attributes[0], Attribute::Reset);
-        assert_eq!(styled_content.style.attributes[1], Attribute::NoItalic);
+        assert!(styled_content.style.attributes.has(Attribute::Bold));
+        assert!(styled_content.style.attributes.has(Attribute::NoItalic));
     }
 }