Redraw UI when returning from external editor

Forces _tui_ to redraw the whole app when returning from the external editor. This is acheived by creating a static channel for sending "app commands".

Author: jonstodle

Diff for: src/components/commit.rs

@@ -2,6 +2,7 @@ use super::{
     textinput::TextInputComponent, visibility_blocking,
     CommandBlocking, CommandInfo, Component, DrawableComponent,
 };
+use crate::poll::QueueEvent;
 use crate::strings::COMMIT_EDITOR_MSG;
 use crate::{
     get_app_config_path,
@@ -133,6 +134,13 @@ impl CommitComponent {
         crate::poll::SHOULD_DO_POLL
             .fetch_add(1, std::sync::atomic::Ordering::SeqCst);
         Command::new(command).args(editor).status()?;
+        // safety: this is set during app setup, and _should_ never be mutated again
+        unsafe {
+            crate::COMMANDS_CHANNEL
+                .as_ref()
+                .unwrap()
+                .send(QueueEvent::FullRedraw)?
+        }
         crate::poll::SHOULD_DO_POLL
             .fetch_add(1, std::sync::atomic::Ordering::SeqCst);
 

Diff for: src/main.rs

@@ -1,4 +1,4 @@
-#![forbid(unsafe_code)]
+// #![forbid(unsafe_code)]
 #![deny(clippy::cargo)]
 //TODO: remove once crossterm upgraded to current mio:
 //https://github.com/crossterm-rs/crossterm/issues/432
@@ -29,7 +29,7 @@ use clap::{
     crate_authors, crate_description, crate_name, crate_version,
     App as ClapApp, Arg,
 };
-use crossbeam_channel::{tick, unbounded, Receiver, Select};
+use crossbeam_channel::{tick, unbounded, Receiver, Select, Sender};
 use crossterm::{
     terminal::{
         disable_raw_mode, enable_raw_mode, EnterAlternateScreen,
@@ -58,6 +58,8 @@ use tui::{
 static TICK_INTERVAL: Duration = Duration::from_secs(5);
 static SPINNER_INTERVAL: Duration = Duration::from_millis(50);
 
+static mut COMMANDS_CHANNEL: Option<Sender<QueueEvent>> = None;
+
 fn main() -> Result<()> {
     process_cmdline()?;
 
@@ -75,6 +77,12 @@ fn main() -> Result<()> {
 
     let mut terminal = start_terminal(io::stdout())?;
 
+    let (tx_commands, rx_commands) = unbounded();
+    // safety: the app hasn't started running yet, so this variable is not yet in use
+    unsafe {
+        COMMANDS_CHANNEL = Some(tx_commands);
+    }
+
     let (tx_git, rx_git) = unbounded();
 
     let mut app = App::new(&tx_git);
@@ -94,6 +102,7 @@ fn main() -> Result<()> {
             &rx_git,
             &ticker,
             &spinner_ticker,
+            &rx_commands,
         )?;
 
         {
@@ -110,6 +119,9 @@ fn main() -> Result<()> {
                         needs_draw = false;
                         spinner.update()
                     }
+                    QueueEvent::FullRedraw => {
+                        terminal.resize(terminal.size()?)?
+                    }
                 }
             }
 
@@ -161,6 +173,7 @@ fn select_event(
     rx_git: &Receiver<AsyncNotification>,
     rx_ticker: &Receiver<Instant>,
     rx_spinner: &Receiver<Instant>,
+    rx_commands: &Receiver<QueueEvent>,
 ) -> Result<Vec<QueueEvent>> {
     let mut events: Vec<QueueEvent> = Vec::new();
 
@@ -170,6 +183,7 @@ fn select_event(
     sel.recv(rx_git);
     sel.recv(rx_ticker);
     sel.recv(rx_spinner);
+    sel.recv(rx_commands);
 
     let oper = sel.select();
     let index = oper.index();
@@ -185,6 +199,7 @@ fn select_event(
         3 => oper
             .recv(rx_spinner)
             .map(|_| events.push(QueueEvent::SpinnerUpdate)),
+        4 => oper.recv(rx_commands).map(|ev| events.push(ev)),
         _ => return Err(anyhow!("unknown select source")),
     }?;
 

Diff for: src/poll.rs

@@ -13,6 +13,7 @@ pub enum QueueEvent {
     SpinnerUpdate,
     GitEvent(AsyncNotification),
     InputEvent(Event),
+    FullRedraw,
 }
 
 static MAX_POLL_DURATION: Duration = Duration::from_secs(2);