feat: got library system loading working

Cargo.lock

@@ -502,6 +502,7 @@ dependencies = [
  "gtk4",
  "gtk4-layer-shell",
  "itertools",
+ "libloading",
  "log",
  "nix",
  "notify",
@@ -1264,6 +1265,16 @@ version = "0.2.174"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1171693293099992e19cddea4e8b849964e9846f4acee11b3948bcc337be8776"
 
+[[package]]
+name = "libloading"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7c4b02199fee7c5d21a5ae7d8cfa79a6ef5bb2fc834d6e9058e89c825efdc55"
+dependencies = [
+ "cfg-if",
+ "windows-link",
+]
+
 [[package]]
 name = "libredox"
 version = "0.1.3"
@@ -2331,6 +2342,12 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "windows-link"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
+
 [[package]]
 name = "windows-sys"
 version = "0.48.0"

crates/ewwii/Cargo.toml

@@ -50,6 +50,8 @@ tokio = { workspace = true, features = ["full"] }
 unescape.workspace = true
 wait-timeout.workspace = true
 rhai.workspace = true
+# Plugin loading
+libloading = "0.8.9"
 
 [dev-dependencies]
 pretty_assertions.workspace = true

crates/ewwii/src/app.rs

@@ -21,14 +21,15 @@ use crate::{
     window_initiator::WindowInitiator,
     *,
 };
-use rhai_impl::parser::ParseConfig;
 use anyhow::{anyhow, bail};
 use gdk::Monitor;
 use gtk4::Window;
 use gtk4::{gdk, glib};
 use itertools::Itertools;
+use once_cell::sync::OnceCell;
 use rhai::Dynamic;
 use rhai_impl::ast::WidgetNode;
+use rhai_impl::parser::ParseConfig;
 use serde::{de::Error as SerdeError, Deserialize, Deserializer};
 use std::{
     cell::{Cell, RefCell},
@@ -39,6 +40,13 @@ use std::{
 };
 use tokio::sync::mpsc::UnboundedSender;
 
+static ACTIVE_PLUGIN: OnceCell<libloading::Library> = OnceCell::new();
+
+fn set_active_plugin(lib: libloading::Library) {
+    // will panic if called more than once
+    ACTIVE_PLUGIN.set(lib).unwrap();
+}
+
 /// A command for the ewwii daemon.
 /// While these are mostly generated from ewwii CLI commands (see [`opts::ActionWithServer`]),
 /// they may also be generated from other places internally.
@@ -90,6 +98,10 @@ pub enum DaemonCommand {
         print: bool,
         sender: DaemonResponseSender,
     },
+    SetPlugin {
+        file_path: String,
+        sender: DaemonResponseSender,
+    },
 }
 
 /// An opened window.
@@ -366,6 +378,12 @@ impl<B: DisplayBackend> App<B> {
                     Err(e) => sender.send_failure(e.to_string())?,
                 };
             }
+            DaemonCommand::SetPlugin { file_path, sender } => {
+                match self.set_ewwii_plugin(file_path) {
+                    Ok(_) => sender.send_success(String::new())?,
+                    Err(e) => sender.send_failure(e.to_string())?,
+                }
+            }
         }
         Ok(())
     }
@@ -483,7 +501,7 @@ impl<B: DisplayBackend> App<B> {
             // so I guess that I will just let it stay right here.
             let config_path = self.paths.get_rhai_path();
             let compiled_ast = self.ewwii_config.get_owned_compiled_ast();
-            
+
             {
                 let mut stored_parser = self.config_parser.borrow_mut();
                 stored_parser.set_opt_level(get_opt_level_from(
@@ -799,6 +817,30 @@ impl<B: DisplayBackend> App<B> {
 
         Ok(())
     }
+
+    pub fn set_ewwii_plugin(&mut self, file_path: String) -> Result<()> {
+        let lib = unsafe {
+            libloading::Library::new(file_path)
+                .map_err(|e| anyhow!("Failed to load plugin: {}", e))?
+        };
+
+        unsafe {
+            // Each plugin exposes: extern "C" fn create_plugin() -> Box<dyn Plugin>
+            let constructor: libloading::Symbol<
+                unsafe extern "C" fn() -> Box<dyn ewwii_plugin_api::Plugin>,
+            > = lib
+                .get(b"create_plugin")
+                .map_err(|e| anyhow!("Failed to find create_plugin: {}", e))?;
+
+            let plugin = constructor(); // instantiate plugin
+            let host = crate::plugin::EwwiiImpl;
+            plugin.init(&host); // call init immediately
+
+            set_active_plugin(lib); // keep library alive
+        }
+
+        Ok(())
+    }
 }
 
 #[derive(Deserialize, Debug)]

crates/ewwii/src/config/ewwii_config.rs

@@ -15,7 +15,10 @@ use rhai_impl::{ast::WidgetNode, parser::ParseConfig};
 
 /// Load an [`EwwiiConfig`] from the config dir of the given [`crate::EwwiiPaths`],
 /// resetting and applying the global YuckFiles object in [`crate::error_handling_ctx`].
-pub fn read_from_ewwii_paths(eww_paths: &EwwiiPaths, parser: &mut ParseConfig) -> Result<EwwiiConfig> {
+pub fn read_from_ewwii_paths(
+    eww_paths: &EwwiiPaths,
+    parser: &mut ParseConfig,
+) -> Result<EwwiiConfig> {
     EwwiiConfig::read_from_dir(eww_paths, parser)
 }
 

crates/ewwii/src/main.rs

@@ -48,6 +48,7 @@ mod gen_diagnostic_macro;
 mod ipc_server;
 mod opts;
 mod paths;
+mod plugin;
 mod server;
 mod util;
 mod widgets;

crates/ewwii/src/opts.rs

@@ -217,6 +217,14 @@ pub enum ActionWithServer {
         #[arg(long = "sprint", short = 'p')]
         print: bool,
     },
+
+    /// Set a plugin (.so) to the ewwii binary
+    #[command(name = "set-plugin")]
+    SetPlugin {
+        /// The .so file to load
+        #[arg(value_parser = absolute_file_path_parser)]
+        file_path: String,
+    },
 }
 
 impl Opt {
@@ -355,6 +363,12 @@ impl ActionWithServer {
                     sender,
                 })
             }
+            ActionWithServer::SetPlugin { file_path } => {
+                return with_response_channel(|sender| app::DaemonCommand::SetPlugin {
+                    file_path,
+                    sender,
+                })
+            }
         };
         (command, None)
     }
@@ -431,3 +445,10 @@ fn parse_inject_var_map(s: &str) -> Result<HashMap<String, String>, String> {
     }
     Ok(map)
 }
+
+fn absolute_file_path_parser(s: &str) -> Result<String, String> {
+    let p = std::path::Path::new(s);
+    std::fs::canonicalize(p)
+        .map_err(|e| format!("Failed to canonicalize '{}': {}", s, e))
+        .map(|abs_path| abs_path.to_string_lossy().into_owned())
+}

crates/ewwii/src/plugin.rs

@@ -1,19 +1,13 @@
-use ewwii_plugin_api::{EwwiiAPI, Plugin};
+use ewwii_plugin_api::EwwiiAPI;
+use rhai::Engine;
+use rhai_impl::parser::ParseConfig;
+use std::sync::{Arc, RwLock};
 
 pub struct EwwiiImpl;
 
-impl HostAPI for EwwiiImpl {
-	// General
+impl EwwiiAPI for EwwiiImpl {
+    // General
     fn log(&self, msg: &str) {
         println!("[HOST LOG] {}", msg);
     }
-
-    // Rhai Engine Stuff
-    fn get_rhai_engine(&self) {
-
-    }
-
-    fn set_rhai_engine(&self, engine: &Engine) {
-
-    }
 }

crates/ewwii/src/server.rs

@@ -98,7 +98,7 @@ pub fn initialize_server<B: DisplayBackend>(
         widget_reg_store: std::rc::Rc::new(std::sync::Mutex::new(None)),
         pl_handler_store: None,
         rt_engine_config: EngineConfValues::default(),
-        config_parser: config_parser,
+        config_parser,
         paths,
         gtk_main_loop: main_loop.clone(),
         phantom: PhantomData,

crates/ewwii_plugin_api/src/lib.rs

@@ -1,13 +1,7 @@
-use rhai::Engine;
-
 /// The shared trait defining the Ewwii plugin API
 pub trait EwwiiAPI: Send + Sync {
     // General stuff
     fn log(&self, msg: &str);
-
-    // Rhai Manipulation Stuff
-    fn get_rhai_engine(&self) -> &mut Engine;
-    fn set_rhai_engine(&self, engine: &Engine);
 }
 
 /// The API format that the plugin should follow