Add always_switch optional config for Acer monitors that don't correctly report they are on the usb-c input

LICENSE

@@ -1,6 +1,7 @@
 MIT License
 
 Copyright (c) 2020 Haim Gelfenbeyn
+Copyright (c) 2024 Luke Nuttall
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -30,7 +30,8 @@ Configuration file settings:
 ```ini
   usb_device = "1050:0407"
   on_usb_connect = "Hdmi1"
-  on_usb_disconnect = "Hdmi2"
+  on_usb_disconnect = "Hdmi2"  
+  always_switch = true
 ```
 
 `usb_device` is which USB device to watch (vendor id / device id in hex), and `on_usb_connect` is which monitor input
@@ -42,6 +43,10 @@ The optional `on_usb_disconnect` settings allows to switch in the other directio
 Note that the preferred way is to have this app installed on both computers. Switching "away" is problematic: if the
 other computer has put the monitors to sleep, they will switch immediately back to the original input.
 
+The optional `always_switch` setting can be used to attempt to switch even if the monitor reports that it currently
+on the input we want to switch to. This is useful for Acer monitors like the XR343CRK, which pretend they are still
+connected to `DisplayPort1` or `0xF`, when you switch to USB-C using `DisplayPort2` or `0x10`.
+
 ### Different inputs on different monitors
 `display-switch` supports per-monitor configuration: add one or more monitor-specific configuration sections to set
 monitor-specific inputs. For example:

src/configuration.rs

@@ -1,5 +1,6 @@
 //
 // Copyright © 2020 Haim Gelfenbeyn
+// Copyright © 2020 Luke Nuttall
 // This code is licensed under MIT license (see LICENSE.txt for details)
 //
 
@@ -35,6 +36,9 @@ struct PerMonitorConfiguration {
 pub struct Configuration {
     #[serde(deserialize_with = "Configuration::deserialize_usb_device")]
     pub usb_device: String,
+    #[serde(default)]
+    #[serde(deserialize_with = "Configuration::deserialize_always_switch")]
+    pub always_switch: bool,
     #[serde(flatten)]
     pub default_input_sources: InputSources,
     monitor1: Option<PerMonitorConfiguration>,
@@ -108,6 +112,14 @@ impl Configuration {
         Ok(s.to_lowercase())
     }
 
+    fn deserialize_always_switch<'de, D>(deserializer: D) -> Result<bool, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let b: bool = Deserialize::deserialize(deserializer)?;
+        Ok(b)
+    }
+
     pub fn config_file_name() -> Result<std::path::PathBuf> {
         let config_dir = if cfg!(target_os = "macos") {
             dirs::preference_dir().ok_or_else(|| anyhow!("Config directory not found"))?
@@ -198,6 +210,45 @@ mod tests {
         assert_eq!(config.usb_device, "dead:beef")
     }
 
+    #[test]
+    fn test_always_switch_is_true_deserialization() {
+        let config = load_test_config(
+            r#"
+            usb_device = "dead:BEEF"
+            always_switch = true
+            on_usb_connect = "DisplayPort2"
+        "#,
+        )
+        .unwrap();
+        assert_eq!(config.always_switch, true)
+    }
+
+    #[test]
+    fn test_always_switch_is_false_deserialization() {
+        let config = load_test_config(
+            r#"
+            usb_device = "dead:BEEF"
+            always_switch = false
+            on_usb_connect = "DisplayPort2"
+        "#,
+        )
+        .unwrap();
+        assert_eq!(config.always_switch, false)
+    }
+
+    #[test]
+    fn test_always_switch_defaults_to_false_deserialization() {
+        let config = load_test_config(
+            r#"
+            usb_device = "dead:BEEF"
+            on_usb_connect = "DisplayPort2"
+        "#,
+        )
+        .unwrap();
+        assert_eq!(config.always_switch, false)
+    }
+
+
     #[test]
     fn test_symbolic_input_deserialization() {
         let config = load_test_config(

src/display_control.rs

@@ -1,5 +1,6 @@
 //
 // Copyright © 2020 Haim Gelfenbeyn
+// Copyright © 2024 Luke Nuttall
 // This code is licensed under MIT license (see LICENSE.txt for details)
 //
 use crate::configuration::{Configuration, SwitchDirection};
@@ -47,12 +48,16 @@ fn are_display_names_unique(displays: &[Display]) -> bool {
     displays.iter().all(|display| hash.insert(display_name(display, None)))
 }
 
-fn try_switch_display(handle: &mut Handle, display_name: &str, input: InputSource) {
+fn try_switch_display(handle: &mut Handle, display_name: &str, input: InputSource, always_switch: bool) {
     match handle.get_vcp_feature(INPUT_SELECT) {
         Ok(raw_source) => {
             if raw_source.value() & 0xff == input.value() {
                 info!("Display {} is already set to {}", display_name, input);
-                return;
+                if always_switch {
+                    info!("Let's try anyway!");
+                } else {
+                    return;
+                }
             }
         }
         Err(err) => {
@@ -121,7 +126,7 @@ pub fn switch(config: &Configuration, switch_direction: SwitchDirection) {
         let input_sources = config.configuration_for_monitor(&display_name);
         debug!("Input sources found for display {}: {:?}", display_name, input_sources);
         if let Some(input) = input_sources.source(switch_direction) {
-            try_switch_display(&mut display.handle, &display_name, input);
+            try_switch_display(&mut display.handle, &display_name, input, config.always_switch);
         } else {
             info!(
                 "Display {} is not configured to switch on USB {}",