Add support for --automatic.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "swayout"
-version = "1.0.0"
+version = "1.1.0"
 edition = "2021"
 description = "A tool to configure sway outputs"
 authors = ["Stephen Byrne"]

README.md

@@ -23,7 +23,7 @@ monitor "left" make="Goldstar Company Ltd" model="LG HDR 4K" serial="0x0000B9C0"
 monitor "right" make="Goldstar Company Ltd" model="LG HDR 4K" serial="0x0000B9BF"
 
 // When I have "left" and "right" hooked up, I want this layout.
-layout "two4k" {
+layout "two4k" automatic=#true {
     output "left" mode="3840x2160" scale="1.5" x=0 y=0 transform="270"
     output "right" mode="3840x2160" scale="1.5" x=1440 y=1120 transform="normal"
 }
@@ -48,16 +48,12 @@ set $select_layout swayout | tofi | xargs swayout
 bindsym $mod+Shift+m exec $select_layout
 ```
 
-## TODO
+If `swayout` is called with the `--automatic` switch, the first layout with `automatic=#true` for which all outputs
-
+are available is enabled. If no automatic layouts are available, `swayout` exits with code 2.
-Things I might do someday:
-
-### Automatic
-
-Add a `automatic` option to layouts and an `--automatic` flag to `swayout`, and have it automatically enable the
-first layout with `automatic=true` for which all outputs are available.
 
 This could be run by `bindswitch lid:toggle exec swayout --automatic`.
 
+## TODO
+
 How to call when an output is connected or disconnected?
 Wayland events via [wayland_client](https://docs.rs/wayland-client/latest/wayland_client/index.html)?

src/config.rs

@@ -5,16 +5,23 @@ use kdl::KdlDocument;
 /// Configuration for swayout.
 pub struct Config {
     /// Monitor name is independent of output name. It can be anything.
-    pub monitors: HashMap<String, Monitor>,
+    pub monitors: Vec<Monitor>,
     /// Definition of layouts: a map of the layout name to the outputs.
     /// The outputs is a map of the monitor name (in `monitors`) to the configuration
     /// of that monitor for this layout.
     /// Available outputs that do not match a monitor in the map are disabled.
-    pub layouts: HashMap<String, HashMap<String, OutputConfig>>,
+    pub layouts: Vec<Layout>,
+}
+
+pub struct Layout {
+    pub name: String,
+    pub automatic: bool,
+    pub outputs: HashMap<String,OutputConfig>,
 }
 
 /// Defines a monitor by make, model, and serial.
 pub struct Monitor {
+    pub name: String,
     pub make: String,
     pub model: String,
     pub serial: String,
@@ -44,31 +51,31 @@ pub fn get_config() -> Config {
     } else {
         // no config files, use an empty rules
         Config {
-            monitors: HashMap::new(),
+            monitors: Vec::new(),
-            layouts: HashMap::new(),
+            layouts: Vec::new(),
         }
     }
 }
 fn parse_config(kdl:String) -> Config {
     let doc:KdlDocument = kdl.parse().expect("failed to parse config KDL");
 
-    let monitors:HashMap<String,Monitor> = doc.nodes().iter()
+    let monitors:Vec<Monitor> = doc.nodes().iter()
         .filter(|node| node.name().value() == "monitor")
         .map(|monitor_node| {
-            let name = String::from(monitor_node[0].as_string().unwrap());
+            Monitor {
-            let monitor = Monitor {
+                name : String::from(monitor_node[0].as_string().unwrap()),
                 make : String::from(monitor_node["make"].as_string().unwrap()),
                 model : String::from(monitor_node["model"].as_string().unwrap()),
                 serial : String::from(monitor_node["serial"].as_string().unwrap()),
-            };
+            }
-            (name, monitor)
         })
         .collect();
 
-    let layouts:HashMap<String,HashMap<String,OutputConfig>> = doc.nodes().iter()
+    let layouts:Vec<Layout> = doc.nodes().iter()
         .filter(|node| node.name().value() == "layout")
         .map(|layout_node| {
             let layout_name = String::from(layout_node[0].as_string().unwrap());
+            let automatic = layout_node.get("automatic").is_some_and(|v| v.as_bool().is_some_and(|a| a));
             let monitor_name_to_output_config:HashMap<String,OutputConfig> = layout_node
                 .children().unwrap().nodes().iter()
                 .map(|output_node| {
@@ -83,7 +90,11 @@ fn parse_config(kdl:String) -> Config {
                     (output, output_config)
                 })
                 .collect();
-            (layout_name,monitor_name_to_output_config)
+            Layout {
+                name : layout_name,
+                automatic: automatic,
+                outputs: monitor_name_to_output_config
+            }
         })
         .collect();
 

src/lib.rs

@@ -1,10 +1,10 @@
 use std::collections::HashMap;
 
 mod config;
-use crate::config::{get_config,OutputConfig};
+use crate::config::{get_config, Config, Layout, OutputConfig};
 
 mod sway;
-use crate::sway::{apply_outputs,get_outputs};
+use crate::sway::{apply_outputs, get_outputs, Output};
 
 /// Determine the available layout names.
 /// Return one layout for each layout defined in the configuration file
@@ -15,41 +15,27 @@ fn get_layouts() -> Vec<String> {
     let available_outputs = get_outputs();
     let config = get_config();
 
-    // Get the names of monitors that are available (that match an available output)
-    let available_monitor_names:Vec<&String> = config.monitors.iter()
-        .filter(|(_monitor_name,monitor)|
-            available_outputs.iter().any(|output|
-                monitor.make == output.make
-                    && monitor.model == output.model
-                    && output.serial == monitor.serial
-            )
-        )
-        .map(|(monitor_name,_monitor)| monitor_name)
-        .collect();
 
     let mut layout_names: Vec<String> = Vec::new();
 
     // Add each layout defined in the config file for which all outputs are available
-    config.layouts.iter().for_each(|(layout_name, layout)| {
+    get_available_layouts(&config, &available_outputs)
-        if layout
+        .iter()
-            .iter()
+        .for_each(|layout| {
-            .all(|(output_name, _output)| available_monitor_names.contains(&output_name))
+            layout_names.push(String::from(&layout.name));
-        {
+        });
-            layout_names.push(String::from(layout_name))
-        }
-    });
 
     // add each individual output (by monitor name if the monitor is defined, else by output name)
     available_outputs.iter().for_each(|output| {
         // if there is a monitor for the output, use the monitor name, else use the output name
         let monitor_opt = config.monitors.iter()
-            .find(|(_monitor_name, monitor)| {
+            .find(|monitor| {
                 monitor.make == output.make
                     && monitor.model == output.model
                     && monitor.serial == output.serial
             });
-        if let Some((monitor_name, _monitor)) = monitor_opt {
+        if let Some(monitor) = monitor_opt {
-            layout_names.push(String::from(monitor_name));
+            layout_names.push(String::from(&monitor.name));
         } else {
             layout_names.push(String::from(&output.name));
         }
@@ -58,6 +44,38 @@ fn get_layouts() -> Vec<String> {
     layout_names
 }
 
+/// Get the names of monitors that are available (that match an available output)
+fn get_available_monitor_names<'a,'b>(config:&'a Config, available_outputs:&'b Vec<Output>) -> Vec<&'a String> {
+    config.monitors.iter()
+        .filter(|monitor|
+            available_outputs.iter().any(|output|
+                monitor.make == output.make
+                    && monitor.model == output.model
+                    && output.serial == monitor.serial
+            )
+        )
+        .map(|monitor| &monitor.name)
+        .collect()
+}
+
+/// Get the layouts for which all monitors are available.
+fn get_available_layouts<'a,'b>(config:&'a Config, available_outputs:&'b Vec<Output>) -> Vec<&'a Layout> {
+    let available_monitor_names:Vec<&String> = get_available_monitor_names(&config, available_outputs);
+
+    let mut layouts: Vec<&'a Layout> = Vec::new();
+
+    // Add each layout defined in the config file for which all outputs are available
+    config.layouts.iter().for_each(|layout| {
+        if layout.outputs.iter()
+            .all(|(output_name, _output)| available_monitor_names.contains(&output_name))
+        {
+            layouts.push(&layout);
+        }
+    });
+
+    layouts
+}
+
 /// Print the name of each layout to standard out, one per line
 pub fn print_layout_names() {
     get_layouts().iter().for_each(|layout| println!("{layout}"))
@@ -75,11 +93,10 @@ pub fn apply_layout(layout_name: &String) {
     let mut output_config_map: HashMap<&String, &OutputConfig> = HashMap::new();
 
     // First check if the layout is defined in the rules
-    let opt_layout = rules.layouts.get(layout_name);
+    if let Some(layout) = rules.layouts.iter().find(|layout| &layout.name == layout_name) {
-    if let Some(layout) = opt_layout {
         // The layout is defined in the rules.
-        layout.iter().for_each(|(monitor_name, output_config)| {
+        layout.outputs.iter().for_each(|(monitor_name, output_config)| {
-            let monitor = &rules.monitors[monitor_name];
+            let monitor = &rules.monitors.iter().find(|monitor| &monitor.name == monitor_name).unwrap();
 
             // find the output for the monitor to get the output name.
             let output_opt = outputs.iter().find(|output| {
@@ -96,7 +113,7 @@ pub fn apply_layout(layout_name: &String) {
     } else {
         // The layout is not defined in the rules.
         // See if it is a monitor name...
-        if let Some(monitor) = rules.monitors.get(layout_name) {
+        if let Some(monitor) = rules.monitors.iter().find(|monitor| &monitor.name == layout_name) {
             // It is a monitor name. Find the matching output...
             if let Some(output) = outputs.iter().find(|output| {
                 output.make == monitor.make && output.model == monitor.model
@@ -119,3 +136,19 @@ pub fn apply_layout(layout_name: &String) {
 
     apply_outputs(&outputs, &output_config_map);
 }
+
+/// Apply the first automatic layout for which all outputs are available.
+/// Return the name of the layout applied or None if no automatic layout was available.
+pub fn apply_automatic() -> Option<String> {
+    let config = get_config();
+    let outputs = get_outputs();
+
+    if let Some(layout) = get_available_layouts(&config, &outputs)
+        .iter()
+        .find(|layout| layout.automatic) {
+        apply_layout(&layout.name);
+        Some(String::from(&layout.name))
+    } else {
+        None
+    }
+}

src/main.rs

@@ -1,4 +1,4 @@
-use std::env;
+use std::{env, process};
 
 fn main() {
     let args: Vec<String> = env::args().collect();
@@ -6,8 +6,19 @@ fn main() {
         // first arg is executable
         swayout::print_layout_names();
     } else if args.len() == 2 {
-        swayout::apply_layout(&args[1]);
+        let arg = &args[1];
+        if arg == "--automatic" {
+            if let Some(layout_name) = swayout::apply_automatic() {
+                println!("{}", layout_name);
+            } else {
+                eprintln!("no automatic layout available");
+                process::exit(2)
+            }
+        } else {
+            swayout::apply_layout(&args[1]);
+        }
     } else {
-        panic!("Usage: {} [layout]", args[0].as_str());
+        eprintln!("Usage: {} [layout]", args[0].as_str());
+        process::exit(1)
     }
 }