From 95d887126a73c0aadb1f9351bb750cfe0dbb5b03 Mon Sep 17 00:00:00 2001
From: Ivan Tham <pickfire@riseup.net>
Date: Sat, 17 Jul 2021 22:47:08 +0800
Subject: [PATCH] Add ctrl-z to suspend

---
 Cargo.lock                    | 14 +++++++
 helix-lsp/Cargo.toml          |  2 +-
 helix-term/Cargo.toml         |  6 ++-
 helix-term/src/application.rs | 77 +++++++++++++++++++++++++++++------
 helix-term/src/commands.rs    |  9 +++-
 helix-term/src/keymap.rs      |  1 +
 helix-view/Cargo.toml         |  2 +-
 7 files changed, 95 insertions(+), 16 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index e262f0813e7c8..0539b016130c8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -379,6 +379,8 @@ dependencies = [
  "pulldown-cmark",
  "serde",
  "serde_json",
+ "signal-hook",
+ "signal-hook-tokio",
  "tokio",
  "toml",
 ]
@@ -899,6 +901,18 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "signal-hook-tokio"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6c5d32165ff8b94e68e7b3bdecb1b082e958c22434b363482cfb89dcd6f3ff8"
+dependencies = [
+ "futures-core",
+ "libc",
+ "signal-hook",
+ "tokio",
+]
+
 [[package]]
 name = "similar"
 version = "1.3.0"
diff --git a/helix-lsp/Cargo.toml b/helix-lsp/Cargo.toml
index be09982186ee1..aa631878aca81 100644
--- a/helix-lsp/Cargo.toml
+++ b/helix-lsp/Cargo.toml
@@ -23,5 +23,5 @@ lsp-types = { version = "0.89", features = ["proposed"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 thiserror = "1.0"
-tokio = { version = "1.8", features = ["full"] }
+tokio = { version = "1", features = ["rt", "rt-multi-thread", "io-util", "io-std", "time", "process", "macros", "fs", "parking_lot"] }
 tokio-stream = "0.1.7"
diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml
index 1ff32276627ef..d35134780b308 100644
--- a/helix-term/Cargo.toml
+++ b/helix-term/Cargo.toml
@@ -29,10 +29,11 @@ helix-lsp = { version = "0.3", path = "../helix-lsp" }
 anyhow = "1"
 once_cell = "1.8"
 
-tokio = { version = "1", features = ["full"] }
+tokio = { version = "1", features = ["rt", "rt-multi-thread", "io-util", "io-std", "time", "process", "macros", "fs", "parking_lot"] }
 num_cpus = "1"
 tui = { path = "../helix-tui", package = "helix-tui", default-features = false, features = ["crossterm"] }
 crossterm = { version = "0.20", features = ["event-stream"] }
+signal-hook = "0.3"
 
 futures-util = { version = "0.3", features = ["std", "async-await"], default-features = false }
 
@@ -54,3 +55,6 @@ toml = "0.5"
 
 serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
+
+[target.'cfg(not(windows))'.dependencies]  # https://github.com/vorner/signal-hook/issues/100
+signal-hook-tokio = { version = "0.3", features = ["futures-v0_3"] }
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 79dd7c3ba352b..8927ad3d281e6 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -18,6 +18,10 @@ use crossterm::{
     event::{Event, EventStream},
     execute, terminal,
 };
+#[cfg(not(windows))]
+use signal_hook::{consts::signal, low_level};
+#[cfg(not(windows))]
+use signal_hook_tokio::Signals;
 
 pub struct Application {
     compositor: Compositor,
@@ -36,6 +40,8 @@ pub struct Application {
     #[allow(dead_code)]
     syn_loader: Arc<syntax::Loader>,
 
+    #[cfg(not(windows))]
+    signals: Signals,
     jobs: Jobs,
     lsp_progress: LspProgressMap,
 }
@@ -99,6 +105,9 @@ impl Application {
 
         editor.set_theme(theme);
 
+        #[cfg(not(windows))]
+        let signals = Signals::new(&[signal::SIGTSTP, signal::SIGCONT])?;
+
         let app = Self {
             compositor,
             editor,
@@ -108,6 +117,8 @@ impl Application {
             theme_loader,
             syn_loader,
 
+            #[cfg(not(windows))]
+            signals,
             jobs: Jobs::new(),
             lsp_progress: LspProgressMap::new(),
         };
@@ -144,12 +155,29 @@ impl Application {
 
             use futures_util::StreamExt;
 
+            #[cfg(not(windows))]
             tokio::select! {
                 biased;
 
                 event = reader.next() => {
                     self.handle_terminal_events(event)
                 }
+                Some(signal) = self.signals.next() => {
+                    use helix_view::graphics::Rect;
+                    match signal {
+                        signal::SIGTSTP => {
+                            self.restore_term().unwrap();
+                            low_level::emulate_default_handler(signal::SIGTSTP).unwrap();
+                        }                        signal::SIGCONT => {
+                            self.claim_term().await.unwrap();
+                            // redraw the terminal
+                            let Rect { width, height, .. } = self.compositor.size();
+                            self.compositor.resize(width, height);
+                            self.render();
+                        }
+                        _ => unreachable!(),
+                    }
+                }
                 Some((id, call)) = self.editor.language_servers.incoming.next() => {
                     self.handle_language_server_message(call, id).await;
                     // limit render calls for fast language server messages
@@ -157,9 +185,30 @@ impl Application {
                     if last || last_render.elapsed() > deadline {
                         self.render();
                         last_render = Instant::now();
-                    }
+                    }                }                Some(callback) = self.jobs.futures.next() => {
+                    self.jobs.handle_callback(&mut self.editor, &mut self.compositor, callback);
+                    self.render();
+                }
+                Some(callback) = self.jobs.wait_futures.next() => {
+                    self.jobs.handle_callback(&mut self.editor, &mut self.compositor, callback);
+                    self.render();
                 }
-                Some(callback) = self.jobs.futures.next() => {
+            }
+            #[cfg(windows)]
+            tokio::select! {
+                biased;
+
+                event = reader.next() => {
+                    self.handle_terminal_events(event)
+                }
+                Some((id, call)) = self.editor.language_servers.incoming.next() => {
+                    self.handle_language_server_message(call, id).await;
+                    // limit render calls for fast language server messages
+                    let last = self.editor.language_servers.incoming.is_empty();
+                    if last || last_render.elapsed() > deadline {
+                        self.render();
+                        last_render = Instant::now();
+                    }                }                Some(callback) = self.jobs.futures.next() => {
                     self.jobs.handle_callback(&mut self.editor, &mut self.compositor, callback);
                     self.render();
                 }
@@ -440,12 +489,23 @@ impl Application {
         }
     }
 
-    pub async fn run(&mut self) -> Result<(), Error> {
+    async fn claim_term(&mut self) -> Result<(), Error> {
         terminal::enable_raw_mode()?;
+        self.editor.close_language_servers(None).await?;
+        Ok(())
+    }
 
+    fn restore_term(&mut self) -> Result<(), Error> {
         let mut stdout = stdout();
+        // reset cursor shape
+        write!(stdout, "\x1B[2 q")?;
+        execute!(stdout, terminal::LeaveAlternateScreen)?;
+        terminal::disable_raw_mode()?;
+        Ok(())
+    }
 
-        execute!(stdout, terminal::EnterAlternateScreen)?;
+    pub async fn run(&mut self) -> Result<(), Error> {
+        self.claim_term().await?;
 
         // Exit the alternate screen and disable raw mode before panicking
         let hook = std::panic::take_hook();
@@ -460,14 +520,7 @@ impl Application {
 
         self.event_loop().await;
 
-        self.editor.close_language_servers(None).await?;
-
-        // reset cursor shape
-        write!(stdout, "\x1B[2 q")?;
-
-        execute!(stdout, terminal::LeaveAlternateScreen)?;
-
-        terminal::disable_raw_mode()?;
+        self.restore_term()?;
 
         Ok(())
     }
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 7e769f4e1dad1..575bad9c575a2 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -50,6 +50,7 @@ use std::{
 
 use once_cell::sync::{Lazy, OnceCell};
 use serde::de::{self, Deserialize, Deserializer};
+use signal_hook::{consts::signal, low_level};
 
 pub struct Context<'a> {
     pub selected_register: helix_view::RegisterSelection,
@@ -279,7 +280,8 @@ impl Command {
         view_mode,
         left_bracket_mode,
         right_bracket_mode,
-        match_mode
+        match_mode,
+        suspend
     );
 }
 
@@ -3671,6 +3673,11 @@ fn surround_delete(cx: &mut Context) {
     })
 }
 
+fn suspend(_cx: &mut Context) {
+    #[cfg(not(windows))]
+    low_level::raise(signal::SIGTSTP).unwrap();
+}
+
 /// Do nothing, just for modeinfo.
 fn noop(_cx: &mut Context) -> bool {
     false
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index 32994c37ab383..050883024746c 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -193,6 +193,7 @@ impl Default for Keymaps {
             key!('z') => Command::view_mode,
 
             key!('"') => Command::select_register,
+            ctrl!('z') => Command::suspend,
         );
         // TODO: decide whether we want normal mode to also be select mode (kakoune-like), or whether
         // we keep this separate select mode. More keys can fit into normal mode then, but it's weird
diff --git a/helix-view/Cargo.toml b/helix-view/Cargo.toml
index cb2032de5457c..632702200f089 100644
--- a/helix-view/Cargo.toml
+++ b/helix-view/Cargo.toml
@@ -24,7 +24,7 @@ crossterm = { version = "0.20", optional = true }
 once_cell = "1.8"
 url = "2"
 
-tokio = { version = "1", features = ["full"] }
+tokio = { version = "1", features = ["rt", "rt-multi-thread", "io-util", "io-std", "time", "process", "macros", "fs", "parking_lot"] }
 futures-util = { version = "0.3", features = ["std", "async-await"], default-features = false }
 
 slotmap = "1"