debug: Add dbus interface to control debug prints

Cargo.deps

@@ -1,6 +1,10 @@
 # Dependencies which change based on build flags
 bitflags = "1.2.*"
 clap = { version = "2.33.*", default-features = false }
+zbus = "1.0.*"
+zvariant = "2.0.*"
+# Newer versions seem to confuse the version of Cargo on Debian Bullseye
+zvariant_derive = "2.0.*"
 
 [dependencies.cairo-rs]
 version = "0.7.*"

debian/control

@@ -23,6 +23,7 @@ Build-Depends:
  librust-serde-derive-1-dev (>= 1.0),
  librust-serde-yaml-0.8-dev (>= 0.8),
  librust-xkbcommon-0.4+wayland-dev (>= 0.4),
+ librust-zbus-dev (>=1.0),
  libwayland-dev (>= 1.16),
  lsb-release,
  python3,

src/debug.rs

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2022 Purism SPC
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+use std::thread;
+use zbus::{Connection, ObjectServer, dbus_interface, fdo};
+
+use crate::event_loop;
+use crate::state;
+
+
+use std::convert::TryInto;
+
+
+/// Accepts commands controlling the debug mode
+struct Manager {
+    sender: event_loop::driver::Threaded,
+    enabled: bool,
+}
+
+#[dbus_interface(name = "sm.puri.SqueekDebug")]
+impl Manager {
+    #[dbus_interface(property, name = "Enabled")]
+    fn get_enabled(&self) -> bool {
+        self.enabled
+    }
+    #[dbus_interface(property, name = "Enabled")]
+    fn set_enabled(&mut self, enabled: bool) {
+        self.enabled = enabled;
+        self.sender
+            .send(state::Event::Debug(
+                if enabled { Event::Enable }
+                else { Event::Disable }
+            ))
+            .unwrap();
+    }
+}
+
+fn start(mgr: Manager) -> Result<(), Box<dyn std::error::Error>> {
+    let connection = Connection::new_session()?;
+    fdo::DBusProxy::new(&connection)?.request_name(
+        "sm.puri.SqueekDebug",
+        fdo::RequestNameFlags::ReplaceExisting.into(),
+    )?;
+
+    let mut object_server = ObjectServer::new(&connection);
+    object_server.at(&"/sm/puri/SqueekDebug".try_into()?, mgr)?;
+
+    loop {
+        if let Err(err) = object_server.try_handle_next() {
+            eprintln!("{}", err);
+        }
+    }
+}
+
+pub fn init(sender: event_loop::driver::Threaded) {
+    let mgr = Manager {
+        sender,
+        enabled: false,
+    };
+    thread::spawn(move || {
+        start(mgr).unwrap();
+    });
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum Event {
+    Enable,
+    Disable,
+}

src/lib.rs

@@ -13,6 +13,8 @@ extern crate gtk_sys;
 extern crate maplit;
 extern crate serde;
 extern crate xkbcommon;
+extern crate zbus;
+extern crate zvariant;
 
 #[cfg(test)]
 #[macro_use]
@@ -23,6 +25,7 @@ mod logging;
 mod action;
 mod animation;
 pub mod data;
+mod debug;
 mod drawing;
 mod event_loop;
 pub mod float_ord;

src/main.rs

@@ -4,6 +4,7 @@
 
 /*! Glue for the main loop. */
 use crate::outputs::OutputId;
+use crate::debug;
 use crate::state;
 use glib::{Continue, MainContext, PRIORITY_DEFAULT, Receiver};
 
@@ -94,6 +95,8 @@ mod c {
         let now = Instant::now();
         let state_manager = driver::Threaded::new(sender, state::Application::new(now));
 
+        debug::init(state_manager.clone());
+
         let outputs = Outputs::new(state_manager.clone());
         let mut wayland = Box::new(Wayland::new(outputs));
         let wayland_raw = &mut *wayland as *mut _;

src/state.rs

@@ -6,6 +6,7 @@
  * It's driven by the loop defined in the loop module. */
 
 use crate::animation;
+use crate::debug;
 use crate::imservice::{ ContentHint, ContentPurpose };
 use crate::main::{ Commands, PanelCommand, PixelSize };
 use crate::outputs;
@@ -14,19 +15,20 @@ use std::cmp;
 use std::collections::HashMap;
 use std::time::Instant;
 
-#[derive(Clone, Copy)]
+
+#[derive(Clone, Copy, Debug)]
 pub enum Presence {
     Present,
     Missing,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct InputMethodDetails {
     pub hint: ContentHint,
     pub purpose: ContentPurpose,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum InputMethod {
     Active(InputMethodDetails),
     InactiveSince(Instant),
@@ -34,12 +36,13 @@ pub enum InputMethod {
 
 /// Incoming events.
 /// This contains events that cause a change to the internal state.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum Event {
     InputMethod(InputMethod),
     Visibility(visibility::Event),
     PhysicalKeyboard(Presence),
     Output(outputs::Event),
+    Debug(debug::Event),
     /// Event triggered because a moment in time passed.
     /// Use to animate state transitions.
     /// The value is the ideal arrival time.
@@ -59,7 +62,7 @@ impl From<outputs::Event> for Event {
 }
 
 pub mod visibility {
-    #[derive(Clone)]
+    #[derive(Clone, Debug)]
     pub enum Event {
         /// User requested the panel to show
         ForceVisible,
@@ -79,7 +82,7 @@ pub mod visibility {
 }
 
 /// The outwardly visible state.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Outcome {
     pub visibility: animation::Outcome,
     pub im: InputMethod,
@@ -137,11 +140,12 @@ impl Outcome {
 /// All state changes return the next state and the optimal time for the next check.
 ///
 /// This state tracker can be driven by any event loop.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Application {
     pub im: InputMethod,
     pub visibility_override: visibility::State,
     pub physical_keyboard: Presence,
+    pub debug_mode_enabled: bool,
     /// The output on which the panel should appear.
     /// This is stored as part of the state
     /// because it's not clear how to derive the output from the rest of the state.
@@ -163,13 +167,29 @@ impl Application {
             im: InputMethod::InactiveSince(now),
             visibility_override: visibility::State::NotForced,
             physical_keyboard: Presence::Missing,
+            debug_mode_enabled: false,
             preferred_output: None,
             outputs: Default::default(),
         }
     }
 
-    pub fn apply_event(self, event: Event, _now: Instant) -> Self {
+    pub fn apply_event(self, event: Event, now: Instant) -> Self {
-        match event {
+        if self.debug_mode_enabled {
+            println!(
+                "Received event:
+{:#?}",
+                event,
+            );
+        }
+        let state = match event {
+            Event::Debug(dbg) => Self {
+                debug_mode_enabled: match dbg {
+                    debug::Event::Enable => true,
+                    debug::Event::Disable => false,
+                },
+                ..self
+            },
+
             Event::TimeoutReached(_) => self,
 
             Event::Visibility(visibility) => Self {
@@ -235,7 +255,19 @@ impl Application {
                     ..self
                 },
             }
+        };
+
+        if state.debug_mode_enabled {
+            println!(
+                "State is now:
+{:#?}
+Outcome:
+{:#?}",
+                state,
+                state.get_outcome(now),
+            );
         }
+        state
     }
 
     fn get_preferred_height(output: &OutputState) -> Option<PixelSize> {