allow setting a custom exit handler

src/lib.rs

@@ -74,3 +74,8 @@ where
 pub fn prompt(questions: Vec<Question>) -> error::Result<Answers> {
     PromptModule::new(questions).prompt_all()
 }
+
+/// Sets the exit handler to call when CTRL+C is received
+pub fn set_exit_handler(handler: fn() -> !) {
+    ui::set_exit_handler(handler);
+}

ui/Cargo.toml

@@ -8,4 +8,5 @@ edition = "2018"
 
 [dependencies]
 crossterm = "0.19.0"
+lazy_static = "1.4.0"
 unicode-segmentation = "1.7.1"

ui/src/lib.rs

@@ -1,6 +1,6 @@
 #![deny(missing_docs, rust_2018_idioms)]
 //! A widget based cli ui rendering library
-use std::{convert::TryFrom, io};
+use std::{convert::TryFrom, io, sync::Mutex};
 
 use crossterm::{
     cursor, event, execute, queue,
@@ -299,11 +299,26 @@ impl<P> Input<P> {
     }
 }
 
-// FIXME: maybe allow this to be changed?
-fn exit() -> ! {
+lazy_static::lazy_static! {
+    static ref EXIT_HANDLER: Mutex<fn() -> !> = Mutex::new(default_exit);
+}
+
+/// Sets the exit handler to call when CTRL+C is received
+pub fn set_exit_handler(handler: fn() -> !) {
+    *EXIT_HANDLER.lock().unwrap() = handler;
+}
+
+fn default_exit() -> ! {
     std::process::exit(130);
 }
 
+fn exit() -> ! {
+    match EXIT_HANDLER.lock() {
+        Ok(exit) => exit(),
+        Err(_) => default_exit(),
+    }
+}
+
 /// Simple helper to make sure if the code panics in between, raw mode is disabled
 struct RawMode {
     _private: (),