From 35606a3daa7ee273845a12f3e03728e0ae23928e Mon Sep 17 00:00:00 2001 From: Blaž Hrastnik Date: Sun, 9 May 2021 17:52:55 +0900 Subject: Inline tui as helix-tui fork. We only rely on some of the rendering primitives and implement our Cursive-style compositor on top. --- Cargo.lock | 29 +- Cargo.toml | 1 + helix-term/Cargo.toml | 2 +- helix-term/src/compositor.rs | 2 +- helix-term/src/main.rs | 1 - helix-term/src/terminal.rs | 221 ----------- helix-tui/.gitignore | 6 + helix-tui/Cargo.toml | 19 + helix-tui/README.md | 6 + helix-tui/src/backend/crossterm.rs | 221 +++++++++++ helix-tui/src/backend/mod.rs | 25 ++ helix-tui/src/backend/test.rs | 151 +++++++ helix-tui/src/buffer.rs | 745 +++++++++++++++++++++++++++++++++++ helix-tui/src/layout.rs | 534 +++++++++++++++++++++++++ helix-tui/src/lib.rs | 134 +++++++ helix-tui/src/style.rs | 281 +++++++++++++ helix-tui/src/symbols.rs | 233 +++++++++++ helix-tui/src/terminal.rs | 216 ++++++++++ helix-tui/src/text.rs | 434 ++++++++++++++++++++ helix-tui/src/widgets/block.rs | 511 ++++++++++++++++++++++++ helix-tui/src/widgets/clear.rs | 36 ++ helix-tui/src/widgets/list.rs | 249 ++++++++++++ helix-tui/src/widgets/mod.rs | 53 +++ helix-tui/src/widgets/paragraph.rs | 197 +++++++++ helix-tui/src/widgets/reflow.rs | 534 +++++++++++++++++++++++++ helix-tui/src/widgets/table.rs | 538 +++++++++++++++++++++++++ helix-tui/tests/terminal.rs | 36 ++ helix-tui/tests/widgets_block.rs | 213 ++++++++++ helix-tui/tests/widgets_list.rs | 88 +++++ helix-tui/tests/widgets_paragraph.rs | 220 +++++++++++ helix-tui/tests/widgets_table.rs | 717 +++++++++++++++++++++++++++++++++ helix-view/Cargo.toml | 2 +- 32 files changed, 6415 insertions(+), 240 deletions(-) delete mode 100644 helix-term/src/terminal.rs create mode 100644 helix-tui/.gitignore create mode 100644 helix-tui/Cargo.toml create mode 100644 helix-tui/README.md create mode 100644 helix-tui/src/backend/crossterm.rs create mode 100644 helix-tui/src/backend/mod.rs create mode 100644 helix-tui/src/backend/test.rs create mode 100644 helix-tui/src/buffer.rs create mode 100644 helix-tui/src/layout.rs create mode 100644 helix-tui/src/lib.rs create mode 100644 helix-tui/src/style.rs create mode 100644 helix-tui/src/symbols.rs create mode 100644 helix-tui/src/terminal.rs create mode 100644 helix-tui/src/text.rs create mode 100644 helix-tui/src/widgets/block.rs create mode 100644 helix-tui/src/widgets/clear.rs create mode 100644 helix-tui/src/widgets/list.rs create mode 100644 helix-tui/src/widgets/mod.rs create mode 100644 helix-tui/src/widgets/paragraph.rs create mode 100644 helix-tui/src/widgets/reflow.rs create mode 100644 helix-tui/src/widgets/table.rs create mode 100644 helix-tui/tests/terminal.rs create mode 100644 helix-tui/tests/widgets_block.rs create mode 100644 helix-tui/tests/widgets_list.rs create mode 100644 helix-tui/tests/widgets_paragraph.rs create mode 100644 helix-tui/tests/widgets_table.rs diff --git a/Cargo.lock b/Cargo.lock index 228f3873..d1bb9374 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -330,6 +330,7 @@ dependencies = [ "fuzzy-matcher", "helix-core", "helix-lsp", + "helix-tui", "helix-view", "ignore", "log", @@ -340,7 +341,18 @@ dependencies = [ "serde_json", "tokio", "toml", - "tui", +] + +[[package]] +name = "helix-tui" +version = "0.1.0" +dependencies = [ + "bitflags", + "cassowary", + "crossterm", + "serde", + "unicode-segmentation", + "unicode-width", ] [[package]] @@ -351,12 +363,12 @@ dependencies = [ "crossterm", "helix-core", "helix-lsp", + "helix-tui", "once_cell", "serde", "slotmap", "tokio", "toml", - "tui", "url", ] @@ -955,19 +967,6 @@ dependencies = [ "regex", ] -[[package]] -name = "tui" -version = "0.15.0" -source = "registry+https://github.com/rust-lang/crates.io-index" -checksum = "861d8f3ad314ede6219bcb2ab844054b1de279ee37a9bc38e3d606f9d3fb2a71" -dependencies = [ - "bitflags", - "cassowary", - "crossterm", - "unicode-segmentation", - "unicode-width", -] - [[package]] name = "unicase" version = "2.6.0" diff --git a/Cargo.toml b/Cargo.toml index 7511688e..22d29260 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -3,6 +3,7 @@ members = [ "helix-core", "helix-view", "helix-term", + "helix-tui", "helix-syntax", "helix-lsp", ] diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml index a86549a7..972d5b73 100644 --- a/helix-term/Cargo.toml +++ b/helix-term/Cargo.toml @@ -21,7 +21,7 @@ once_cell = "1.4" tokio = { version = "1", features = ["full"] } num_cpus = "1" -tui = { version = "0.15", default-features = false, features = ["crossterm"] } +tui = { path = "../helix-tui", package = "helix-tui", default-features = false, features = ["crossterm"] } crossterm = { version = "0.19", features = ["event-stream"] } clap = { version = "3.0.0-beta.2 ", default-features = false, features = ["std", "cargo"] } diff --git a/helix-term/src/compositor.rs b/helix-term/src/compositor.rs index 4570cab9..7b828358 100644 --- a/helix-term/src/compositor.rs +++ b/helix-term/src/compositor.rs @@ -67,7 +67,7 @@ pub trait Component: Any + AnyComponent { use anyhow::Error; use std::io::stdout; use tui::backend::CrosstermBackend; -type Terminal = crate::terminal::Terminal>; +type Terminal = tui::terminal::Terminal>; pub struct Compositor { layers: Vec>, diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs index b0d244b7..386c2333 100644 --- a/helix-term/src/main.rs +++ b/helix-term/src/main.rs @@ -4,7 +4,6 @@ mod application; mod commands; mod compositor; mod keymap; -mod terminal; mod ui; use application::Application; diff --git a/helix-term/src/terminal.rs b/helix-term/src/terminal.rs deleted file mode 100644 index fc9bc5ba..00000000 --- a/helix-term/src/terminal.rs +++ /dev/null @@ -1,221 +0,0 @@ -use std::io; -use tui::{ - backend::Backend, - buffer::Buffer, - layout::Rect, - widgets::{StatefulWidget, Widget}, -}; - -#[derive(Debug, Clone, PartialEq)] -/// UNSTABLE -enum ResizeBehavior { - Fixed, - Auto, -} - -#[derive(Debug, Clone, PartialEq)] -/// UNSTABLE -pub struct Viewport { - area: Rect, - resize_behavior: ResizeBehavior, -} - -impl Viewport { - /// UNSTABLE - pub fn fixed(area: Rect) -> Viewport { - Viewport { - area, - resize_behavior: ResizeBehavior::Fixed, - } - } -} - -#[derive(Debug, Clone, PartialEq)] -/// Options to pass to [`Terminal::with_options`] -pub struct TerminalOptions { - /// Viewport used to draw to the terminal - pub viewport: Viewport, -} - -/// Interface to the terminal backed by Termion -#[derive(Debug)] -pub struct Terminal -where - B: Backend, -{ - backend: B, - /// Holds the results of the current and previous draw calls. The two are compared at the end - /// of each draw pass to output the necessary updates to the terminal - buffers: [Buffer; 2], - /// Index of the current buffer in the previous array - current: usize, - /// Whether the cursor is currently hidden - hidden_cursor: bool, - /// Viewport - viewport: Viewport, -} - -impl Drop for Terminal -where - B: Backend, -{ - fn drop(&mut self) { - // Attempt to restore the cursor state - if self.hidden_cursor { - if let Err(err) = self.show_cursor() { - eprintln!("Failed to show the cursor: {}", err); - } - } - } -} - -impl Terminal -where - B: Backend, -{ - /// Wrapper around Terminal initialization. Each buffer is initialized with a blank string and - /// default colors for the foreground and the background - pub fn new(backend: B) -> io::Result> { - let size = backend.size()?; - Terminal::with_options( - backend, - TerminalOptions { - viewport: Viewport { - area: size, - resize_behavior: ResizeBehavior::Auto, - }, - }, - ) - } - - /// UNSTABLE - pub fn with_options(backend: B, options: TerminalOptions) -> io::Result> { - Ok(Terminal { - backend, - buffers: [ - Buffer::empty(options.viewport.area), - Buffer::empty(options.viewport.area), - ], - current: 0, - hidden_cursor: false, - viewport: options.viewport, - }) - } - - // /// Get a Frame object which provides a consistent view into the terminal state for rendering. - // pub fn get_frame(&mut self) -> Frame { - // Frame { - // terminal: self, - // cursor_position: None, - // } - // } - - pub fn current_buffer_mut(&mut self) -> &mut Buffer { - &mut self.buffers[self.current] - } - - pub fn backend(&self) -> &B { - &self.backend - } - - pub fn backend_mut(&mut self) -> &mut B { - &mut self.backend - } - - /// Obtains a difference between the previous and the current buffer and passes it to the - /// current backend for drawing. - pub fn flush(&mut self) -> io::Result<()> { - let previous_buffer = &self.buffers[1 - self.current]; - let current_buffer = &self.buffers[self.current]; - let updates = previous_buffer.diff(current_buffer); - self.backend.draw(updates.into_iter()) - } - - /// Updates the Terminal so that internal buffers match the requested size. Requested size will - /// be saved so the size can remain consistent when rendering. - /// This leads to a full clear of the screen. - pub fn resize(&mut self, area: Rect) -> io::Result<()> { - self.buffers[self.current].resize(area); - self.buffers[1 - self.current].resize(area); - self.viewport.area = area; - self.clear() - } - - /// Queries the backend for size and resizes if it doesn't match the previous size. - pub fn autoresize(&mut self) -> io::Result<()> { - if self.viewport.resize_behavior == ResizeBehavior::Auto { - let size = self.size()?; - if size != self.viewport.area { - self.resize(size)?; - } - }; - Ok(()) - } - - /// Synchronizes terminal size, calls the rendering closure, flushes the current internal state - /// and prepares for the next draw call. - pub fn draw(&mut self, cursor_position: Option<(u16, u16)>) -> io::Result<()> { - // // Autoresize - otherwise we get glitches if shrinking or potential desync between widgets - // // and the terminal (if growing), which may OOB. - // self.autoresize()?; - - // let mut frame = self.get_frame(); - // f(&mut frame); - // // We can't change the cursor position right away because we have to flush the frame to - // // stdout first. But we also can't keep the frame around, since it holds a &mut to - // // Terminal. Thus, we're taking the important data out of the Frame and dropping it. - // let cursor_position = frame.cursor_position; - - // Draw to stdout - self.flush()?; - - match cursor_position { - None => self.hide_cursor()?, - Some((x, y)) => { - self.show_cursor()?; - self.set_cursor(x, y)?; - } - } - - // Swap buffers - self.buffers[1 - self.current].reset(); - self.current = 1 - self.current; - - // Flush - self.backend.flush()?; - Ok(()) - } - - pub fn hide_cursor(&mut self) -> io::Result<()> { - self.backend.hide_cursor()?; - self.hidden_cursor = true; - Ok(()) - } - - pub fn show_cursor(&mut self) -> io::Result<()> { - self.backend.show_cursor()?; - self.hidden_cursor = false; - Ok(()) - } - - pub fn get_cursor(&mut self) -> io::Result<(u16, u16)> { - self.backend.get_cursor() - } - - pub fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> { - self.backend.set_cursor(x, y) - } - - /// Clear the terminal and force a full redraw on the next draw call. - pub fn clear(&mut self) -> io::Result<()> { - self.backend.clear()?; - // Reset the back buffer to make sure the next update will redraw everything. - self.buffers[1 - self.current].reset(); - Ok(()) - } - - /// Queries the real size of the backend. - pub fn size(&self) -> io::Result { - self.backend.size() - } -} diff --git a/helix-tui/.gitignore b/helix-tui/.gitignore new file mode 100644 index 00000000..dcb33fbb --- /dev/null +++ b/helix-tui/.gitignore @@ -0,0 +1,6 @@ +target +Cargo.lock +*.log +*.rs.rustfmt +.gdb_history +.idea/ diff --git a/helix-tui/Cargo.toml b/helix-tui/Cargo.toml new file mode 100644 index 00000000..badefe4c --- /dev/null +++ b/helix-tui/Cargo.toml @@ -0,0 +1,19 @@ +[package] +name = "helix-tui" +version = "0.1.0" +authors = ["Blaž Hrastnik "] +description = """ +A library to build rich terminal user interfaces or dashboards +""" +edition = "2018" + +[features] +default = ["crossterm"] + +[dependencies] +bitflags = "1.0" +cassowary = "0.3" +unicode-segmentation = "1.2" +unicode-width = "0.1" +crossterm = { version = "0.19", optional = true } +serde = { version = "1", "optional" = true, features = ["derive"]} diff --git a/helix-tui/README.md b/helix-tui/README.md new file mode 100644 index 00000000..97b3d1d9 --- /dev/null +++ b/helix-tui/README.md @@ -0,0 +1,6 @@ +# helix-tui + +This library is a fork of the great library +[tui-rs](https://github.com/fdehau/tui-rs/). We've mainly relied on the double +buffer implementation and render diffing, side-stepping it's widget and +layouting. diff --git a/helix-tui/src/backend/crossterm.rs b/helix-tui/src/backend/crossterm.rs new file mode 100644 index 00000000..f6703e14 --- /dev/null +++ b/helix-tui/src/backend/crossterm.rs @@ -0,0 +1,221 @@ +use crate::{ + backend::Backend, + buffer::Cell, + layout::Rect, + style::{Color, Modifier}, +}; +use crossterm::{ + cursor::{Hide, MoveTo, Show}, + execute, queue, + style::{ + Attribute as CAttribute, Color as CColor, Print, SetAttribute, SetBackgroundColor, + SetForegroundColor, + }, + terminal::{self, Clear, ClearType}, +}; +use std::io::{self, Write}; + +pub struct CrosstermBackend { + buffer: W, +} + +impl CrosstermBackend +where + W: Write, +{ + pub fn new(buffer: W) -> CrosstermBackend { + CrosstermBackend { buffer } + } +} + +impl Write for CrosstermBackend +where + W: Write, +{ + fn write(&mut self, buf: &[u8]) -> io::Result { + self.buffer.write(buf) + } + + fn flush(&mut self) -> io::Result<()> { + self.buffer.flush() + } +} + +impl Backend for CrosstermBackend +where + W: Write, +{ + fn draw<'a, I>(&mut self, content: I) -> io::Result<()> + where + I: Iterator, + { + let mut fg = Color::Reset; + let mut bg = Color::Reset; + let mut modifier = Modifier::empty(); + let mut last_pos: Option<(u16, u16)> = None; + for (x, y, cell) in content { + // Move the cursor if the previous location was not (x - 1, y) + if !matches!(last_pos, Some(p) if x == p.0 + 1 && y == p.1) { + map_error(queue!(self.buffer, MoveTo(x, y)))?; + } + last_pos = Some((x, y)); + if cell.modifier != modifier { + let diff = ModifierDiff { + from: modifier, + to: cell.modifier, + }; + diff.queue(&mut self.buffer)?; + modifier = cell.modifier; + } + if cell.fg != fg { + let color = CColor::from(cell.fg); + map_error(queue!(self.buffer, SetForegroundColor(color)))?; + fg = cell.fg; + } + if cell.bg != bg { + let color = CColor::from(cell.bg); + map_error(queue!(self.buffer, SetBackgroundColor(color)))?; + bg = cell.bg; + } + + map_error(queue!(self.buffer, Print(&cell.symbol)))?; + } + + map_error(queue!( + self.buffer, + SetForegroundColor(CColor::Reset), + SetBackgroundColor(CColor::Reset), + SetAttribute(CAttribute::Reset) + )) + } + + fn hide_cursor(&mut self) -> io::Result<()> { + map_error(execute!(self.buffer, Hide)) + } + + fn show_cursor(&mut self) -> io::Result<()> { + map_error(execute!(self.buffer, Show)) + } + + fn get_cursor(&mut self) -> io::Result<(u16, u16)> { + crossterm::cursor::position() + .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string())) + } + + fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> { + map_error(execute!(self.buffer, MoveTo(x, y))) + } + + fn clear(&mut self) -> io::Result<()> { + map_error(execute!(self.buffer, Clear(ClearType::All))) + } + + fn size(&self) -> io::Result { + let (width, height) = + terminal::size().map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?; + + Ok(Rect::new(0, 0, width, height)) + } + + fn flush(&mut self) -> io::Result<()> { + self.buffer.flush() + } +} + +fn map_error(error: crossterm::Result<()>) -> io::Result<()> { + error.map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string())) +} + +impl From for CColor { + fn from(color: Color) -> Self { + 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 }, + } + } +} + +#[derive(Debug)] +struct ModifierDiff { + pub from: Modifier, + pub to: Modifier, +} + +impl ModifierDiff { + fn queue(&self, mut w: W) -> io::Result<()> + where + W: io::Write, + { + //use crossterm::Attribute; + let removed = self.from - self.to; + if removed.contains(Modifier::REVERSED) { + map_error(queue!(w, SetAttribute(CAttribute::NoReverse)))?; + } + if removed.contains(Modifier::BOLD) { + map_error(queue!(w, SetAttribute(CAttribute::NormalIntensity)))?; + if self.to.contains(Modifier::DIM) { + map_error(queue!(w, SetAttribute(CAttribute::Dim)))?; + } + } + if removed.contains(Modifier::ITALIC) { + map_error(queue!(w, SetAttribute(CAttribute::NoItalic)))?; + } + if removed.contains(Modifier::UNDERLINED) { + map_error(queue!(w, SetAttribute(CAttribute::NoUnderline)))?; + } + if removed.contains(Modifier::DIM) { + map_error(queue!(w, SetAttribute(CAttribute::NormalIntensity)))?; + } + if removed.contains(Modifier::CROSSED_OUT) { + map_error(queue!(w, SetAttribute(CAttribute::NotCrossedOut)))?; + } + if removed.contains(Modifier::SLOW_BLINK) || removed.contains(Modifier::RAPID_BLINK) { + map_error(queue!(w, SetAttribute(CAttribute::NoBlink)))?; + } + + let added = self.to - self.from; + if added.contains(Modifier::REVERSED) { + map_error(queue!(w, SetAttribute(CAttribute::Reverse)))?; + } + if added.contains(Modifier::BOLD) { + map_error(queue!(w, SetAttribute(CAttribute::Bold)))?; + } + if added.contains(Modifier::ITALIC) { + map_error(queue!(w, SetAttribute(CAttribute::Italic)))?; + } + if added.contains(Modifier::UNDERLINED) { + map_error(queue!(w, SetAttribute(CAttribute::Underlined)))?; + } + if added.contains(Modifier::DIM) { + map_error(queue!(w, SetAttribute(CAttribute::Dim)))?; + } + if added.contains(Modifier::CROSSED_OUT) { + map_error(queue!(w, SetAttribute(CAttribute::CrossedOut)))?; + } + if added.contains(Modifier::SLOW_BLINK) { + map_error(queue!(w, SetAttribute(CAttribute::SlowBlink)))?; + } + if added.contains(Modifier::RAPID_BLINK) { + map_error(queue!(w, SetAttribute(CAttribute::RapidBlink)))?; + } + + Ok(()) + } +} diff --git a/helix-tui/src/backend/mod.rs b/helix-tui/src/backend/mod.rs new file mode 100644 index 00000000..ed125200 --- /dev/null +++ b/helix-tui/src/backend/mod.rs @@ -0,0 +1,25 @@ +use std::io; + +use crate::buffer::Cell; +use crate::layout::Rect; + +#[cfg(feature = "crossterm")] +mod crossterm; +#[cfg(feature = "crossterm")] +pub use self::crossterm::CrosstermBackend; + +mod test; +pub use self::test::TestBackend; + +pub trait Backend { + fn draw<'a, I>(&mut self, content: I) -> Result<(), io::Error> + where + I: Iterator; + fn hide_cursor(&mut self) -> Result<(), io::Error>; + fn show_cursor(&mut self) -> Result<(), io::Error>; + fn get_cursor(&mut self) -> Result<(u16, u16), io::Error>; + fn set_cursor(&mut self, x: u16, y: u16) -> Result<(), io::Error>; + fn clear(&mut self) -> Result<(), io::Error>; + fn size(&self) -> Result; + fn flush(&mut self) -> Result<(), io::Error>; +} diff --git a/helix-tui/src/backend/test.rs b/helix-tui/src/backend/test.rs new file mode 100644 index 00000000..46b37261 --- /dev/null +++ b/helix-tui/src/backend/test.rs @@ -0,0 +1,151 @@ +use crate::{ + backend::Backend, + buffer::{Buffer, Cell}, + layout::Rect, +}; +use std::{fmt::Write, io}; +use unicode_width::UnicodeWidthStr; + +/// A backend used for the integration tests. +#[derive(Debug)] +pub struct TestBackend { + width: u16, + buffer: Buffer, + height: u16, + cursor: bool, + pos: (u16, u16), +} + +/// Returns a string representation of the given buffer for debugging purpose. +fn buffer_view(buffer: &Buffer) -> String { + let mut view = String::with_capacity(buffer.content.len() + buffer.area.height as usize * 3); + for cells in buffer.content.chunks(buffer.area.width as usize) { + let mut overwritten = vec![]; + let mut skip: usize = 0; + view.push('"'); + for (x, c) in cells.iter().enumerate() { + if skip == 0 { + view.push_str(&c.symbol); + } else { + overwritten.push((x, &c.symbol)) + } + skip = std::cmp::max(skip, c.symbol.width()).saturating_sub(1); + } + view.push('"'); + if !overwritten.is_empty() { + write!( + &mut view, + " Hidden by multi-width symbols: {:?}", + overwritten + ) + .unwrap(); + } + view.push('\n'); + } + view +} + +impl TestBackend { + pub fn new(width: u16, height: u16) -> TestBackend { + TestBackend { + width, + height, + buffer: Buffer::empty(Rect::new(0, 0, width, height)), + cursor: false, + pos: (0, 0), + } + } + + pub fn buffer(&self) -> &Buffer { + &self.buffer + } + + pub fn resize(&mut self, width: u16, height: u16) { + self.buffer.resize(Rect::new(0, 0, width, height)); + self.width = width; + self.height = height; + } + + pub fn assert_buffer(&self, expected: &Buffer) { + assert_eq!(expected.area, self.buffer.area); + let diff = expected.diff(&self.buffer); + if diff.is_empty() { + return; + } + + let mut debug_info = String::from("Buffers are not equal"); + debug_info.push('\n'); + debug_info.push_str("Expected:"); + debug_info.push('\n'); + let expected_view = buffer_view(expected); + debug_info.push_str(&expected_view); + debug_info.push('\n'); + debug_info.push_str("Got:"); + debug_info.push('\n'); + let view = buffer_view(&self.buffer); + debug_info.push_str(&view); + debug_info.push('\n'); + + debug_info.push_str("Diff:"); + debug_info.push('\n'); + let nice_diff = diff + .iter() + .enumerate() + .map(|(i, (x, y, cell))| { + let expected_cell = expected.get(*x, *y); + format!( + "{}: at ({}, {}) expected {:?} got {:?}", + i, x, y, expected_cell, cell + ) + }) + .collect::>() + .join("\n"); + debug_info.push_str(&nice_diff); + panic!("{}", debug_info); + } +} + +impl Backend for TestBackend { + fn draw<'a, I>(&mut self, content: I) -> Result<(), io::Error> + where + I: Iterator, + { + for (x, y, c) in content { + let cell = self.buffer.get_mut(x, y); + *cell = c.clone(); + } + Ok(()) + } + + fn hide_cursor(&mut self) -> Result<(), io::Error> { + self.cursor = false; + Ok(()) + } + + fn show_cursor(&mut self) -> Result<(), io::Error> { + self.cursor = true; + Ok(()) + } + + fn get_cursor(&mut self) -> Result<(u16, u16), io::Error> { + Ok(self.pos) + } + + fn set_cursor(&mut self, x: u16, y: u16) -> Result<(), io::Error> { + self.pos = (x, y); + Ok(()) + } + + fn clear(&mut self) -> Result<(), io::Error> { + self.buffer.reset(); + Ok(()) + } + + fn size(&self) -> Result { + Ok(Rect::new(0, 0, self.width, self.height)) + } + + fn flush(&mut self) -> Result<(), io::Error> { + Ok(()) + } +} diff --git a/helix-tui/src/buffer.rs b/helix-tui/src/buffer.rs new file mode 100644 index 00000000..8a227ce7 --- /dev/null +++ b/helix-tui/src/buffer.rs @@ -0,0 +1,745 @@ +use crate::{ + layout::Rect, + style::{Color, Modifier, Style}, + text::{Span, Spans}, +}; +use std::cmp::min; +use unicode_segmentation::UnicodeSegmentation; +use unicode_width::UnicodeWidthStr; + +/// A buffer cell +#[derive(Debug, Clone, PartialEq)] +pub struct Cell { + pub symbol: String, + pub fg: Color, + pub bg: Color, + pub modifier: Modifier, +} + +impl Cell { + pub fn set_symbol(&mut self, symbol: &str) -> &mut Cell { + self.symbol.clear(); + self.symbol.push_str(symbol); + self + } + + pub fn set_char(&mut self, ch: char) -> &mut Cell { + self.symbol.clear(); + self.symbol.push(ch); + self + } + + pub fn set_fg(&mut self, color: Color) -> &mut Cell { + self.fg = color; + self + } + + pub fn set_bg(&mut self, color: Color) -> &mut Cell { + self.bg = color; + self + } + + pub fn set_style(&mut self, style: Style) -> &mut Cell { + if let Some(c) = style.fg { + self.fg = c; + } + if let Some(c) = style.bg { + self.bg = c; + } + self.modifier.insert(style.add_modifier); + self.modifier.remove(style.sub_modifier); + self + } + + pub fn style(&self) -> Style { + Style::default() + .fg(self.fg) + .bg(self.bg) + .add_modifier(self.modifier) + } + + pub fn reset(&mut self) { + self.symbol.clear(); + self.symbol.push(' '); + self.fg = Color::Reset; + self.bg = Color::Reset; + self.modifier = Modifier::empty(); + } +} + +impl Default for Cell { + fn default() -> Cell { + Cell { + symbol: " ".into(), + fg: Color::Reset, + bg: Color::Reset, + modifier: Modifier::empty(), + } + } +} + +/// A buffer that maps to the desired content of the terminal after the draw call +/// +/// No widget in the library interacts directly with the terminal. Instead each of them is required +/// to draw their state to an intermediate buffer. It is basically a grid where each cell contains +/// a grapheme, a foreground color and a background color. This grid will then be used to output +/// the appropriate escape sequences and characters to draw the UI as the user has defined it. +/// +/// # Examples: +/// +/// ``` +/// use helix_tui::buffer::{Buffer, Cell}; +/// use helix_tui::layout::Rect; +/// use helix_tui::style::{Color, Style, Modifier}; +/// +/// let mut buf = Buffer::empty(Rect{x: 0, y: 0, width: 10, height: 5}); +/// buf.get_mut(0, 2).set_symbol("x"); +/// assert_eq!(buf.get(0, 2).symbol, "x"); +/// buf.set_string(3, 0, "string", Style::default().fg(Color::Red).bg(Color::White)); +/// assert_eq!(buf.get(5, 0), &Cell{ +/// symbol: String::from("r"), +/// fg: Color::Red, +/// bg: Color::White, +/// modifier: Modifier::empty() +/// }); +/// buf.get_mut(5, 0).set_char('x'); +/// assert_eq!(buf.get(5, 0).symbol, "x"); +/// ``` +#[derive(Debug, Clone, PartialEq)] +pub struct Buffer { + /// The area represented by this buffer + pub area: Rect, + /// The content of the buffer. The length of this Vec should always be equal to area.width * + /// area.height + pub content: Vec, +} + +impl Default for Buffer { + fn default() -> Buffer { + Buffer { + area: Default::default(), + content: Vec::new(), + } + } +} + +impl Buffer { + /// Returns a Buffer with all cells set to the default one + pub fn empty(area: Rect) -> Buffer { + let cell: Cell = Default::default(); + Buffer::filled(area, &cell) + } + + /// Returns a Buffer with all cells initialized with the attributes of the given Cell + pub fn filled(area: Rect, cell: &Cell) -> Buffer { + let size = area.area() as usize; + let mut content = Vec::with_capacity(size); + for _ in 0..size { + content.push(cell.clone()); + } + Buffer { area, content } + } + + /// Returns a Buffer containing the given lines + pub fn with_lines(lines: Vec) -> Buffer + where + S: AsRef, + { + let height = lines.len() as u16; + let width = lines + .iter() + .map(|i| i.as_ref().width() as u16) + .max() + .unwrap_or_default(); + let mut buffer = Buffer::empty(Rect { + x: 0, + y: 0, + width, + height, + }); + for (y, line) in lines.iter().enumerate() { + buffer.set_string(0, y as u16, line, Style::default()); + } + buffer + } + + /// Returns the content of the buffer as a slice + pub fn content(&self) -> &[Cell] { + &self.content + } + + /// Returns the area covered by this buffer + pub fn area(&self) -> &Rect { + &self.area + } + + /// Returns a reference to Cell at the given coordinates + pub fn get(&self, x: u16, y: u16) -> &Cell { + let i = self.index_of(x, y); + &self.content[i] + } + + /// Returns a mutable reference to Cell at the given coordinates + pub fn get_mut(&mut self, x: u16, y: u16) -> &mut Cell { + let i = self.index_of(x, y); + &mut self.content[i] + } + + /// Returns the index in the Vec for the given global (x, y) coordinates. + /// + /// Global coordinates are offset by the Buffer's area offset (`x`/`y`). + /// + /// # Examples + /// + /// ``` + /// # use helix_tui::buffer::Buffer; + /// # use helix_tui::layout::Rect; + /// let rect = Rect::new(200, 100, 10, 10); + /// let buffer = Buffer::empty(rect); + /// // Global coordinates to the top corner of this buffer's area + /// assert_eq!(buffer.index_of(200, 100), 0); + /// ``` + /// + /// # Panics + /// + /// Panics when given an coordinate that is outside of this Buffer's area. + /// + /// ```should_panic + /// # use helix_tui::buffer::Buffer; + /// # use helix_tui::layout::Rect; + /// let rect = Rect::new(200, 100, 10, 10); + /// let buffer = Buffer::empty(rect); + /// // Top coordinate is outside of the buffer in global coordinate space, as the Buffer's area + /// // starts at (200, 100). + /// buffer.index_of(0, 0); // Panics + /// ``` + pub fn index_of(&self, x: u16, y: u16) -> usize { + debug_assert!( + x >= self.area.left() + && x < self.area.right() + && y >= self.area.top() + && y < self.area.bottom(), + "Trying to access position outside the buffer: x={}, y={}, area={:?}", + x, + y, + self.area + ); + ((y - self.area.y) * self.area.width + (x - self.area.x)) as usize + } + + /// Returns the (global) coordinates of a cell given its index + /// + /// Global coordinates are offset by the Buffer's area offset (`x`/`y`). + /// + /// # Examples + /// + /// ``` + /// # use helix_tui::buffer::Buffer; + /// # use helix_tui::layout::Rect; + /// let rect = Rect::new(200, 100, 10, 10); + /// let buffer = Buffer::empty(rect); + /// assert_eq!(buffer.pos_of(0), (200, 100)); + /// assert_eq!(buffer.pos_of(14), (204, 101)); + /// ``` + /// + /// # Panics + /// + /// Panics when given an index that is outside the Buffer's content. + /// + /// ```should_panic + /// # use helix_tui::buffer::Buffer; + /// # use helix_tui::layout::Rect; + /// let rect = Rect::new(0, 0, 10, 10); // 100 cells in total + /// let buffer = Buffer::empty(rect); + /// // Index 100 is the 101th cell, which lies outside of the area of this Buffer. + /// buffer.pos_of(100); // Panics + /// ``` + pub fn pos_of(&self, i: usize) -> (u16, u16) { + debug_assert!( + i < self.content.len(), + "Trying to get the coords of a cell outside the buffer: i={} len={}", + i, + self.content.len() + ); + ( + self.area.x + i as u16 % self.area.width, + self.area.y + i as u16 / self.area.width, + ) + } + + /// Print a string, starting at the position (x, y) + pub fn set_string(&mut self, x: u16, y: u16, string: S, style: Style) + where + S: AsRef, + { + self.set_stringn(x, y, string, usize::MAX, style); + } + + /// Print at most the first n characters of a string if enough space is available + /// until the end of the line + pub fn set_stringn( + &mut self, + x: u16, + y: u16, + string: S, + width: usize, + style: Style, + ) -> (u16, u16) + where + S: AsRef, + { + let mut index = self.index_of(x, y); + let mut x_offset = x as usize; + let graphemes = UnicodeSegmentation::graphemes(string.as_ref(), true); + let max_offset = min(self.area.right() as usize, width.saturating_add(x as usize)); + for s in graphemes { + let width = s.width(); + if width == 0 { + continue; + } + // `x_offset + width > max_offset` could be integer overflow on 32-bit machines if we + // change dimenstions to usize or u32 and someone resizes the terminal to 1x2^32. + if width > max_offset.saturating_sub(x_offset) { + break; + } + + self.content[index].set_symbol(s); + self.content[index].set_style(style); + // Reset following cells if multi-width (they would be hidden by the grapheme), + for i in index + 1..index + width { + self.content[i].reset(); + } + index += width; + x_offset += width; + } + (x_offset as u16, y) + } + + pub fn set_spans<'a>(&mut self, x: u16, y: u16, spans: &Spans<'a>, width: u16) -> (u16, u16) { + let mut remaining_width = width; + let mut x = x; + for span in &spans.0 { + if remaining_width == 0 { + break; + } + let pos = self.set_stringn( + x, + y, + span.content.as_ref(), + remaining_width as usize, + span.style, + ); + let w = pos.0.saturating_sub(x); + x = pos.0; + remaining_width = remaining_width.saturating_sub(w); + } + (x, y) + } + + pub fn set_span<'a>(&mut self, x: u16, y: u16, span: &Span<'a>, width: u16) -> (u16, u16) { + self.set_stringn(x, y, span.content.as_ref(), width as usize, span.style) + } + + #[deprecated( + since = "0.10.0", + note = "You should use styling capabilities of `Buffer::set_style`" + )] + pub fn set_background(&mut self, area: Rect, color: Color) { + for y in area.top()..area.bottom() { + for x in area.left()..area.right() { + self.get_mut(x, y).set_bg(color); + } + } + } + + pub fn set_style(&mut self, area: Rect, style: Style) { + for y in area.top()..area.bottom() { + for x in area.left()..area.right() { + self.get_mut(x, y).set_style(style); + } + } + } + + /// Resize the buffer so that the mapped area matches the given area and that the buffer + /// length is equal to area.width * area.height + pub fn resize(&mut self, area: Rect) { + let length = area.area() as usize; + if self.content.len() > length { + self.content.truncate(length); + } else { + self.content.resize(length, Default::default()); + } + self.area = area; + } + + /// Reset all cells in the buffer + pub fn reset(&mut self) { + for c in &mut self.content { + c.reset(); + } + } + + /// Merge an other buffer into this one + pub fn merge(&mut self, other: &Buffer) { + let area = self.area.union(other.area); + let cell: Cell = Default::default(); + self.content.resize(area.area() as usize, cell.clone()); + + // Move original content to the appropriate space + let size = self.area.area() as usize; + for i in (0..size).rev() { + let (x, y) = self.pos_of(i); + // New index in content + let k = ((y - area.y) * area.width + x - area.x) as usize; + if i != k { + self.content[k] = self.content[i].clone(); + self.content[i] = cell.clone(); + } + } + + // Push content of the other buffer into this one (may erase previous + // data) + let size = other.area.area() as usize; + for i in 0..size { + let (x, y) = other.pos_of(i); + // New index in content + let k = ((y - area.y) * area.width + x - area.x) as usize; + self.content[k] = other.content[i].clone(); + } + self.area = area; + } + + /// Builds a minimal sequence of coordinates and Cells necessary to update the UI from + /// self to other. + /// + /// We're assuming that buffers are well-formed, that is no double-width cell is followed by + /// a non-blank cell. + /// + /// # Multi-width characters handling: + /// + /// ```text + /// (Index:) `01` + /// Prev: `コ` + /// Next: `aa` + /// Updates: `0: a, 1: a' + /// ``` + /// + /// ```text + /// (Index:) `01` + /// Prev: `a ` + /// Next: `コ` + /// Updates: `0: コ` (double width symbol at index 0 - skip index 1) + /// ``` + /// + /// ```text + /// (Index:) `012` + /// Prev: `aaa` + /// Next: `aコ` + /// Updates: `0: a, 1: コ` (double width symbol at index 1 - skip index 2) + /// ``` + pub fn diff<'a>(&self, other: &'a Buffer) -> Vec<(u16, u16, &'a Cell)> { + let previous_buffer = &self.content; + let next_buffer = &other.content; + let width = self.area.width; + + let mut updates: Vec<(u16, u16, &Cell)> = vec![]; + // Cells invalidated by drawing/replacing preceeding multi-width characters: + let mut invalidated: usize = 0; + // Cells from the current buffer to skip due to preceeding multi-width characters taking their + // place (the skipped cells should be blank anyway): + let mut to_skip: usize = 0; + for (i, (current, previous)) in next_buffer.iter().zip(previous_buffer.iter()).enumerate() { + if (current != previous || invalidated > 0) && to_skip == 0 { + let x = i as u16 % width; + let y = i as u16 / width; + updates.push((x, y, &next_buffer[i])); + } + + to_skip = current.symbol.width().saturating_sub(1); + + let affected_width = std::cmp::max(current.symbol.width(), previous.symbol.width()); + invalidated = std::cmp::max(affected_width, invalidated).saturating_sub(1); + } + updates + } +} + +#[cfg(test)] +mod tests { + use super::*; + + fn cell(s: &str) -> Cell { + let mut cell = Cell::default(); + cell.set_symbol(s); + cell + } + + #[test] + fn it_translates_to_and_from_coordinates() { + let rect = Rect::new(200, 100, 50, 80); + let buf = Buffer::empty(rect); + + // First cell is at the upper left corner. + assert_eq!(buf.pos_of(0), (200, 100)); + assert_eq!(buf.index_of(200, 100), 0); + + // Last cell is in the lower right. + assert_eq!(buf.pos_of(buf.content.len() - 1), (249, 179)); + assert_eq!(buf.index_of(249, 179), buf.content.len() - 1); + } + + #[test] + #[should_panic(expected = "outside the buffer")] + fn pos_of_panics_on_out_of_bounds() { + let rect = Rect::new(0, 0, 10, 10); + let buf = Buffer::empty(rect); + + // There are a total of 100 cells; zero-indexed means that 100 would be the 101st cell. + buf.pos_of(100); + } + + #[test] + #[should_panic(expected = "outside the buffer")] + fn index_of_panics_on_out_of_bounds() { + let rect = Rect::new(0, 0, 10, 10); + let buf = Buffer::empty(rect); + + // width is 10; zero-indexed means that 10 would be the 11th cell. + buf.index_of(10, 0); + } + + #[test] + fn buffer_set_string() { + let area = Rect::new(0, 0, 5, 1); + let mut buffer = Buffer::empty(area); + + // Zero-width + buffer.set_stringn(0, 0, "aaa", 0, Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec![" "])); + + buffer.set_string(0, 0, "aaa", Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["aaa "])); + + // Width limit: + buffer.set_stringn(0, 0, "bbbbbbbbbbbbbb", 4, Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["bbbb "])); + + buffer.set_string(0, 0, "12345", Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["12345"])); + + // Width truncation: + buffer.set_string(0, 0, "123456", Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["12345"])); + } + + #[test] + fn buffer_set_string_zero_width() { + let area = Rect::new(0, 0, 1, 1); + let mut buffer = Buffer::empty(area); + + // Leading grapheme with zero width + let s = "\u{1}a"; + buffer.set_stringn(0, 0, s, 1, Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["a"])); + + // Trailing grapheme with zero with + let s = "a\u{1}"; + buffer.set_stringn(0, 0, s, 1, Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["a"])); + } + + #[test] + fn buffer_set_string_double_width() { + let area = Rect::new(0, 0, 5, 1); + let mut buffer = Buffer::empty(area); + buffer.set_string(0, 0, "コン", Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["コン "])); + + // Only 1 space left. + buffer.set_string(0, 0, "コンピ", Style::default()); + assert_eq!(buffer, Buffer::with_lines(vec!["コン "])); + } + + #[test] + fn buffer_with_lines() { + let buffer = + Buffer::with_lines(vec!["┌────────┐", "│コンピュ│", "│ーa 上で│", "└────────┘"]); + assert_eq!(buffer.area.x, 0); + assert_eq!(buffer.area.y, 0); + assert_eq!(buffer.area.width, 10); + assert_eq!(buffer.area.height, 4); + } + + #[test] + fn buffer_diffing_empty_empty() { + let area = Rect::new(0, 0, 40, 40); + let prev = Buffer::empty(area); + let next = Buffer::empty(area); + let diff = prev.diff(&next); + assert_eq!(diff, vec![]); + } + + #[test] + fn buffer_diffing_empty_filled() { + let area = Rect::new(0, 0, 40, 40); + let prev = Buffer::empty(area); + let next = Buffer::filled(area, Cell::default().set_symbol("a")); + let diff = prev.diff(&next); + assert_eq!(diff.len(), 40 * 40); + } + + #[test] + fn buffer_diffing_filled_filled() { + let area = Rect::new(0, 0, 40, 40); + let prev = Buffer::filled(area, Cell::default().set_symbol("a")); + let next = Buffer::filled(area, Cell::default().set_symbol("a")); + let diff = prev.diff(&next); + assert_eq!(diff, vec![]); + } + + #[test] + fn buffer_diffing_single_width() { + let prev = Buffer::with_lines(vec![ + " ", + "┌Title─┐ ", + "│ │ ", + "│ │ ", + "└──────┘ ", + ]); + let next = Buffer::with_lines(vec![ + " ", + "┌TITLE─┐ ", + "│ │ ", + "│ │ ", + "└──────┘ ", + ]); + let diff = prev.diff(&next); + assert_eq!( + diff, + vec![ + (2, 1, &cell("I")), + (3, 1, &cell("T")), + (4, 1, &cell("L")), + (5, 1, &cell("E")), + ] + ); + } + + #[test] + #[rustfmt::skip] + fn buffer_diffing_multi_width() { + let prev = Buffer::with_lines(vec![ + "┌Title─┐ ", + "└──────┘ ", + ]); + let next = Buffer::with_lines(vec![ + "┌称号──┐ ", + "└──────┘ ", + ]); + let diff = prev.diff(&next); + assert_eq!( + diff, + vec![ + (1, 0, &cell("称")), + // Skipped "i" + (3, 0, &cell("号")), + // Skipped "l" + (5, 0, &cell("─")), + ] + ); + } + + #[test] + fn buffer_diffing_multi_width_offset() { + let prev = Buffer::with_lines(vec!["┌称号──┐"]); + let next = Buffer::with_lines(vec!["┌─称号─┐"]); + + let diff = prev.diff(&next); + assert_eq!( + diff, + vec![(1, 0, &cell("─")), (2, 0, &cell("称")), (4, 0, &cell("号")),] + ); + } + + #[test] + fn buffer_merge() { + let mut one = Buffer::filled( + Rect { + x: 0, + y: 0, + width: 2, + height: 2, + }, + Cell::default().set_symbol("1"), + ); + let two = Buffer::filled( + Rect { + x: 0, + y: 2, + width: 2, + height: 2, + }, + Cell::default().set_symbol("2"), + ); + one.merge(&two); + assert_eq!(one, Buffer::with_lines(vec!["11", "11", "22", "22"])); + } + + #[test] + fn buffer_merge2() { + let mut one = Buffer::filled( + Rect { + x: 2, + y: 2, + width: 2, + height: 2, + }, + Cell::default().set_symbol("1"), + ); + let two = Buffer::filled( + Rect { + x: 0, + y: 0, + width: 2, + height: 2, + }, + Cell::default().set_symbol("2"), + ); + one.merge(&two); + assert_eq!( + one, + Buffer::with_lines(vec!["22 ", "22 ", " 11", " 11"]) + ); + } + + #[test] + fn buffer_merge3() { + let mut one = Buffer::filled( + Rect { + x: 3, + y: 3, + width: 2, + height: 2, + }, + Cell::default().set_symbol("1"), + ); + let two = Buffer::filled( + Rect { + x: 1, + y: 1, + width: 3, + height: 4, + }, + Cell::default().set_symbol("2"), + ); + one.merge(&two); + let mut merged = Buffer::with_lines(vec!["222 ", "222 ", "2221", "2221"]); + merged.area = Rect { + x: 1, + y: 1, + width: 4, + height: 4, + }; + assert_eq!(one, merged); + } +} diff --git a/helix-tui/src/layout.rs b/helix-tui/src/layout.rs new file mode 100644 index 00000000..5248f7bf --- /dev/null +++ b/helix-tui/src/layout.rs @@ -0,0 +1,534 @@ +use std::cell::RefCell; +use std::cmp::{max, min}; +use std::collections::HashMap; + +use cassowary::strength::{REQUIRED, WEAK}; +use cassowary::WeightedRelation::*; +use cassowary::{Constraint as CassowaryConstraint, Expression, Solver, Variable}; + +#[derive(Debug, Hash, Clone, Copy, PartialEq, Eq)] +pub enum Corner { + TopLeft, + TopRight, + BottomRight, + BottomLeft, +} + +#[derive(Debug, Hash, Clone, PartialEq, Eq)] +pub enum Direction { + Horizontal, + Vertical, +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] +pub enum Constraint { + // TODO: enforce range 0 - 100 + Percentage(u16), + Ratio(u32, u32), + Length(u16), + Max(u16), + Min(u16), +} + +impl Constraint { + pub fn apply(&self, length: u16) -> u16 { + match *self { + Constraint::Percentage(p) => length * p / 100, + Constraint::Ratio(num, den) => { + let r = num * u32::from(length) / den; + r as u16 + } + Constraint::Length(l) => length.min(l), + Constraint::Max(m) => length.min(m), + Constraint::Min(m) => length.max(m), + } + } +} + +#[derive(Debug, Clone, PartialEq, Eq, Hash)] +pub struct Margin { + pub vertical: u16, + pub horizontal: u16, +} + +#[derive(Debug, Clone, Copy, PartialEq)] +pub enum Alignment { + Left, + Center, + Right, +} + +#[derive(Debug, Clone, PartialEq, Eq, Hash)] +pub struct Layout { + direction: Direction, + margin: Margin, + constraints: Vec, +} + +thread_local! { + static LAYOUT_CACHE: RefCell>> = RefCell::new(HashMap::new()); +} + +impl Default for Layout { + fn default() -> Layout { + Layout { + direction: Direction::Vertical, + margin: Margin { + horizontal: 0, + vertical: 0, + }, + constraints: Vec::new(), + } + } +} + +impl Layout { + pub fn constraints(mut self, constraints: C) -> Layout + where + C: Into>, + { + self.constraints = constraints.into(); + self + } + + pub fn margin(mut self, margin: u16) -> Layout { + self.margin = Margin { + horizontal: margin, + vertical: margin, + }; + self + } + + pub fn horizontal_margin(mut self, horizontal: u16) -> Layout { + self.margin.horizontal = horizontal; + self + } + + pub fn vertical_margin(mut self, vertical: u16) -> Layout { + self.margin.vertical = vertical; + self + } + + pub fn direction(mut self, direction: Direction) -> Layout { + self.direction = direction; + self + } + + /// Wrapper function around the cassowary-rs solver to be able to split a given + /// area into smaller ones based on the preferred widths or heights and the direction. + /// + /// # Examples + /// ``` + /// # use helix_tui::layout::{Rect, Constraint, Direction, Layout}; + /// let chunks = Layout::default() + /// .direction(Direction::Vertical) + /// .constraints([Constraint::Length(5), Constraint::Min(0)].as_ref()) + /// .split(Rect { + /// x: 2, + /// y: 2, + /// width: 10, + /// height: 10, + /// }); + /// assert_eq!( + /// chunks, + /// vec![ + /// Rect { + /// x: 2, + /// y: 2, + /// width: 10, + /// height: 5 + /// }, + /// Rect { + /// x: 2, + /// y: 7, + /// width: 10, + /// height: 5 + /// } + /// ] + /// ); + /// + /// let chunks = Layout::default() + /// .direction(Direction::Horizontal) + /// .constraints([Constraint::Ratio(1, 3), Constraint::Ratio(2, 3)].as_ref()) + /// .split(Rect { + /// x: 0, + /// y: 0, + /// width: 9, + /// height: 2, + /// }); + /// assert_eq!( + /// chunks, + /// vec![ + /// Rect { + /// x: 0, + /// y: 0, + /// width: 3, + /// height: 2 + /// }, + /// Rect { + /// x: 3, + /// y: 0, + /// width: 6, + /// height: 2 + /// } + /// ] + /// ); + /// ``` + pub fn split(&self, area: Rect) -> Vec { + // TODO: Maybe use a fixed size cache ? + LAYOUT_CACHE.with(|c| { + c.borrow_mut() + .entry((area, self.clone())) + .or_insert_with(|| split(area, self)) + .clone() + }) + } +} + +fn split(area: Rect, layout: &Layout) -> Vec { + let mut solver = Solver::new(); + let mut vars: HashMap = HashMap::new(); + let elements = layout + .constraints + .iter() + .map(|_| Element::new()) + .collect::>(); + let mut results = layout + .constraints + .iter() + .map(|_| Rect::default()) + .collect::>(); + + let dest_area = area.inner(&layout.margin); + for (i, e) in elements.iter().enumerate() { + vars.insert(e.x, (i, 0)); + vars.insert(e.y, (i, 1)); + vars.insert(e.width, (i, 2)); + vars.insert(e.height, (i, 3)); + } + let mut ccs: Vec = + Vec::with_capacity(elements.len() * 4 + layout.constraints.len() * 6); + for elt in &elements { + ccs.push(elt.width | GE(REQUIRED) | 0f64); + ccs.push(elt.height | GE(REQUIRED) | 0f64); + ccs.push(elt.left() | GE(REQUIRED) | f64::from(dest_area.left())); + ccs.push(elt.top() | GE(REQUIRED) | f64::from(dest_area.top())); + ccs.push(elt.right() | LE(REQUIRED) | f64::from(dest_area.right())); + ccs.push(elt.bottom() | LE(REQUIRED) | f64::from(dest_area.bottom())); + } + if let Some(first) = elements.first() { + ccs.push(match layout.direction { + Direction::Horizontal => first.left() | EQ(REQUIRED) | f64::from(dest_area.left()), + Direction::Vertical => first.top() | EQ(REQUIRED) | f64::from(dest_area.top()), + }); + } + if let Some(last) = elements.last() { + ccs.push(match layout.direction { + Direction::Horizontal => last.right() | EQ(REQUIRED) | f64::from(dest_area.right()), + Direction::Vertical => last.bottom() | EQ(REQUIRED) | f64::from(dest_area.bottom()), + }); + } + match layout.direction { + Direction::Horizontal => { + for pair in elements.windows(2) { + ccs.push((pair[0].x + pair[0].width) | EQ(REQUIRED) | pair[1].x); + } + for (i, size) in layout.constraints.iter().enumerate() { + ccs.push(elements[i].y | EQ(REQUIRED) | f64::from(dest_area.y)); + ccs.push(elements[i].height | EQ(REQUIRED) | f64::from(dest_area.height)); + ccs.push(match *size { + Constraint::Length(v) => elements[i].width | EQ(WEAK) | f64::from(v), + Constraint::Percentage(v) => { + elements[i].width | EQ(WEAK) | (f64::from(v * dest_area.width) / 100.0) + } + Constraint::Ratio(n, d) => { + elements[i].width + | EQ(WEAK) + | (f64::from(dest_area.width) * f64::from(n) / f64::from(d)) + } + Constraint::Min(v) => elements[i].width | GE(WEAK) | f64::from(v), + Constraint::Max(v) => elements[i].width | LE(WEAK) | f64::from(v), + }); + } + } + Direction::Vertical => { + for pair in elements.windows(2) { + ccs.push((pair[0].y + pair[0].height) | EQ(REQUIRED) | pair[1].y); + } + for (i, size) in layout.constraints.iter().enumerate() { + ccs.push(elements[i].x | EQ(REQUIRED) | f64::from(dest_area.x)); + ccs.push(elements[i].width | EQ(REQUIRED) | f64::from(dest_area.width)); + ccs.push(match *size { + Constraint::Length(v) => elements[i].height | EQ(WEAK) | f64::from(v), + Constraint::Percentage(v) => { + elements[i].height | EQ(WEAK) | (f64::from(v * dest_area.height) / 100.0) + } + Constraint::Ratio(n, d) => { + elements[i].height + | EQ(WEAK) + | (f64::from(dest_area.height) * f64::from(n) / f64::from(d)) + } + Constraint::Min(v) => elements[i].height | GE(WEAK) | f64::from(v), + Constraint::Max(v) => elements[i].height | LE(WEAK) | f64::from(v), + }); + } + } + } + solver.add_constraints(&ccs).unwrap(); + for &(var, value) in solver.fetch_changes() { + let (index, attr) = vars[&var]; + let value = if value.is_sign_negative() { + 0 + } else { + value as u16 + }; + match attr { + 0 => { + results[index].x = value; + } + 1 => { + results[index].y = value; + } + 2 => { + results[index].width = value; + } + 3 => { + results[index].height = value; + } + _ => {} + } + } + + // Fix imprecision by extending the last item a bit if necessary + if let Some(last) = results.last_mut() { + match layout.direction { + Direction::Vertical => { + last.height = dest_area.bottom() - last.y; + } + Direction::Horizontal => { + last.width = dest_area.right() - last.x; + } + } + } + results +} + +/// A container used by the solver inside split +struct Element { + x: Variable, + y: Variable, + width: Variable, + height: Variable, +} + +impl Element { + fn new() -> Element { + Element { + x: Variable::new(), + y: Variable::new(), + width: Variable::new(), + height: Variable::new(), + } + } + + fn left(&self) -> Variable { + self.x + } + + fn top(&self) -> Variable { + self.y + } + + fn right(&self) -> Expression { + self.x + self.width + } + + fn bottom(&self) -> Expression { + self.y + self.height + } +} + +/// 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 + } +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn test_vertical_split_by_height() { + let target = Rect { + x: 2, + y: 2, + width: 10, + height: 10, + }; + + let chunks = Layout::default() + .direction(Direction::Vertical) + .constraints( + [ + Constraint::Percentage(10), + Constraint::Max(5), + Constraint::Min(1), + ] + .as_ref(), + ) + .split(target); + + assert_eq!(target.height, chunks.iter().map(|r| r.height).sum::()); + chunks.windows(2).for_each(|w| assert!(w[0].y <= w[1].y)); + } + + #[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); + } +} diff --git a/helix-tui/src/lib.rs b/helix-tui/src/lib.rs new file mode 100644 index 00000000..5f59fd3d --- /dev/null +++ b/helix-tui/src/lib.rs @@ -0,0 +1,134 @@ +//! [tui](https://github.com/fdehau/tui-rs) is a library used to build rich +//! terminal users interfaces and dashboards. +//! +//! ![](https://raw.githubusercontent.com/fdehau/tui-rs/master/assets/demo.gif) +//! +//! # Get started +//! +//! ## Adding `tui` as a dependency +//! +//! ```toml +//! [dependencies] +//! tui = "0.15" +//! crossterm = "0.19" +//! ``` +//! +//! The same logic applies for all other available backends. +//! +//! ## Creating a `Terminal` +//! +//! Every application using `tui` should start by instantiating a `Terminal`. It is a light +//! abstraction over available backends that provides basic functionalities such as clearing the +//! screen, hiding the cursor, etc. +//! +//! ```rust,no_run +//! use std::io; +//! use helix_tui::Terminal; +//! use helix_tui::backend::CrosstermBackend; +//! +//! fn main() -> Result<(), io::Error> { +//! let stdout = io::stdout(); +//! let backend = CrosstermBackend::new(stdout); +//! let mut terminal = Terminal::new(backend)?; +//! Ok(()) +//! } +//! ``` +//! +//! You may also refer to the examples to find out how to create a `Terminal` for each available +//! backend. +//! +//! ## Building a User Interface (UI) +//! +//! Every component of your interface will be implementing the `Widget` trait. The library comes +//! with a predefined set of widgets that should meet most of your use cases. You are also free to +//! implement your own. +//! +//! Each widget follows a builder pattern API providing a default configuration along with methods +//! to customize them. The widget is then rendered using the [`Frame::render_widget`] which take +//! your widget instance an area to draw to. +//! +//! The following example renders a block of the size of the terminal: +//! +//! ```rust,no_run +//! use std::io; +//! use crossterm::terminal; +//! use helix_tui::Terminal; +//! use helix_tui::backend::CrosstermBackend; +//! use helix_tui::widgets::{Widget, Block, Borders}; +//! use helix_tui::layout::{Layout, Constraint, Direction}; +//! +//! fn main() -> Result<(), io::Error> { +//! terminal::enable_raw_mode()?; +//! let stdout = io::stdout(); +//! let backend = CrosstermBackend::new(stdout); +//! let mut terminal = Terminal::new(backend)?; +//! terminal.draw(|f| { +//! let size = f.size(); +//! let block = Block::default() +//! .title("Block") +//! .borders(Borders::ALL); +//! f.render_widget(block, size); +//! })?; +//! Ok(()) +//! } +//! ``` +//! +//! ## Layout +//! +//! The library comes with a basic yet useful layout management object called `Layout`. As you may +//! see below and in the examples, the library makes heavy use of the builder pattern to provide +//! full customization. And `Layout` is no exception: +//! +//! ```rust,no_run +//! use std::io; +//! use crossterm::terminal; +//! use helix_tui::Terminal; +//! use helix_tui::backend::CrosstermBackend; +//! use helix_tui::widgets::{Widget, Block, Borders}; +//! use helix_tui::layout::{Layout, Constraint, Direction}; +//! +//! fn main() -> Result<(), io::Error> { +//! terminal::enable_raw_mode()?; +//! let stdout = io::stdout(); +//! let backend = CrosstermBackend::new(stdout); +//! let mut terminal = Terminal::new(backend)?; +//! terminal.draw(|f| { +//! let chunks = Layout::default() +//! .direction(Direction::Vertical) +//! .margin(1) +//! .constraints( +//! [ +//! Constraint::Percentage(10), +//! Constraint::Percentage(80), +//! Constraint::Percentage(10) +//! ].as_ref() +//! ) +//! .split(f.size()); +//! let block = Block::default() +//! .title("Block") +//! .borders(Borders::ALL); +//! f.render_widget(block, chunks[0]); +//! let block = Block::default() +//! .title("Block 2") +//! .borders(Borders::ALL); +//! f.render_widget(block, chunks[1]); +//! })?; +//! Ok(()) +//! } +//! ``` +//! +//! This let you describe responsive terminal UI by nesting layouts. You should note that by +//! default the computed layout tries to fill the available space completely. So if for any reason +//! you might need a blank space somewhere, try to pass an additional constraint and don't use the +//! corresponding area. + +pub mod backend; +pub mod buffer; +pub mod layout; +pub mod style; +pub mod symbols; +pub mod terminal; +pub mod text; +pub mod widgets; + +pub use self::terminal::{Terminal, TerminalOptions, Viewport}; diff --git a/helix-tui/src/style.rs b/helix-tui/src/style.rs new file mode 100644 index 00000000..f322d304 --- /dev/null +++ b/helix-tui/src/style.rs @@ -0,0 +1,281 @@ +//! `style` contains the primitives used to control how your user interface will look. + +use bitflags::bitflags; + +#[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), +} + +bitflags! { + /// Modifier changes the way a piece of text is displayed. + /// + /// They are bitflags so they can easily be composed. + /// + /// ## Examples + /// + /// ```rust + /// # use helix_tui::style::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_tui::style::{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_tui::style::{Color, Modifier, Style}; +/// # use helix_tui::buffer::Buffer; +/// # use helix_tui::layout::Rect; +/// 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_tui::style::{Color, Modifier, Style}; +/// # use helix_tui::buffer::Buffer; +/// # use helix_tui::layout::Rect; +/// 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, + pub bg: Option, + 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_tui::style::{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_tui::style::{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_tui::style::{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_tui::style::{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_tui::style::{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::*; + + fn styles() -> Vec