Fix detection of initial rotation state

This ensures that if rot8 starts while the window server output is
rotated, but the physical device is in a "normal" position, rot8 will
detect the initial misalignment and rotate the window server's output to
reflect the device's physical state.

This scenario occurs if you frequently toggle rot8 on and off as form of
rotation lock, and you:

1. Use rot8 to rotate the output sideways
2. Turn rot8 off
3. Move the physical device back into a "normal" position
4. Turn rot8 back on

Cargo.lock

@@ -1,5 +1,13 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "aho-corasick"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
@@ -42,16 +50,47 @@ name = "glob"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "itoa"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "libc"
 version = "0.2.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "memchr"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "numtoa"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "proc-macro2"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.54"
@@ -65,12 +104,64 @@ dependencies = [
  "redox_syscall 0.1.54 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "regex"
+version = "1.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "rot8"
 version = "0.1.1"
 dependencies = [
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "glob 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "ryu"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "serde"
+version = "1.0.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "serde_derive 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.99"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ryu 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -78,6 +169,16 @@ name = "strsim"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "syn"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "termion"
 version = "1.5.2"
@@ -97,11 +198,24 @@ dependencies = [
  "unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "thread_local"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "unicode-width"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "unicode-xid"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "vec_map"
 version = "0.8.1"
@@ -127,19 +241,34 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
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 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
 "checksum clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5067f5bb2d80ef5d68b4c87db81601f0b75bca627bc2ef76b141d7b846a3c6d9"
 "checksum glob 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+"checksum itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
+"checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
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Cargo.toml

@@ -11,5 +11,8 @@ keywords = ["sway", "x11", "display", "rotation"]
 edition = "2018"
 
 [dependencies]
-glob = "0.3"
 clap = "2.33"
+glob = "0.3"
+regex = "1"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"

src/main.rs

@@ -1,37 +1,107 @@
 extern crate clap;
 extern crate glob;
+extern crate regex;
+
 use clap::{App, Arg};
 use glob::glob;
+use serde::Deserialize;
 use std::fs;
 use std::process::Command;
 use std::thread;
 use std::time::Duration;
 
-enum BackendMode {
+enum Backend {
     Sway,
     Xorg,
 }
 
+#[derive(Deserialize)]
+struct SwayOutput {
+    name: String,
+    transform: String,
+}
+
+fn get_window_server_rotation_state(display: &str, backend: &Backend) -> Result<String, String> {
+    match backend {
+        Backend::Sway => {
+            let raw_rotation_state = String::from_utf8(
+                Command::new("swaymsg")
+                    .arg("-t")
+                    .arg("get_outputs")
+                    .arg("--raw")
+                    .output()
+                    .expect("Swaymsg get outputs command failed to start")
+                    .stdout,
+            )
+            .unwrap();
+            let deserialized: Vec<SwayOutput> = serde_json::from_str(&raw_rotation_state)
+                .expect("Unable to deserialize swaymsg JSON output");
+            for output in deserialized {
+                if output.name == display {
+                    return Ok(output.transform);
+                }
+            }
+
+            return Err(format!(
+                "Unable to determine rotation state: display {} not found in 'swaymsg -t get_outputs'",
+                display
+            )
+            .to_owned());
+        }
+        Backend::Xorg => {
+            let raw_rotation_state = String::from_utf8(
+                Command::new("xrandr")
+                    .output()
+                    .expect("Xrandr get outputs command failed to start")
+                    .stdout,
+            )
+            .unwrap();
+            let xrandr_output_pattern = regex::Regex::new(format!(
+                    r"^{} connected .+? .+? (normal |inverted |left |right )?\(normal left inverted right x axis y axis\) .+$",
+                    regex::escape(display),
+            ).as_str()).unwrap();
+            for xrandr_output_line in raw_rotation_state.split("\n") {
+                if !xrandr_output_pattern.is_match(xrandr_output_line) {
+                    continue;
+                }
+
+                let xrandr_output_captures =
+                    xrandr_output_pattern.captures(xrandr_output_line).unwrap();
+                if let Some(transform) = xrandr_output_captures.get(1) {
+                    return Ok(transform.as_str().to_owned());
+                } else {
+                    return Ok("normal".to_owned());
+                }
+            }
+
+            return Err(format!(
+                "Unable to determine rotation state: display {} not found in xrandr output",
+                display
+            )
+            .to_owned());
+        }
+    }
+}
+
 fn main() -> Result<(), String> {
-    let mut old_state = "normal";
     let mut new_state: &str;
     let mut path_x: String = "".to_string();
     let mut path_y: String = "".to_string();
     let mut matrix: [&str; 9];
     let mut x_state: &str;
 
-    let mode = if String::from_utf8(Command::new("pidof").arg("sway").output().unwrap().stdout)
+    let backend = if String::from_utf8(Command::new("pidof").arg("sway").output().unwrap().stdout)
         .unwrap()
         .len()
         >= 1
     {
-        BackendMode::Sway
+        Backend::Sway
     } else if String::from_utf8(Command::new("pidof").arg("Xorg").output().unwrap().stdout)
         .unwrap()
         .len()
         >= 1
     {
-        BackendMode::Xorg
+        Backend::Xorg
     } else {
         return Err("Unable to find Sway or Xorg procceses".to_owned());
     };
@@ -66,6 +136,8 @@ fn main() -> Result<(), String> {
     let sleep = matches.value_of("sleep").unwrap_or("default.conf");
     let display = matches.value_of("display").unwrap_or("default.conf");
     let touchscreen = matches.value_of("touchscreen").unwrap_or("default.conf");
+    let old_state_owned = get_window_server_rotation_state(display, &backend)?;
+    let mut old_state = old_state_owned.as_str();
 
     for entry in glob("/sys/bus/iio/devices/iio:device*/in_accel_*_raw").unwrap() {
         match entry {
@@ -77,8 +149,7 @@ fn main() -> Result<(), String> {
                 } else if path.to_str().unwrap().contains("z_raw") {
                     continue;
                 } else {
-                    println!("{:?}", path);
+                    panic!("Unknown accelerometer device path {:?}", path);
-                    panic!();
                 }
             }
             Err(e) => println!("{:?}", e),
@@ -124,22 +195,22 @@ fn main() -> Result<(), String> {
         }
 
         if new_state != old_state {
-            match mode {
+            match backend {
-                BackendMode::Sway => {
+                Backend::Sway => {
                     Command::new("swaymsg")
                         .arg("output")
                         .arg(display)
                         .arg("transform")
                         .arg(new_state)
                         .spawn()
-                        .expect("rotate command failed to start");
+                        .expect("Swaymsg rotate command failed to start");
                 }
-                BackendMode::Xorg => {
+                Backend::Xorg => {
                     Command::new("xrandr")
                         .arg("-o")
                         .arg(x_state)
                         .spawn()
-                        .expect("rotate command failed to start");
+                        .expect("Xrandr rotate command failed to start");
 
                     Command::new("xinput")
                         .arg("set-prop")
@@ -149,7 +220,7 @@ fn main() -> Result<(), String> {
                         .arg("Matrix")
                         .args(&matrix)
                         .spawn()
-                        .expect("rotate command failed to start");
+                        .expect("Xinput rotate command failed to start");
                 }
             }
             old_state = new_state;