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helix/helix-view/src/graphics.rs

482 lines
15 KiB
Rust

use bitflags::bitflags;
use std::cmp::{max, min};
#[derive(Debug, Clone, Copy, PartialEq)]
/// UNSTABLE
pub enum CursorKind {
/// █
Block,
/// |
Bar,
/// _
Underline,
/// Hidden cursor, can set cursor position with this to let IME have correct cursor position.
Hidden,
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Margin {
pub vertical: u16,
pub horizontal: u16,
}
/// A simple rectangle used in the computation of the layout and to give widgets an hint about the
/// area they are supposed to render to.
#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
pub struct Rect {
pub x: u16,
pub y: u16,
pub width: u16,
pub height: u16,
}
impl Default for Rect {
fn default() -> Rect {
Rect {
x: 0,
y: 0,
width: 0,
height: 0,
}
}
}
impl Rect {
/// Creates a new rect, with width and height limited to keep the area under max u16.
/// If clipped, aspect ratio will be preserved.
pub fn new(x: u16, y: u16, width: u16, height: u16) -> Rect {
let max_area = u16::max_value();
let (clipped_width, clipped_height) =
if u32::from(width) * u32::from(height) > u32::from(max_area) {
let aspect_ratio = f64::from(width) / f64::from(height);
let max_area_f = f64::from(max_area);
let height_f = (max_area_f / aspect_ratio).sqrt();
let width_f = height_f * aspect_ratio;
(width_f as u16, height_f as u16)
} else {
(width, height)
};
Rect {
x,
y,
width: clipped_width,
height: clipped_height,
}
}
pub fn area(self) -> u16 {
self.width * self.height
}
pub fn left(self) -> u16 {
self.x
}
pub fn right(self) -> u16 {
self.x.saturating_add(self.width)
}
pub fn top(self) -> u16 {
self.y
}
pub fn bottom(self) -> u16 {
self.y.saturating_add(self.height)
}
pub fn inner(self, margin: &Margin) -> Rect {
if self.width < 2 * margin.horizontal || self.height < 2 * margin.vertical {
Rect::default()
} else {
Rect {
x: self.x + margin.horizontal,
y: self.y + margin.vertical,
width: self.width - 2 * margin.horizontal,
height: self.height - 2 * margin.vertical,
}
}
}
pub fn union(self, other: Rect) -> Rect {
let x1 = min(self.x, other.x);
let y1 = min(self.y, other.y);
let x2 = max(self.x + self.width, other.x + other.width);
let y2 = max(self.y + self.height, other.y + other.height);
Rect {
x: x1,
y: y1,
width: x2 - x1,
height: y2 - y1,
}
}
pub fn intersection(self, other: Rect) -> Rect {
let x1 = max(self.x, other.x);
let y1 = max(self.y, other.y);
let x2 = min(self.x + self.width, other.x + other.width);
let y2 = min(self.y + self.height, other.y + other.height);
Rect {
x: x1,
y: y1,
width: x2 - x1,
height: y2 - y1,
}
}
pub fn intersects(self, other: Rect) -> bool {
self.x < other.x + other.width
&& self.x + self.width > other.x
&& self.y < other.y + other.height
&& self.y + self.height > other.y
}
}
#[derive(Debug, Clone, Copy, PartialEq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub enum Color {
Reset,
Black,
Red,
Green,
Yellow,
Blue,
Magenta,
Cyan,
Gray,
DarkGray,
LightRed,
LightGreen,
LightYellow,
LightBlue,
LightMagenta,
LightCyan,
White,
Rgb(u8, u8, u8),
Indexed(u8),
}
#[cfg(feature = "term")]
impl From<Color> for crossterm::style::Color {
fn from(color: Color) -> Self {
use crossterm::style::Color as CColor;
match color {
Color::Reset => CColor::Reset,
Color::Black => CColor::Black,
Color::Red => CColor::DarkRed,
Color::Green => CColor::DarkGreen,
Color::Yellow => CColor::DarkYellow,
Color::Blue => CColor::DarkBlue,
Color::Magenta => CColor::DarkMagenta,
Color::Cyan => CColor::DarkCyan,
Color::Gray => CColor::Grey,
Color::DarkGray => CColor::DarkGrey,
Color::LightRed => CColor::Red,
Color::LightGreen => CColor::Green,
Color::LightBlue => CColor::Blue,
Color::LightYellow => CColor::Yellow,
Color::LightMagenta => CColor::Magenta,
Color::LightCyan => CColor::Cyan,
Color::White => CColor::White,
Color::Indexed(i) => CColor::AnsiValue(i),
Color::Rgb(r, g, b) => CColor::Rgb { r, g, b },
}
}
}
bitflags! {
/// Modifier changes the way a piece of text is displayed.
///
/// They are bitflags so they can easily be composed.
///
/// ## Examples
///
/// ```rust
/// # use helix_view::graphics::Modifier;
///
/// let m = Modifier::BOLD | Modifier::ITALIC;
/// ```
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct Modifier: u16 {
const BOLD = 0b0000_0000_0001;
const DIM = 0b0000_0000_0010;
const ITALIC = 0b0000_0000_0100;
const UNDERLINED = 0b0000_0000_1000;
const SLOW_BLINK = 0b0000_0001_0000;
const RAPID_BLINK = 0b0000_0010_0000;
const REVERSED = 0b0000_0100_0000;
const HIDDEN = 0b0000_1000_0000;
const CROSSED_OUT = 0b0001_0000_0000;
}
}
/// Style let you control the main characteristics of the displayed elements.
///
/// ```rust
/// # use helix_view::graphics::{Color, Modifier, Style};
/// Style::default()
/// .fg(Color::Black)
/// .bg(Color::Green)
/// .add_modifier(Modifier::ITALIC | Modifier::BOLD);
/// ```
///
/// It represents an incremental change. If you apply the styles S1, S2, S3 to a cell of the
/// terminal buffer, the style of this cell will be the result of the merge of S1, S2 and S3, not
/// just S3.
///
/// ```rust
/// # use helix_view::graphics::{Rect, Color, Modifier, Style};
/// # use helix_tui::buffer::Buffer;
/// let styles = [
/// Style::default().fg(Color::Blue).add_modifier(Modifier::BOLD | Modifier::ITALIC),
/// Style::default().bg(Color::Red),
/// Style::default().fg(Color::Yellow).remove_modifier(Modifier::ITALIC),
/// ];
/// let mut buffer = Buffer::empty(Rect::new(0, 0, 1, 1));
/// for style in &styles {
/// buffer.get_mut(0, 0).set_style(*style);
/// }
/// assert_eq!(
/// Style {
/// fg: Some(Color::Yellow),
/// bg: Some(Color::Red),
/// add_modifier: Modifier::BOLD,
/// sub_modifier: Modifier::empty(),
/// },
/// buffer.get(0, 0).style(),
/// );
/// ```
///
/// The default implementation returns a `Style` that does not modify anything. If you wish to
/// reset all properties until that point use [`Style::reset`].
///
/// ```
/// # use helix_view::graphics::{Rect, Color, Modifier, Style};
/// # use helix_tui::buffer::Buffer;
/// let styles = [
/// Style::default().fg(Color::Blue).add_modifier(Modifier::BOLD | Modifier::ITALIC),
/// Style::reset().fg(Color::Yellow),
/// ];
/// let mut buffer = Buffer::empty(Rect::new(0, 0, 1, 1));
/// for style in &styles {
/// buffer.get_mut(0, 0).set_style(*style);
/// }
/// assert_eq!(
/// Style {
/// fg: Some(Color::Yellow),
/// bg: Some(Color::Reset),
/// add_modifier: Modifier::empty(),
/// sub_modifier: Modifier::empty(),
/// },
/// buffer.get(0, 0).style(),
/// );
/// ```
#[derive(Debug, Clone, Copy, PartialEq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct Style {
pub fg: Option<Color>,
pub bg: Option<Color>,
pub add_modifier: Modifier,
pub sub_modifier: Modifier,
}
impl Default for Style {
fn default() -> Style {
Style {
fg: None,
bg: None,
add_modifier: Modifier::empty(),
sub_modifier: Modifier::empty(),
}
}
}
impl Style {
/// Returns a `Style` resetting all properties.
pub fn reset() -> Style {
Style {
fg: Some(Color::Reset),
bg: Some(Color::Reset),
add_modifier: Modifier::empty(),
sub_modifier: Modifier::all(),
}
}
/// Changes the foreground color.
///
/// ## Examples
///
/// ```rust
/// # use helix_view::graphics::{Color, Style};
/// let style = Style::default().fg(Color::Blue);
/// let diff = Style::default().fg(Color::Red);
/// assert_eq!(style.patch(diff), Style::default().fg(Color::Red));
/// ```
pub fn fg(mut self, color: Color) -> Style {
self.fg = Some(color);
self
}
/// Changes the background color.
///
/// ## Examples
///
/// ```rust
/// # use helix_view::graphics::{Color, Style};
/// let style = Style::default().bg(Color::Blue);
/// let diff = Style::default().bg(Color::Red);
/// assert_eq!(style.patch(diff), Style::default().bg(Color::Red));
/// ```
pub fn bg(mut self, color: Color) -> Style {
self.bg = Some(color);
self
}
/// Changes the text emphasis.
///
/// When applied, it adds the given modifier to the `Style` modifiers.
///
/// ## Examples
///
/// ```rust
/// # use helix_view::graphics::{Color, Modifier, Style};
/// let style = Style::default().add_modifier(Modifier::BOLD);
/// let diff = Style::default().add_modifier(Modifier::ITALIC);
/// let patched = style.patch(diff);
/// assert_eq!(patched.add_modifier, Modifier::BOLD | Modifier::ITALIC);
/// assert_eq!(patched.sub_modifier, Modifier::empty());
/// ```
pub fn add_modifier(mut self, modifier: Modifier) -> Style {
self.sub_modifier.remove(modifier);
self.add_modifier.insert(modifier);
self
}
/// Changes the text emphasis.
///
/// When applied, it removes the given modifier from the `Style` modifiers.
///
/// ## Examples
///
/// ```rust
/// # use helix_view::graphics::{Color, Modifier, Style};
/// let style = Style::default().add_modifier(Modifier::BOLD | Modifier::ITALIC);
/// let diff = Style::default().remove_modifier(Modifier::ITALIC);
/// let patched = style.patch(diff);
/// assert_eq!(patched.add_modifier, Modifier::BOLD);
/// assert_eq!(patched.sub_modifier, Modifier::ITALIC);
/// ```
pub fn remove_modifier(mut self, modifier: Modifier) -> Style {
self.add_modifier.remove(modifier);
self.sub_modifier.insert(modifier);
self
}
/// Results in a combined style that is equivalent to applying the two individual styles to
/// a style one after the other.
///
/// ## Examples
/// ```
/// # use helix_view::graphics::{Color, Modifier, Style};
/// let style_1 = Style::default().fg(Color::Yellow);
/// let style_2 = Style::default().bg(Color::Red);
/// let combined = style_1.patch(style_2);
/// assert_eq!(
/// Style::default().patch(style_1).patch(style_2),
/// Style::default().patch(combined));
/// ```
pub fn patch(mut self, other: Style) -> Style {
self.fg = other.fg.or(self.fg);
self.bg = other.bg.or(self.bg);
self.add_modifier.remove(other.sub_modifier);
self.add_modifier.insert(other.add_modifier);
self.sub_modifier.remove(other.add_modifier);
self.sub_modifier.insert(other.sub_modifier);
self
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_rect_size_truncation() {
for width in 256u16..300u16 {
for height in 256u16..300u16 {
let rect = Rect::new(0, 0, width, height);
rect.area(); // Should not panic.
assert!(rect.width < width || rect.height < height);
// The target dimensions are rounded down so the math will not be too precise
// but let's make sure the ratios don't diverge crazily.
assert!(
(f64::from(rect.width) / f64::from(rect.height)
- f64::from(width) / f64::from(height))
.abs()
< 1.0
)
}
}
// One dimension below 255, one above. Area above max u16.
let width = 900;
let height = 100;
let rect = Rect::new(0, 0, width, height);
assert_ne!(rect.width, 900);
assert_ne!(rect.height, 100);
assert!(rect.width < width || rect.height < height);
}
#[test]
fn test_rect_size_preservation() {
for width in 0..256u16 {
for height in 0..256u16 {
let rect = Rect::new(0, 0, width, height);
rect.area(); // Should not panic.
assert_eq!(rect.width, width);
assert_eq!(rect.height, height);
}
}
// One dimension below 255, one above. Area below max u16.
let rect = Rect::new(0, 0, 300, 100);
assert_eq!(rect.width, 300);
assert_eq!(rect.height, 100);
}
fn styles() -> Vec<Style> {
vec![
Style::default(),
Style::default().fg(Color::Yellow),
Style::default().bg(Color::Yellow),
Style::default().add_modifier(Modifier::BOLD),
Style::default().remove_modifier(Modifier::BOLD),
Style::default().add_modifier(Modifier::ITALIC),
Style::default().remove_modifier(Modifier::ITALIC),
Style::default().add_modifier(Modifier::ITALIC | Modifier::BOLD),
Style::default().remove_modifier(Modifier::ITALIC | Modifier::BOLD),
]
}
#[test]
fn combined_patch_gives_same_result_as_individual_patch() {
let styles = styles();
for &a in &styles {
for &b in &styles {
for &c in &styles {
for &d in &styles {
let combined = a.patch(b.patch(c.patch(d)));
assert_eq!(
Style::default().patch(a).patch(b).patch(c).patch(d),
Style::default().patch(combined)
);
}
}
}
}
}
}