1 files changed, 184 insertions, 0 deletions
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..7eb4a41
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,184 @@
+use std::fs;
+use std::io;
+use std::path::{Path, PathBuf};
+use std::process::{Command, Child, Stdio};
+use std::sync::{Mutex, Arc};
+use systray;
+use dialog::{self, DialogBox};
+use tempfile::tempdir;
+use crate::error::*;
+
+mod error;
+
+const ICON_EXCLAM_PNG: &[u8] = include_bytes!("../resources/exclam.png");
+const ICON_OK_PNG: &[u8] = include_bytes!("../resources/ok.png");
+
+fn join(sep: &str, v: &[String]) -> String {
+    let mut res = String::new();
+    let mut first = true;
+    for item in v {
+        if first { first = false; }
+        else { res.push_str(sep); }
+        res.push_str(item);
+    }
+    res
+}
+
+struct State {
+    // Child is 'cat >/dev/null', with stdin piped.
+    // Close stdin to terminate.
+    inhibitor: Option<(Child, Vec<String>)>,
+    ok_path: String,
+    exclam_path: String,
+}
+
+impl State {
+    fn new(ok_path: &str, exclam_path: &str) -> State {
+        State {
+            inhibitor: None,
+            ok_path: ok_path.to_string(),
+            exclam_path: exclam_path.to_string(),
+        }
+    }
+
+    fn what_inhibited(&self) -> Option<&[String]> {
+        match &self.inhibitor {
+            Some((_, v)) => Some(v),
+            None => None,
+        }
+    }
+
+    fn inhibit(&mut self, what: &[String]) -> io::Result<()> {
+        self.uninhibit()?;
+
+        let mut whatarg = "--what=".to_string();
+        whatarg.push_str(&join(":", what));
+
+        let child = Command::new("systemd-inhibit")
+                        .arg(whatarg)
+                        .arg("--who=Tom's acpi-inhibitor")
+                        .arg("--why=User request")
+                        .arg("cat")
+                        .stdin(Stdio::piped())
+                        .stdout(Stdio::null())
+                        .spawn()?;
+        self.inhibitor = Some((child, what.to_vec()));
+
+        Ok(())
+    }
+
+    fn uninhibit(&mut self) -> io::Result<()> {
+        if let Some((ch, _)) = &mut self.inhibitor {
+            // This automatically closes the child's stdin
+            ch.wait()?;
+            self.inhibitor = None;
+        }
+
+        Ok(())
+    }
+
+    fn poll(&mut self) -> io::Result<()> {
+        if let Some((ch, _)) = &mut self.inhibitor {
+            if ch.try_wait()?.is_some() {
+                self.inhibitor = None;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+fn show_dialog(title: &str, body: &str) -> io::Result<()> {
+    dialog::Message::new(body).title(title).show()
+        .map_err(|e| io::Error::new(io::ErrorKind::Other, format!("{}", e)))
+}
+
+fn status_message(state: &mut State) -> io::Result<String> {
+    state.poll()?;
+
+    let mut msg;
+    match state.what_inhibited() {
+        Some(what) => {
+            msg = "Currently inhibiting: ".to_string();
+            msg.push_str(&join(", ", what));
+        }
+        None => {
+            msg = "Currently functioning normally (not inhibited)".to_string();
+        }
+    }
+
+    Ok(msg)
+}
+
+fn update_icon(app: &mut systray::Application, state: &mut State) -> io::Result<()> {
+    match state.what_inhibited() {
+        Some(_) => app.set_icon_from_file(&state.exclam_path).iores(),
+        None => app.set_icon_from_file(&state.ok_path).iores(),
+    }
+}
+
+fn materialise_icon(dir: &Path, fname: &str, bytes: &[u8]) -> io::Result<PathBuf> {
+    let mut pathbuf = dir.to_path_buf();
+    pathbuf.push(fname);
+    fs::write(&pathbuf, bytes)?;
+    Ok(pathbuf)
+}
+
+fn main() -> io::Result<()> {
+    let resources_dir = tempdir()?;
+    let resources_path = resources_dir.path();
+
+    let icon_ok_path = materialise_icon(&resources_path, "ok.png", ICON_OK_PNG)?;
+    let icon_exclam_path = materialise_icon(&resources_path, "exclam.png", ICON_EXCLAM_PNG)?;
+
+    let mut app = systray::Application::new().iores()?;
+
+    let state = Arc::new(Mutex::new(State::new(
+        icon_ok_path.to_str().unwrap(),
+        icon_exclam_path.to_str().unwrap()
+    )));
+
+    app.set_icon_from_file(icon_ok_path.to_str().unwrap()).iores()?;
+
+    {
+        let state = state.clone();
+        app.add_menu_item("Status", move |window| {
+            let mut state = state.as_ref().lock().unwrap();
+            let msg = status_message(&mut state)?;
+            update_icon(window, &mut state)?;
+            show_dialog("acpi-inhibitor status", &msg)
+        }).iores()?;
+    }
+
+    app.add_menu_separator().iores()?;
+
+    macro_rules! switcher_menu {
+        ($label:expr, $keys:expr) => {{
+            let state = state.clone();
+            app.add_menu_item($label, move |mut window| {
+                let mut state = state.as_ref().lock().unwrap();
+                let keys = $keys;
+                if state.what_inhibited() == Some(keys) {
+                    state.uninhibit()?;
+                } else {
+                    state.inhibit(keys)?;
+                }
+                update_icon(&mut window, &mut state)?;
+                Ok::<_, io::Error>(())
+            }).iores()?;
+        }}
+    }
+
+    switcher_menu!("Shutdown/sleep/idle", &["shutdown".to_string(), "sleep".to_string(), "idle".to_string()]);
+
+    switcher_menu!("Lid switch", &["handle-lid-switch".to_string()]);
+
+    app.add_menu_separator().iores()?;
+
+    app.add_menu_item("Quit", |window| {
+        window.quit();
+        Ok::<_, systray::Error>(())
+    }).iores()?;
+
+    app.wait_for_message().iores()
+}