Codify dialog exit statuses and make them less error-prone

dialog-gtk3/src/main.rs

@@ -4,9 +4,9 @@ use gethostname::gethostname;
 use glib::{GString, clone, SourceId};
 use gtk::{prelude::*, Button, Entry, Label, Plug, Window};
 use log::{debug, error, warn};
-use std::{io::{self, Write}, process::exit, thread, time::Duration};
+use std::{io::{self, Write}, thread, time::Duration};
 
-use bscreensaver_util::{init_logging, settings::Configuration, desktop::NewLoginCommand};
+use bscreensaver_util::{init_logging, DialogExitStatus, settings::Configuration, desktop::NewLoginCommand};
 
 const DIALOG_UPDATE_INTERVAL: Duration = Duration::from_millis(100);
 const DIALOG_TIMEOUT: Duration = Duration::from_secs(60);
@@ -70,7 +70,7 @@ fn main() -> anyhow::Result<()> {
                 let plug_window = match plug.window().unwrap().downcast::<X11Window>() {
                     Err(err) => {
                         error!("Failed to find XID of unlock dialog window: {}", err);
-                        exit(2);
+                        DialogExitStatus::OtherError.exit();
                     },
                     Ok(w) => w,
                 };
@@ -85,7 +85,7 @@ fn main() -> anyhow::Result<()> {
                 let mut out_locked = out.lock();
                 if let Err(err) = out_locked.write_all(&xid_buf).and_then(|_| out_locked.flush()) {
                     error!("Failed to write XID to stdout: {}", err);
-                    exit(2);
+                    DialogExitStatus::OtherError.exit();
                 };
             });
 
@@ -102,7 +102,7 @@ fn main() -> anyhow::Result<()> {
     // an examination of the gtk source suggesting that the header should send
     // a delete-event to the toplevel (which should be the plug) when the close
     // button is clicked.  For some reason, though, we never get the delete-event.
-    dialog.connect_delete_event(|_, _| exit(1));
+    dialog.connect_delete_event(|_, _| DialogExitStatus::AuthCanceled.exit());
     dialog.connect_realize(|_| debug!("DIALOG REALIZED"));
     dialog.connect_map(|_| debug!("DIALOG MAPPED"));
     dialog.connect_unmap(|_| debug!("DIALOG UNMAPPED"));
@@ -164,14 +164,14 @@ fn main() -> anyhow::Result<()> {
         .build();
     vbox.pack_start(&auth_status_label, false, false, 0);
 
-    rx.attach(None, clone!(@strong auth_status_label => move |(exit_status, auth_dots_id): (i32, SourceId)| {
+    rx.attach(None, clone!(@strong auth_status_label => move |(exit_status, auth_dots_id): (DialogExitStatus, SourceId)| {
         auth_dots_id.remove();
-        if exit_status != 0 {
+        if exit_status != DialogExitStatus::AuthSucceeded {
             auth_status_label.set_label("Authentication Failed!");
             auth_status_label.set_opacity(1.0);
-            glib::timeout_add_seconds_local_once(1, move || exit(exit_status));
+            glib::timeout_add_seconds_local_once(1, move || exit_status.exit());
         } else {
-            exit(exit_status);
+            exit_status.exit();
         }
         glib::Continue(true)
     }));
@@ -232,7 +232,7 @@ fn main() -> anyhow::Result<()> {
     hbox.pack_start(&password_box, true, true, 8);
     password_box.connect_key_press_event(|_, ev| {
         if ev.keyval().name() == Some(GString::from("Escape")) {
-            exit(1);
+            DialogExitStatus::AuthCanceled.exit();
         }
         gtk::Inhibit(false)
     });
@@ -254,7 +254,7 @@ fn main() -> anyhow::Result<()> {
                 if let Err(err) = new_login_command.run() {
                     warn!("Failed to run new login command: {}", err);
                 } else {
-                    exit(1);
+                    DialogExitStatus::OtherError.exit();
                 }
             });
         });
@@ -282,13 +282,13 @@ fn main() -> anyhow::Result<()> {
         let tx = tx.clone();
         thread::spawn(move || {
             let status = if authenticate(&username, &password) {
-                0
+                DialogExitStatus::AuthSucceeded
             } else {
-                -1
+                DialogExitStatus::AuthFailed
             };
             if let Err(err) = tx.send((status, auth_dots_id)) {
                 error!("Failed to send exit status to main thread: {}", err);
-                exit(2);
+                DialogExitStatus::OtherError.exit();
             }
         });
     }));
@@ -309,7 +309,7 @@ fn main() -> anyhow::Result<()> {
     glib::timeout_add_local(DIALOG_UPDATE_INTERVAL, clone!(@strong timer => move || {
         let new_fraction = timer.fraction() - delta;
         if new_fraction <= 0.0 {
-            exit(1);
+            DialogExitStatus::AuthTimedOut.exit();
         }
         timer.set_fraction(new_fraction);
         Continue(true)

util/src/lib.rs

@@ -6,6 +6,22 @@ pub mod settings;
 
 pub const BSCREENSAVER_WM_CLASS: &[u8] = b"bscreensaver\0Bscreensaver\0";
 
+#[repr(i32)]
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum DialogExitStatus {
+    AuthFailed = -1,
+    AuthSucceeded = 0,
+    AuthCanceled = 1,
+    AuthTimedOut = 2,
+    OtherError = 3,
+}
+
+impl DialogExitStatus {
+    pub fn exit(&self) -> ! {
+        std::process::exit(*self as i32);
+    }
+}
+
 pub fn init_logging(env_name: &str) {
     env_logger::builder()
         .format_timestamp_millis()